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2261. SDSS DR10 radio-loud quasars sample
ID:
ivo://CDS.VizieR/J/A+A/631/A46
Title:
SDSS DR10 radio-loud quasars sample
Short Name:
J/A+A/631/A46
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a study of a sample of 223 radio loud quasars (up to redshift <0.3) in order to investigate their spectral properties. Twenty-six of these radio loud quasars are identified as Flat Spect rum Radio Quasars (FSRQs) and fifty-four are identified as Steep Spectrum Radio Quasars (SSRQs) based on their radio spectral index. We study the [OIII] line properties of these quasars to investigate the origin and properties of blue wings (shift of the profile towards lower wavelengths) and blue outliers (shift of the whole spectroscopic feature). Most of the quasars show blue wings with velocities up to 420km/s. We find that around 17% of the quasars show outliers with velocities spanning 4 19 to -315km/s. Finally, we revisit the M_BH_-{sigma} relation of our sample using [SII]{lambda}6716, 6731 and [OIII] linewidths as surrogates for stellar velocity dispersions, {sigma}, to investigate their location on the M_BH_-{sigma} relation for quiescent galaxies. Due to strong blending of [SII] with H_{alpha}_, we could estimate {sigma}_[SII]_ of only 123 quasars. We find that the radio-loud quasars do not show a relationship between M_BH_ and {sigma}_[SII]/[OIII]_ up to a redshift of 0.3, although they cluster around the local relation. We find an overall offset of 0.12+/-0.05dex of our sample of radio loud quasars from the M_BH_-{sigma} relation of quiescent galaxies. Quasars in our highest redshift bin (z=0.25-0.3) show a deviation of ~0.33+/-0.06dex with respect to the local relation. Implications of the results are discussed.
2262. SDSS-III APOGEE H-band spectral line lists
ID:
ivo://CDS.VizieR/J/ApJS/221/24
Title:
SDSS-III APOGEE H-band spectral line lists
Short Name:
J/ApJS/221/24
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the H-band spectral line lists adopted by the Apache Point Observatory Galactic Evolution Experiment (APOGEE). The APOGEE line lists comprise astrophysical, theoretical, and laboratory sources from the literature, as well as newly evaluated astrophysical oscillator strengths and damping parameters. We discuss the construction of the APOGEE line list, which is one of the critical inputs for the APOGEE Stellar Parameters and Chemical Abundances Pipeline, and present three different versions that have been used at various stages of the project. The methodology for the newly calculated astrophysical line lists is reviewed. The largest of these three line lists contains 134457 molecular and atomic transitions. In addition to the format adopted to store the data, the line lists are available in MOOG, Synspec, and Turbospectrum formats. The limitations of the line lists along with guidance for its use on different spectral types are discussed. We also present a list of H-band spectral features that are either poorly represented or completely missing in our line list. This list is based on the average of a large number of spectral fit residuals for APOGEE observations spanning a wide range of stellar parameters.
2263. SDSS-III/APOGEE. I. Be stars
ID:
ivo://CDS.VizieR/J/AJ/149/7
Title:
SDSS-III/APOGEE. I. Be stars
Short Name:
J/AJ/149/7
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Apache Point Observatory Galactic Evolution Experiment (APOGEE) has amassed the largest ever collection of multi-epoch, high-resolution (R~22500), H-band spectra for B-type emission line (Be) stars. These stars were targeted by APOGEE as telluric standard stars and subsequently identified via visual inspection as Be stars based on HI Brackett series emission or shell absorption in addition to otherwise smooth continua and occasionally non-hydrogen emission features. The 128/238 APOGEE Be stars for which emission had never previously been reported serve to increase the total number of known Be stars by ~6%. Because the H band is relatively unexplored compared to other wavelength regimes, we focus here on identification of the H-band lines and analysis of the emission peak velocity separations ({Delta}v_p_) and emission peak intensity ratios (V/R) of the usually double-peaked HI and non-hydrogen emission lines. HI Br11 emission is found to preferentially form in the circumstellar disks at an average distance of ~2.2 stellar radii. Increasing {Delta}v_p_ toward the weaker Br12-Br20 lines suggests these lines are formed interior to Br11. By contrast, the observed IR FeII emission lines present evidence of having significantly larger formation radii; distinctive phase lags between IR FeII and HI Brackett emission lines further supports that these species arise from different radii in Be disks. Several emission lines have been identified for the first time including CI 16895, a prominent feature in the spectra for almost a fifth of the sample and, as inferred from relatively large {Delta}v_p_ compared to the Br11-Br20, a tracer of the inner regions of Be disks. Emission lines at 15760{AA} and 16781{AA} remain unidentified, but usually appear along with and always have similar line profile morphology to FeII 16878. Unlike the typical metallic lines observed for Be stars in the optical, the H-band metallic lines, such as FeII 16878, never exhibit any evidence of shell absorption, even when the HI lines are clearly shell-dominated. The first known example of a quasi-triple-peaked Br11 line profile is reported for HD253659, one of several stars exhibiting intra- and/or extra-species V/R and radial velocity variation within individual spectra. Br11 profiles are presented for all discussed stars, as are full APOGEE spectra for a portion of the sample.
2264. SDSS-III DR9 DLA catalogue
ID:
ivo://CDS.VizieR/J/A+A/547/L1
Title:
SDSS-III DR9 DLA catalogue
Short Name:
J/A+A/547/L1
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a study of the column density distribution and cosmological mass density of neutral gas from a survey of Damped Lyman-alpha systems in the Sloan Digital Sky Survey III Data Release 9.
2265. SDSS-II SNe survey: search and follow-up
ID:
ivo://CDS.VizieR/J/AJ/135/348
Title:
SDSS-II SNe survey: search and follow-up
Short Name:
J/AJ/135/348
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Sloan Digital Sky Survey-II Supernova Survey has identified a large number of new transient sources in a 300deg^2^ region along the celestial equator during its first two seasons of a three-season campaign. Multi-band (ugriz) light curves were measured for most of the sources, which include solar system objects, galactic variable stars, active galactic nuclei, supernovae (SNe), and other astronomical transients. The imaging survey is augmented by an extensive spectroscopic follow-up program to identify SNe, measure their redshifts, and study the physical conditions of the explosions and their environment through spectroscopic diagnostics. During the survey, light curves are rapidly evaluated to provide an initial photometric type of the SNe, and a selected sample of sources are targeted for spectroscopic observations. In the first two seasons, 476 sources were selected for spectroscopic observations, of which 403 were identified as SNe. For the type Ia SNe, the main driver for the survey, our photometric typing and targeting efficiency is 90%. Only 6% of the photometric SN Ia candidates were spectroscopically classified as non-SN Ia instead, and the remaining 4% resulted in low signal-to-noise, unclassified spectra.
2266. SDSS-II SN Survey: host-galaxy spectral data
ID:
ivo://CDS.VizieR/J/ApJ/821/115
Title:
SDSS-II SN Survey: host-galaxy spectral data
Short Name:
J/ApJ/821/115
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using the largest single-survey sample of Type Ia supernovae (SNe Ia) to date, we study the relationship between properties of SNe Ia and those of their host galaxies, focusing primarily on correlations with Hubble residuals (HRs). Our sample consists of 345 photometrically classified or spectroscopically confirmed SNe Ia discovered as part of the SDSS-II Supernova Survey (SDSS-SNS). This analysis utilizes host-galaxy spectroscopy obtained during the SDSS-I/II spectroscopic survey and from an ancillary program on the SDSS-III Baryon Oscillation Spectroscopic Survey that obtained spectra for nearly all host galaxies of SDSS-II SN candidates. In addition, we use photometric host-galaxy properties from the SDSS-SNS data release such as host stellar mass and star formation rate. We confirm the well-known relation between HR and host-galaxy mass and find a 3.6{sigma} significance of a nonzero linear slope. We also recover correlations between HR and host-galaxy gas-phase metallicity and specific star formation rate as they are reported in the literature. With our large data set, we examine correlations between HR and multiple host-galaxy properties simultaneously and find no evidence of a significant correlation. We also independently analyze our spectroscopically confirmed and photometrically classified SNe Ia and comment on the significance of similar combined data sets for future surveys.
2267. SDSS-II SN Survey: SNe II-P standardization
ID:
ivo://CDS.VizieR/J/ApJ/708/661
Title:
SDSS-II SN Survey: SNe II-P standardization
Short Name:
J/ApJ/708/661
Date:
21 Oct 2021
Publisher:
CDS
Description:
We apply the Standardized Candle Method (SCM) for Type II Plateau supernovae (SNe II-P), which relates the velocity of the ejecta of a SN to its luminosity during the plateau, to 15 SNe II-P discovered over the three season run of the Sloan Digital Sky Survey-II Supernova Survey. The redshifts of these SNe - 0.027<z<0.144 - cover a range hitherto sparsely sampled in the literature; in particular, our SNe II-P sample contains nearly as many SNe in the Hubble flow (z>0.01) as all of the current literature on the SCM combined. We find that the SDSS SNe have a very small intrinsic I-band dispersion (0.22mag), which can be attributed to selection effects. When the SCM is applied to the combined SDSS-plus-literature set of SNe II-P, the dispersion increases to 0.29mag, larger than the scatter for either set of SNe separately. We show that the standardization cannot be further improved by eliminating SNe with positive plateau decline rates, as proposed in Poznanski et al. (2009ApJ...694.1067P). We thoroughly examine all potential systematic effects and conclude that for the SCM to be useful for cosmology, the methods currently used to determine the FeII velocity at day 50 must be improved, and spectral templates able to encompass the intrinsic variations of Type II-P SNe will be needed.
2268. SDSS-II supernovae NTT and NOT spectroscopy
ID:
ivo://CDS.VizieR/J/A+A/526/A28
Title:
SDSS-II supernovae NTT and NOT spectroscopy
Short Name:
J/A+A/526/A28
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Sloan Digital Sky Survey II (SDSS-II) Supernova Survey, conducted between 2005 and 2007, was designed to detect a large number of type Ia supernovae around z~0.2, the redshift "gap" between low-z and high-z supernova searches. The survey has provided multi-band (ugriz) photometric lightcurves for variable targets, and supernova candidates were scheduled for spectroscopic observations, primarily to provide supernova classification and accurate redshifts. We present supernova spectra obtained in 2006 and 2007 using the New Technology Telescope (NTT) and the Nordic Optical Telescope (NOT). We provide an atlas of supernova spectra in the range z=0.03-0.32 that complements the well-sampled lightcurves from SDSS-II in the forthcoming three-year SDSS supernova cosmology analysis. The sample can, for example, be used for spectral studies of type Ia supernovae, which are critical for understanding potential systematic effects when supernovae are used to determine cosmological distances. The spectra were reduced in a uniform manner, and special care was taken in estimating the uncertainties for the different processing steps. Host-galaxy light was subtracted when possible and the supernova type fitted using the SuperNova IDentification code (SNID). We also present comparisons between spectral and photometric dating using SALT lightcurve fits to the photometry from SDSS-II, as well as the global distribution of our sample in terms of the lightcurve parameters: stretch and colour.
2269. SDSS J102839.11+450009.4 Fe II emission lines
ID:
ivo://CDS.VizieR/J/ApJ/674/668
Title:
SDSS J102839.11+450009.4 Fe II emission lines
Short Name:
J/ApJ/674/668
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report identification of SDSS J102839.11+450009.4 as a peculiarly interesting quasar. It shows very prominent narrow emission lines (NELs) in FeII that are remarkably different from the broad FeII multiplets commonly observed in quasars and Seyfert 1 galaxies. The FeII NEL spectrum is dominated in the UV by transitions to the low-lying ground levels with even parity, and by forbidden transitions in the optical, suggesting its formation in a warm collisionally ionized low density medium.
2270. SDSS J160429.12+100002.2 spectra
ID:
ivo://CDS.VizieR/J/A+A/650/A102
Title:
SDSS J160429.12+100002.2 spectra
Short Name:
J/A+A/650/A102
Date:
21 Oct 2021
Publisher:
CDS
Description:
In the past, SDSS J160429.12+100002.2 was spectroscopically classified as a blue horizontal branch (BHB) star. Assuming a luminosity that is characteristic of BHB stars, the object's radial velocity and proper motions from Gaia Early Data Release 3 would imply that its Galactic rest-frame velocity exceeds its local escape velocity. Consequently, the object would be considered a hypervelocity star, which would prove particularly interesting because its Galactic trajectory points in our direction. However, based on the spectroscopic analysis of follow-up observations, we show that the object is actually a short-period (P~3.4h) single-lined spectroscopic binary system with a visible B-type star (effective temperature Teff=15840+/-160K and surface gravity log(g)=4.86+/-0.04) that is less luminous than typical BHB stars. Accordingly, the distance of the system is lower than originally thought, which renders its Galactic orbit bound to the Galaxy. Nevertheless, it is still an extreme halo object on a highly retrograde orbit. The abundances of He, C, N, O, Ne, Mg, Al, Si, S, and Ca are subsolar by factors from 3 to more than 100, while Fe is enriched by a factor of about 6. This peculiar chemical composition pattern is most likely caused by atomic diffusion processes. Combining constraints from astrometry, orbital motion, photometry, and spectroscopy, we conclude that the visible component is an unevolved proto-helium white dwarf with a thin hydrogen envelope that was stripped by a substellar companion through common-envelope ejection. Its unique configuration renders the binary system an interesting test bed for stellar binary evolution in general and common-envelope evolution in particular.

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