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2181. uvby Photometry of G-type dwarfs
ID:
ivo://CDS.VizieR/J/A+AS/104/429
Title:
uvby Photometry of G-type dwarfs
Short Name:
J/A+AS/104/429
Date:
21 Oct 2021
Publisher:
CDS
Description:
(no description available)
2182. UVES Advanced Data Products Quasar Sample. VI.
ID:
ivo://CDS.VizieR/J/MNRAS/458/4074
Title:
UVES Advanced Data Products Quasar Sample. VI.
Short Name:
J/MNRAS/458/4074
Date:
21 Oct 2021
Publisher:
CDS
Description:
The circumgalactic medium (CGM) can be probed through the analysis of absorbing systems in the line of sight to bright background quasars. We present measurements of the metallicity of a new sample of 15 sub-damped Lyman {alpha} absorbers (sub-DLAs, defined as absorbers with 19.0 z_abs_<=3.104 from the ESO Ultra-Violet Echelle Spectrograph (UVES) Advanced Data Products Quasar Sample (EUADP). We combine these results with other measurements from the literature to produce a compilation of metallicity measurements for 92 sub-DLAs as well as a sample of 362 DLAs. We apply a multi-element analysis to quantify the amount of dust in these two classes of systems. We find that either the element depletion patterns in these systems differ from the Galactic depletion patterns or they have a different nucleosynthetic history than our own Galaxy. We propose a new method to derive the velocity width of absorption profiles, using the modelled Voigt profile features. The correlation between the velocity width {Delta}V_90_ of the absorption profile and the metallicity is found to be tighter for DLAs than for sub-DLAs. We report hints of a bimodal distribution in the [Fe/H] metallicity of low redshift (z<1.25) sub-DLAs, which is unseen at higher redshifts. This feature can be interpreted as a signature from the metal-poor, accreting gas and the metal-rich, outflowing gas, both being traced by sub-DLAs at low redshifts.
2183. UV-excess objects Spacelab-1 survey IV.
ID:
ivo://CDS.VizieR/J/A+AS/107/385
Title:
UV-excess objects Spacelab-1 survey IV.
Short Name:
J/A+AS/107/385
Date:
21 Oct 2021
Publisher:
CDS
Description:
(no description available)
2184. UV-FIR SED results of SDSS QSOs and their hosts
ID:
ivo://CDS.VizieR/J/ApJ/824/70
Title:
UV-FIR SED results of SDSS QSOs and their hosts
Short Name:
J/ApJ/824/70
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this work, we present a study of 207 quasars selected from the Sloan Digital Sky Survey quasar catalogs and the Herschel Stripe 82 survey. Quasars within this sample are high-luminosity quasars with a mean bolometric luminosity of 10^46.4^erg/s. The redshift range of this sample is within z Herschel-SPIRE bands, the quasar sample is complete yet highly biased. Based on the multi-wavelength photometric observation data, we conducted a spectral energy distribution (SED) fitting through UV to FIR. Parameters such as active galactic nucleus (AGN) luminosity, far-IR (FIR) luminosity, stellar mass, as well as many other AGN and galaxy properties are deduced from the SED fitting results. The mean star formation rate (SFR) of the sample is 419M_{sun}_/yr and the mean gas mass is ~10^11.3^M_{sun}_. All of these results point to an IR luminous quasar system. Compared with star formation main sequence (MS) galaxies, at least 80 out of 207 quasars are hosted by starburst galaxies. This supports the statement that luminous AGNs are more likely to be associated with major mergers. The SFR increases with the redshift up to z=2. It is correlated with the AGN bolometric luminosity, where L_FIR_{propto}L_Bol_^0.46+/-0.03^. The AGN bolometric luminosity is also correlated with the host galaxy mass and gas mass. Yet the correlation between L_FIR_ and L_Bol_ has higher significant level, implies that the link between AGN accretion and the SFR is more primal. The M_BH_/M_*_ ratio of our sample is 0.02, higher than the value 0.005 in the local universe. It might indicate an evolutionary trend of the M_BH_/M_*_ scaling relation.
2185. UV galaxies in CANDELS from z=8 to z=4
ID:
ivo://CDS.VizieR/J/ApJ/756/164
Title:
UV galaxies in CANDELS from z=8 to z=4
Short Name:
J/ApJ/756/164
Date:
21 Oct 2021
Publisher:
CDS
Description:
We study the evolution of galaxy rest-frame ultraviolet (UV) colors in the epoch 4<~z<~8. We use new wide-field near-infrared data in the Great Observatories Origins Deep Survey-South field from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey, Hubble Ultra Deep Field (HUDF) 2009, and Early Release Science programs to select galaxies via photometric redshift measurements. Our sample consists of 2812 candidate galaxies at z>~3.5, including 113 at z=~7-8. We fit the observed spectral energy distribution to a suite of synthetic stellar population models and measure the value of the UV spectral slope ({beta}) from the best-fit model spectrum. We run simulations to show that this measurement technique results in a smaller scatter on {beta} than other methods, as well as a reduced number of galaxies with catastrophically incorrect {beta} measurements (i.e., {Delta}{beta}>1).
2186. UV mag of candidate galaxies at 3~<z~<8.5
ID:
ivo://CDS.VizieR/J/ApJ/810/71
Title:
UV mag of candidate galaxies at 3~<z~<8.5
Short Name:
J/ApJ/810/71
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a robust measurement and analysis of the rest-frame ultraviolet (UV) luminosity functions at z=4-8. We use deep Hubble Space Telescope imaging over the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey/GOODS fields, the Hubble Ultra Deep Field, and the Hubble Frontier Field deep parallel observations near the Abell 2744 and MACS J0416.1-2403 clusters. The combination of these surveys provides an effective volume of 0.6-1.2x10^6^Mpc^3^ over this epoch, allowing us to perform a robust search for faint (M_UV_=-18) and bright (M_UV_<-21) high-redshift galaxies. We select candidate galaxies using a well-tested photometric redshift technique with careful screening of contaminants, finding a sample of 7446 candidate galaxies at 3.5<z<8.5, with >1000 galaxies at z~6-8. We measure both a stepwise luminosity function for candidate galaxies in our redshift samples, and a Schechter function, using a Markov Chain Monte Carlo analysis to measure robust uncertainties. At the faint end, our UV luminosity functions agree with previous studies, yet we find a higher abundance of UV-bright candidate galaxies at z>=6.
2187. UVOT, ZTF gri LCs and spectra of the SN Ia 2019yvq
ID:
ivo://CDS.VizieR/J/ApJ/898/56
Title:
UVOT, ZTF gri LCs and spectra of the SN Ia 2019yvq
Short Name:
J/ApJ/898/56
Date:
16 Mar 2022 00:53:53
Publisher:
CDS
Description:
Early observations of Type Ia supernovae (SNe Ia) provide essential clues for understanding the progenitor system that gave rise to the terminal thermonuclear explosion. We present exquisite observations of SN 2019yvq, the second observed SN Ia, after iPTF 14atg, to display an early flash of emission in the ultraviolet (UV) and optical. Our analysis finds that SN 2019yvq was unusual, even when ignoring the initial flash, in that it was moderately underluminous for an SN Ia (M_g_~-18.5mag at peak) yet featured very high absorption velocities (v~15000km/s for SiII{lambda}6355 at peak). We find that many of the observational features of SN 2019yvq, aside from the flash, can be explained if the explosive yield of radioactive 56Ni is relatively low (we measure M_56Ni_=0.31+/-0.05M_{sun}_) and it and other iron-group elements are concentrated in the innermost layers of the ejecta. To explain both the UV/optical flash and peak properties of SN 2019yvq we consider four different models: interaction between the SN ejecta and a nondegenerate companion, extended clumps of ^56^Ni in the outer ejecta, a double-detonation explosion, and the violent merger of two white dwarfs. Each of these models has shortcomings when compared to the observations; it is clear additional tuning is required to better match SN 2019yvq. In closing, we predict that the nebular spectra of SN 2019yvq will feature either H or He emission, if the ejecta collided with a companion, strong [CaII] emission, if it was a double detonation, or narrow [OI] emission, if it was due to a violent merger.
2188. UV to far-IR photometry of galaxies
ID:
ivo://CDS.VizieR/J/ApJS/199/22
Title:
UV to far-IR photometry of galaxies
Short Name:
J/ApJS/199/22
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this paper, we present a sample of cluster galaxies devoted to study the environmental influence on the star formation activity. This sample of galaxies inhabits in clusters showing a rich variety in their characteristics and have been observed by the SDSS-DR6 down to M_B_~-18, and by the Galaxy Evolution Explorer AIS throughout sky regions corresponding to several megaparsecs. We assign the broadband and emission-line fluxes from ultraviolet to far-infrared to each galaxy performing an accurate spectral energy distribution for spectral fitting analysis. The clusters follow the general X-ray luminosity versus velocity dispersion trend of L_X_{propto}{sigma}^4.4^_c_.
2189. VANDAM IV. Free-free emission from protostars
ID:
ivo://CDS.VizieR/J/ApJS/238/19
Title:
VANDAM IV. Free-free emission from protostars
Short Name:
J/ApJS/238/19
Date:
21 Oct 2021
Publisher:
CDS
Description:
Emission from protostars at centimeter radio wavelengths has been shown to trace the free-free emission arising from ionizing shocks as a result of jets and outflows driven by protostars. Therefore, measuring properties of protostars at radio frequencies can provide valuable insights into the nature of their outflows and jets. We present a C-band (4.1 and 6.4cm) survey of all known protostars (Class0 and ClassI) in Perseus as part of the VLA Nascent Disk and Multiplicity (VANDAM) Survey. We examine the known correlations between radio flux density and protostellar parameters, such as bolometric luminosity and outflow force, for our sample. We also investigate the relationship between radio flux density and far-infrared line luminosities from Herschel. We show that free-free emission most likely originates from J-type shocks; however, the large scatter indicates that those two types of emission probe different time and spatial scales. Using C-band fluxes, we removed an estimation of free-free contamination from the corresponding Ka- band (9mm) flux densities that primarily probe dust emission from embedded disks. We find that the compact (<1") dust emission is lower for Class I sources (median dust mass 96M_{Earth}_) relative to Class 0 (248M_{Earth}_), but several times higher than in Class II (5-15M_{Earth}_). If this compact dust emission is tracing primarily the embedded disk, as is likely for many sources, this result provides evidence of decreasing disk masses with protostellar evolution, with sufficient mass for forming giant planet cores primarily at early times.
2190. VANDAM survey of Orion protostars. II.
ID:
ivo://CDS.VizieR/J/ApJ/890/130
Title:
VANDAM survey of Orion protostars. II.
Short Name:
J/ApJ/890/130
Date:
07 Mar 2022 13:26:15
Publisher:
CDS
Description:
We have conducted a survey of 328 protostars in the Orion molecular clouds with the Atacama Large Millimeter/submillimeter Array at 0.87mm at a resolution of ~0.1" (40au), including observations with the Very Large Array at 9mm toward 148 protostars at a resolution of ~0.08" (32au). This is the largest multiwavelength survey of protostars at this resolution by an order of magnitude. We use the dust continuum emission at 0.87 and 9mm to measure the dust disk radii and masses toward the Class 0, Class I, and flat-spectrum protostars, characterizing the evolution of these disk properties in the protostellar phase. The mean dust disk radii for the Class 0, Class I, and flat-spectrum protostars are 44.9_-3.4_^+5.8^, 37.0_-3.0_^+4.9^, and 28.5_-2.3_^+3.7^au, respectively, and the mean protostellar dust disk masses are 25.9_-4.0_^+7.7^, 14.9_-2.2_^+3.8^, 11.6_-1.9_^+3.5^M_{Earth}_, respectively. The decrease in dust disk masses is expected from disk evolution and accretion, but the decrease in disk radii may point to the initial conditions of star formation not leading to the systematic growth of disk radii or that radial drift is keeping the dust disk sizes small. At least 146 protostellar disks (35% of 379 detected 0.87mm continuum sources plus 42 nondetections) have disk radii greater than 50au in our sample. These properties are not found to vary significantly between different regions within Orion. The protostellar dust disk mass distributions are systematically larger than those of Class II disks by a factor of >4, providing evidence that the cores of giant planets may need to at least begin their formation during the protostellar phase.

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