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14261. Spectroscopy of the foreground population in Orion A
ID:
ivo://CDS.VizieR/J/AJ/153/188
Title:
Spectroscopy of the foreground population in Orion A
Short Name:
J/AJ/153/188
Date:
21 Oct 2021
Publisher:
CDS
Description:
We perform a spectroscopic survey of the foreground population in Orion A with MMT/Hectospec. We use these data, along with archival spectroscopic data and photometric data, to derive spectral types, extinction values, and masses for 691 stars. Using the Spitzer Space Telescope data, we characterize the disk properties of these sources. We identify 37 new transition disk (TD) objects, 1 globally depleted disk candidate, and 7 probable young debris disks. We discover an object with a mass of less than 0.018-0.030 M_{sun}_, which harbors a flaring disk. Using the H{alpha} emission line, we characterize the accretion activity of the sources with disks, and confirm that the fraction of accreting TDs is lower than that of optically thick disks (46%+/-7% versus 73%+/-9%, respectively). Using kinematic data from the Sloan Digital Sky Survey and APOGEE INfrared Spectroscopy of the Young Nebulous Clusters program (IN-SYNC), we confirm that the foreground population shows similar kinematics to their local molecular clouds and other young stars in the same regions. Using the isochronal ages, we find that the foreground population has a median age of around 1-2 Myr, which is similar to that of other young stars in Orion A. Therefore, our results argue against the presence of a large and old foreground cluster in front of Orion A.
14262. Spectroscopy of the Galactic bar. I.
ID:
ivo://CDS.VizieR/J/ApJ/691/1387
Title:
Spectroscopy of the Galactic bar. I.
Short Name:
J/ApJ/691/1387
Date:
21 Oct 2021
Publisher:
CDS
Description:
We use Fabry-Perot absorption line imaging spectroscopy to measure radial velocities using the CaII line in 3360 stars toward three lines of sight in the Milky Way's bar: Baade's Window and offset position at (l,b)~(+/-5.0,-3.5{deg}). This sample includes 2488 bar red clump giants, 339 bar M/K-giants, and 318 disk main-sequence stars. We measure the first four moments of the stellar velocity distribution of the red clump giants, and find it to be symmetric and flat-topped. We also measure the line-of-sight average velocity and dispersion of the red clump giants as a function of distance in the bar.
14263. Spectroscopy of TTau and Herbig Ae/Be candidates
ID:
ivo://CDS.VizieR/J/ApJ/657/884
Title:
Spectroscopy of TTau and Herbig Ae/Be candidates
Short Name:
J/ApJ/657/884
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present our diagnosis of the role that massive stars play in the formation of low- and intermediate-mass stars in OB associations (the lambda Ori region, Ori OB1, and Lac OB1 associations).
14264. Spectroscopy of Tuc-Hor candidate members
ID:
ivo://CDS.VizieR/J/AJ/147/146
Title:
Spectroscopy of Tuc-Hor candidate members
Short Name:
J/AJ/147/146
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the selection and spectroscopic confirmation of 129 new late-type (SpT=K3-M6) members of the Tucana-Horologium moving group, a nearby (d~40pc), young ({tau}~40Myr) population of comoving stars. We also report observations for 13 of the 17 known Tuc-Hor members in this spectral type range, and that 62 additional candidates are likely to be unassociated field stars; the confirmation frequency for new candidates is therefore 129/191=67%. We have used radial velocities, H{alpha} emission, and Li_6708_ absorption to distinguish between contaminants and bona fide members. Our expanded census of Tuc-Hor increases the known population by a factor of ~3 in total and by a factor of ~8 for members with SpT>=K3, but even so, the K-M dwarf population of Tuc-Hor is still markedly incomplete. Our expanded census allows for a much more detailed study of Tuc-Hor than was previously feasible. The spatial distribution of members appears to trace a two-dimensional sheet, with a broad distribution in X and Y, but a very narrow distribution (+/-5pc) in Z. The corresponding velocity distribution is very small, with a scatter of +/-1.1km/s about the mean UVW velocity for stars spanning the entire 50pc extent of Tuc-Hor. We also show that the isochronal age ({tau}~20-30Myr) and the lithium depletion boundary age ({tau}~40Myr) disagree, following the trend in other pre-main-sequence populations for isochrones to yield systematically younger ages. The H{alpha} emission line strength follows a trend of increasing equivalent width with later spectral type, as is seen for young clusters. We find that moving group members have been depleted of measurable lithium for spectral types of K7.0-M4.5. None of our targets have significant infrared excesses in the WISE W3 band, yielding an upper limit on warm debris disks of F<0.7%. Finally, our purely kinematic and color-magnitude selection procedure allows us to test the efficiency and completeness for activity-based selection of young stars. We find that 60% of K-M dwarfs in Tuc-Hor do not have ROSAT counterparts and would have been omitted in X-ray-selected samples. In contrast, GALEX UV-selected samples using a previously suggested criterion for youth achieve completeness of 77% and purity of 78%, and we suggest new SpT-dependent selection criteria that will yield >95% completeness for {tau}~40Myr populations with GALEX data available.
14265. Spectroscopy of Type Ia supernovae
ID:
ivo://CDS.VizieR/J/A+A/477/717
Title:
Spectroscopy of Type Ia supernovae
Short Name:
J/A+A/477/717
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a quantitative study of a new data set of high redshift Type Ia supernovae spectra, observed at the Gemini telescopes during the first 34 months of the Supernova Legacy Survey. During this time 123 supernovae candidates were observed, of which 87 have been identified as SNe Ia at a median redshift of z=0.720. Spectra from the entire second year of the survey and part of the third year (59 total SNe candidates with 46 confirmed SNe Ia) are published here for the first time. The spectroscopic measurements made on this data set are used determine if these distant SNe comprise a population similar to those observed locally. Rest-frame equivalent width and ejection velocity measurements are made on four spectroscopic features. Corresponding measurements are presented for a set of 167 spectra from 24 low-z SNe Ia from the literature.
14266. Spectroscopy of Ultraluminous IR galaxies
ID:
ivo://CDS.VizieR/J/AJ/132/2596
Title:
Spectroscopy of Ultraluminous IR galaxies
Short Name:
J/AJ/132/2596
Date:
21 Oct 2021
Publisher:
CDS
Description:
We investigate the types of nuclear environments that produce OH megamasers (OHMs) with a study of the optical spectra of 40 OHM host galaxies and a control sample of 30 non-masing (ultra)luminous infrared galaxies ([U]LIRGs). The optical spectrophotometry provides spatially resolved spectra of multiple nuclei in a few of these merging systems. Of the 40 OHMs classified, 33% are starbursts, 42% are LINERs, and 25% are Seyfert 2 galaxies; the classification of the non-masing control sample is similar.
14267. Spectroscopy of UltraStrong Emission Line galaxies
ID:
ivo://CDS.VizieR/J/ApJ/668/853
Title:
Spectroscopy of UltraStrong Emission Line galaxies
Short Name:
J/ApJ/668/853
Date:
21 Oct 2021
Publisher:
CDS
Description:
We describe the results of a narrowband search for ultrastrong emission line galaxies (USELs) with EW(H{beta})>=30{AA}. A total of 542 candidate galaxies are found in a one-half square degree survey using two ~120{AA} filters centered at 8150 and 9140{AA} with Subaru SuprimeCam. Follow-up spectroscopy for randomly selected objects in the candidate sample with Keck II DEIMOS shows that they consist of [OIII] {lambda}5007-, [OII] {lambda}3727-, and H{alpha}-selected strong emission line galaxies at intermediate redshift (z<1) and Ly{alpha}-emitting galaxies at high redshift (z>>5).
14268. Spectroscopy of UMa II and Coma Ber
ID:
ivo://CDS.VizieR/J/ApJ/708/560
Title:
Spectroscopy of UMa II and Coma Ber
Short Name:
J/ApJ/708/560
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present spectra of six metal-poor stars in two of the ultra-faint dwarf galaxies orbiting the Milky Way (MW), Ursa Major II, and Coma Berenices obtained with the Keck/High Resolution Echelle Spectrometer (HIRES). These observations include the first high-resolution spectroscopic observations of extremely metal-poor ([Fe/H]<-3.0) stars not belonging to the MW halo field star population. We obtain abundance measurements and upper limits for 26 elements between carbon and europium. The entire sample of stars spans a range of -3.2<[Fe/H]<-2.3, and we confirm that each galaxy contains a large intrinsic spread of Fe abundances. A comparison with MW halo stars of similar metallicities reveals substantial agreement between the abundance patterns of the ultra-faint dwarf galaxies and the MW halo for the light, {alpha}, and iron-peak elements (C to Zn). The abundances of neutron-capture elements (Sr to Eu) in the ultra-faint dwarf galaxies are extremely low, consistent with the most metal-poor halo stars, but not with the typical halo abundance pattern at [Fe/H]>~-3.0. Not only are our results broadly consistent with a galaxy formation model that predicts that massive dwarf galaxies are the source of the metal-rich component ([Fe/H]>-2.5) of the MW halo, but they also suggest that the faintest known dwarfs may be the primary contributors to the metal-poor end of the MW halo metallicity distribution.
14269. Spectroscopy of V Tri
ID:
ivo://CDS.VizieR/J/AJ/153/248
Title:
Spectroscopy of V Tri
Short Name:
J/AJ/153/248
Date:
21 Oct 2021
Publisher:
CDS
Description:
Time-series, multi-color photometry and high-resolution spectra of the short-period eclipsing binary V Tri were obtained through observation. The completely covered light and radial velocity (RV) curves of the binary system are presented. All times of light minima derived from both photoelectric and CCD photometry were used to calculate the orbital period and new ephemerides of the eclipsing system. The analysis of the O-C diagram reveals that the orbital period is 0.58520481 days, decreasing at a rate of dP/dt=-7.80x10^-8^ day/yr. The mass transfer between the two components and the light-time-travel effect due to a third body could be used to explain the period decrease. However, a semi-detached configuration with the lower-mass component filling and the primary nearly filling each of their Roche lobes was derived from the synthesis of the light and RV curves by using the 2015 version of the Wilson-Devinney code. We consider the period decrease to be the nonconservative mass transfer from the secondary component to the primary and the mass loss of the system, which was thought to be an EB type, while it should be an EA type (semi-detached Algol-type) from our study. The masses, radii, and luminosities of the primary and secondary are 1.60+/-0.07M_{sun}_, 1.64+/-0.02R_{sun}_, and 14.14+/-0.73L_{sun}_ and 0.74+/-0.02M_{sun}_, 1.23+/-0.02R_{sun}_, and 1.65+/-0.05L_{sun}_, respectively.
14270. Spectroscopy of WASP planet host stars
ID:
ivo://CDS.VizieR/J/MNRAS/428/3164
Title:
Spectroscopy of WASP planet host stars
Short Name:
J/MNRAS/428/3164
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have made a detailed spectral analysis of 11 Wide Angle Search for Planets (WASP) planet host stars using high signal-to-noise ratio (S/N) HARPS spectra. Our line list was carefully selected from the spectra of the Sun and Procyon, and we made a critical evaluation of the atomic data. The spectral lines were measured using equivalent widths. The procedures were tested on the Sun and Procyon prior to be being used on the WASP stars. The effective temperature (Teff), surface gravity (logg), microturbulent velocity (v_mic_) and metallicity were determined for all the stars.

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