bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect Of Green Marketing Concept On Consumer Intention To Buy Savana Project Product
Authors: Alamin Rizky Faizal , Ratnasari Ike
Published: February 2020

This study aims to determine and analyze the influence part of the green marketing concept where the variables studied include green product, green promotion, green packaging. Towards Savana Project product buying intention, and to know and analyze which variables have the dominant influence on consumer buying interest. The population of this study is all prospective buyers of Savana Project products using the Non-Probability Sampling Method, namely convenience sampling where members of the population can be easily selected as samples. The number of samples in this study were 121 respondents. The analysis technique used is multiple linear regression analysis. Based on the results of the analysis show that all variables simultaneously have a significant effect on buying intention, and are able to contribute to customer loyalty variables by 58.8%. Partially only green products that do not have a significant influence on buying interest. While the other two, namely green promotion and green packaging have a significant influence on consumer buying interest. green promotion becomes the dominant influence variable on customer loyalty with a regression coefficient of 0.501 greater than the other three variables. This shows that green promotion is a variable that greatly influences consumer buying interest.
Analysis of Differences in Share Performance between SOEs and Non-SOEs Based on Short-Term Underpricing and Long-Term Underperformance
Authors: Mointi Novriska , Pongoliu Yayu Isyana
Published: February 2020

This study aims to determine the differences in the performance of shares of SOEs and Non-SOEs companies that conduct IPOs on the Indonesia Stock Exchange in the period 2010-2014 based on short-term underpricing and long-term underperformance. Sampling is done by using purposive sampling technique. Data analysis techniques used the independent sample parametric test and the non-parametric difference test mann whitney u test. The results showed that there were no differences in the performance of shares of SOE and Non-SOE companies conducting IPOs on the Indonesia Stock Exchange in the 2010-2014 period based on short-term underpricing. This means that in the short term investments in shares of Non-BUMN companies are more profitable for investors and are detrimental to the company because the funds obtained are less. But in testing based on long-term underperformance, the results of the study showed that there were differences in the performance of the shares of SOE and Non-SOE companies conducting IPOs on the IDX for the 2010-2014 period. This shows that BUMN companies have better performance than Non-BUMN companies, because government ownership gives more value and can operate in various sectors.
High-resolution Spectroscopic Study of Dwarf Stars in the Northern Sky: Lithium, Carbon, and Oxygen Abundances
Authors: Stonkutė E. , Chorniy Y. , Tautvaišienė G. , Drazdauskas A. , Minkevičiūtė R. , Mikolaitis Š. , Kjeldsen H. , Essen C. von , Pakštienė E. , Bagdonas V.
Published: February 2020

Abundances of lithium, carbon, and oxygen have been derived using spectral synthesis for a sample of 249 bright F, G, and K Northern Hemisphere dwarf stars from the high-resolution spectra acquired with the VUES spectrograph at the Molėtai Astronomical Observatory of Vilnius University. The sample stars have metallicities, effective temperatures, and ages between (–0.7

0.4) dex, (5000

6900) K, (1

12) Gyr, accordingly. We confirm a so far unexplained lithium abundance decrease at supersolar metallicities—A(Li) in our sample stars, which drop by 0.7 dex in the [Fe/H] range from +0.10 to +0.55 dex. Furthermore, we identified stars with similar ages, atmospheric parameters, and rotational velocities, but with significantly different lithium abundances, which suggests that additional specific evolutionary factors should be taken into account while interpreting the stellar lithium content. Nine stars with predominantly supersolar metallicities, i.e., about 12% among 78 stars with C and O abundances determined, have the C/O number ratios larger than 0.65, thus may form carbon-rich rocky planets. Ten planet-hosting stars, available in our sample, do not show a discernible difference from the stars with no planets detected regarding their lithium content.
Dynamical Masses of Young Stars. II. Young Taurus Binaries Hubble 4, FF Tau, and HP Tau/G3
Authors: Rizzuto Aaron C. , Dupuy Trent J. , Ireland Michael J. , Kraus Adam L.
Published: February 2020

One of the most effective ways to test stellar evolutionary models is to measure dynamical masses for binary systems at a range of temperatures. In this paper, we present orbits of three young K+M binary systems in Taurus (Hubble 4, FF Tau, and HP Tau/G3) with very long baseline interferometry parallaxes. We obtained precision astrometry with Keck II/NIRC2, optical photometry with Hubble Space Telescope/Wide Field Camera 3, and low-resolution optical spectra with WIFeS on the ANU 2.3 m telescope. We fit orbital solutions and dynamical masses with uncertainties of 1%–5% for the three binary systems. The spectrum, photometry, and mass for Hubble 4 are inconsistent with a binary system, suggesting that it may be a triple system where the primary component consists of two stars. For HP Tau/G3 and FF Tau, model masses derived from spectral energy distribution-determined component temperatures and luminosities agree with the dynamical masses, with a small offset toward larger model masses. We find model ages for the primary components of these systems of ∼3 Myr, but find that the secondaries appear younger by a factor of two. These estimates also disagree with the age of the physically associated G-type star HP Tau/G2, which is older (∼5 Myr) according to the same models. This discrepancy is equivalent to a luminosity underprediction of 0.1–0.2 dex, or a temperature overprediction of 100–300 K, for K/M-type stars at a given model age. We interpret this as further evidence for a systematic error in pre-main-sequence evolutionary tracks for convective stars. Our results reinforce that the ages of young populations determined from the locus of M-type members on the HR diagram may require upward revision.
6.7 GHz CH3OH Absorption toward the N3 Galactic Center Point Source
Authors: Butterfield Natalie O. , Ginsburg Adam , Ludovici Dominic A. , Barnes Ashley , Dunnagan Riley , Lang Cornelia C. , Morris Mark R.
Published: February 2020

We present evidence of 6.7 GHz methanol (CH3OH) and 4.8 GHz formaldehyde (H2CO) absorption toward the Galactic Center (GC) point source “N3.” Both absorption features are unresolved and spatially aligned with N3. The 6.7 GHz CH3OH contains a single-velocity component (centered at ∼10 km s−1), while the 4.8 GHz H2CO shows two-velocity components (centered at ∼−3 and +8 km s−1). We find that the velocities of these absorption components are similar to that of emission lines from other molecules (e.g., SiO and HC3N) detected toward this compact source (−13 to +25 km s−1; “N3 cloud”). The detection of these absorption features is a firm indication that some of the molecular gas in the N3 molecular cloud is on the near side of the continuum source. Analysis of the CH3OH absorption kinematics shows a relatively large velocity dispersion (3.8 km s−1) for the size scale of this feature (<0.″1, <0.01 pc at the GC), when compared with other similarly sized GC clouds in the Larson line width–size relationship. Furthermore, this line width is closer to velocity dispersion measurements for size scales of 1.3 pc, which is roughly the width of the N3 cloud (25″; 1.0 pc). We argue that this relatively broad line width, over a small cross-sectional area, is due to turbulence through the depth of the cloud, where the cloud has a presumed line-of-sight thickness of ∼1 pc.
The Gas Accretion History of Low-mass Halos within the Cosmic Web from Cosmological Simulations
Authors: Chun Kyungwon , Smith Rory , Shin Jihye , Kim Sungsoo S. , Raouf Mojtaba
Published: February 2020

Using high-resolution hydrodynamical cosmological simulations, we study the gas accretion history of low-mass halos located in a field-like, low-density environment. We track their evolution individually from the early, pre-reionization era, through reionization, and beyond until z = 0. Before reionization, low-mass halos accrete cool cosmic-web gas at a very rapid rate, often reaching the highest gas mass they will ever have. But when reionization occurs, we see that almost all halos lose significant quantities of their gas content, although some respond less quickly than others. We find that the response rate is influenced by halo mass first, and secondarily by their internal gas density at the epoch of reionization. Reionization also fully ionizes the cosmic-web gas by z ∼ 6. As a result, the lowest mass halos (M ∼ 106
h
−1
M
⊙ at z = 6) can never again re-accrete gas from the cosmic web, and by z ∼ 5 have lost all their internal gas to ionization, resulting in a halt in star formation at this epoch. However, more massive halos can recover from their gas mass loss, and re-accrete ionized cosmic-web gas. We find the efficiency of this re-accretion is a function of halo mass first, followed by local surrounding gas density. Halos that are closer to the cosmic-web structure can accrete denser gas more rapidly. We find that our lower mass halos have a sweet spot for rapid, dense gas accretion at distances of roughly 1–5 virial radii from the most massive halos in our sample (>108
h
−1
M
⊙), as these tend to be embedded deeply within the cosmic web.
LIGO/Virgo Sources from Merging Black Holes in Ultradwarf Galaxies
Authors: Conselice Christopher J. , Bhatawdekar Rachana , Palmese Antonella , Hartley William G.
Published: February 2020

The origins of the black hole–black hole mergers discovered through gravitational waves with the LIGO/Virgo Collaboration are a mystery. We investigate the idea that some of these black holes originate from the centers of extremely low mass ultradwarf galaxies that have merged together in the distant past at z > 1. Extrapolating the central black hole/stellar mass ratio suggests that the black holes in these mergers could arise from galaxies of masses ∼105–106
M
⊙. We investigate whether these galaxies merge at a rate consistent with the observed black hole rate of ∼9.7–101 Gpc−3 yr−1 using the latest LIGO/Virgo results. We show that in the nearby universe the merger rate and number densities of ultradwarf galaxies are too low, by an order or magnitude, to produce these black hole mergers. However, by considering that the merger fraction, merger timescales, and the number densities of low-mass galaxies all conspire at z > 1–1.5 to increase the merger rate for these galaxies at higher redshifts, we argue that it is possible that these observed gravitational wave events could arise from black holes in the centers of low-mass galaxies. The major uncertainty in this calculation is the merger dynamical timescales for black holes in low-mass galaxies. Our results suggest that a very long black hole merger timescale of 4–7 Gyr is needed, consistent with an extended merger history. Further simulations of black hole merger timescales are needed to test this possibility; however, our theory can be tested by searching for host galaxies of gravitational wave events. Results from these searches will put limits on dwarf galaxy mergers and/or the presence and formation mechanisms of black holes through Population III stars in the lowest-mass galaxies.
Resolving Linear Polarization due to Emission and Extinction of Aligned Dust Grains on NGC 1333 IRAS4A with JVLA and ALMA
Authors: Ko 柯嘉 Chia-Lin 琳 , Liu 呂浩 Hauyu Baobab 宇 , Lai 賴詩 Shih-Ping 萍 , Ching 慶道 Tao-Chung 沖 , Rao Ramprasad , Girart Josep Miquel
Published: February 2020

We report high angular resolution observations of linearly polarized dust emission toward the Class 0 young stellar object NGC1333 IRAS4A (hereafter IRAS4A) using the Karl G. Jansky Very Large Array at K (11.5–16.7 mm), Ka (8.1–10.3 mm), and Q bands (6.3–7.9 mm), and using the Atacama Large Millimeter Array (ALMA) at Band 6 (1.3 mm) and Band 7 (0.85–0.89 mm). On 100–1000 au scales, all of these observations consistently trace the hourglass-shaped magnetic field topology as shown in the previous studies. In the innermost 100 au region of IRAS4A1, the polarization position angles (E field) detected at 6.3–16.7 mm are consistent; however, they are nearly 90° offset from those detected at 1.3 mm and 0.85–0.89 mm. Such a 90° offset may be explained by the inner ∼100 au area being optically thick at wavelengths shorter than ∼1.5 mm, whereby the observations probe the absorption of aligned dust against the weakly or unpolarized warm dust emission from the innermost region. This can also consistently explain why the highest angular resolution ALMA images at Band 7 show that the polarization percentage increases with dust brightness temperature in the inner ∼100 au region of IRAS4A1. Following this interpretation and assuming that the dust grains are aligned with the magnetic fields, the inferred magnetic field position angle based on the 90° rotated at 6.3–7.9 mm in the central peak of IRAS4A1 is ∼−22°, which is approximately consistent with the outflow direction of ∼−9°.
Diversity of Kilonova Light Curves
Authors: Kawaguchi Kyohei , Shibata Masaru , Tanaka Masaomi
Published: February 2020

We perform radiative transfer simulations for kilonova in various situations, including the cases of prompt collapse to a black hole from neutron star mergers, high-velocity ejecta possibly accelerated by magnetars, and a black hole–neutron star merger. Our calculations are done employing ejecta profiles predicted by numerical-relativity simulations and a new line list for all the r-process elements. We found that: (i) the optical emission for binary neutron stars promptly collapsing to a black hole would be fainter by ≳1–2 mag than that found in GW170817, while the infrared emission could be as bright as that in GW170817 if the post-merger ejecta is as massive as ≈0.01 M
⊙; (ii) the kilonova would be brighter than that observed in GW170817 for the case that the ejecta is highly accelerated by the electromagnetic energy injection from the remnant, but within a few days it would decline rapidly and the magnitude would become fainter than in GW170817; and (iii) the optical emission from a black hole–neutron star merger ejecta could be as bright as that observed in GW170817 for the case that sufficiently large amount of matter is ejected (≳0.02 M
⊙), while the infrared brightness would be brighter by 1–2 mag at the same time. We show that the difference in the ejecta properties would be imprinted in the differences in the peak brightness and time of peak. This indicates that we may be able to infer the type of the central engine for kilonovae by observation of the peak in the multiple band.
Large-scale Structures in the CANDELS Fields: The Role of the Environment in Star Formation Activity
Authors: Chartab Nima , Mobasher Bahram , Darvish Behnam , Finkelstein Steve , Guo Yicheng , Kodra Dritan , Lee Kyoung-Soo , Newman Jeffrey A. , Pacifici Camilla , Papovich Casey , Sattari Zahra , Shahidi Abtin , Dickinson Mark E. , Faber Sandra M. , Ferguson Henry C. , Giavalisco Mauro , Jafariyazani Marziye
Published: February 2020

We present a robust method, weighted von Mises kernel density estimation, along with boundary correction to reconstruct the underlying number density field of galaxies. We apply this method to galaxies brighter than Hubble Space Telescope

AB mag in the redshift range 0.4 ≤ z ≤ 5 in the five CANDELS fields (GOODS-N, GOODS-S, EGS, UDS, and COSMOS). We then use these measurements to explore the environmental dependence of the star formation activity of galaxies. We find strong evidence of environmental quenching for massive galaxies (M ≳ 1011
M
⊙) out to z ∼ 3.5 such that an overdense environment hosts ≳20% more massive quiescent galaxies than an underdense region. We also find that environmental quenching efficiency grows with stellar mass and reaches ∼60% for massive galaxies at z ∼ 0.5. The environmental quenching is also more efficient than stellar mass quenching for low-mass galaxies (M ≲ 1010
M
⊙) at low and intermediate redshifts (z ≲ 1.2). Our findings concur thoroughly with the “overconsumption” quenching model where the termination of cool gas accretion (cosmological starvation) happens in an overdense environment and the galaxy starts to consume its remaining gas reservoir in depletion time. The depletion time depends on the stellar mass and could explain the evolution of environmental quenching efficiency with stellar mass.
A Curious Case of Circular Polarization in the 25 GHz Methanol Maser Line toward OMC-1
Authors: Sarma A. P. , Momjian E.
Published: February 2020

We report the detection of a circular polarization signature in the Stokes V profile of a 25 GHz Class I CH3OH maser toward the high-mass star-forming region OMC-1. Such a feature usually constitutes a detection of the Zeeman effect. If due to a magnetic field in OMC-1, this would represent the first detection and discovery of the Zeeman effect in the 25 GHz Class I CH3OH maser. The feature in Stokes V is detected in two observations with different angular resolutions taken eight years apart with the Very Large Array; for our 2009 D-configuration observations, the fitted value for z

is 152 ± 12 Hz, where z is the Zeeman splitting factor and

is the line-of-sight magnetic field. For our 2017 C-configuration observations, the fitted value for z

 = 149 ± 19 Hz, likely for the same maser spot. These correspond to

in the range 171–214 mG, depending on which hyperfine transition is responsible for the maser line. While these

values are high, they are not implausible. If the magnetic field increases in proportion to the molecular hydrogen density in shocked regions, then our detected fields predict values for the pre-shock magnetic field that are in agreement with observations. With

 = 171–214 mG, the magnetic energy in the post-shocked regions where these 25 GHz Class I CH3OH masers occur would dominate over the kinetic energy density and be at least of the order of the pressure in the shock, implying that the magnetic field would exert significant influence over the dynamics of these regions.
Solitons and Turbulence in Solar Wind at 1 au: Multi-satellite Data and FDTD Simulations
Authors: Shah Asif , Rehman Saeed-Ur , Haque Qamar-UL , Mahmood Shahzad
Published: February 2020

During 2015 January 1–31 multi-satellite data at 1 au showed the propagation of single soliton pulses, the formation of soliton trains, and their ultimate development into the turbulence in solar wind magnetic field, density, speed, temperature, and dynamic pressure. This work is motivated by a basic research question: what are the differences in the conditions for excitation of soliton pulse, soliton train, and turbulence in the solar wind? To answer this question, a convective and dispersive system is considered and simulated via the finite difference time domain (FDTD) method. It is found that when a system is initially driven by a weak shock wave only a single soliton pulse will propagate. When the convection coefficient is smaller than or equal to the dispersion coefficient and system is driven by a strong shock then soliton trains are formed. The development of turbulence occurs when the convective coefficient dominates the dispersion coefficient and the system is driven by a stronger shock. Combining the findings of FDTD simulations with the Hall magnetohydrodynamic model, it is concluded that an enhanced interplanetary magnetic field in the magnetic sheath and the declining ion density after corotation interaction region interface provide favorable conditions for the solitons formation. Contrarily, the declining magnetic field in ejecta provides pertinent conditions for the evolution of Alfvénic turbulence. Our findings are critical for understanding the wave development into turbulence in solar wind.
Flash Ionization Signatures in the Type Ibn Supernova SN 2019uo
Authors: Gangopadhyay Anjasha , Misra Kuntal , Hiramatsu Daichi , Wang Shan-Qin , Hosseinzadeh Griffin , Wang Xiaofeng , Valenti Stefano , Zhang Jujia , Howell D. Andrew , Arcavi Iair , Anupama G. C. , Burke Jamison , Dastidar Raya , Itagaki Koichi , Kumar Brajesh , Kumar Brijesh , Li Long , McCully Curtis , Mo Jun , Pandey Shashi Bhushan , Pellegrino Craig , Sai Hanna , Sahu D. K. , Sanwal Pankaj , Singh Avinash , Singh Mridweeka , Zhang Jicheng , Zhang Tianmeng , Zhang Xinhan
Published: February 2020

We present photometric and spectroscopic observations of the type Ibn supernova (SN) 2019uo, the second ever SN Ibn with flash ionization (He ii, C iii, N iii) features in its early spectra. SN 2019uo displays a rapid post-peak luminosity decline of 0.1 mag day−1 similar to most of the SNe Ibn, but is fainter (

mag) than a typical SN Ibn and shows a color evolution that places it between SNe Ib and the most extreme SNe Ibn. SN 2019uo shows P-cygni He i features in the early spectra which gradually evolve and become emission dominated post peak. It also shows faster evolution in line velocities as compared to most other members of the type Ibn subclass. The bolometric light curve is fairly well described by a 56Ni + circumstellar interaction model.
Gamma-Ray Emission of 60Fe and 26Al Radioactivity in Our Galaxy
Authors: Wang W. , Siegert T. , Dai Z. G. , Diehl R. , Greiner J. , Heger A. , Krause M. , Lang M. , Pleintinger M. M. M. , Zhang X. L.
Published: February 2020

The isotopes 60Fe and 26Al originate from massive stars and their supernovae, reflecting ongoing nucleosynthesis in the Galaxy. We studied the gamma-ray emission from these isotopes at characteristic energies 1173, 1332, and 1809 keV with over 15 yr of SPI data, finding a line flux in 60Fe combined lines of

and the Al line flux of

above the background and continuum emission for the whole sky. Based on the exponential disk grid maps, we characterize the emission extent of 26Al to find scale parameters

and

kpc; however, the 60Fe lines are too weak to spatially constrain the emission. Based on a point-source model test across the Galactic plane, the 60Fe emission would not be consistent with a single strong point source in the Galactic center or somewhere else, providing a hint of a diffuse nature. We carried out comparisons of emission morphology maps using different candidate source tracers for both 26Al and 60Fe emissions and suggest that the 60Fe emission is more likely to be concentrated toward the Galactic plane. We determine the 60Fe/26Al γ-ray flux ratio at 18.4% ± 4.2% when using a parameterized spatial morphology model. Across the range of plausible morphologies, it appears possible that 26Al and 60Fe are distributed differently in the Galaxy. Using the best-fitting maps for each of the elements, we constrain flux ratios in the range 0.2–0.4. We discuss the implications for massive star models and their nucleosynthesis.
Spatially Resolved Analysis of Neutral Winds, Stars, and Ionized Gas Kinematics with MEGARA/GTC: New Insights on the Nearby Galaxy UGC 10205
Authors: Catalán-Torrecilla C. , Castillo-Morales Á. , Gil de Paz A. , Gallego J. , Carrasco E. , Iglesias-Páramo J. , Cedazo R. , Chamorro-Cazorla M. , Pascual S. , García-Vargas M. L. , Cardiel N. , Gómez-Alvarez P. , Pérez-Calpena A. , Martínez-Delgado I. , Dullo B. T. , Coelho P. , Bruzual G. , Charlot S.
Published: February 2020

We present a comprehensive analysis of the multiphase structure of the interstellar medium (ISM) and the stellar kinematics in the edge-on nearby galaxy UGC 10205 using integral field spectroscopy (IFS) data taken with Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía (MEGARA) at the GTC. We explore both the neutral and the ionized gas phases using the interstellar Na i D doublet absorption (LR−V setup, R ∼ 6000) and the Hα emission line (HR−R setup, R ∼ 18000), respectively. The high-resolution data show the complexity of the Hα emission-line profile revealing the detection of up to three kinematically distinct gaseous components. Despite of this fact, a thin-disk model is able to reproduce the bulk of the ionized gas motions in the central regions of UGC 10205. The use of asymmetric drift corrections is needed to reconciliate the ionized and the stellar velocity rotation curves. We also report the detection of outflowing neutral gas material blueshifted by ∼ 87 km s−1. The main physical properties that describe the observed outflow are a total mass M
out = (4.55 ± 0.06) × 107
M
☉ and a cold-gas mass outflow rate

M

̇

out

=
0.78
±
0.03

M
☉ yr−1. This work points out the necessity of exploiting high-resolution IFS data to understand the multiphase components of the ISM and the multiple kinematical components in the central regions of nearby galaxies.
Microlensing Analysis for the Gravitational Lens Systems SDSS0924+0219, Q1355-2257, and SDSS1029+2623
Authors: Rojas K. , Motta V. , Mediavilla E. , Jiménez-Vicente J. , Falco E. , Fian C.
Published: February 2020

We use spectroscopic observations of the gravitationally lensed systems SDSS0924+0219(BC), Q1355-2257(AB), and SDSS1029+2623(BC) to analyze microlensing and dust extinction in the observed components. We detect chromatic microlensing effects in the continuum and microlensing in the broad emission line profiles of the systems SDSS0924+0219(BC) and Q1355-2257(AB). Using magnification maps to simulate microlensing and modeling the emitting region as a Gaussian intensity profile with size r

s
∝ λ

p
, we obtain the probability density functions for a logarithmic size prior to

. In the case of SDSS0924+0219, we obtain

lt-d (at 1σ), which is larger than the range of other estimates, and p = 0.8 ± 0.2 (at 1σ), which is smaller than predicted by the thin disk theory, but still in agreement with previous results. In the case of Q1355-2257 we obtain (at 1σ)

lt-d, which is also larger than the theoretical prediction, and p = 2.0 ± 0.7, which is in agreement with the theory within errors. SDSS1029+2326 spectra show evidence of extinction, probably produced by a galaxy in the vicinity of image C. Fitting an extinction curve to the data we estimate ΔE ∼ 0.2 in agreement with previous results. We found no evidence of microlensing for this system.
Gamma Rays from Kilonova: A Potential Probe of r-process Nucleosynthesis
Authors: Korobkin Oleg , Hungerford Aimee M. , Fryer Christopher L. , Mumpower Matthew R. , Misch G. Wendell , Sprouse Trevor M. , Lippuner Jonas , Surman Rebecca , Couture Aaron J. , Bloser Peter F. , Shirazi Farzane , Even Wesley P. , Vestrand W. Thomas , Miller Richard S.
Published: February 2020

The mergers of compact binaries with at least one neutron star component are the potential leading sites of the production and ejection of r-process elements. Discoveries of galactic binary pulsars, short gamma-ray bursts, and gravitational-wave detections have all been constraining the rate of these events, while the gravitational wave plus broadband electromagnetic coverage of binary neutron star merger (GW170817) has also placed constraints on the properties (mass and composition) of the merger ejecta. But uncertainties and ambiguities in modeling the optical and infrared emission make it difficult to definitively measure the distribution of heavy isotopes in these mergers. In contrast, gamma rays emitted in the decay of these neutron-rich ejecta may provide a more direct measurement of the yields. We calculate the gamma production in remnants of neutron star mergers, considering two epochs: a kilonova epoch, lasting about two weeks, and a much later epoch of tens and hundreds of thousands of years after the merger. For the kilonova epoch, when the expanding ejecta is still only partially transparent to gamma radiation, we use 3D radiative transport simulations to produce the spectra. We show that the gamma-ray spectra associated with beta- and alpha-decay provide a fingerprint of the ejecta properties and, for a sufficiently nearby remnant, may be detectable, even for old remnants. We compare our gamma spectra with the potential detection limits of next generation detectors, including the Lunar Occultation Explorer (LOX), the All-sky Medium Energy Gamma-ray Observatory (AMEGO), and the Compton Spectrometer and Imager (COSI). We show that fission models can be discriminated via the presence of short-lived fission fragments in the remnant spectra.
Deciphering the Local Interstellar Spectra of Secondary Nuclei with the Galprop/Helmod Framework and a Hint for Primary Lithium in Cosmic Rays
Authors: Boschini M. J. , Torre S. Della , Gervasi M. , Grandi D. , Jøhannesson G. , Vacca G. La , Masi N. , Moskalenko I. V. , Pensotti S. , Porter T. A. , Quadrani L. , Rancoita P. G. , Rozza D. , Tacconi M.
Published: February 2020

Local interstellar spectra (LIS) of secondary cosmic-ray (CR) nuclei, lithium, beryllium, boron, and partially secondary nitrogen, are derived in the rigidity range from 10 MV to ∼200 TV using the most recent experimental results combined with state-of-the-art models for CR propagation in the Galaxy and in the heliosphere. The lithium spectrum appears somewhat flatter at high energies compared to other secondary species, which may imply a primary lithium component. Two propagation packages, GALPROP and HelMod, are combined to provide a single framework that is run to reproduce direct measurements of CR species at different modulation levels, and at both polarities of the solar magnetic field. An iterative maximum-likelihood method is developed that uses GALPROP-predicted LIS as input to HelMod, which provides the modulated spectra for specific time periods of the selected experiments for the model-data comparison. The proposed LIS accommodates the low-energy interstellar spectra measured by Voyager 1, the High Energy Astrophysics Observatory-3 (HEAO-3), and the Cosmic Ray Isotope Spectrometer on board of the Advanced Composition Explorer (ACE/CRIS), as well as the high-energy observations by the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA), Alpha Magnetic Spectrometer-02 (AMS-02), and earlier experiments that are made deep in the heliosphere. The interstellar and heliospheric propagation parameters derived in this study are consistent with our earlier results for propagation of CR protons, helium, carbon, oxygen, antiprotons, and electrons.
Implications from Late-time X-Ray Detections of Optically Selected Tidal Disruption Events: State Changes, Unification, and Detection Rates
Authors: Jonker P. G. , Stone N. C. , Generozov A. , Velzen S. van , Metzger B.
Published: February 2020

We present Chandra X-ray observations of four optically selected tidal disruption events (TDEs) obtained 4–9 yr after discovery. Three sources were detected with luminosities between 9 × 1040 and 3 × 1042 erg s−1. The spectrum of PTF09axc is consistent with a power law of index 2.5 ± 0.1, whereas the spectrum of PTF09ge is very soft. The power-law spectrum of PTF09axc and prior literature findings provide evidence that TDEs transition from an early-time soft state to a late-time hard state many years after disruption. We propose that the time to peak luminosity for optical and X-ray emission may differ substantially in TDEs, with X-rays being produced or becoming observable later. This delay helps explain the differences in observed properties such as L
opt/L
X of optically and X-ray-selected TDEs. We update TDE rate predictions for the eROSITA instrument: it ranges from 3 to 990 yr−1, depending sensitively on the distribution of black hole spins and the time delay between disruption and peak X-ray brightness. We further predict an asymmetry in the number of retrograde and prograde disks in samples of optically and X-ray-selected TDEs. The details of the observational biases can contribute to observed differences between optically and X-ray-selected TDEs (with optically selected TDEs being fainter in X-rays for retrograde TDE disks).
What is the Solar Wind Frame of Reference?
Authors: Němeček Zdeněk , Ďurovcová Tereza , Šafránková Jana , Němec František , Matteini Lorenzo , Stansby David , Janitzek Nils , Berger Lars , Wimmer-Schweingruber Robert F.
Published: February 2020

Various solar wind ion species move with different speeds and theoretical considerations as well as limited observations in a region close to the Sun show that heavy solar wind ions tend to flow faster than protons, at least in less-aged fast solar wind streams. The solar wind flow carries the frozen-in interplanetary magnetic field (IMF) and this situation evokes three related questions: (i) what is the proper solar wind speed, (ii) is this speed equal to the speed of the dominant component, whatever that may be, and (iii) what is the speed of the magnetic field? We show that simple theoretical considerations based on the MHD approximation as well as on the dynamics of charged particles in electric and magnetic fields suggest that the IMF velocity of motion (de Hoffmann–Teller (HT) velocity) would be deliberated as the velocity appropriate for solar wind studies. Our analysis based on the Wind, Helios, ACE, and SOHO observations of differential streaming of solar wind populations shows that their energy is conserved in the HT frame. On the other hand, the noise and temporal resolution of the data do not allow us to decide whether the total momentum is also conserved in this frame.
The Lyman Continuum Escape Survey. II. Ionizing Radiation as a Function of the [O iii]/[O ii] Line Ratio
Authors: Nakajima Kimihiko , Ellis Richard S. , Robertson Brant E. , Tang Mengtao , Stark Daniel P.
Published: February 2020

We discuss the rest-frame optical emission line spectra of a large (∼50) sample of z ∼ 3.1 Lyα emitting galaxies (LAEs) whose physical properties suggest such sources are promising analogs of galaxies in the reionization era. Reliable Lyman continuum (LyC) escape fractions have now been determined for a large sample of such LAEs from the LymAn Continuum Escape Survey (LACES) undertaken via deep Hubble Space Telescope imaging in the SSA22 survey area reported in Fletcher et al. Using new measures of [O ii] emission secured from Keck MOSFIRE spectra we re-examine, for a larger sample, earlier claims that LyC leakages may correlate with the nebular emission line ratio [O iii]/[O ii] as expected for density-bound H ii regions. We find that a large [O iii]/[O ii] line ratio is indeed a necessary condition for LyC leakage, strengthening earlier claims made using smaller samples at various redshifts. However, not all LAEs with large [O iii]/[O ii] line ratios are leakers and leaking radiation appears not to be associated with differences in other spectral diagnostics. This suggests the detection of leaking radiation is modulated by an additional property, possibly the viewing angle for porous H ii regions. We discuss our new results in the context of the striking bimodality of LAE leakers and non-leakers found in the LACES program and the implications for the sources of cosmic reionization.
Final Spitzer IRAC Observations of the Rise and Fall of SN 1987A
Authors: Arendt Richard G. , Dwek Eli , Bouchet Patrice , John Danziger I. , Gehrz Robert D. , Park Sangwook , Woodward Charles E.
Published: February 2020

Spitzer's final Infrared Array Camera observations of SN 1987A show the 3.6 and 4.5 μm emission from the equatorial ring (ER) continues a period of steady decline. Deconvolution of the images reveals that the emission is dominated by the ring, not the ejecta, and is brightest on the west side. Decomposition of the marginally resolved emission also confirms this, and shows that the west side of the ER has been brightening relative to the other portions of the ER. The infrared morphological changes resemble those seen in both the soft X-ray emission and the optical emission. The integrated ER light curves at 3.6 and 4.5 μm are more similar to the optical light curves than the soft X-ray light curve, though differences would be expected if dust is responsible for this emission and its destruction is rapid. Future observations with the James Webb Space Telescope will continue to monitor the ER evolution, and will reveal the true spectrum and nature of the material responsible for the broadband emission at 3.6 and 4.5 μm. The present observations also serendipitously reveal a nearby variable source, subsequently identified as a Be star, that has gone through a multiyear outburst during the course of these observations.
Search for Eccentric Binary Neutron Star Mergers in the First and Second Observing Runs of Advanced LIGO
Authors: Nitz Alexander H. , Lenon Amber , Brown Duncan A.
Published: February 2020

We present a search for gravitational waves from merging binary neutron stars (BNSs) which have non-negligible eccentricity as they enter the Laser Interferometer Gravitational Wave Observatory (LIGO) observing band. We use the public Advanced LIGO data which covers the period from 2015 through 2017 and contains ∼164 days of LIGO–Hanford and LIGO–Livingston coincident observing time. The search was conducted using matched-filtering using the PyCBC toolkit. We find no significant BNS candidates beyond GW170817, which has previously been reported by searches for binaries in circular orbits. We place a 90% upper limit of ∼1700 mergers Gpc−3 yr−1 for eccentricities ≲0.43 at a dominant-mode gravitational-wave frequency of 10 Hz. The absence of a detection with these data is consistent with theoretical predictions of eccentric BNS merger rates. Using our measured rate we estimate the sensitive volume of future gravitational-wave detectors and compare this to theoretical rate predictions. We find that, in the absence of a prior detection, the rate limits set by six months of Cosmic Explorer observations would constrain all current plausible models of eccentric BNS formation.
X-Ray Ionization of Planet-opened Gaps in Protostellar Disks
Authors: Kim S. Y. , Turner N. J.
Published: February 2020

Young planets with masses approaching Jupiter’s have tides strong enough to clear gaps around their orbits in the protostellar disk. Gas flow through the gaps regulates the planets’ further growth and governs the disk’s evolution. Magnetic forces may drive that flow if the gas is sufficiently ionized to couple to the fields. We compute the ionizing effects of the X-rays from the central young star, using Monte Carlo radiative transfer calculations to find the spectrum of Compton-scattered photons reaching the planet’s vicinity. The scattered X-rays ionize the gas at rates similar to or greater than the interstellar cosmic-ray rate near planets with the masses of Saturn and of Jupiter, located at 5 au and at 10 au, in disks with the interstellar mass fraction of sub-micron dust and with the dust depleted by a factor 100. Solving a gas–grain recombination reaction network yields charged particle populations whose ability to carry currents is sufficient to partly couple the magnetic fields to the gas around the planet. Most cases can undergo Hall-shear instability, and some can launch magnetocentrifugal winds. However, the material on the planet’s orbit has diffusivities so large in all the cases we examine that magnetorotational turbulence is prevented and the non-ideal terms govern the magnetic field’s evolution. Thus the flow of gas in the gaps opened by young giant planets depends crucially on the finite conductivity.
The Effects of Plasma Lensing on the Inferred Dispersion Measures of Fast Radiobursts
Authors: Er Xinzhong , Yang Yuan-Pei , Rogers Adam
Published: February 2020

Radio signals are delayed when propagating through plasma. This type of delay is frequency dependent and is usually used for estimating the projected number density of electrons along the line of sight, called the dispersion measure (DM). The dense and clumpy distribution of plasma can cause refractive deflections of radio signals, analogous to lensing effects. Similar to gravitational lensing, there are two contributions to the time delay effect in plasma lensing: a geometric delay, due to increased path length of the signal, and a dispersive delay due to the change of speed of light in a plasma medium. We show the delay time for two models of the plasma distribution, and point out that the estimated DM can be biased. Since the contribution of the geometric effect can be comparable to that of the dispersive delay, the bias in the measured DM can be dramatically large if plasma lensing effects are not taken into account when signals propagate through a high-density gradient clump of plasma.
SDSS-IV MaNGA: Variations in the N/O–O/H Relation Bias Metallicity Gradient Measurements
Authors: Schaefer Adam L. , Tremonti Christy , Belfiore Francesco , Pace Zachary , Bershady Matthew A. , Andrews Brett H. , Drory Niv
Published: February 2020

In this Letter we use strong line calibrations of the N/O and O/H in Mapping Galaxies at Apache Point Observatory (MaNGA) galaxy survey spaxel data to explore the systematics introduced by variations in N/O on various strong-line metallicity diagnostics. We find radial variations in N/O at fixed O/H that correlate with total galaxy stellar mass and that can induce ∼40% systematic uncertainties in oxygen abundance gradients when nitrogen-dependent abundance calibrations are used. Empirically, we find that departures from the expected N/O are associated with variation in the local star formation efficiency, as predicted by recent chemical evolution models for galaxies, but we cannot rule out other processes such as radial migration also playing a role.
Evaluation of cardiovascular risk factors in people living with HIV in São Paulo, Brazil
Authors: Melo Elizabete Santos , Antonini Marcela , Costa Christefany Régia Braz , Sorensen William , Gir Elucir , Reis Renata Karina
Published: February 2020

Introduction: HIV infection as a chronic disease has emerged from treatment advances over the past three decades. From this perspective, the diseases associated with AIDS are not a main threat for patients who use Antiretroviral Therapy (ART). A new set of HIV associated complications have emerged resulting in comorbidities related to aging and ART exposure as cardiovascular disease (CVD). This study aimed to evaluate the cardiovascular risk factors in people living with HIV (PLWH) in Brazil.

Methodology: This was a cross-sectional study carried out at all Specialized Care Services for people living with HIV in the Southeast of Brazil. A sociodemographic and clinical questionnaire was used and cardiovascular risk assessed through the Framingham Score. Data analysis was performed by Chi-square, Fisher’s exact test and logistic regression.

Results: The majority were male, over 40 years old and they showed a mean age of 44 years. Current hypertension, diabetes, altered body mass index, presence of metabolic syndrome and altered abdominal circumference were also associated with cardiovascular risk. After regression analysis, male sex, older age, smoking, diabetes, hypertension and metabolic syndrome were related as predictive factors for a higher cardiovascular risk.

Conclusions: The results demonstrate that combination of the prevention of modifiable risk factors with considerable changes in lifestyle are determining factors for success in the therapeutic of PLWH. High levels of motivation are essential for behavioral changes, and nurses are ideally position to provide safe care with nonpharmacological strategies for CVD risk reduction.
QuEChER method for air microbiological monitoring in hospital environments
Authors: Tavera Busso Iván , Herrera Florencia , Tames María F , González Gasquez Ignacio , Camisassa Lilia N , Carreras Hebe A
Published: February 2020

Introduction: Nosocomial pathogens have become a priority issue for public health, since they are responsible for increased morbidity and mortality in hospitalized patients and the development of multi-resistant microorganisms, as well. Recent studies found strong evidence that airborne transmission plays a key role in many nosocomial infections. Thus, we aim to develop a QuEChER methodology for the characterization of airborne microbial levels, analyzing potential variables that modify the air microbiological load.

Methodology: Particulate matter levels and suspended and settled bioaerosols were determined simultaneously employing optical sensors, Harvard impactors and settle plates, respectively. Environmental variables were also measured at different sites during different working shifts and seasons.

Results: We found a straightforward relationship between airborne particles, air exchange rates, and people influx. Levels of suspended microorganisms were related to fine particulate matter concentration, CO2 and ambient temperature. A positive linear relationship (R2 = 0.9356) was also found between fine particulate matter and CO2 levels and air microbial load.

Conclusion: The QuEChER methodology is an effective methodology that could be used to improve the surveillance of nosocomial pathogens in developing countries hospitals where air quality is scarcely controlled.
Prediction of sofosbuvir response using interleukin-6 serum level and single nucleotide polymorphism of interferon lambda- 4
Authors: Saafan Amal E , Abobaker Ashraf , Abbas Mohamed S , El-Gendy Ahmed
Published: February 2020

Introduction: In Egypt, 15% of the populations are suffering from chronic hepatitis C especially genotype 4. Sofosbuvir was approved by FDA in December 2013 for treatment of HCV genotypes 2 and 3 in combination with Ribavirin, and for genotypes 1 and 4 in combination with Peg-IFN. Recently, polymorphism of different genes and plasma levels of IL-6 were utilized for better prediction of HCV clearance. This study aimed at early prediction of the efficacy of HCV treatment with Sofosbuvir (Sovaldi) and comparing the antiviral efficacy of dual and triple Sovaldi combination therapy.

Methodology: Blood samples were collected from 100 HCV positive patients and detected by real time PCR at three time intervals. SNP genotyping of INFL-4 gene was estimated by using real-time PCR with predesigned primers and Taqman probes. IL-6 serum level was estimated before, during and after the end of the treatment using ELISA assay based on human IL-6 KIT.

Results: SNP genotyping of INFL-4 gene showed that 13.1% of patients carried ∆G/∆G, 30.4% patients had TT/TT and 56.5% patients possessed heterozygote allele ∆G/TT. Clinical data displayed that 13 patients were got relapsed at SVR 12. Serum level of IL-6 was noticed higher in HCV patients than healthy ones. Noteworthy, it was increased during treatment then decreased to a minimal level than begining of treatment.

Conclusion: SNP in INFL-4 gene has displayed no effect in response to Sofosbuvir. Dual therapy had the same effect like triple therapy, so interferon could be withdrawn from the treatment regimen.