adsabs/WIESP2022-NER huggingface dataset:
Paper: 2017MNRAS.465.1401S (fulltext)
etal. 2006 ; Hao etal. 2014 ), so one might expect that their far-IR SEDs are also unchanged. On the basis of the assumption that the intrinsic AGN emission as a function of wavelength is broadly independent of AGN luminosity [for L , 5100 or L X(210keV) 10 43.5 ergs 1 AGN] and redshift (at least up to z 3.5), my results indicate that, on average, the far-IR/submm emission in the most luminous QSOs at the tail of the 2 z 4 optical luminosity function (Richards etal. 2006 ) is primarily produced by the AGN. This implies that for such systems, the emission in the Herschel bands and longer wavelengths such as those probed by SCUBA-2 at 850m would be AGN dominated; thus, wide-area Herschel and SCUBA-2 surveys will contain a population of QSOs which are primarily powered by AGN. Moreover, the SFRs of such systems cannot be determined with X-ray to submm broad-band photometry, and other means such as IR spectral lines will need to be used. Note that this does not mean that the host galaxies of luminous QSOs do not have star formation, perhaps even a considerable amount: I calculate a 3 upper limit on the SFR of 3165 and 643M yr 1 for the two QSO samples studied here. It simply means that the contribution from star formation is not detected in the broad-band SED as it is energetically less prominent than the AGN power at all wavelengths. This conclusion is in disagreement with the work of N16 . N16 use an AGN torus template to decompose their QSO SEDs into an AGN torus component and a star-forming component. The torus template used by N16 has a steeper far-IR slope than the S16 AGN SED, falling by about 0.5dex between 50 and 70m, compared to a 0.1dex change in the S16 AGN SED. This implies that a smaller fraction of the far-IR emission is attributed to the AGN in the work of N16 , and indeed, they find that star formation is a significant contributor to emission in the Herschel bands. In S16 , however, we argued that using torus templates in SED decomposition can significantly underestimate the AGN power in the far-IR, as they often lack an extended dust component, which would, in turn, boost the contribution required from star formation. Other works which use SED decomposition to separate the AGN and star formation contributions also find that QSOs have IR luminosities systematically larger than the IR luminosity produced by a torus component (e.g. Leipski etal. 2014 ; Drouart etal. 2016 ; Gruppioni etal. 2016 ; Podigachoski etal. 2016 ). Although traditionally this has been assigned to star formation, here I argue that a significant fraction, and in some cases all, of this excess IR luminosity can be attributed to AGN-heated dust at kpc scales. Using a bolometric correction factor f = 4, where L AGN, bol f L , 5100 , and an efficiency of = 0.1 to convert AGN luminosity into black hole accretion rate (BHAR) as in N16 , I calculate a 3 upper limit on the SFR/BHAR ratio of 23 for the N16 sample and 36 for the T15 sample. However, note that higher
Paper: 2018ApJ...863...53Y (acknowledgments)
We thank Deepto Chakrabarty for useful conversations and for providing input on the effective collecting area of RXTE -PCA and NICER. We are also grateful to Jean in’t Zand and the referee for valuable comments on the manuscript.
Paper: 2018MNRAS.473..286S (fulltext)
Previous studies argued that some fraction of PNe were shaped by brown dwarf or planet companions (e.g. Soker 1996 and De Marco Soker 2011 ). The rest were shaped by stellar companions. Under the assumed low mass-loss rate, AGB stars reach much larger radii, in particular, relative to their maximum radius on the RGB. This leaves a relatively large range of initial planetary orbital separations for planets to be engulfed during the upper AGB phase of their parent stars. The much larger radius of the AGB stars not only increases the chance for planetary interaction, but also implies that the envelope is more vulnerable to the influence of the planet towards higher final mass-loss rate. A higher mass-loss rate also implies a faster post-AGB evolution. Both effects make the formation of a PN much more likely. Our assumed low mass-loss rate, therefore, supports the notion that a fraction of elliptical PNe were shaped by sub-stellar companions. The planetary nebula luminosity function (PNLF). Observations show that the brightest PNe in [O iii ] λ5007, i.e. the bright-end cutoff of the PNLF, does not depend on the age or metallicity of the stellar population (e.g. Ciardullo 2010 ). Namely, old stellar populations for which stars of initial mass of M 1, ZAMS ≃ 1–1.2 M ⊙ are forming PNe have their brightest [O iii ] λ5007 PNe as young stellar populations have. This is still a puzzle as the post-AGB stellar luminosity to ionize the nebula should be at least ≈5000 L ⊙ . Our results hint to a possible solution to this puzzle. As evident from the last column of Table 2 , in the case of a reduced mass-loss rate the post-AGB stellar luminosity of stars with initial masses of M 1, ZAMS ≳ 1.05 M ⊙ is L pAGB ≳ 5000 L ⊙ . This, together with the interaction with a low-mass companion on the upper AGB will have the necessary ingredient for a bright PN, a dense nebula of mass ≳ 0.2 M ⊙ and a bright central ionizing star. The full solution to the puzzle might include another component. Miller Bertolami ( 2016 ) finds in a new set of simulations that the post-AGB luminosity values are higher than the values obtained in older simulations. He does not fully address the topic of the PNLF in old stellar populations, whereas we here present preliminary results on the matter. Mendez ( 2017 ) does show a fit to the PNLF of NGC 4697 based on the Miller Bertolami ( 2016 ) tracks, yet notes that it is not a full solution to the PNLF puzzle. It is conceivable that the new simulations of Miller Bertolami ( 2016 ) together with our assumed low mass-loss rate with a late engulfment of a planet (or a brown dwarf or a low-mass star), account for the brightest PNe in old stellar populations. We point out another difference in the two works, where in contrast to Miller Bertolami ( 2016 ), we focus on binary-shaped PNe (non spherical). The initial-final mass relation. There is an observed relation between the initial mass of stars and the mass of their descendant WDs (e.g. Kalirai
Paper: 2019ApJ...880..134G (acknowledgments)
M.N. is supported by the Sloan Foundation. We would like to thank the Flatiron Institute and Columbia University for providing the infrastructure and support for this research. We also thank the anonymous referee for giving important suggestions to improve this work. We are grateful to Glennys Farrar, Angus Beane, and David W Hogg for helpful conversations.
Paper: 2018ApJ...856..147O (acknowledgments)
We gratefully appreciate the comments from the anonymous referee that significantly improved this article. S.O. also thank Dr. Kazuya Saigo for helpful discussions. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2015.1.01025.S. ALMA is a partnership of the ESO (representing its member states), NSF (USA), and NINS (Japan), together with the NRC (Canada), NSC and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by the ESO, AUI/NRAO, and NAOJ. This research has also made use of data from the Herschel Gould Belt Survey (HGBS) project ( http://gouldbelt-herschel.cea.fr ). The HGBS is a Herschel Key Programme jointly carried out by SPIRE Specialist Astronomy Group 3 (SAG 3), scientists of several institutes in the PACS Consortium (CEA Saclay, INAF-IFSI Rome and INAF-Arcetri, KU Leuven, and MPIA Heidelberg), and scientists of the Herschel Science Center (HSC). Data analysis was carried out in part on a common-use data analysis computer system at the Astronomy Data Center (ADC) of the National Astronomical Observatory of Japan. Facilities: ALMA , Herschel .
Paper: 2017ApJ...840...68G (fulltext)
in any stripping of disk stars, as required in the harassment scenario. In addition, Aguerri ( 2016 ) concluded, based on his analysis of the – n diagram, that most dwarf ETGs in clusters are not transformed disk galaxies. In CG 611, minor mergers may have brought in some gas and stars in a clumpy manner, which is known to lead to the growth of disks, including counter-rotating cores and halos (Sancisi et al. 2008 ; González-Samaniego et al. 2014 ; Lane et al. 2015 ; Christensen et al. 2016 ). 25 25 https://www.youtube.com/watch?v=_Ssc1GsqHds As noted by Genel et al. ( 2010 ), minor mergers and smooth accretion, rather than major mergers, dominate galaxy growth (see also Murali et al. 2002 ; Semelin Combes 2005 ; Maller et al. 2006 ), and this supply channel also favors the formation of disks. Smooth gas flow onto a galaxy can occur via spherical accretion of ∼10 4 –10 5 K halo gas (e.g., White Frenk 1991 , see their Section 7; Birnboim Dekel 2003 ) or more directly from unshocked cold streams (e.g., Kereš et al. 2005 ; Dekel Birnboim 2006 ; Brooks et al. 2009 ; Dekel et al. 2009 ; Cornuault et al. 2016 ). This cold mode of delivery may be the most efficient of the mechanisms (Genel et al. 2010 ; Lu et al. 2011 ; van de Voort et al. 2011 ) and Pichon et al. ( 2011 ) have revealed how these cold gas streams can build a disk in a coherent planar manner (see also Danovich et al. 2012 , 2014 ; Prieto et al. 2013 ; and Stewart et al. 2013 ). Examining the kinematics of a larger sample of isolated dwarf ETGs will enable one to compare their properties with cluster dwarf ETGs and in so doing learn about their collective origin. For example, Paudel et al. ( 2010 ) have suggested that old metal-poor dwarf ETGs found in the central high-density regions of clusters may have formed along with the cluster while the younger more metal-rich dwarf ETGs (which tend to have disk features) have fallen in at a later time. While plausible, the assumption that the infalling galaxies were disk galaxies that underwent a structural transformation may need revising if isolated dwarf ETGs already have the same structural and kinematic properties as this cluster population. CG 611 is one such galaxy that suggests they do, and Janz et al. ( 2017 ) presents a further eight such galaxies. A related issue is the dominance at low masses of dwarf ETGs in clusters and the prevalence of (higher mass) Scd-Im galaxies in the field. Although we do not answer this question, obviously past claims that have attempted to answer this solely in terms of harassment and transformation of late-type galaxies need to be reconsidered, because dwarf ETGs similar to those in clusters are now known to also exist in the field. There is a formation channel for dwarf ETGs that does not involve the harassment of disk galaxies. In the Λ cold dark matter (ΛCDM) model of galaxy formation, low-mass dwarf galaxies naturally form, and help to build up bigger galaxies. One can speculate that these small
Paper: 2017ApJ...842...66W (fulltext)
P. Bastien et al. 2017, in preparation). The OMC 1 region was observed 21 times between 2016 January 11 and 25 in a mixture of very dry weather (Band 1; ) and dry weather (Band 2; ) under JCMT project reference numbers M16AL004 (BISTRO) and M15BEC02 (POL-2 commissioning). In order to determine the behavior of rms noise in our observations as a function of integration time, we measured the standard deviation on the Stokes Q and Stokes U values in a region with relatively constant signal in both the Stokes Q and the Stokes U maps, located between OMC 1 and the Orion Bar. This region, centered at approximately , was chosen because it was relatively flat, moderately unpolarized, low in emission, and away from the brightest sources, and because there was no region entirely without signal in the central part of the map. Figure 2 shows how the noise integrates down in this 21-repeat (∼14 hr) POL-2 observation. Figure 2. Mean measured rms noise in Q and U as a function of time (in minutes) at a single off-source position. The data points show the scatter on the individual measurements, and the line is the running mean. A behavior consistent with is seen, as in the ideal case. The polarization noise in Figure 2 is seen to integrate down close to , as in the ideal case. The scatter of individual measurements reduces satisfactorily as the data are subsequently combined. We find that there is no evidence of any “noise floor” in long integrations. From this plot we see that this data set has reached 2.1 mJy beam −1 rms noise in 13.5 hr. An rms noise value of ∼2 mJy beam −1 was set as the target value for the BISTRO survey. Appendices A and B list a series of tests that we carried out to confirm the repeatability of our measurements and to demonstrate consistency with previous data. 4. First Data from the Survey Figure 3 shows a polarization map taken with POL-2 of the OMC 1 region of the “integral filament” in the Orion A molecular cloud, with half-vectors rotated by 90° to trace the B-field direction. Only vectors with a signal-to-noise ratio of 3 or greater in polarization fraction are shown (i.e., ). The Orion A molecular cloud is a well-resolved and well-studied region of high-mass star formation (e.g., Bally 2008 ; O’Dell et al. 2008 ). It is the closest region of high-mass star formation, located at a distance of 388 ± 5 pc (Kounkel et al. 2017 ). The half-vector lengths show the percentage polarization, with a 5% scale bar in the corner to give the calibration. The underlying image is an 850 μ m total intensity map of the same region taken using SCUBA-2. Figure 3. Polarization map of the OMC 1 region of the “integral filament” in Orion A, with half-vectors rotated by 90° to show the B-field direction. The Orion Bar can be seen in the southeastern part of the map. Half-vectors with are shown. The background image is a SCUBA-2 850 μ m emission map taken using the standard SCUBA-2 DAISY mapping mode. The half-vector gray-scale is chosen for contrast
Paper: 2015ApJ...809..155Y (acknowledgments)
This work is supported by NSFC under contract No. 41304133, 41474147, 41231069, 41222032, 41174148, 41421003, and 41204105. The numerical calculations have been completed on a computing system at Peking University. Figure 3 was partly produced by VAPOR (Clyne et al. 2007 ). L.P.Y., J.S.H., C.Y.T., E.M., and X.W. are also members of the ISSI/ISSI-BJ International Team-304.
Paper: 2015ApJ...805..155W (acknowledgments)
Many thanks are in order to A. Usmanov, G. Zank, and A. Dosch for fruitful discussions. Financial support for the project FI 706/8-2 (within Research Unit 1048), as well as for the projects FI 706/14-1 and HE 3279/15-1 funded by the Deutsche Forschungsgemeinschaft (DFG), and FWF-Projekt I1111 is acknowledged.
Paper: 2017ApJ...851..125L (acknowledgments)
We acknowledge support from the Academy of Finland and the University of Oulu Graduate School. We thank an anonymous reviewer for a constructive report that helped us to improve the paper.
Paper: 2020ApJ...896....8J (fulltext)
propagate over a distance that is an order of magnitude bigger than its diameter, as suggested by the weak nonlinear theory and numerical simulations (Stern Radko 1998 ), as well as by experiments in nonrotating water tanks with a rectangular shape (Voropayev et al. 1999 ). More recent water-tank experiments (Cariteau Flór 2006 ) have demonstrated that it still has a finite lifetime, because the secondary component of such strongly asymmetric vortex pair starts to wrap around the principal monopole, creating a strain that eventually gives rise to an elliptic instability due to the parametric resonance between the oscillation of inertial waves and the ambient strain field; for details, see Cariteau Flór ( 2006 ). It should be noted that the behavior of Chaplygin vortices in a fully 3D geometry is still an open question, because no reliable 3D simulations and experiments have been reported in the literature and we are unable to predict whether the dynamical 3D turbulence of the solar wind and of Earth’s magnetosheath is dominated by stable dipolar (Larichev Reznik 1976 ; Petviashvili Pokhotelov 1992 ; Kuvshinov et al. 1999 ) vortices, or by long-lived, mostly monopolar Chaplygin structures. Their monopolar components feature a jump of the plasma density and of the compressional magnetic field B z at the edge. In the presence of a compressional magnetic field, such jumps are associated with a current shaped as a thin hollow cylinder at r = r 0 , which probably reduces its stability in high- β turbulent plasmas. In a high- β plasma, we have found two distinct types of coherent vortices propagating in the perpendicular direction. The first is identified as a generalized shear Alfvén structure that possesses both the torsional and the compressional components of the magnetic field perturbation. It has a zero parallel electric field and, being homogeneous along its axis that is inclined toward the ambient magnetic field, it sweeps along the z -axis with a velocity u z that is in the Alfvén speed range; the transverse phase velocity is equal to , where θ is the (small) pitch angle between the structure and the background magnetic field. While in a sufficiently incompressible plasma , it has the structure of a moving Chaplygin vortex with a monopole superimposed on a dipole; in plasmas with β ∼ 1, its monopolar component is likely to be unstable and short-lived due to the emergence of a thin, (electron-scale) current layer and/or a sharp peak of charge density at its edge. The compressible magnetic field associated with such a vortex is restricted to the interior of the vortex core, while the transverse perturbation “leaks” from the core to larger distances. The second type of propagating structure obtainable analytically possesses a finite compressional magnetic field and parallel electric field, as well as perpendicular fluid velocity and density perturbation, but vanishing parallel ion fluid velocity and transverse perturbations of the magnetic
Paper: 2015MNRAS.446.1750F (acknowledgments)
DRF acknowledges support from STFC (ST/L00075X/1), including provision of local computing resources. FL thanks the CPER Haute-Normandie/CNRT/Energie, Electronique, Matériaux, and the CNRS national programme ‘Physique et Chimie du Milieu Interstellaire’. We thank Alexandre Faure for providing the IOS results in the appendix.
Paper: 2017ApJ...842L..14F (fulltext)
( z ∼ 7) and with the cosmic SFR derived by Bouwens et al. ( 2015 ; or Finkelstein et al. 2015 ) up to z ∼ 10. We conclude that gaea is able to reproduce the overall evolution of the LFs, GSMF, and cosmic SFR over the redshift range 0 z 10. It is worth stressing that the good level of agreement shown in this Letter is obtained without any retuning of the feedback parameters (which have been calibrated by Hirschmann et al. 2016 against lower-redshift observables). Our findings agree with recent results from the MUFASA simulation suite (Davé et al. 2016 ), which implements a kinetic feedback scheme with scalings based on the parameterization provided in Muratov et al. ( 2015 ). They show that the MUFASA runs are able to reproduce the evolution of cosmic SFR and the GSMF at and the evolution of its low-mass end slope up to z ∼ 6 (where the simulated volume is too small to efficiently sample the high-mass end of the GSMF). A critical point of the analysis presented here is the treatment of dust attenuation. In this Letter, we consider both intrinsic and dust-attenuated magnitudes. Despite the simplified dust model adopted, we show that the bright ends of the corresponding LFs bracket the observed LFs. Our results are in qualitative agreement with the Bouwens et al. ( 2009 ) inferences based on the UV continuum of the sources, i.e., that dust attenuation should decrease at increasing redshifts, becoming negligible at . We note that a significant level of dust attenuation is required by the fiducial feedback scheme to match the shape of the observed LFs, in agreement with previous studies (Lo Faro et al. 2009 ; Lacey et al. 2011 ; Cai et al. 2014 ). Intrinsic and attenuated LFs converge below the knee of the LFs, again in qualitative agreement with the estimates by Bouwens et al. ( 2009 ) of a lower dust attenuation for fainter sources. The predicted level of dust attenuation at high redshift thus represents a powerful discriminant between different feedback schemes. Therefore, further insight into our understanding of galaxy evolution at is tightly connected to a better description of this key aspect. From a theoretical perspective, the implementation of a self-consistent dust treatment in theoretical models of galaxy evolution, able to follow dust production and destruction alongside with galaxy assembly (see, e.g., the recent work by Popping et al. 2016 ), represents a promising avenue. In addition, dust provides an important channel for molecular hydrogen formation and can therefore play a crucial role in regulating star formation at different cosmic epochs. This modeling is beyond the aims of this Letter and will be the subject of future work. Here, we just highlight that our conclusions will change dramatically if a substantial fraction of the SFR density is related to highly obscured objects, as some studies suggest at (Rowan-Robinson et al. 2016 ). In order to clearly assess the contribution of dusty sources to the SFR density at ,
Paper: 2016ApJ...816...91I (fulltext)
K, and purple: 7100 K. Table 1 summarizes the brightness temperatures of the sunspot umbra and quiet regions surrounded by the red and white rectangles, respectively, in Figures 2 – 4 . The brightness temperature of the 115 GHz image is also defined by the histogram of the observed level. The quiet region level at 115 GHz was set as 7500 K from Selhorst et al. ( 2005 ). Hence, the quiet-region levels of the radio emissions are defined by the data of the entire disk. Therefore, the brightness temperatures of the quiet regions surrounded by the white rectangles are different from the quiet-region values (9000 K at 34 GHz and 7500 K at 115 GHz). Table 1 Radio Brightness Temperatures of the Umbra and Quiet Regions Note . The umbra and quiet regions are surrounded by red and white rectangles, respectively, in Figures 2 – 4 . In this study, we selected an additional eight active regions observed by the NoRH at 34 GHz, in order to confirm the generality of this finding of low umbral contrast. The selected active regions contained relatively large and well-isolated sunspots including the sunspots observed on 2014 January 8 (see Figure 2 ) and 2014 October 24 (see Figure 3 ). We did not use the data from the sunspot observed on 2014 February 12 (Figure 4 ) because that sunspot was not large relative to the others. Although the NoRH observes the Sun every day, we limited the selection of regions to those with large sunspots located near the disk center for which SDO /AIA data are available. We also eliminated the data affected by flares and the spatial aliasing effect. We chose a 20′′ square region at the center of the umbra for each sunspot and derived the averaged brightness temperature of the center regions. Table 2 lists the 10 selected sunspots. Table 2 Radio Brightness Temperatures and UV/EUV Emissions at 1700 and 304 Å of the 10 Umbrae 4. DISCUSSION 4.1. Image Quality In this study, we applied two types of image synthesis, i.e., the CLEAN and Steer-CLEAN syntheses. Our result shows that the Steer-CLEAN synthesis provides a smoother image. This effect is more apparent in the quiet regions in Figures 1 (a) and (b). The standard deviations of the brightness temperatures of the sky region surrounded by the white rectangles in Figures 1 (a) and (b) are 377 and 284 K, respectively. Hence, the Steer-CLEAN synthesis provides a slightly better image from the same NoRH data. However, the Steer-CLEAN synthesis provides smoother structures in the peak brightness region. Hence, the dynamic ranges of these images (the ratio between the peak brightness and the standard deviation of the sky region) are almost the same (∼21 dB). It should be noted that the sky region surrounded by the white rectangles in Figure 1 partially contains the aliasing structures of the disk. Hence, the noise level of the sky region varies strongly with the region of our focus. Although the best spatial resolution of the NoRH at 34 GHz is about 5′′, the typical spatial resolutions in