Source: http://worldwidescience.org/topicpages/b/bohrium+273.html
Timestamp: 2016-10-28 12:10:22
Document Index: 418362012

Matched Legal Cases: ['§ 1952', '§ 273', '§ 199', '§ 273', 'art 262', '§ 273', '§ 273', '§ 273', 'art 27', '§ 27', '§ 273', '§ 273', 'art 273', 'art 273', 'art 266', 'art 273', '§ 273', 'art 273', 'art 273', '§ 273', '§ 273', 'arte 16']

bohrium 273: Topics by WorldWideScience.org
Sample records for bohrium 273
International Nuclear Information System (INIS) Off-line and on-line studies have been performed with radioactive tracers of various elements to develop a chemical separation procedure for bohrium (element 107). The proposed procedure is intended for use in the fast solvent extraction system SISAK. The homologs technetium and rhenium were used to model the chemical behavior of bohrium. The results show that high decontamination factors can be obtained for technetium and rhenium with respect to unwanted contaminants like trivalent actinides, polonium and the Group 5 elements. (author)
29 CFR 1952.273 - Developmental schedule.
... 29 Labor 9 2010-07-01 2010-07-01 false Developmental schedule. 1952.273 Section 1952.273 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) APPROVED STATE PLANS FOR ENFORCEMENT OF STATE STANDARDS Vermont § 1952.273 Developmental...
39 CFR 273.10 - Reports.
... 39 Postal Service 1 2010-07-01 2010-07-01 false Reports. 273.10 Section 273.10 Postal Service... REMEDIES ACT § 273.10 Reports. (a) Not later than October 31 of each year, the Postmaster General shall prepare and transmit to the appropriate committees and subcommittees of the Congress an annual...
46 CFR 199.273 - Immersion suits.
... 46 Shipping 7 2010-10-01 2010-10-01 false Immersion suits. 199.273 Section 199.273 Shipping COAST... SYSTEMS FOR CERTAIN INSPECTED VESSELS Additional Requirements for Cargo Vessels § 199.273 Immersion suits. (a) Each cargo vessel must carry an immersion suit approved under approval series 160.171 of...
Dicty_cDB: VHD273 [Dicty_cDB
Full Text Available VH (Link to library) VHD273 (Link to dictyBase) - - - Contig-U16379-1 VHD273P (Link to Original site) VHD2...73F 596 VHD273Z 684 VHD273P 1260 - - Show VHD273 Library VH (Link to library) Clone ID VHD2...e URL http://dictycdb.biol.tsukuba.ac.jp/CSM/VH/VHD2-D/VHD273Q.Seq.d/ Representative seq. ID VHD2...73P (Link to Original site) Representative DNA sequence >VHD273 (VHD273Q) /CSM/VH/VHD2-D/VHD2...ore E Sequences producing significant alignments: (bits) Value VHD273 (VHD273Q) /CSM/VH/VHD2-D/VHD273Q.Seq.d
25 CFR 273.31 - Distribution formula.
... 25 Indians 1 2010-04-01 2010-04-01 false Distribution formula. 273.31 Section 273.31 Indians... formula. (a) Funds shall be distributed to eligible contractors based upon the number of eligible Indian... formula. (b) The Assistant Secretary may make exceptions to the provisions of paragraph (a) of...
40 CFR 273.16 - Employee training.
... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Employee training. 273.16 Section 273.16 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED... Employee training. A small quantity handler of universal waste must inform all employees who handle or...
40 CFR 273.36 - Employee training.
... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Employee training. 273.36 Section 273.36 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED... Employee training. A large quantity handler of universal waste must ensure that all employees...
3C 273 - half a century later
Slavcheva-Mihova, L.; Mihov, B.; I. Iliev
We have presented an optical monitoring of 3C 273, the first quasar discovered fifty years ago. It does not show variability both on intra-night and long-term time scales. To facilitate the further monitoring of 3C 273, we compiled the available calibrations of the comparison stars in its field into a mean sequence.
25 CFR 273.45 - Indian preference.
... 25 Indians 1 2010-04-01 2010-04-01 false Indian preference. 273.45 Section 273.45 Indians BUREAU... preference. (a) Any contract made by the Bureau with a State, school district or Indian corporation shall provide that the contractor shall, to the greatest extent feasible, give preference in and...
International Nuclear Information System (INIS) The success of theoretical and experimental study of fermium (Z=100) enlightened authors to perform further investigation of heavy elements. The authors studied some low-lying absorption spectroscopy and the resonant absorption probability of bohrium (Z=107) by using MCDF method which included the correlation effects and relativistic effects systematically. The authors hope the results will be useful for the further experiments
International Nuclear Information System (INIS) The success of theoretical and experimental study of fermium (z=100) enlightened us to perform further investigation of heavy elements. We studied some low-lying absorption spectroscopy and the resonant absorption probability of bohrium (Z=107) by using MCDF method which considered the correlation effects and relativistic effects systematically. We hope our results will be useful for the further experiments. (authors)
A Supernova Factory in Mrk 273?
Bondi, M; Dallacasa, D; Muxlow, T W B
We report on 1.6 and 5.0 GHz observations of the ultraluminous infrared galaxy (ULIRG) Mrk 273, using the European VLBI Network (EVN) and the Multi-Element Radio-Linked Interferometer Network (MERLIN). We also make use of published 1.4 GHz VLBA observations of Mrk 273 by Carilli & Taylor (2000). Our 5 GHz images have a maximum resolution of 5-10 mas, which corresponds to linear resolutions of 3.5-7 pc at the distance of Mrk 273, and are the most sensitive high-resolution radio observations yet made of this ULIRG. Component N1, often pinpointed as a possible AGN, displays a steep spectral index ($\\alpha = 1.2 \\pm 0.1; S_\
Paciesas, W.S.; Mallozzi, R. S.; Pendleton, G. N.; Harmon, B. A.; Wilson, C. A.; Zhang, S. N.; Fishman, G. J.
The quasar 3C273 has been detected by all instruments on CGRO. The emission from this source is monitored continuously by BATSE using Earth occultation. We present results of a preliminary analysis of BATSE data, including light curves of the 3C273 flux covering approximately 150 days in the interval April-August 1991 and approximately 350 days in the interval July 1992-April 1993. The source intensity in the energy range 50-300 keV is typically approx. 0.002 ph cm(exp -2)s(exp -1). We find weak evidence for variations of as much as a factor of 3 in the intensity. We derive spectral parameters of 3C273 during the intervals TJD 8422-8435 (15-28 June 1991) and TJD 8532-8546 (3-17 October 1991) for comparison with other CGRO instruments.
Courvoisier, Thierry J. -L.
We review the observed properties of the bright quasar 3C~273 and discuss the implications of these observations for the emission processes and in view of gaining a more global understanding of the object. Continuum and line emission are discussed. The emission from the radio domain to gamma rays are reviewed. Emphasis is given to variability studies across the spectrum as a means to gain some understanding on the relationships between the emission components. 3C~273 has a small scale jet and...
... eligibility requirements listed in § 273.5. A student will remain exempt during normal periods of class attendance, vacation, and recess. If the student graduates, enrolls less than half-time, is suspended or... accordance with the Child Care and Development Block Grant provisions of 45 CFR 98.43, and based on...
40 CFR 273.56 - Exports.
... countries specified in 40 CFR 262.58(a)(1) (in which case the transporter is subject to the requirements of 40 CFR part 262, subpart H) may not accept a shipment if the transporter knows the shipment does not... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Exports. 273.56 Section...
7 CFR 273.1 - Household concept.
.... Editorial Note: For Federal Register citations affecting § 273.1, see the List of CFR Sections Affected... under 22 years of age who is living with his or her natural or adoptive parent(s) or step-parent(s); and (iii) A child (other than a foster child) under 18 years of age who lives with and is under...
... recertification process, the State agency must conduct a face-to-face interview with a member of the household or... requirement for a face-to-face interview once every 12 months may be waived in accordance with § 273.2(e)(2...-month period, the State agency may choose to conduct a face-to-face interview with that household...
25 CFR 273.2 - Definitions.
... may have resulted from socio-economic conditions of the parents, from cultural or language differences or other factors, and as provided by § 273.34(b). (u) “Tribal government,” “tribal governing body.... (e) “Economic enterprise” means any commercial, industrial, agricultural, or business activity...
Radio jet of 3C273
International Nuclear Information System (INIS) Radio observation at 408 MHz of 3C273 are reported which show that the brightness of the postulated counter-jet is <1/100 of the brightness of the visible jet. Possible explanations of these observations are discussed. (U.K.)
IRIS photometry of 3C273
International Nuclear Information System (INIS) Twenty-seven blue plates of 3C 273 originally measured by Zwicky, Karpowicz, and Rudnicki using the Argelander method and measurement of image diameters were remeasured on an iris photometer to improve their precision. These measures, including two later observations, have an accuracy approximately +-0.1m. Some errors in the Julian day numbers given in the earlier study are corrected
Lanning, H.H.
Twenty-seven blue plates of 3C 273 originally measured by Zwicky, Karpowicz, and Rudnicki using the Argelander method and measurement of image diameters were remeasured on an iris photometer to improve their precision. These measures, including two later observations, have an accuracy approximately +-0.1m. Some errors in the Julian day numbers given in the earlier study are corrected.
48 CFR 719.273-6 - Application process.
... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Application process. 719.273-6 Section 719.273-6 Federal Acquisition Regulations System AGENCY FOR INTERNATIONAL DEVELOPMENT...Ã©gÃ© Program 719.273-6 Application process. Entities interested in becoming a Mentor firm...
27 CFR 27.3 - Delegations of the Administrator.
....27, Delegation of the Administrator's Authorities in 27 CFR Part 27, Importation of Distilled Spirits... Administrator. 27.3 Section 27.3 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU... § 27.3 Delegations of the Administrator. The regulatory authorities of the Administrator contained...
7 CFR 273.20 - SSI cash-out.
... 7 Agriculture 4 2010-01-01 2010-01-01 false SSI cash-out. 273.20 Section 273.20 Agriculture... FOOD STAMP AND FOOD DISTRIBUTION PROGRAM CERTIFICATION OF ELIGIBLE HOUSEHOLDS § 273.20 SSI cash-out. (a) Ineligibility. No individual who receives supplemental security income (SSI) benefits and/or State...
Thevenon, Julien; Callier, Patrick; Poquet, Hélène; 2014-01-01
BACKGROUND: Since the advent of array-CGH, numerous new microdeletional syndromes have been delineated while others remain to be described. Although 3q29 subtelomeric deletion is a well-described syndrome, there is no report on 3q interstitial deletions. METHODS: We report for the first time seven...... patients with interstitial deletions at the 3q27.3q28 locus gathered through the Decipher database, and suggest this locus as a new microdeletional syndrome. RESULTS: The patients shared a recognisable facial dysmorphism and marfanoid habitus, associated with psychosis and mild to severe intellectual...... disability (ID). Most of the patients had no delay in gross psychomotor acquisition, but had severe impaired communicative and adaptive skills. Two small regions of overlap were defined. The first one, located on the 3q27.3 locus and common to all patients, was associated with psychotic troubles and mood...
International Nuclear Information System (INIS) Using the very long baseline interferometry technique observations of the radio structure of the quasar 3C273 have been obtained from mid-1977 to mid-1980 at 10.65 and 5.0 GHz. Maps based on the 10.65 GHz results are presented which provide unambiguous evidence of superluminal expansion. It is argued that the apparent constant velocity of 9.6c observed in this period is an important constraint on superluminal expansion theories. (U.K.)
The radio jet of 3C273
International Nuclear Information System (INIS) Most radio sources are two-sided and a minority are one-sided. The first-known and brightest example is 3C273, a high-luminosity QSO, showing 'super-luminal' proper motions in the core. The explanation of such one-sided sources may follow one of two lines: on the one hand, the ejection of material from the central object may truly be one-sided, while on the other hand the ejection may be two-sided but at a relativistic speed, so that the receding half is hidden by Doppler beaming. (Auth.)
Inner radio jet of 3C273
Zensus, J.A.; Cohen, M.H.; Baaaath, L.B.; Nicolson, G.D.
Radio maps of 3C273 obtained with very long baseline interferometry (VLBI) have been limited by low dynamic range and poor north-south resolution resulting from the low declination of this quasar. Dramatic improvement can now be achieved using larger arrays and antennas in the Southern Hemisphere. A new VLBI map, made at 5 GHz with angular resolution and dynamic range unsurpassed at this frequency for this source, shows a narrow jet extending to a projected distance lsub(proj) approx. 125 h/sup -1/ parsecs from the core. Superluminal motion exists out to at least lsub(proj) &apos;&apos;approx =&apos;&apos; 46 h/sup -1/ parsecs. Successive superluminal components emerge from the core and appear to move on a fixed curved path with similar speeds of about 1 milliarcseconds per year.
... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Internal controls. 719.273...Ã©gÃ© Program 719.273-10 Internal controls. (a) OSDBU will oversee the Program and will work in... objectives. OSDBU will establish internal controls as checks and balances applicable to the Program....
48 CFR 852.273-70 - Late offers.
... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Late offers. 852.273-70... SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of Provisions and Clauses 852.273-70 Late offers. As prescribed in 873.110(a), insert the following provision: Late Offers (JAN 2003) This provision...
Dicty_cDB: SSD273 [Dicty_cDB
Full Text Available SS (Link to library) SSD273 (Link to dictyBase) - G02144 DDB0231105 Contig-U12265-1 SSD273E (Lin ... ' polyadenylated late RNA transcribed from the DNA resolution ... sequences at the terminal hairpin loop region of t ... ' polyadenylated late RNA transcribed from the DNA resolution ... sequences at the terminal hairpin loop region of t ...
... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Applicability-Mercury-containing... WASTES (CONTINUED) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT General § 273.4 Applicability—Mercury-containing equipment. (a) Mercury-containing equipment covered under this part 273. The requirements of...
40 CFR 273.2 - Applicability-batteries.
... under 40 CFR part 273. (1) The requirements of this part apply to persons managing batteries, as... which are not managed under 40 CFR part 266, subpart G, are subject to management under this part. (b) Batteries not covered under 40 CFR part 273. The requirements of this part do not apply to persons...
39 CFR 273.6 - Evaluation by reviewing official.
... 39 Postal Service 1 2010-07-01 2010-07-01 false Evaluation by reviewing official. 273.6 Section... PROGRAM FRAUD CIVIL REMEDIES ACT § 273.6 Evaluation by reviewing official. (a) Based upon the investigatory report prepared by the Investigating Official, the Reviewing Official shall determine...
Chaotic Feature in the Light Curve of 3C 273
Some nonlinear dynamical techniques, including state-space reconstruction and correlation integral, are used to analyze the light curve of 3C 273. The result is compared with a chaotic model. The similarity between them suggests that there is a low-dimensional chaotic attractor in the light curve of 3C 273.
Dicty_cDB: SSC273 [Dicty_cDB
Full Text Available SS (Link to library) SSC273 (Link to dictyBase) - - - Contig-U07980-1 SSC273F (Link to Original ... ents: (bits) Value EU276418_1( EU276418 |pid:none) Olive ... flounder iridovirus strain O... 36 0.47 AB043979_1 ...
Radio jet of the quasar 3C273
Flatters, C.; Conway, R.G.
Although 3C273 was one of the first quasars to be identified, the extended feature 3C273A, which can be detected at radio, optical and X-ray wavelengths, remains an enigma. The source is an extreme example of a one-sided radio source (3C273A has no detectable counter component) and this fact, coupled with the presence of the optical emission, makes it unlikely that 3C273A is a normal (slow-moving) radio lobe. Superluminal transverse motion at milliarc second scales shows that relativistic velocities occur within the quasar itself, 3C273B; it is an open question whether these velocities persist out to 3C273A. It has been widely suggested that Doppler beaming causes the one-sidedness of this and similar sources by suppressing the receding half of the source, but there are no spectral lines by which the Doppler shift of 3C273A could be directly measured. Thus, any (indirect) indication of the velocity is of interest. Here new MERLIN observations of the brightness and polarization of the radio jet of 3C273 at a resolution of 0.35 arc s are presented. One of the most marked features of the new map, the high polarization found within the head of the source, is hard to explain. If the motion is indeed fast, then relativistic aberration should be taken into account; it suggests that this leads to a natural explanation of the high observed polarization. 18 references, 1 figure, 1 table.
A Modified Stratified Model for 3C 273 Jet
Liu, Wen-Po; Shen, Zhi-Qiang
We present a modified stratified jet model to interpret the observed spectral energy distributions of knots in 3C 273 jet. Based on the hypothesis of the single index of the particle energy spectrum at injection and identical emission processes among all the knots, the observed difference of spectral shape among different 3C273 knots can be understood as a manifestation of deviation of the equivalent Doppler factor of stratified emission regions in individual knot from a characteristic one. T...
Liu, Wen-Po
We present a modified stratified jet model to interpret the observed spectral energy distributions of knots in 3C 273 jet. Based on the hypothesis of the single index of the particle energy spectrum at injection and identical emission processes among all the knots, the observed difference of spectral shape among different 3C273 knots can be understood as a manifestation of deviation of the equivalent Doppler factor of stratified emission regions in individual knot from a characteristic one. The summed spectral energy distribution of all the ten knots in 3C 273 jet can be well fitted by two components, low-energy (radio to optical) component dominated by the synchrotron radiation and high-energy component (UV, X-ray and $\\gamma$-ray) dominated by the inverse Compton scattering of the cosmic microwave background. This gives a consistent spectral index of $\\alpha=0.88$ ($S_\
Fan, J. H.; Kurtanidze, O.; Liu, Y.; Yuan, Y. H.; Hao, J. M.; Cai, W.; Xiao, H. B.; Pei, Z. Y.
In this work, we reported the optical photometry monitoring results for two brightest nearby quasars, PHL 1811 and 3C 273 using the ST-6 camera at Abastumani Observatory, Georgia. For PHL 1811, we found 3 microvariability events with time scale of ΔT = 6.0 min. For 3C273, we found that the largest variations are ΔV = 0.369 +/- 0.028 mag, ΔR = 0.495 +/- 0.076 mag, and ΔI = 0.355 +/- 0.009 mag. When periodicity analysis methods are adopted to the available data, a period of p = 5.80 +/- 1.12 years is obtained for PHL 1811, and p = 21.10 +/- 0.14, 10.00 +/- 0.14, 7.30 +/- 0.09, 13.20 +/- 0.09, 2.10 +/- 0.06, and 0.68 +/- 0.05 years are obtained for 3C 273.
New infrared spectral component of the quasar 3C273
Robson, E.I.; Gear, W.K.; Brown, L.M.J.; Courvoisier, T.J.-L.; Smith, M.G.; Griffin, M.J.; Blecha, A.
Following the dramatic infrared to millimetre-wavelength flare seen in the quasar 3C273 during 1983, the authors have continued to monitor its overall continuum emission. Recent measurements show that the 10-..mu..m to 3-mm emission has decayed to a level well below any seen previously, while the 1-4-..mu..m emission has remained relatively constant. This behaviour has revealed the presence of an apparently non-variable component which dominates the near-infrared emission in 3C273 and includes the small &apos;bump&apos; at approx. 3.5 ..mu..m in the power-law continuum.
On the Jet Activity in 3C 273
In this paper we comment on the possibility for intermittent jet activity in quasar 3C 273 on different time-scales. We propose, that striking morphology of the large-scale radio jet in this source, as well as the apparent lack of its counterpart on the opposite side of the active center, may be explained in a framework of a restarting jet model. In particular, we propose that 3C 273 radio source is intrinsically two-sided, and represents an analogue of double-double radio galaxies, but only ...
Esposito, V; R. Walter(ISDC); Jean, P.; Tramacere, A.; M. Türler; A. Lähteenmäki(Aalto University Metsähovi Radio Observatory, Kylmälä, Finland); Tornikoski, M.
Aims. The high energy spectrum of 3C 273 is usually understood in terms of inverse-Compton emission in a relativistic leptonic jet. This model predicts variability patterns and delays that could be tested with simultaneous observations from the radio to the GeV range. Methods. The instruments IBIS, SPI, JEM-X on board INTEGRAL, PCA on board RXTE, and LAT on board Fermi have enough sensitivity to follow the spectral variability of 3C 273 from the keV to the GeV. We looked for correlations betw...
....” means that the alien is lawfully present as defined at 8 CFR 103.12(a). (b) Reporting illegal aliens. (1... participating in the Program from any demand made under 8 CFR 213a.4(a) for the value of food stamp benefits... 7 Agriculture 4 2010-01-01 2010-01-01 false Citizenship and alien status. 273.4 Section...
Dicty_cDB: CFK273 [Dicty_cDB
Full Text Available CF (Link to library) CFK273 (Link to dictyBase) - - - Contig-U08029-1 - (Link to Original site) ... 152123_6( AC152123 |pid:none) Genomic sequence for broccoli ... [Bra... 99 5e-20 DQ980427_1( DQ980427 |pid:none) P ...
Structure of caesium disulfate at 120 and 273 K
Ståhl, Kenny; Berg, Rolf W.; Eriksen, Kim Michael; Fehrmann, Rasmus
The crystal structures of Cs2S2O7 at 120 and 273 K have been determined from X-ray single-crystal data. Caesium disulfate represents a new structure type with a uniquely high number of independent formula units at 120 K: In one part caesium ions form a tube surrounding the disulfate ions, [Cs8(S2...
7 CFR 273.2 - Office operations and application processing.
... individual participated in that State. The normal processing standards of 7 CFR 273.2(g) apply. The State..., age, religion, political beliefs, or disability. “To file a complaint of discrimination, write USDA... eligibility. The SSA Quarters of Coverage History System (QCHS) is available for purposes of verifying...
Optical polarization in the jet of 3C273
International Nuclear Information System (INIS) A linear polarization map of the optical jet of 3C273 is presented. Along the whole length of the visible jet significant levels of polarization are detected with an orientation approximately perpendicular to the jet axis. The results remove the need to invoke a non-synchrotron contribution to the optical emission from the jet. (author)
Is the 3C273 quasar mach nearer?
International Nuclear Information System (INIS) Effect of ''superlight'' expansion of some quasars resulting from cosmologic interpretation of red shift is considered. Possibility of determining distance to 3C273 quasar, taking account of its expansion angular velocity in frames of Doppler interpretation of quasar red shift value, is discussed
Scarrott, S.M.; Warren-Smith, R.F.
A linear polarization map of the optical jet of 3C273 is presented. Along the whole length of the visible jet significant levels of polarization are detected with an orientation approximately perpendicular to the jet axis. The results remove the need to invoke a non-synchrotron contribution to the optical emission from the jet.
The jet in the quasar 3C273
International Nuclear Information System (INIS) The quasar 3C273 has been mapped with the six telescope array, MERLIN, at both 408 MHz and 1666 MHz, yielding maps with resolutions of 0.9 and 0.35 arc s. Both maps show evidence for quasi-sinusoidal wiggles. Two models explaining this, are shortly discussed. (Auth.)
40 CFR 273.3 - Applicability-pesticides.
... collection program. (b) Pesticides not covered under 40 CFR part 273. The requirements of this part do not... are managed by farmers in compliance with 40 CFR 262.70. (40 CFR 262.70 addresses pesticides disposed... label, providing the container is triple rinsed in accordance with 40 CFR 261.7(b)(3)); (2)...
..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE AQUATIC PLANT CONTROL Pt. 273, App. E Appendix E to Part 273.... When herbicides or defoliants volatize, the resulting vapors may be poisonous to humans, and they...
The blue-bump of 3C 273
Paltani, S.; Courvoisier, T. J-L.; R. Walter(ISDC)
We present optical and ultraviolet observations of 3C273 covering the whole life of the IUE satellite. We analyze the variability properties of the light curves, and find that two variable components, written B and R respectively, must contribute to the blue-bump emission in this object. The B component produces most of the variability in the ultraviolet domain. A maximum time scale of variability of about 2 yr identical at all wavelengths is found. If discrete events produce this component, ...
Delta-function Approximation SSC Model in 3C 273
S. J. Kang; Y. G. Zheng; Q. Wu
We obtain an approximate analytical solution using approximate calculation on the traditional one-zone synchrotron self-Compton (SSC) model. In this model, we describe the electron energy distribution by a broken power-law function with a sharp cut-off, and non-thermal photons are produced by both synchrotron and inverse Compton scattering of synchrotron photons. We calculate the radiation energy spectrum of electrons by the function. We apply this model to the multi-wavelength Spectral Energy Distributions (SED) of the 3C 273 in different states, and obtain excellent fits to the observed spectra of this source.
MERLIN radio observations of the quasar 3C 273
International Nuclear Information System (INIS) MERLIN observations of the radio jet of the quasar 3C 273 at 408 and 1666 Mhz are presented. Most of the important features previously seen at 408 MHz are confirmed. The jet extends from 12 to 23 arcsec from the quasar, and has a single bright head at 408 MHz. At the higher resolution of the 1666-MHz map the head is seen to consist of at least three subcomponents, the brightest of which is set back from the outermost point of the jet. The ridgeline of emission shows oscillations from side to side ('wiggles'), the wavelength of which decreases markedly as the bright head is approached. (author)
HST/STIS Spectroscopy of 3C 273
Heap, S. R.; Williger, G. M.; Dave, R.; Weymann, R. J.; Jenkins, E. B.; Tripp, T. M.
We present preliminary results on the low-redshift Lyman alpha forest as based on STIS spectra of 3C 273. A total of 121 intergalactic Lyman alpha-absorbing systems were detected, of which 60 are above the 3.5 sigma completness limit, log N(HI)~12.3. The median Doppler parameter, b=27 km/s, is similar to that seen at high redshift. However the distribution of HI column densities (dN/dN(HI) propto N(HI)^-beta) has a steeper slope, beta = 2.02 +- 0.21, than is seen at high redshift. Overall, th...
Page, K. L.; Turner, M. J. L.; Done, C.; O'Brien, P. T.; Reeves, J. N.; Sembay, S.; Stuhlinger, M
A series of nine XMM-Newton observations of the radio-loud quasar 3C 273 are presented, concentrating mainly on the soft excess. Although most of the individual observations do not show evidence for iron emission, co-adding them reveals a weak, broad line (EW ~ 56 eV). The soft excess component is found to vary, confirming previous work, and can be well fitted with multiple blackbody components, with temperatures ranging between ~40 and ~330 eV, together with a power-law. Alternatively, a Com...
The jet of 3C 273 observed with ROSAT HRI
Roeser, Hermann-Josef; Meisenheimer, Klaus; Neumann, Martin; Conway, R. G.; Perley, R.A.
ROSAT HRI observations of 3C 273 reveal X-ray emission all along the optically visible jet with the peak of emission at the inner end. Whereas the X-ray emission from the innermost knot A is consistent with a continuation of the radio-to-optical synchrotron continuum, a second population of particles with higher maximum energy has to be invoked to explain the X-ray emission from knots B, C and D in terms of synchrotron radiation. Inverse Compton emission could account for the X-ray flux from ...
The radio jet of the quasar 3C273
International Nuclear Information System (INIS) The authors present here new MERLIN observations of the brightness and polarization of the radio jet of the quasar 3C273 at a resolution of 0.35 arc s. One of the most marked features of the map, the high polarization found within the head of the source, is hard to explain. If the motion is indeed fast, then relativistic aberration should be taken into account; it is suggested that this leads to a natural explanation of the high observed polarization. (author)
Paltani, S.; Turler, M.
In this paper we apply the reverberation method to determine the mass of the black hole in 3C273 from the Ly a and C iv emission lines using archival IUE observations. Following the standard assumptions of the method, we find a maximum-likelihood estimate of the mass of 6.59 10^9 Mo, with a 1 sigma confidence interval 5.69-8.27 10^9 Mo. This estimate is more than one order of magnitude larger than that obtained in a previous study using Balmer lines. We reanalyze the optical data and show tha...
Rapid variability of 3C273 at 300 GHz
International Nuclear Information System (INIS) With a broadband bolometer mounted on the 3.6 m ESO telescope the authors have measured 3C273 at 300 GHz 6 times in 6 days. During this series of measurements they observed a sudden drop in flux density by 11.6 +- 2.9 Jy (spectral index assumed to be zero, and all known errors included). In an interpretation with the model of bulk relativistic motion the brightness temperature inferred can be combined with the observed superluminal motion, and strict limits on the model parameters can be derived. (Auth.)
Esposito, Valentino; Walter, Roland; Jean, Pierre; Tramacere, Andrea
The high energy spectral shape of 3C 273 is usually understood in terms of Inverse-Compton emission in a relativistic leptonic jet. This model predicts variability patterns and delays which could be tested if simultaneous observations are available from the infrared to the GeV range. The instruments IBIS, SPI, JEM-X on board INTEGRAL, PCA on board RXTE and LAT on board Fermi have enough sensitivity to follow the spectral variability from the keV to the GeV and to compare them with model predi...
Ultraviolet spectrum of quasi-stellar object 3C273
Davidsen, A. F.; Hartig, G. F.; Fastie, W. G.
The first direct observation of the ultraviolet spectrum of a quasi-stellar object (QSO) has been made with a rocket-borne telescope. The emission line spectrum of 3C273 is similar to the spectra of high-redshift QSOs, but no absorption is observed. The results provide important new constraints on theoretical models of QSOs, place a severe limit on the density of neutral hydrogen in the intergalactic medium, and suggest a cosmological origin for much of the absorption seen in high-redshift QSOs. Comparison of the ultraviolet spectrophotometry of low- and high-redshift QSOs suggests that the universe is closed, with a deceleration parameter of about 1.
Evolution of 3C 273 at 10.7 GHz
International Nuclear Information System (INIS) The quasar 3C 273 has been observed at 10.7 GHz at three epochs spanning 1984.1-1985.6. Two new superluminal components, C5 and C7a, are separating from the core with apparent transverse velocity v/c = (8.0 + or - 0.2)/h and (5.1 + or - 0.3)/h. The old components C3 and C4 may still be recognizable, with C4 having moved from 2.5 to perhaps 10 mas from the core in 7 yr. Nonmonotonic curvature near the core is confirmed. 8 references
Evolution of 3C 273 at 10. 7 GHz
Cohen, M.H.; Zensus, J.A.; Biretta, J.A.; Comoretto, G.; Kaufmann, P.
The quasar 3C 273 has been observed at 10.7 GHz at three epochs spanning 1984.1-1985.6. Two new superluminal components, C5 and C7a, are separating from the core with apparent transverse velocity v/c = (8.0 + or - 0.2)/h and (5.1 + or - 0.3)/h. The old components C3 and C4 may still be recognizable, with C4 having moved from 2.5 to perhaps 10 mas from the core in 7 yr. Nonmonotonic curvature near the core is confirmed. 8 references.
Vivian, U; Sanders, David; Max, Claire; Armus, Lee; Iwasawa, Kazushi; Evans, Aaron; Kewley, Lisa; Fazio, Giovanni
There is X-ray, optical, and mid-infrared imaging and spectroscopic evidence that the late-stage ultraluminous infrared galaxy merger Mrk 273 hosts a powerful active galactic nucleus (AGN). However, the exact location of the AGN and the nature of the nuclei have been difficult to determine due to dust obscuration and the limited wavelength coverage of available high-resolution data. Here we present near-infrared integral-field spectra and images of the nuclear region of Mrk 273 taken with OSIRIS and NIRC2 on the Keck II Telescope with laser guide star adaptive optics. We observe three spatially resolved components, and analyze the local molecular and ionized gas emission lines and their kinematics. We confirm the presence of the hard X-ray AGN in the southwest nucleus. In the north nucleus, we find a strongly rotating gas disk whose kinematics indicate a central black hole of mass 1.04 +/- 0.1 x 10^9 Msun. The H2 emission line shows an increase in velocity dispersion along the minor axis in both directions, a...
Molecular hydrogen emission from the bright quasar 3C273
International Nuclear Information System (INIS) The discovery of broad emission lines in polarized light from the type 2 Seyfert galaxy NGCl068 led to postulation of the existence of a type 1 Seyfert nucleus shrouded from our direct view by a torus of molecular gas. Theoretical development of this idea included the suggestion that low-angular-momentum clouds in the torus are captured by the central source, fuelling the observed activity. The difficulty in applying this model to all active galactic nuclei (AGNs) is the lack of convincing evidence for molecular gas in 'bare' nucleus objects such as the quasar 3C273, which exhibits a simple power-law continuum and no excess of thermal dust emission. Here we present observations, made during the course of a survey for rotation and vibration lines of H2 emission from type 1 Seyferts and quasars, of molecular hydrogen emission from 3C273. This is the first time such emission has been seen from a radio-loud quasar. (author)
In this paper we apply the reverberation method to determine the mass of the black hole in 3C273 from the Ly a and C iv emission lines using archival IUE observations. Following the standard assumptions of the method, we find a maximum-likelihood estimate of the mass of 6.59 10^9 Mo, with a 1 sigma confidence interval 5.69-8.27 10^9 Mo. This estimate is more than one order of magnitude larger than that obtained in a previous study using Balmer lines. We reanalyze the optical data and show that the method applied to the Ha, Hb, and Hg Balmer lines produce mass estimates lower by a factor 2.5, but already much larger than the previous estimate derived from the same lines. The finding of such a high mass in a face-on object is a strong indication that the gas motion is not confined to the accretion disk. The new mass estimate makes 3C273 accreting with an accretion rate about six times lower than the Eddington rate. We discuss the implications of our result for the broad-line-region size and black-hole mass vs l...
Kawara, Kimiaki (National Astronomical Observatory, Mitaka, Tokyo (Japan)); Nishida, Minoru (Kyoto Univ. (Japan). Dept. of Physics); Gregory, Brooke (Cerro Tololo Inter-American Observatory, La Serena (Chile) Royal Observatory, Edinburgh (UK))
The discovery of broad emission lines in polarized light from the type 2 Seyfert galaxy NGCl068 led to postulation of the existence of a type 1 Seyfert nucleus shrouded from our direct view by a torus of molecular gas. Theoretical development of this idea included the suggestion that low-angular-momentum clouds in the torus are captured by the central source, fuelling the observed activity. The difficulty in applying this model to all active galactic nuclei (AGNs) is the lack of convincing evidence for molecular gas in &apos;bare&apos; nucleus objects such as the quasar 3C273, which exhibits a simple power-law continuum and no excess of thermal dust emission. Here we present observations, made during the course of a survey for rotation and vibration lines of H{sub 2} emission from type 1 Seyferts and quasars, of molecular hydrogen emission from 3C273. This is the first time such emission has been seen from a radio-loud quasar. (author).
Milliarcsecond polarization structure of the superluminal quasar 3C 273
Roberts, D.H.; Kollgaard, R.I.; Brown, L.F.; Gabuzda, D.C.; Wardle, J.F. C. (Brandeis Univ., Waltham, MA (USA))
A 2 x 10 marcsec-resolution determination is presented for the total intensity and linear polarization structures of the superluminal quasar 3C 273 at 5 GHz. Substantial polarized flux was detected from several superluminal components of the jet, whose fractional polarization increased symmetrically with distance from the core; the most distant component is highly polarized and exhibits a highly ordered magnetic field. Within a few marcsec of the core, the inferred magnetic field orientation varies rapidly with position along the jet. The primarily longitudinal magnetic field orientation is concluded to become established within 20 marcsec of the core. A highly disorganized magnetic field is the most plausible explanation for the low degree of polarization in the innermost regions of the jet. 48 refs.
International Nuclear Information System (INIS) A 2 x 10 marcsec-resolution determination is presented for the total intensity and linear polarization structures of the superluminal quasar 3C 273 at 5 GHz. Substantial polarized flux was detected from several superluminal components of the jet, whose fractional polarization increased symmetrically with distance from the core; the most distant component is highly polarized and exhibits a highly ordered magnetic field. Within a few marcsec of the core, the inferred magnetic field orientation varies rapidly with position along the jet. The primarily longitudinal magnetic field orientation is concluded to become established within 20 marcsec of the core. A highly disorganized magnetic field is the most plausible explanation for the low degree of polarization in the innermost regions of the jet. 48 refs
International Nuclear Information System (INIS) The first direct observation of the ultraviolet spectrum of a quasi-stellar object has been made with a rocket-borne telescope. The emission line spectrum of 3C273 is similar to the spectra of high-redshift QSOs, but no absorption is observed. The results provide important new constraints on theoretical models of QSOs, place a severe limit on the density of neutral hydrogen in the intergalactic medium, and suggest a cosmological origin for much of the absorption seen in high-redshift QSOs. Comparison of the ultraviolet spectrophotometry of low- and high-redshift QSOs suggests that the universe is closed, with the deceleration parameter q0 approximately 1. (author)
The X-ray emission of 3C273
International Nuclear Information System (INIS) The X-ray emission of 3C273 in the 0.2-35 keV band has been studied, with EXOSAT and Ginga, over the period 1983 December to 1988 December. The overall flux is variable on a time-scale of weeks by a factor of 2. The spectral index in the 2-10 keV band (α ∼ 0.5) is significantly different from the 'canonical' AGN index of α = 0.7. There are small but significant variations with time in the spectral index which are not statistically correlated with the overall X-ray flux level. Iron emission with an equivalent width of ∼ 50 eV is detected in one of the Ginga observations. (author)
Ultraviolet emission-line variability in 3C273
International Nuclear Information System (INIS) Evidence is presented for correlated variability between the ultraviolet continuum and the Lyα emission line in the luminous quasar 3C273. Using IUE data covering a period of ∼ 1000 d, Lyα varied by 15 per cent whilst the continuum varied by a factor of 2. A time series analysis gives a lag for Lyα relative to the ultraviolet continuum of 74 ± 33 d. The broad flat-topped shape of the cross-correlation function, and the small amplitude of the Lyα variability, indicate that the derived lag is a measure of the inner radius of a geometrically thick broad-line region. (author)
Ultraviolet continuum variability of the quasar 3C273
International Nuclear Information System (INIS) The authors report the first observations of variability in the ultraviolet spectrum of the quasar 3C273 (redshift, z=0.158) as observed by the International Ultraviolet Explorer in the period 1978-84. The flux at lambdasub(observed)=1,675 A increased by 1.25 between April and June 1982, then decreased by a factor 2 between June 1982 and April 1983. The amplitude of these variations and the constancy of the intensity of the Lyα emission line during the same period are indications that the ultraviolet variations are caused by variations of the black body and/or non-thermal components. The flux variations are accompanied by variations of the spectral shape. An interpretation is presented of the observed variability in terms of a discontinuous and variable distribution of the temperature on the photosphere emitting the ultraviolet continuum. (author)
Turner, M.J.L.; Williams, O.R. (Leicester Univ. (UK). Dept. of Astronomy); Courvoisier, T.J.-L. (Geneva Observatory (Switzerland)) (and others)
The X-ray emission of 3C273 in the 0.2-35 keV band has been studied, with EXOSAT and Ginga, over the period 1983 December to 1988 December. The overall flux is variable on a time-scale of weeks by a factor of 2. The spectral index in the 2-10 keV band ({alpha} {approx} 0.5) is significantly different from the &apos;canonical&apos; AGN index of {alpha} = 0.7. There are small but significant variations with time in the spectral index which are not statistically correlated with the overall X-ray flux level. Iron emission with an equivalent width of {approx} 50 eV is detected in one of the Ginga observations. (author).
O&apos; Brien, P.T.; Harries, T.J. (University Coll., London (UK). Dept. of Physics and Astronomy)
Evidence is presented for correlated variability between the ultraviolet continuum and the Ly{alpha} emission line in the luminous quasar 3C273. Using IUE data covering a period of {approx} 1000 d, Ly{alpha} varied by 15 per cent whilst the continuum varied by a factor of 2. A time series analysis gives a lag for Ly{alpha} relative to the ultraviolet continuum of 74 {+-} 33 d. The broad flat-topped shape of the cross-correlation function, and the small amplitude of the Ly{alpha} variability, indicate that the derived lag is a measure of the inner radius of a geometrically thick broad-line region. (author).
International Nuclear Information System (INIS) Radio maps of 3C273 obtained with very long baseline interferometry (VLBI) have been limited by low dynamic range and poor north-south resolution resulting from the low declination of this quasar. Dramatic improvement can now be achieved using larger arrays and antennas in the Southern Hemisphere. A new VLBI map, made at 5 GHz with angular resolution and dynamic range unsurpassed at this frequency for this source, shows a narrow jet extending to a projected distance lsub(proj) ∼ 125 h-1 parsecs from the core. Superluminal motion exists out to at least lsub(proj) ''approx ='' 46 h-1 parsecs. Successive superluminal components emerge from the core and appear to move on a fixed curved path with similar speeds of about 1 milliarcseconds per year. (author)
25 CFR 273.38 - Equal quality and standard of education.
... 25 Indians 1 2010-04-01 2010-04-01 false Equal quality and standard of education. 273.38 Section 273.38 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR INDIAN SELF-DETERMINATION AND... Equal quality and standard of education. Contracts with State education agencies or school...
The disc-jet-spin connection: 3C273
Black hole spin is difficult to measure as it leaves an imprint only close to the horizon, but it may be required to produce most dramatic relativistic jets. For stellar mass black holes there are two established methods to measure spin, from the disc continuum peak temperature in disc dominated states, and from the iron line profile in states with more hard X-ray flux. However, these two methods do not always agree! In AGN the higher black hole mass means a lower disc temperature, so the peak is in the unobservable EUV region, and only the iron line method can be used, but in very high mass AGN, the disc temperature is so low that the peak starts to be visible in the far UV. We use archival data from 3C273 where the observed far UV emission clearly requires a disc around a high spin black hole. The accretion flow dissipates all the available accretion energy, yet the jet in this system is known to be as powerful as the observed accretion flow. Since there is no accretion power left, the jet must be powered by another source of energy - and the only one remaining is black hole spin.
The milliarcsecond structure of 3C 273 at 22 GHz
International Nuclear Information System (INIS) The first VLBI images at 22 GHz of the jet in the quasar 3C 273 are presented. In addition to the compact core region, two emission regions can be identified with features seen at lower frequencies; they separate from the core with constant speeds of 0.65 + or - 0.09 and 0.92 + or - 0.11 mas/yr, corresponding to apparent superluminal motion of 4.3 + or - 0.3c and 6.1 + or - 0.3c (for Ho = 100 km/s Mpc, qo = 0.5). The core region brightened at about the estimated epoch of zero separation for the latest superluminal component, suggesting a causal relationship. The curved ridge line of the jet smoothly extends inward towards the core, although no pronounced bends in the range of core distance 0.5-2.5 mas are seen. No significant evidence is found against a common path of subsequent superluminal features. An apparent frequency dependence in the position of one superluminal feature tentatively suggests that opacity effects across the jet direction are present. The results are consistent with an interpretation of the superluminal features as shocks in an underlying relativistic flow, although alternative explanations cannot be ruled out. 43 refs
Zensus, J.A.; Biretta, J.A.; Unwin, S.C.; Cohen, M.H. (National Radio Astronomy Observatory, Socorro, NM (USA) Owens Valley Radio Observatory, Pasadena, CA (USA))
The first VLBI images at 22 GHz of the jet in the quasar 3C 273 are presented. In addition to the compact core region, two emission regions can be identified with features seen at lower frequencies; they separate from the core with constant speeds of 0.65 + or - 0.09 and 0.92 + or - 0.11 mas/yr, corresponding to apparent superluminal motion of 4.3 + or - 0.3c and 6.1 + or - 0.3c (for Ho = 100 km/s Mpc, qo = 0.5). The core region brightened at about the estimated epoch of zero separation for the latest superluminal component, suggesting a causal relationship. The curved ridge line of the jet smoothly extends inward towards the core, although no pronounced bends in the range of core distance 0.5-2.5 mas are seen. No significant evidence is found against a common path of subsequent superluminal features. An apparent frequency dependence in the position of one superluminal feature tentatively suggests that opacity effects across the jet direction are present. The results are consistent with an interpretation of the superluminal features as shocks in an underlying relativistic flow, although alternative explanations cannot be ruled out. 43 refs.
Paltani, S; Walter, R
We present optical and ultraviolet observations of 3C273 covering the whole life of the IUE satellite. We analyze the variability properties of the light curves, and find that two variable components, written B and R respectively, must contribute to the blue-bump emission in this object. The B component produces most of the variability in the ultraviolet domain. A maximum time scale of variability of about 2 yr identical at all wavelengths is found. If discrete events produce this component, the event rate is ~3-30 yr^-1. Assuming an isotropic emission, each event must liberate about 10^51 erg in the form of optical-to-ultraviolet radiation. The spectral properties of the B component suggest that reprocessing on a truncated disk, or partially- thick bremsstrahlung may be the emission mechanism. We find evidence of a lag of a few days between the light curves of the B component at optical and ultraviolet wavelengths. Neither the variability properties, nor the spectral properties of the R component can be accu...
7 CFR 273.10 - Determining household eligibility and benefit levels.
... Register citations affecting § 273.10, see the List of CFR Sections Affected, which appears in the Finding...) or the Transitional Child Care (TCC) program shall not be deductible. A utility expense which...
An asymmetrical synchrotron model for knots in the 3C 273 jet
Liu, Wen-Po; Y. J. Chen; Wang, Chun-Cheng
To interpret the emission of knots in the 3C 273 jet from radio to X-rays, we propose a synchrotron model in which, owing to the shock compression effect, the injection spectra from a shock into the upstream and downstream emission regions are asymmetric. Our model could well explain the spectral energy distributions of knots in the 3C 273 jet, and predictions regarding the knots spectra could be tested by future observations.
Ángel Argilés
Full Text Available National Kidney Foundation CKD staging has allowed uniformity in studies on CKD. However, early diagnosis and predicting progression to end stage renal disease are yet to be improved. Seventy six patients with different levels of CKD, including outpatients and dialysed patients were studied for transcriptome, metabolome and proteome description. High resolution urinary proteome analysis was blindly performed in the 53 non-anuric out of the 76 CKD patients. In addition to routine clinical parameters, CKD273, a urinary proteomics-based classifier and its peptides were quantified. The baseline values were analyzed with regard to the clinical parameters and the occurrence of death or renal death during follow-up (3.6 years as the main outcome measurements. None of the patients with CKD2730.55. Unsupervised clustering analysis of the CKD273 peptides separated the patients into two main groups differing in CKD associated parameters. Among the 273 biomarkers, peptides derived from serum proteins were relatively increased in patients with lower glomerular filtration rate, while collagen-derived peptides were relatively decreased (p<0.05; Spearman. CKD273 was different in the groups with different renal function (p<0.003. The CKD273 classifier separated CKD patients according to their renal function and informed on the likelihood of experiencing adverse outcome. Recently defined in a large population, CKD273 is the first proteomic-based classifier successfully tested for prognosis of CKD progression in an independent cohort.
The exponential law for superluminal expansion of quasar 3C273
International Nuclear Information System (INIS) The radioastronomical technique of VLBI achieves an angular resolution better than 1 marcs, equivalent to a physical resolution of the order of light-years. In even the most distant galaxies such objects can be easily detected. In four extreme cases, three quasars (3C273, 3C279 and 3C345) and one seyfert galaxy (3C120) have been seen to expand with an apparent speed more than twice the speed of light. The evidence for such 'superluminal' expansion has been based on rather limited data, and the interpretation has been uncertain; but the recent development of the VLBI technique of hybrid mapping allows us to map the radio brightness distribution to show the expansion directly and unambiguously. This article uses the data of the quasar 3C273 presented earlier and presents a formula for the observation of superluminal expansion velocity of quasar 3C273. (Auth.)
A flare in the millimetre to IR spectrum of 3C273
International Nuclear Information System (INIS) Over the past two years the millimetre and submillimetre spectrum of 3C273 (ref.1) has been monitored and a quiescent millimetre-to-far-IR spectrum with an index α = -0.7 (Ssubupsilon) is proportional to upsilonsup(α) connecting smoothly to the radio and mid-IR was found and the discovery of a concurrent flare in the IR-to-near-millimetre spectrum of 3C273 implies that the emission over this range of frequency originates in the same region of the source. The flare was seen to propagate to longer wavelengths whilst decaying at shorter wavelengths. The time scale of the flare is suggestive of an event within the central 0.1 pc of the source. Millimetre wavelength variability of 3C273 has been reported but with very little temporal overlap with present data. (author)
Flare in the millimetre to IR spectrum of 3C273
Robson, E.I. (Preston Polytechnic (UK). Div. of Physics and Astronomy); Gear, W.K.; Clegg, P.E.; Ade, P.A.R.; Griffin, M.J. (Queen Mary Coll., London (UK). Dept. of Physics); Smith, M.G. (Royal Observatory, Edinburgh (UK)); Nolt, I.G.; Radostitz, J.V. (Oregon Univ., Eugene (USA). Dept. of Physics); Howard, R.J. (National Radio Astronomy Observatory, Tucson, AR (USA))
Over the past two years the millimetre and submillimetre spectrum of 3C273 (ref.1) has been monitored and a quiescent millimetre-to-far-IR spectrum with an index ..cap alpha.. = -0.7 (Ssubupsilon) is proportional to upsilonsup(..cap alpha..) connecting smoothly to the radio and mid-IR was found and the discovery of a concurrent flare in the IR-to-near-millimetre spectrum of 3C273 implies that the emission over this range of frequency originates in the same region of the source. The flare was seen to propagate to longer wavelengths whilst decaying at shorter wavelengths. The time scale of the flare is suggestive of an event within the central 0.1 pc of the source. Millimetre wavelength variability of 3C273 has been reported but with very little temporal overlap with present data.
Faraday rotation in the MOJAVE blazars: 3C 273 a case study
Hovatta, T.; Lister, M. L.; Aller, M. F.; H. D. Aller(Astronomy Department, University of Michigan, Ann Arbor); Homan, D. C.; Kovalev, Y.Y.; Pushkarev, A. B.; Savolainen, T.
Radio polarimetric observations of Active Galactic Nuclei can reveal the magnetic field structure in the parsec-scale jets of these sources. We have observed the gamma-ray blazar 3C 273 as part of our multi-frequency survey with the Very Long Baseline Array to study Faraday rotation in a large sample of jets. Our observations re-confirm the transverse rotation measure gradient in 3C 273. For the first time the gradient is seen to cross zero which is further indication for a helical magnetic f...
A new infrared spectral component of the quasar 3C273
International Nuclear Information System (INIS) Following the dramatic infrared to millimetre-wavelength flare seen in the quasar 3C273 during 1983, the authors have continued to monitor its overall continuum emission. Recent measurements show that the 10-μm to 3-mm emission has decayed to a level well below any seen previously, while the 1-4-μm emission has remained relatively constant. This behaviour has revealed the presence of an apparently non-variable component which dominates the near-infrared emission in 3C273 and includes the small 'bump' at approx. 3.5 μm in the power-law continuum. (author)
2003--2005 INTEGRAL and XMM-Newton observations of 3C 273
Chernyakova, M.; Neronov, A.; Courvoisier, T. J. -L.; Turler, M.; Soldi, S.; Beckmann, V.; Lubinski, P.; R. Walter(ISDC); Page, K. L.; Stuhlinger, M; Staubert, R.; McHardy, I.M.
The aim of this paper is to study the evolution of the broadband spectrum of one of the brightest and nearest quasars 3C 273. We analyze the data obtained during quasi-simultaneous INTEGRAL and XMM monitoring of the blazar 3C 273 in 2003--2005 in the UV, X-ray and soft gamma-ray bands and study the results in the context of the long-term evolution of the source. The 0.2-100 keV spectrum of the source is well fitted by a combination of a soft cut-off power law and a hard power law. No improvem...
An HST Proper-Motion Study of the Large-scale Jet of 3C273
Meyer, Eileen T.; Sparks, William B.; Georganopoulos, Markos; Anderson, Jay; van der Marel, Roeland; Biretta, John; Sohn, Sangmo Tony; Chiaberge, Marco; Perlman, Eric; Norman, Colin
The radio galaxy 3C 273 hosts one of the nearest and best-studied powerful quasar jets. Having been imaged repeatedly by the Hubble Space Telescope (HST) over the past twenty years, it was chosen for an HST program to measure proper motions in the kiloparsec-scale resolved jets of nearby radio-loud active galaxies. The jet in 3C 273 is highly relativistic on sub-parsec scales, with apparent proper motions up to 15$c$ observed by VLBI (Lister et al., 2013). In contrast, we find that the kpc-sc...
Courvoisier, T. J. -L.; Beckmann, V.; Bourban, G.; Chenevez, J.; Chernyakova, M.; Deluit, S.; Favre, P; Grindlay, J. E.; Lund, N.; O'Brien, P; Page, K; Produit, N.; M. Türler; Turner, M. J. L.; Staubert, R.
INTEGRAL has observed the bright quasar 3C 273 on 3 epochs in January 2003 as one of the first observations of the open programme. The observation on January 5 was simultaneous with RXTE and XMM-Newton observations. We present here a first analysis of the continuum emission as observed by these 3 satellites in the band from 3 keV to 500 keV. The continuum spectral energy distribution of 3C 273 was observed to be weak and steep in the high energies during this campaign. We present the actual s...
Proton Synchrotron Radiation from Extended Jets of PKS 0637-752 and 3C 273
Bhattacharyya, Wrijupan; Gupta, Nayantara
Recently, the IC/CMB X-ray mechanism has been strongly disfavoured for 3C 273 and PKS 0637-752 since the anomalously hard and steady gamma-ray emission predicted by such models violates the observational results from Fermi-LAT. Here we propose the proton synchrotron origin of the X ray-gamma ray flux from the knots of PKS 0637-752 with a reasonable budget in luminosity, by considering synchrotron radiation from an accelerated proton population. Moreover, for the source 3C 273, some of the opt...
Simultaneous X-ray and infrared variability in the quasar 3C273
McHardy, Ian; Lawson, Anthony; Newsam, Andrew; Marscher, Alan; Robson, Ian; Stevens, Jason
From a combination of high quality X-ray observations from the NASA Rossi X-ray Timing Explorer (RXTE), and infrared observations from the UK Infrared Telescope (UKIRT) we show that the medium energy X-ray (3-20 keV) and near infrared fluxes in the quasar 3C273 are highly correlated. It is widely believed that the X-ray emission in quasars like 3C273 arises from Compton scattering of low energy seed photons and our observations provide the first reliable detection of correlated variations in ...
The Low-Redshift Lyman Alpha Forest toward 3C 273
Williger, G. M.; Carswell, R. F.; Weymann, R. J.; Jenkins, E. B.; Sembach, K. R.; Tripp, T. M.; Davé, R.; Haberzettl, L.; Heap, S. R.
We present an analysis of the Ly-a forest toward 3C 273 from the Space Telescope Imaging Spectrograph at ~7 km/s resolution, along with re-processed data from the Far Ultraviolet Spectroscopic Explorer. The high UV flux of 3C 273 allows us to probe the weak, low z absorbers. The main sample consists of 21 HI absorbers that we could discriminate to a sensitivity of log NHI~ 12.5. The redshift density for absorbers with 13.1
Kataoka, Jun; Tanihata, Chiharu; Kawai, Nobuyuki; Takahara, Fumio; Takahashi, Tadayuki; Edwards, Philip G.; Makino, Fumiyoshi
We present the results of a long-look monitoring of 3C273 with RXTE between 1996 and 2000. A total of 230 observations amounts to a net exposure of 845ksec, with this spectral and variability analysis of 3C273 covering the longest observation period available at hard X-ray energies. Flux variations by a factor of 4 have been detected over 4years, whereas less than 30% flux variations have been observed for individual flares on time-scales of 3 days. Two temporal methods, the power spectrum de...
Turler, M.; Chernyakova, M.; Courvoisier, T. J. -L.; Foellmi, C.; Aller, M. F.; H. D. Aller(Astronomy Department, University of Michigan, Ann Arbor); Kraus, A.; Krichbaum, T. P.; A. Lahteenmaki(Aalto University Metsahovi Radio Observatory, Kylmala, Finland); Marscher, A.; McHardy, I.M.; O'Brien, P. T.; Page, K. L.; Popescu, L; Robson, E. I.
Aims. The aim of this work is to identify and study spectral features in the quasar 3C 273 usually blended by its strong jet emission. Method. A historic minimum in the sub-millimetre emission of 3C 273 triggered coordinated multi-wavelength observations in June 2004. X-ray observations from the INTEGRAL, XMM-Newton and RXTE satellites are complemented by ground-based optical, infrared, millimetre and radio observations. The overall spectrum is used to model the infrared and X-ray spectral co...
The structure of X-ray jet of quasar 3C 273
International Nuclear Information System (INIS) The X-ray internal structure of extragalactic jets is analyzed. The Lucy-Richardson deconvolution algorithm is used to restore the image of X-ray sources. The analysis was done for Chandra observations of core-dominated quasar 3C 273. The transverse profiles are built for the jet knots
7 CFR 273.23 - Simplified application and standardized benefit projects.
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... accordance with 7 CFR 273.17 if it is later determined that the reduction in the public assistance grant was... inability or unwillingness to provide documentation of the alien's immigration status, the State agency must... fleeing to avoid prosecution or custody for a crime, or an attempt to commit a crime, that would...
From Centimeter to Millimeter Wavelengths A High Angular Resolution Study of 3C273
Krichbaum, T P; Zensus, J A
We monitored 3C273 with VLBI at 15-86 GHz since 1990. We discuss component trajectories, opacity effects at the jet base, a rotating and perhaps precessing jet, and outburst-ejection relations from Gamma-ray to radio bands.
RXTE Observations of 3C273 between 1996 and 2000 Variability Timescale and Jet Power
Kataoka, J; Kawai, N; Takahara, F; Takahashi, T; Edwards, P G; Makino, F; Kataoka, Jun; Tanihata, Chiharu; Kawai, Nobuyuki; Takahara, Fumio; Takahashi, Tadayuki; Edwards, Philip G.; Makino, Fumiyoshi
We present the results of a long-look monitoring of 3C273 with RXTE between 1996 and 2000. A total of 230 observations amounts to a net exposure of 845ksec, with this spectral and variability analysis of 3C273 covering the longest observation period available at hard X-ray energies. Flux variations by a factor of 4 have been detected over 4years, whereas less than 30% flux variations have been observed for individual flares on time-scales of 3 days. Two temporal methods, the power spectrum density (PSD) and the structure function (SF), have been used to study the variability characteristics of 3C273. The hard X-ray photon spectra generally show a power-law shape with a differential photon index of G = 1.6+-0.1. In 10 of 261 data segments, exceptions to power-law behaviour have been found: (i) an additional soft excess below 4keV, and (ii) a broad Fe fluorescent line feature with EW = 100-200 eV. Our new observations of these previously reported X-ray features may imply that 3C273 is a unique object whose hard...
Yuan, Yuhai; Fan, Junhui
In the radio band, the relationship between the emission spectrum ( α) and flux density ( F) can demonstrate the emission theory and process. In this paper, we used the radio data of 3C273 and 3C446 from UMRAO (the University of Michigan Radio Observatory) to calculate the spectral indices ( α), and analyzed the relationship between spectral indices ( α) and flux densities ( F). We obtained the following results. (1) There were anti-correlations between α and F, for 3C273, α=-0.024 F 14.5+0.91, with the correlation coefficient r=-0.92, the chance p3C273, the time spans of two α- F circles were 8.43 years and 7.79 years; for 3C446, the time spans of two α- F circles were 5.66 years and 6.64 years. Not only for 3C273, but also for 3C446, the time spans were consistent with the quasi-periodicities calculated from the lightcurve or spectral variance.
Courvoisier, T.J.L.; Beckmann, V.; Bourban, G.; Chenevez, Jérôme; Chernyakova, M.; Deluit, S.; Favre, P.; Grindlay, J.E.; Lund, Niels; O'Brien, P.; Page, K.; Produit, N.; Turler, M.; Turner, M.J.L.; Staubert, R.; Stuhlinger, M.; Walter, Rasmus; Zdziarski, A.A.
INTEGRAL has observed the bright quasar 3C 273 on 3 epochs in January 2003 as one of the first observations of the open programme. The observation on January 5 was simultaneous with RXTE and XMM-Newton observations. We present here a first analysis of the continuum emission as observed by these 3...
48 CFR 719.273 - The U.S. Agency for International Development (USAID) Mentor-Protégé Program.
... International Development (USAID) Mentor-ProtÃ©gÃ© Program. 719.273 Section 719.273 Federal Acquisition Regulations System AGENCY FOR INTERNATIONAL DEVELOPMENT SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS The U.S. Agency for International Development (USAID) Mentor-ProtÃ©gÃ© Program 719.273 The U.S. Agency...
Soft X-ray Variability of the Bright Quasar 3C273
We present the results from ROSAT observations of 3C273 in the soft X-ray band. The light variation of 3C273 was investigated for three different energy bands of soft, medium, and hard. The maximum variability with a factor of 2 for 551 dayswas confirmed at all three different bands. This appears to be a periodic variation within the period of roughly 6 months. However, the short-term or micro variation was not so distinct and the light variation of each band did not show any correlation between them. The hardness ratio for hard and soft bands shows irregular variation but there was no correlation between them. There is no distinct variation of the photon index in the case of simple power law model fitting. For power law + free absorption model fitting, the average photon index () is 2.08.
Distribution of X-ray Emission from Jet Knots of 3C273
Bannikova, E Yu
The jet of the quasar 3C273 is observed at different spectral bands. This jet has a knot structure. Jet radiation in radio and optical bands are connected with synchrotron mechanism, while the emission mechanism producing the X-rays is controversial. We suppose that the X-rays observed for two knots nearest to the quasar can originate from the inverse Compton scattering of external source radiation on relativistic electrons. But in the jet region with constant low X-ray intensity the inverse Compton scattering on cosmic microwave background photons (IC/CMB) is essential because the energy density of external source decreases. Upon this scenario the constraints on the angle between the jet axis and line sight values have been obtained. Also, some physical parameters for two nearest knots of the jet of 3C273 have been estimated.
INTEGRAL has observed the bright quasar 3C 273 on 3 epochs in January 2003 as one of the first observations of the open programme. The observation on January 5 was simultaneous with RXTE and XMM-Newton observations. We present here a first analysis of the continuum emission as observed by these 3...... satellites in the band from similar or equal to3 keV to similar or equal to500 keV. The continuum spectral energy distribution of 3C 273 was observed to be weak and steep in the high energies during this campaign. We present the actual status of the cross calibrations between the instruments on the three...
Radio emission from the jet and lobe of 3C273
International Nuclear Information System (INIS) New maps of 3C273 at 151 and 408 MHz are presented using the MERLIN interferometer, with dynamic range of 4x103:1 and 104:1, respectively. These show that (1) there is an extended region or lobe to the south of the main jet, (2) the radio emission of the jet is continuous from the core to beyond the limit of the optical jet and (3) no counter-component can be found in the opposite direction to the jet. The ridge-line of the jet shows a 'wiggle', the wavelength (lambda) of which decreases by a factor of 6 along its length. The data suggest that 3C273 is intrinsically one-sided. (author)
27.3-day and 13.6-day atmospheric tide
LI; GuoQing; ZONG; HaiFeng
An analysis of time variations in the earth's length of day (LOD) for 25 years (1973-1998) versus atmospheric circulation changes and lunar phase is presented. It is found that, on the average, there is a 27.3-day and 13.6-day period oscillation in global zonal wind speed, atmospheric geopotential height, and LOD following alternating changes in lunar phase. Every 5-9 days (6.8 days on average), the fields of global atmospheric zonal wind and geopotential height and LOD undergo a sudden change in relation to a change in lunar declination. The observed atmospheric oscillation with this time period may be viewed as a type of atmospheric tide.Ten atmospheric tidal cases have been analyzed by comparing changes in LOD, global zonal wind speed and atmospheric geopotential height versus change in lunar declination. Taken together these cases reveal prominent 27.3-day and 13.6-day tides. The lunar forcing on the earth's atmosphere is great and obvious changes occur in global fields of zonal wind speed and atmospheric geopotential height over the equatorial and low latitude areas.The driving force for the 27.3-day and 13.6-day atmospheric tides is the periodic change in lunar forcing during the moon's revolution around the earth. When the moon is located on the celestial equator the lunar declination equals zero and the lunar tidal forcing on the atmosphere reaches its maximum, at this time the global zonal wind speed increases and the earth's rotation rate decreases and LOD increases. Conversely, when the moon reaches its most northern or southern positions the lunar declination is maximized, lunar tidal forcing decreases, global zonal wind speed decreases, earth's rotation rate increases and LOD decreases.27.3-day and 13.6-day period atmospheric tides deserve deeper study. Lunar tidal forcing should be considered in models of atmospheric circulation and in short and medium range weather forecasting.
OPTICAL MONITORING OF TWO BRIGHTEST NEARBY QUASARS, PHL 1811 AND 3C 273
Fan, J. H.; Liu, Y.; Yuan, Y. H. [Center for Astrophysics, Guangzhou University, Guangzhou 510006 (China); Kurtanidze, O.; Chanishvili, R. [Abastumani Observatory, Mt. Kanobili, 0301 Abastumani, Georgia (United States); Richter, G. M. [Astrophysikalisches Institut Potsdam, An der Sternwarte 16, D-14482 Potsdam (Germany)
Variability is one of the most observable characteristics of active galactic nuclei, and it is important when considering the emission mechanism. In this paper, we report optical photometry monitoring of two nearby brightest quasars, PHL 1811 and 3C 273, using the ST-6 camera attached to the Newtonian focus and the Ap6E CCD camera attached to the primary focus of the 70 cm meniscus telescope at the Abastumani Observatory, Georgia. PHL 1811 was monitored during the period from 2002 September to 2012 December, while 3C 273 was monitored during the period from 1998 February to 2008 May. During our monitoring period, the two sources did not show any significant intra-day variability. The largest detected variations are ΔR = 0.112 ± 0.010 mag. for PHL 1811, ΔB = 0.595 ± 0.099 mag, ΔV = 0.369 ± 0.028 mag, ΔR = 0.495 ± 0.076 mag, and ΔI = 0.355 ± 0.009 mag for 3C 273. When the periodicity analysis methods are adopted for the observations of the sources, a period of p = 5.80 ± 1.12 yr is obtained for PHL 1811 in the R light curve in the present work, and periods of p = 21.10 ± 0.14, 10.00 ± 0.14, 7.30 ± 0.09, 13.20 ± 0.09, 2.10 ± 0.06, and 0.68 ± 0.05 yr are obtained for 3C 273 based on the data in the present work combined with historical works.
International Nuclear Information System (INIS) Variability is one of the most observable characteristics of active galactic nuclei, and it is important when considering the emission mechanism. In this paper, we report optical photometry monitoring of two nearby brightest quasars, PHL 1811 and 3C 273, using the ST-6 camera attached to the Newtonian focus and the Ap6E CCD camera attached to the primary focus of the 70 cm meniscus telescope at the Abastumani Observatory, Georgia. PHL 1811 was monitored during the period from 2002 September to 2012 December, while 3C 273 was monitored during the period from 1998 February to 2008 May. During our monitoring period, the two sources did not show any significant intra-day variability. The largest detected variations are ΔR = 0.112 ± 0.010 mag. for PHL 1811, ΔB = 0.595 ± 0.099 mag, ΔV = 0.369 ± 0.028 mag, ΔR = 0.495 ± 0.076 mag, and ΔI = 0.355 ± 0.009 mag for 3C 273. When the periodicity analysis methods are adopted for the observations of the sources, a period of p = 5.80 ± 1.12 yr is obtained for PHL 1811 in the R light curve in the present work, and periods of p = 21.10 ± 0.14, 10.00 ± 0.14, 7.30 ± 0.09, 13.20 ± 0.09, 2.10 ± 0.06, and 0.68 ± 0.05 yr are obtained for 3C 273 based on the data in the present work combined with historical works
Beaming and precession in the inner jet of 3C273
Zulema Abraham; Romero, Gustavo E.
We have used all the available VLBI data to determine the kinematical evolution of the inner jet of 3C273. The position angles, velocities and formation epochs of different superluminal components are compatible with a precessing inner jet. The time dependence of the Doppler factor for this jet is computed and the implications for the gamma-ray emission are discussed. Additionally, the model, when considered along with simultaneous radio and X-ra y variability observations provides an upper b...
Relationship between X-ray and ultraviolet emission in 3C 273
Paltani, S.; Courvoisier, T. J. -L.; Turler, M.; R. Walter(ISDC)
In 3C 273, ultraviolet flux and X-ray flux measured by BATSE are not well correlated, contrarily to predictions of several models, unless the X-ray flux lags the UV emission by 1.75 yr. The absence of observed correlation at small lag cannot be due to spectral variability. A Comptonizing corona model is however compatible with all UV and X-ray observations covering the BATSE period.
A high-resolution multi-wavelength study of the jet in 3C 273
Jester, S.; Roeser, H. -J.; Meisenheimer, K.; Perley, R.; Garrington, S.
We present HST images at 622 nm and 300 nm of the optical jet in 3C273 and determine the run of the optical spectral index at 0.2" along the jet. We find no evidence for localized acceleration or loss sites, and support for a little-changing spectral shape throughout the jet. We consider this further evidence in favour of a distributed acceleration process.
Simulations of the relativistic parsec-scale jet in 3C273
Perucho, M; Lobanov, A. P.; Marti, J. M.
We present a hydrodynamical 3D simulation of the relativistic jet in 3C273, in comparison to previous linear perturbation analysis of Kelvin-Helmholtz instability developing in the jet. Our aim is to assess advantages and limitations of both analytical and numerical approaches and to identify spatial and temporal scales on which the linear regime of Kelvin-Helmholtz instability can be applied in studies of morphology and kinematics of parsec-scale jets.
The radio galaxy 3C 273 hosts one of the nearest and best-studied powerful quasar jets. Having been imaged repeatedly by the Hubble Space Telescope (HST) over the past twenty years, it was chosen for an HST program to measure proper motions in the kiloparsec-scale resolved jets of nearby radio-loud active galaxies. The jet in 3C 273 is highly relativistic on sub-parsec scales, with apparent proper motions up to 15c observed by very long baseline interferometry. In contrast, we find that the kiloparsec-scale knots are compatible with being stationary, with a mean speed of -0.2 ± 0.5c over the whole jet. Assuming the knots are packets of moving plasma, an upper limit of 1c implies a bulk Lorentz factor Γ < 2.9. This suggests that the jet has either decelerated significantly by the time it reaches the kiloparsec scale, or that the knots in the jet are standing shock features. The second scenario is incompatible with the inverse Compton off the Cosmic Microwave Background (IC/CMB) model for the X-ray emission of these knots, which requires the knots to be in motion, but IC/CMB is also disfavored in the first scenario due to energetic considerations, in agreement with the recent finding of Meyer & Georganopoulos which ruled out the IC/CMB model for the X-ray emission of 3C 273 via gamma-ray upper limits.
McHardy, I; Newsam, A; Marscher, A P; Robson, I; Stevens, J; Hardy, Ian Mc; Lawson, Anthony; Newsam, Andrew; Marscher, Alan; Robson, Ian; Stevens, Jason
From a combination of high quality X-ray observations from the NASA Rossi X-ray Timing Explorer (RXTE), and infrared observations from the UK Infrared Telescope (UKIRT) we show that the medium energy X-ray (3-20 keV) and near infrared fluxes in the quasar 3C273 are highly correlated. It is widely believed that the X-ray emission in quasars like 3C273 arises from Compton scattering of low energy seed photons and our observations provide the first reliable detection of correlated variations in 3C273 between the X-ray band and any lower energy band. For a realistic electron distribution we demonstrate that it is probable that each decade of the seed photon distribution from the mm to IR waveband contributes roughly equally to the medium energy X-ray flux. However the expected mm variations are too small to be detected above the noise, probably explaining the lack of success of previous searches for a correlation between X-ray and mm variations. In addition we show that the infrared leads the X-rays by 0.75+/-0.2...
Attridge, J M
(86) GHz Very Long Baseline Polarimetry probes magnetic field structures within the cores of Active Galactic Nuclei at higher angular resolutions and a spectral octave higher than previously achievable. Observations of 3C273 and 3C279 taken in April 2000 with the Coordinated Millimeter VLBI Array have resulted in the first total intensity (Stokes I) and linear polarization VLBI images reported of any source at 86 GHz. These results reveal the 86 GHz electric vector position angles within the jets of 3C273 and 3C279 to be orthogonal to each other, and the core of 3C273 to be unpolarized. If this lack of polarization is due to Faraday depolarization alone, the dispersion in rotation measure is >=90000 rad/m^2 for the core of 3C273.
Scintillation observations of the 3C48, 3C273 and 3C295 at 25 MHz
International Nuclear Information System (INIS) Interplanetary scintillations of 3C 48, 3C 273, and 3C 295 have been observed at 25 MHz. 3C 48 is found to possess a halo. 3C 295 at the decametric waves becomes an one -component source. 3C 273 has the same angular structure as in the meter - wavelength range. The models of the sources corresponding to the present observations are proposed
Turler, M.; Paltani, S.; Courvoisier, T. J. -L.; Aller, M. F.; H. D. Aller(Astronomy Department, University of Michigan, Ann Arbor); Blecha, A.; Bouchet, P.; Lainela, M.; McHardy, I.M.; Robson, E. I.; J. A. Stevens; Terasranta, H.; Tornikoski, M.; Ulrich, M.-H.; Waltman, E. B.
We present a wide multi-wavelength database of most observations of the quasar 3C 273 obtained during the last 30 years. This database is the most complete set of observations available for an active galactic nucleus (AGN). It contains nearly 20'000 observations grouped together into 70 light curves covering 16 orders of magnitude in frequency from the radio to the gamma-ray domain. The database is constituted of many previously unpublished observations and of most publicly available data gat...
HST and MERLIN Observations of the Jet in 3C273
Bahcall, J. N.; Kirhakos, S; D. P. Schneider; Davis, R. J.; Muxlow, T.W.B.; Garrington, S.T.; Conway, R. G.; Unwin, S. C.
We present red and blue images of the jet of the quasar 3C273 obtained with the WFPC2 on the Hubble Space Telescope as well as a new radio map made with the MERLIN array. The images are of significantly better quality than that of previous data. The two maps are aligned to an accuracy of 0.020$''$; this accuracy is achieved because both the quasar and the jet are contained in both the radio and optical images. The start of the optical jet is marked by an elongated knot which appears identical...
Bannikova, E. Yu.; Mykhailova, M. S.
The jet of the quasar 3C273 is observed at different spectral bands. This jet has a knot structure. Jet radiation in radio and optical bands are connected with synchrotron mechanism, while the emission mechanism producing the X-rays is controversial. We suppose that the X-rays observed for two knots nearest to the quasar can originate from the inverse Compton scattering of external source radiation on relativistic electrons. But in the jet region with constant low X-ray intensity the inverse ...
Particle acceleration in the hotspot of the jet of quasar 3C273
International Nuclear Information System (INIS) Recent radio, optical and near-infrared observations of the dominant hotspot at the outer end of the quasar jet 3C273A have revealed a complex spectrum, which provides a unique probe of the acceleration process supplying the synchrotron-emitting electrons. The authors present theoretical calculations of the electron spectrum produced by non-relativistic shock acceleration which, include both synchrotron losses and a finite emission region. The resultant synchrotron spectrum fits the observations, providing a natural explanation for the steep spectrum at radio to infrared frequencies, the observed flattening at ν 14 Hz. The model yields a new magnetic field estimate of 70 nT. (author)
Multi-band variability in the blazar 3C 273 with XMM-Newton
Kalita, Nibedita; Gupta, Alok C.; Wiita, Paul J.; Bhagwan, Jai; Duorah, Kalpana
We have undertaken a nearly simultaneous optical/UV and X-ray variability study of the flat spectrum radio quasar, 3C 273 using data available from the XMM$-$Newton satellite mission from June 2000 to July 2012. Here we focus on the multi-wavelength flux variability on both intra-day and long time scales of this very well known radio-loud source. We found high flux variability over long time scales in all bands for which observations were made. The optical/UV variability amplitude was more th...
Faraday Rotation Measure Gradients from a Helical Magnetic Field in 3C 273
Zavala, R. T.; Taylor, G. B.
Using high frequency (12-22 GHz) VLBA observations we confirm the existence of a Faraday rotation measure gradient of ~ 500 rad/m^2/mas transverse to the jet axis in the quasar 3C 273. The gradient is seen in two epochs spaced roughly six months apart. This stable transverse rotation measure gradient is expected if a helical magnetic field wraps around the jet. The overall order to the magnetic field in the inner projected 40 parsecs is consistent with a helical field. However, we find an une...
Asada, Keiichi; Inoue, Makoto; Kameno, Seiji; Nagai, Hiroshi
The existence of a gradient in the Faraday rotation measure (RM) of the quasar 3C 273 jet is confirmed by follow-up observations. A gradient transverse to the jet axis is seen for more than 20 mas in projected distance. Taking account of the viewing angle, we estimate it to be more than 100 pc. Comparing to the distribution of the RM in 1995, we detect a time variation of it at the same distance from the core over 7 yr. We discuss the origin of the Faraday rotation based on this rapid time va...
Wavelet Analysis of AGN X-Ray Time Series: A QPO in 3C 273?
Espaillat, C.; Bregman, J.; Hughes, P; Lloyd-Davies, E.
Quasi-periodic signals have yielded important constraints on the masses of black holes in galactic X-ray binaries, and here we extend this to active galactic nuclei (AGNs). We employ a wavelet technique to analyze 19 observations of 10 AGNs obtained with the XMM-Newton EPIC pn camera. We report the detection of a candidate 3.3 ks quasi period in 3C 273. If this period represents an orbital timescale originating near a last stable orbit of 3Rs, it implies a central black hole mass of 7.3x10^6 ...
Multi-wavelength Observations of 3C 273 in 1993-1995
We present the results of the multi-wavelength campaigns on 3C 273 in 1993-1995. During the observations in late 1993 this quasar showed an increase of its flux for energies greater equal 100 MeV from about 2.1 x 10^-7 photons/cm^2/s to approximately 5.6 x 10^-7 photons/cm^2/s during a radio outburst at 14.5, 22 and 37 GHz. However, no one-to-one correlation of the gamma-ray radiation with any frequency could be found. The photon spectral index of the high energy spectrum changed from (3.20 +...
Uchiyama, Y.; Urry, C. M.; Cheung, C. C.; Jester, S.; van Duyne, J.; Coppi, P.; Sambruna, R. M.; Takahashi, T.; Tavecchio, F.; Maraschi, L.
We have performed infrared imaging of the jet of the quasar 3C 273 at wavelengths 3.6 and 5.8 microns with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope. When combined with the radio, optical and X-ray measurements, the IRAC photometry clearly shows that the optical emission is dominated by the high-energy component of the jet, not by the radio synchrotron component, as had been assumed to date. The high-energy component may be due to a second synchrotron component or to IC ...
Constraining the location of rapid gamma-ray flares in the FSRQ 3C 273
Rani, B.; Lott, B.; Krichbaum, T. P.; Fuhrmann, L.; Zensus, J. A.
We present a \\gamma-ray photon flux and spectral variability study of the flat-spectrum radio quasar 3C 273 over a rapid flaring activity period between September 2009 to April 2010. Five major flares are observed in the source during this period. The most rapid flare observed in the source has a flux doubling time of 1.1 hr. The rapid \\gamma-ray flares allow us to constrain the location and size of the \\gamma-ray emission region in the source. The \\gamma \\gamma-opacity constrains the Doppler...
Turler, M.; Courvoisier, T. J. -L.; Paltani, S.
We present a phenomenological jet model which is able to reproduce well the observed variations of the submillimetre-to-radio emission of the bright quasar 3C 273 during the last 20 years. It is a generalization of the original shock model of Marscher & Gear (1985), which is now able to describe an accelerating or decelerating shock wave, in a curved, non-conical and non-adiabatic jet. The model defines the properties of a synchrotron outburst which is expected to be emitted by the jet materi...
Full Text Available We have used all the available VLBI data to determine the kinematical evolution of the inner jet of 3C273. The position angles, velocities and formation epochs of different superluminal components are compatible with a precessing inner jet. The time dependence of the Doppler factor for this jet is computed and the implications for the gamma-ray emission are discussed. Additionally, the model, when considered along with simultaneous radio and X-ra y variability observations provides an upper bound to the Hubble constant (H0<~ 80 km/s/Mpc.
The variability of the quasar 3C 273: a radio to gamma-ray view
Soldi, S; Türler, M
We have analysed the first 15 months of Fermi/LAT data of the radio loud quasar 3C 273. Intense gamma-ray activity has been detected, showing an average flux of F(> 100 MeV) = 1.4e-6 ph/cm^2/s, with a peak at F(> 100 MeV) = 5.6e-6 ph/cm^2/s detected during a flare in September 2009. Together with the brightening of the source, a possible hardening of the gamma-ray spectrum is observed, pointing to a shift of the inverse Compton peak toward higher energies than the 1-10 MeV range in which 3C 273 inverse Compton emission is typically observed to peak. During the 15 months of observations the photon index is measured to vary between 2.4 and 3.3, with an average value of 2.78 +/- 0.03. When compared to the observations at other wavelengths, the gamma-rays show the largest flux variations and we discuss the possibility that two different components are responsible for the inverse Compton hump emission below and above the MeV peak.
Chernyakova, M; Courvoisier, T J L; Türler, M; Soldi, S; Beckmann, V; Lubinski, P; Walter, R; Page, K L; Stuhlinger, M; Staubert, R; McHardy, I M
The aim of this paper is to study the evolution of the broadband spectrum of one of the brightest and nearest quasars 3C 273. We analyze the data obtained during quasi-simultaneous INTEGRAL and XMM monitoring of the blazar 3C 273 in 2003--2005 in the UV, X-ray and soft gamma-ray bands and study the results in the context of the long-term evolution of the source. The 0.2-100 keV spectrum of the source is well fitted by a combination of a soft cut-off power law and a hard power law. No improvement of the fit is achieved if one replaces the soft cut-off power law by either a blackbody, or a disk reflection model. During the observation period the source has reached the historically softest state in the hard X-ray domain with a photon index $\\Gamma=1.82\\pm 0.01$. Comparing our data with available archived X-ray data from previous years, we find a secular evolution of the source toward softer X-ray emission (the photon index has increased by $\\Delta\\Gamma\\simeq 0.3-0.4$ over the last thirty years). We argue that e...
Kalita, Nibedita; Wiita, Paul J; Bhagwan, Jai; Duorah, Kalpana
We have undertaken a nearly simultaneous optical/UV and X-ray variability study of the flat spectrum radio quasar, 3C 273 using data available from the XMM$-$Newton satellite mission from June 2000 to July 2012. Here we focus on the multi-wavelength flux variability on both intra-day and long time scales of this very well known radio-loud source. We found high flux variability over long time scales in all bands for which observations were made. The optical/UV variability amplitude was more than twice than that in the X-ray bands. There is some frequency dependence of the variability in optical/UV bands in the sense that the variability amplitude increases with increasing frequency; however, the X-ray emissions disagree with this trend as the variability amplitude decreases from soft to hard X-ray bands. On intra-day time scales 3C 273 showed small amplitude variability in X-ray bands. A hardness ratio analysis in the X-ray regime indicates that the particle acceleration mechanism dominates the cooling mechani...
Marchenko, Volodymyr; Ostrowski, Michal; Stawarz, Lukasz; Bohdan, Artem; Jamrozy, Marek; Hnatyk, Bohdan
We present a detailed analysis of the best-quality multi-wavelength data gathered for the large-scale jet in the core-dominated quasar 3C 273. We analyze all the archival observations of the target with the Chandra X-ray Observatory, the far-ultraviolet observations with the Hubble Space Telescope, and a 8.4 GHz maps obtained with the Very Large Array. In our study we focus on investigating the morphology of the outflow at different frequencies, and therefore we apply various techniques for the image deconvolution, paying particular attention to a precise modeling of the Chandra and Hubble point spread functions. We find that the prominent brightness enhancements in the X-ray and far-ultraviolet jet of 3C 273 - the "knots" - are not point-like, and can be resolved transversely as extended features with sizes of about $\\simeq 0.5$ kpc. Also, the radio outflow is wider than the deconvolved X-ray/ultraviolet jet. Finally, the intensity peaks of the X-ray knots are located systematically upstream of the correspon...
High-Fidelity VLA Imaging of the Radio Structure of 3C273
Perley, R A
3C273, the nearest bright quasar, comprises a strong nuclear core and a bright, one-sided jet extending ~ 23 arcseconds to the SW. The source has been the subject of imaging campaigns in all wavebands. Extensive observations of this source have been made with the Very Large Array and other telescopes as part of a campaign to understand the jet emission mechanisms. Partial results from the VLA radio campaign have been published, but to date, the complete set of VLA imaging results has not been made available. We have utilized the VLA to determine the radio structure of 3C273 in Stokes I, Q, and U, over the widest possible frequency and resolution range. The VLA observed the source in all four of its configurations, and with all eight of its frequency bands, spanning 73.8 MHz to 43 GHz. The data were taken in a pseudo-spectral line mode to minimize the VLA's correlator errors, and were fully calibrated with subsequent self-calibration techniques to maximise image fidelity. Images in Stokes parameters I, Q, and ...
Williger, G M; Weymann, R J; Jenkins, E B; Sembach, K R; Tripp, T M; Davé, R; Haberzettl, L; Heap, S R
We present an analysis of the Ly-a forest toward 3C 273 from the Space Telescope Imaging Spectrograph at ~7 km/s resolution, along with re-processed data from the Far Ultraviolet Spectroscopic Explorer. The high UV flux of 3C 273 allows us to probe the weak, low z absorbers. The main sample consists of 21 HI absorbers that we could discriminate to a sensitivity of log NHI~ 12.5. The redshift density for absorbers with 13.1= 12.5, it is consistent with numerical model predictions. The Doppler parameter distribution is consistent with other low z samples. We find no evidence for a break in the column density power-law distribution to log NHI=12.3. A broad Ly-a absorber (BLA) is within Delta v == 12.6, consistent with the level predicted from hydrodynamical simulations, and indication for a Ly-a forest void at 0.09<0.12. We find at least two components for the z=0.0053 Virgo absorber, but the total NHI column is not significantly changed.