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3111. W51/e2 and G34.3+0.2 IRAM spectra
ID:
ivo://CDS.VizieR/J/A+A/582/A64
Title:
W51/e2 and G34.3+0.2 IRAM spectra
Short Name:
J/A+A/582/A64
Date:
21 Oct 2021
Publisher:
CDS
Description:
With only a few low- and high-mass star-formation regions studied in detail so far, it is unclear what role the environment plays in complex molecule formation. In this light, a comparison of relative abundances of related species between sources might be useful for explaining any observed differences. We seek to measure the relative abundance between three important complex organic molecules, ethylene glycol ((CH_2_OH)_2_), glycolaldehyde (CH_2_OHCHO) and methyl formate (HCOOCH_3_), toward high-mass protostars and thereby provide additional constraints on their formation pathways. We use IRAM30 m single-dish observations of the three species toward two high-mass star-forming regions - W51/e2 and G34.3+0.2 - and report a tentative detection of (CH_2_OH)_2_ toward both sources.
3112. WFC3/UVIS quasar-stacked spectrum at z=~2.4
ID:
ivo://CDS.VizieR/J/MNRAS/449/4204
Title:
WFC3/UVIS quasar-stacked spectrum at z=~2.4
Short Name:
J/MNRAS/449/4204
Date:
21 Oct 2021
Publisher:
CDS
Description:
The ionizing continuum from active galactic nuclei is fundamental for interpreting their broad emission lines and understanding their impact on the surrounding gas. Furthermore, it provides hints on how matter accretes on to supermassive black holes. Using Hubble Space Telescope's Wide Field Camera 3, we have constructed the first stacked ultraviolet (rest-frame wavelengths 600-2500{AA}) spectrum of 53 luminous quasars at z=~2.4, with a state-of-the-art correction for the intervening Lyman forest and Lyman continuum absorption. The continuum slope (f_{nu}_{prop.to}{nu}^{alpha}{nu}^) of the full sample shows a break at ~912{AA} with spectral index {alpha}_{nu}_=-0.61+/-0.01 at {lambda}>912{AA} and a softening at shorter wavelengths ({alpha}_{nu}_=-1.70+/-0.61 at {lambda}<=912{AA}). Our analysis proves that a proper intergalactic medium absorption correction is required to establish the intrinsic continuum emission of quasars. We interpret our average ultraviolet spectrum in the context of photoionization, accretion disc models, and quasar contribution to the ultraviolet background. We find that observed broad line ratios are consistent with those predicted assuming an ionizing slope of {alpha}_ion_=-2.0, similar to the observed ionizing spectrum in the same wavelength range. The continuum break and softening are consistent with accretion disc plus X-ray corona models when black hole spin is taken into account. Our spectral energy distribution yields a 30 per cent increase to previous estimates of the specific quasar emissivity, such that quasars may contribute significantly to the total specific Lyman limit emissivity estimated from the Ly{alpha} forest at z<3.2.
3113. White dwarf candidates in SDSS DR10
ID:
ivo://CDS.VizieR/J/MNRAS/448/2260
Title:
White dwarf candidates in SDSS DR10
Short Name:
J/MNRAS/448/2260
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a method which uses cuts in colour-colour and reduced proper motion-colour space to select white dwarfs without the recourse to spectroscopy while allowing an adjustable compromise between completeness and efficiency. Rather than just producing a list of white dwarf candidates, our method calculates a probability of being a white dwarf (P_WD_) for any object with available multiband photometry and proper motion. We applied this method to all objects in the Sloan Digital Sky Survey (SDSS) Data Release 10 (DR10) photometric footprint and to a few selected sources in DR7 which did not have reliable photometry in DR9 or DR10. This application results in a sample of 61 969 DR10 and 3799 DR7 photometric sources with calculated P_WD_ from which it is possible to select a sample of ~23000 high-fidelity white dwarf candidates with T_eff_>~7000K and g<=19. This sample contains over 14000 high confidence white dwarfs candidates which have not yet received spectroscopic follow-up. These numbers show that, to date, the spectroscopic coverage of white dwarfs in the SDSS photometric footprint is, on average, only ~40 percent complete. While we describe here in detail the application of our selection to the SDSS catalogue, the same method could easily be applied to other multicolour, large area surveys. We also publish a list of 8701 bright (g<=19) white dwarfs with SDSS spectroscopy, of which 1781 are new identifications in DR9/DR10.
3114. White dwarf population of Messier 67
ID:
ivo://CDS.VizieR/J/ApJ/867/62
Title:
White dwarf population of Messier 67
Short Name:
J/ApJ/867/62
Date:
21 Oct 2021
Publisher:
CDS
Description:
White dwarfs (WDs) are excellent forensic tools for studying end-of-life issues surrounding low- and intermediate-mass stars, and the old, solar metallicity open star cluster Messier 67 is a proven laboratory for the study of stellar evolution for solar-type stars. In this paper, we present a detailed spectroscopic study of brighter (M_g_<=12.4) WDs in Messier 67, and in combination with previously published proper motion membership determinations, we identify a clean, representative sample of cluster WDs, including 13 members with hydrogen-dominated atmospheres, at least one of which is a candidate double degenerate, and 5 members with helium-dominated atmospheres. Using this sample we test multiple predictions surrounding the final stages of stellar evolution in solar-type stars. In particular, the stochasticity of the integrated mass lost by ~1.5 solar mass stars is less than 7% of the WD remnant mass. We identify WDs likely resulting from binary evolution, including at least one blue straggler remnant and two helium-core WDs. We observe no evidence of a significant population of helium-core WDs formed by enhanced mass loss on the red giant branch of the cluster. The distribution of WD atmospheric compositions is fully consistent with that in the field, limiting proposed mechanisms for the suppression of helium atmosphere WD formation in star clusters. In short, the WD population of Messier 67 is fully consistent with basic predictions of single- and multiple-star stellar evolution theories for solar metallicity stars.
3115. White dwarfs from the Kiso survey
ID:
ivo://CDS.VizieR/J/ApJ/714/1037
Title:
White dwarfs from the Kiso survey
Short Name:
J/ApJ/714/1037
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a spectroscopic analysis of white dwarfs found in the Kiso survey. Spectroscopic observations at high signal-to-noise ratio have been obtained for all DA and DB stars in the Kiso Schmidt ultraviolet excess survey (KUV stars). These observations led to the reclassification of several KUV objects, including the discovery of three unresolved DA+DB double-degenerate binaries. The atmospheric parameters (T_eff_ and logg) are obtained from detailed model atmosphere fits to optical spectroscopic data. The mass distribution of our sample is characterized by a mean value of 0.606M_{sun}_ and a dispersion of 0.135M_{sun}_ for DA stars, and 0.758M_{sun}_ and a dispersion of 0.192M_{sun}_ for DB stars. Absolute visual magnitudes obtained from our spectroscopic fits allow us to derive an improved luminosity function for the DA and DB stars identified in the Kiso survey. Our luminosity function is found to be significantly different from earlier estimates based on empirical photometric calibrations of M_V_ for the same sample. The results for the DA stars now appear entirely consistent with those obtained for the PG survey using the same spectroscopic approach. The space density for DA stars with M_V_<=12.75 is 2.80x10^-4^pc^-3^ in the Kiso survey, which is 9.6% smaller than the value found in the PG survey.
3116. Wide binaries in Taurus and Upper Sco
ID:
ivo://CDS.VizieR/J/ApJ/703/1511
Title:
Wide binaries in Taurus and Upper Sco
Short Name:
J/ApJ/703/1511
Date:
21 Oct 2021
Publisher:
CDS
Description:
We describe an astrometric and spectroscopic campaign to confirm the youth and association of a complete sample of candidate wide companions in Taurus and Upper Sco. Our survey found 15 new binary systems (three in Taurus and 12 in Upper Sco) with separations of 3"-30" (500-5000AU) among all of the known members with masses of 2.5-0.012M_{sun}_. The total sample of 49 wide systems in these two regions conforms to only some expectations from field multiplicity surveys. Higher mass stars have a higher frequency of wide binary companions, and there is a marked paucity of wide binary systems near the substellar regime. However, the separation distribution appears to be log-flat, rather than declining as in the field, and the mass ratio distribution is more biased toward similar-mass companions than the initial mass function or the field G-dwarf distribution. The maximum separation also shows no evidence of a limit at <~5000AU until the abrupt cessation of any wide binary formation at system masses of ~0.3M_{sun}_. We attribute this result to the post-natal dynamical sculpting that occurs for most field systems; our binary systems will escape to the field intact, but most field stars are formed in denser clusters and undergo significant dynamical evolution. In summary, only wide binary systems with total masses <~0.3M_{sun}_ appear to be "unusually wide."
3117. WINERED CN-red band emission in comet C/2013 R1
ID:
ivo://CDS.VizieR/J/AJ/154/45
Title:
WINERED CN-red band emission in comet C/2013 R1
Short Name:
J/AJ/154/45
Date:
21 Oct 2021
Publisher:
CDS
Description:
Although high-resolution spectra of the CN red-system band are considered useful in cometary sciences, e.g., in the study of isotopic ratios of carbon and nitrogen in cometary volatiles, there have been few reports to date due to the lack of high-resolution (R={lambda}/{Delta}{lambda}>20000) spectrographs in the near-infrared region around ~1 {mu}m. Here, we present the high-resolution emission spectrum of the CN red-system band in comet C/2013 R1 (Lovejoy), acquired by the near-infrared high-resolution spectrograph WINERED mounted on the 1.3 m Araki telescope at the Koyama Astronomical Observatory, Kyoto, Japan. We applied our fluorescence excitation models for CN, based on modern spectroscopic studies, to the observed spectrum of comet C/2013 R1 (Lovejoy) to search for CN isotopologues (^13^C^14^N and ^12^C^15^N). We used a CN fluorescence excitation model involving both a "pure" fluorescence excitation model for the outer coma and a "fully collisional" fluorescence excitation model for the inner coma region. Our emission model could reproduce the observed ^12^C^14^N red-system band of comet C/2013 R1 (Lovejoy). The derived mixing ratio between the two excitation models was 0.94(+0.02/-0.03):0.06(+0.03/-0.02), corresponding to the radius of the collision-dominant region of ~800-1600 km from the nucleus. No isotopologues were detected. The observed spectrum is consistent, within error, with previous estimates in comets of ^12^C/^13^C (~90) and ^14^N/^15^N (~150).
3118. WISE/DEIMOS Redshift Catalog DR2 & extended data
ID:
ivo://CDS.VizieR/J/ApJ/866/44
Title:
WISE/DEIMOS Redshift Catalog DR2 & extended data
Short Name:
J/ApJ/866/44
Date:
21 Oct 2021
Publisher:
CDS
Description:
The WISE satellite surveyed the entire sky multiple times in four infrared (IR) wavelengths (3.4, 4.6, 12, and 22{mu}m). This all-sky IR photometric survey makes it possible to leverage many of the large publicly available spectroscopic redshift surveys to measure galaxy properties in the IR. While characterizing the cross-matching of WISE data to a single survey is a straightforward process, doing it with six different redshift surveys takes a fair amount of space to characterize adequately, because each survey has unique caveats and characteristics that need addressing. This work describes a data set that results from matching five public redshift surveys with the AllWISE data release, along with a reanalysis of the data described in Lake+ (2012, J/AJ/143/7). The combined data set has an additional flux limit of 80{mu}Jy (19.14 AB mag) in WISE's W1 filter, imposed in order to limit it to targets with high completeness and reliable photometry in the AllWISE data set. Consistent analysis of all of the data is only possible if the color bias discussed in Ilbert+ (2004MNRAS.351..541I) is addressed (e.g., the techniques explored in Lake+ 2017AJ....153..189L). The sample defined herein is used in a companion paper in this series to measure the luminosity function of galaxies at 2.4{mu}m rest-frame wavelength, and the selection process of the sample is optimized for this purpose.
3119. WIYN spectroscopy in the deep SWIRE field
ID:
ivo://CDS.VizieR/J/ApJS/182/625
Title:
WIYN spectroscopy in the deep SWIRE field
Short Name:
J/ApJS/182/625
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of spectroscopy using HYDRA on the WIYN 3.5m telescope of objects in the deep SWIRE radio field. The goal of the project was to determine spectroscopic redshifts for as many of the brighter objects in the field as possible, especially those detected in the radio and at 24um. These redshifts are primarily being used in studies of galaxy evolution and the connection of that evolution to active galactic nuclei and star formation. Redshifts measured for 365 individual objects are reported. The redshifts range from 0.03 to 2.5, mostly with z<0.9. The sources were selected to be within the WIYN HYDRA field of approximately 30' in radius from the center of the SWIRE deep field, 10:46:00, +59:01:00 (J2000). Optical sources for spectroscopic observation were selected from an r-band image of the field. A priority list of spectroscopic targets was established in the following order: 20cm detections, 24m detections, galaxies with r<20 and the balance made up of fainter galaxies in the field. We provide a table listing the galaxy positions, measured redshift and error, and note any emission lines that were visible in the spectrum. In practice, almost all the galaxies with r<19 were observed including all of the radio sources and most of the 24um sources with r<20 and a sample of radio sources which had fainter optical counterparts on the r-band image.
3120. W51 line of sight deuterium fractionation
ID:
ivo://CDS.VizieR/J/A+A/597/A45
Title:
W51 line of sight deuterium fractionation
Short Name:
J/A+A/597/A45
Date:
21 Oct 2021
Publisher:
CDS
Description:
Herschel/HIFI observations toward the compact HII region W51 has revealed the presence of a cold dense core along its line of sight in a high-velocity stream located just in front of W51. This detection has been made possible through absorption measurements of low-energy transitions of HDO, NH_3_, and C_3_ against the bright background emitted by the star-forming region. We present a follow-up study of this core using the high sensitivity and high spectral resolution provided by the IRAM 30m telescope. We report new detections of this core in absorption for DCO^+^ (2-1, 3-2), H^13^CO^+^ (1-0), DNC (3-2), HN^13^C (1-0), p-H_2_CO (2_0,2_-1_0,1_, 3_0,3_-2_0,2_), and in emission for o-NH2D. We also report interferometric observation of this last species using the IRAM/NOEMA telescope, revealing the fragmented nature of the source through the detection of two cores, separated by 0.19-0.24pc, with average sizes of less than 0.16-0.19pc. From a non-LTE analysis, we are able to estimate the density (~2.5x10^4^cm^-3^) and temperature (~10K) of this component, typical of what is found in dark clouds. This component (called W51-core) has the same DCO^+^/HCO^+^ ratio (0.02) as TMC-1 and a high DNC/HNC ratio (0.14). Detection of these deuterated species indicates that W51-core is similar to an early-phase low-mass star-forming region, formed from the interaction between the W51 giant molecular cloud and the high-velocity stream in front of it. The W51 complex being at about 5kpc, these findings lead to what is the first detection of the earliest phase of low-mass star-forming region at such a large distance.

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