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1061. High-resolution IR airglow spectrum
ID:
ivo://CDS.VizieR/J/A+A/555/A78
Title:
High-resolution IR airglow spectrum
Short Name:
J/A+A/555/A78
Date:
21 Oct 2021
Publisher:
CDS
Description:
A flux-calibrated high-resolution spectrum of the airglow emission is a practical {lambda}-calibration reference for astronomical spectral observations. It is also useful for constraining the molecular parameters of the OH molecule and the physical conditions in the upper mesosphere. We used the data collected during the first technical commissioning of the GIANO spectrograph at the Telescopio Nazionale Galileo (TNG). The high-resolution (R>~50000) spectrum simultaneously covers the 0.95-2.4 micron wavelength range. Relative flux calibration is achieved by the simultaneous observation of a spectrophotometric standard star. We derived a list of improved positions and intensities of OH infrared lines. The list includes {Lambda}-split doublets, many of which are spectrally resolved. Compared with previous works, the new results correct errors in the wavelengths of the Q-branch transitions. The relative fluxes of OH lines from different vibrational bands show remarkable deviations from theoretical predictions: the {DELTA} v=3,4 lines are a factor of 2 and 4 brighter than expected. We also found evidence of a significant fraction (1-4%) of OH molecules with non-thermal population of high-J levels. Finally, we list wavelengths and fluxes of 153 lines not attributable to OH. Most of these can be associated with O_2_, while 37 lines in the H band are not identified. The O_2_ and unidentified lines in the H band account for ~=5% of the total airglow flux in this band.
1062. High resolution NIR RVs of K2-M4 low-mass stars
ID:
ivo://CDS.VizieR/J/ApJ/822/40
Title:
High resolution NIR RVs of K2-M4 low-mass stars
Short Name:
J/ApJ/822/40
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of a precise near-infrared (NIR) radial velocity (RV) survey of 32 low-mass stars with spectral types K2-M4 using CSHELL at the NASA InfraRed Telescope Facility in the K band with an isotopologue methane gas cell to achieve wavelength calibration and a novel, iterative RV extraction method. We surveyed 14 members of young (~25-150Myr) moving groups, the young field star {epsilon} Eridani, and 18 nearby (<25pc) low-mass stars and achieved typical single-measurement precisions of 8-15m/s with a long-term stability of 15-50m/s over longer baselines. We obtain the best NIR RV constraints to date on 27 targets in our sample, 19 of which were never followed by high-precision RV surveys. Our results indicate that very active stars can display long-term RV variations as low as ~25-50m/s at ~2.3125{mu}m, thus constraining the effect of jitter at these wavelengths. We provide the first multiwavelength confirmation of GJ876bc and independently retrieve orbital parameters consistent with previous studies. We recovered RV variabilities for HD160934AB and GJ725AB that are consistent with their known binary orbits, and nine other targets are candidate RV variables with a statistical significance of 3{sigma}-5{sigma}. Our method, combined with the new iSHELL spectrograph, will yield long-term RV precisions of <~5m/s in the NIR, which will allow the detection of super-Earths near the habitable zone of mid-M dwarfs.
1063. High-resolution NIR spectra of local giants
ID:
ivo://CDS.VizieR/J/ApJ/817/40
Title:
High-resolution NIR spectra of local giants
Short Name:
J/ApJ/817/40
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a sample of 705 local giant stars observed using the New Mexico State University 1m telescope with the Sloan Digital Sky Survey-III/Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectrograph, for which we estimate stellar ages and the local star formation history (SFH). The high-resolution (R~22500), near infrared (1.51-1.7{mu}m) APOGEE spectra provide measurements of stellar atmospheric parameters (temperature, surface gravity, [M/H], and [{alpha}/M]). Due to the smaller uncertainties in surface gravity possible with high-resolution spectra and accurate Hipparcos distance measurements, we are able to calculate the stellar masses to within 30%. For giants, the relatively rapid evolution up the red giant branch allows the age to be constrained by the mass. We examine methods of estimating age using both the mass-age relation directly and a Bayesian isochrone matching of measured parameters, assuming a constant SFH. To improve the SFH prior, we use a hierarchical modeling approach to constrain the parameters of the model SFH using the age probability distribution functions of the data. The results of an {alpha}-dependent Gaussian SFH model show a clear age-[{alpha}/M] relation at all ages. Using this SFH model as the prior for an empirical Bayesian analysis, we determine ages for individual stars. The resulting age-metallicity relation is flat, with a slight decrease in [M/H] at the oldest ages and a ~0.5 dex spread in metallicity across most ages. For stars with ages <~1Gyr we find a smaller spread, consistent with radial migration having a smaller effect on these young stars than on the older stars.
1064. High-resolution obs. of CO isotopologues in YSOs
ID:
ivo://CDS.VizieR/J/ApJ/813/120
Title:
High-resolution obs. of CO isotopologues in YSOs
Short Name:
J/ApJ/813/120
Date:
21 Oct 2021
Publisher:
CDS
Description:
This study reports an unusual heterogeneity in [^12^C^16^O]/[^13^C^16^O] abundance ratios of carbon monoxide observed in the gas phase toward seven ~solar-mass young stellar objects (YSOs) and three dense foreground clouds in the nearby star-forming regions, Ophiuchus, Corona Australis, Orion, and Vela, and an isolated core, L43. Robust isotope ratios were derived using infrared absorption spectroscopy of the 4.7{mu}m fundamental and 2.3{mu}m overtone rovibrational bands of CO at very high spectral resolution ({lambda}/{Delta}{lambda}~95000), observed with the Cryogenic Infrared Echelle Spectrograph (CRIRES) on the Very Large Telescope. We find [^12^C^16^O]/[^13^C^16^O] values ranging from ~85 to 165, significantly higher than those of the local interstellar medium (ISM) (~65-69). These observations are evidence for isotopic heterogeneity in carbon reservoirs in solar-type YSO environments, and encourage the need for refined galactic chemical evolution models to explain the ^12^C/^13^C discrepancy between the solar system and local ISM. The oxygen isotope ratios are consistent with isotopologue-specific photodissociation by CO self-shielding toward the disks, VV CrA N and HL Tau, further substantiating models predicting CO self-shielding on disk surfaces. However, we find that CO self-shielding is an unlikely general explanation for the high [^12^C^16^O]/[^13^C^16^O] ratios observed in this study. Comparison of the solid CO against gas-phase [^12^C^16^O]/[^13^C^16^O] suggests that interactions between CO ice and gas reservoirs need to be further investigated as at least a partial explanation for the unusually high [^12^C^16^O]/[^13^C^16^O] observed.
1065. High-resolution spectra of * bet CMi
ID:
ivo://CDS.VizieR/J/ApJ/836/112
Title:
High-resolution spectra of * bet CMi
Short Name:
J/ApJ/836/112
Date:
21 Oct 2021
Publisher:
CDS
Description:
The late-type Be star {beta} CMi is remarkably stable compared to other Be stars that have been studied. This has led to a realistic model of the outflowing Be disk by Klement+ (2015A&A...584A..85K). These results showed that the disk is likely truncated at a finite radius from the star, which Klement et al. suggest is evidence for an unseen binary companion in orbit. Here we report on an analysis of the Ritter Observatory spectroscopic archive of {beta} CMi to search for evidence of the elusive companion. We detect periodic Doppler shifts in the wings of the H{alpha} line with a period of 170 days and an amplitude of 2.25km/s, consistent with a low-mass binary companion (M~0.42M_{sun}_). We then compared small changes in the violet-to-red peak height changes (V/R) with the orbital motion. We find weak evidence that it does follow the orbital motion, as suggested by recent Be binary models by Panoglou et al. Our results, which are similar to those for several other Be stars, suggest that {beta} CMi may be a product of binary evolution where Roche lobe overflow has spun up the current Be star, likely leaving a hot subdwarf or white dwarf in orbit around the star. Unfortunately, no direct sign of this companion star is found in the very limited archive of International Ultraviolet Explorer spectra.
1066. High-resolution spectra of 9 RGB stars in NGC6681
ID:
ivo://CDS.VizieR/J/ApJ/846/23
Title:
High-resolution spectra of 9 RGB stars in NGC6681
Short Name:
J/ApJ/846/23
Date:
21 Oct 2021
Publisher:
CDS
Description:
We obtain high-resolution spectra of nine red giant branch stars in NGC 6681 and perform the first detailed abundance analysis of stars in this cluster. We confirm cluster membership for these stars based on consistent radial velocities of 214.5+/-3.7km/s and find a mean [Fe/H]=-1.63+/-0.07dex and [{alpha}/Fe]=0.42+/-0.11dex. Additionally, we confirm the existence of a Na-O anti-correlation in NGC 6681 and identify two populations of stars with unique abundance trends. With the use of HST photometry from Sarajedini+ (2007AJ....133.1658S) and Piotto+ (2015AJ....149...91P) we are able to identify these two populations as discrete sequences in the cluster CMD. Although we cannot confirm the nature of the polluter stars responsible for the abundance differences in these populations, these results do help put constraints on possible polluter candidates.
1067. High resolution spectra of VLM stars
ID:
ivo://CDS.VizieR/J/MNRAS/301/1031
Title:
High resolution spectra of VLM stars
Short Name:
J/MNRAS/301/1031
Date:
21 Oct 2021
Publisher:
CDS
Description:
A high resolution optical spectral atlas for three very low-mass stars are provided, along with a high resolution observation of an atmospheric absorption calibrator. This is the data used to produce Figures 4-9 in the paper. These data were acquired with CASPEC on the ESO3.6m telescope. The FWHM resolution is 16km/s (eg. 0.043nm at 800nm), at a dispersion of 9km/s. Incomplete wavelength coverage produces inter-order gaps at wavelengths longer than 804.5nm.
1068. High-resolution spectroscopy of TESS stars
ID:
ivo://CDS.VizieR/J/ApJS/248/19
Title:
High-resolution spectroscopy of TESS stars
Short Name:
J/ApJS/248/19
Date:
21 Oct 2021
Publisher:
CDS
Description:
Accurate atmospheric parameters and chemical composition of stars play a vital role in characterizing physical parameters of exoplanetary systems and understanding of their formation. A full asteroseismic characterization of a star is also possible if its main atmospheric parameters are known. The NASA Transiting Exoplanet Survey Satellite (TESS) space telescope will play a very important role in searching of exoplanets around bright stars and stellar asteroseismic variability research. We have observed all 302 bright (V<8mag) and cooler than F5 spectral class stars in the northern TESS continuous viewing zone with a 1.65m telescope at the Moletai Astronomical Observatory of Vilnius University and the high-resolution Vilnius University Echelle Spectrograph. We uniformly determined the main atmospheric parameters, ages, orbital parameters, velocity components, and precise abundances of 24 chemical species (C(C2), N(CN), [OI], NaI, MgI, AlI, SiI, SiII, CaI, CaII, ScI, ScII, TiI, TiII, VI, CrI, CrII, MnI, FeI, FeII, CoI, NiI, CuI, and ZnI) for 277 slowly rotating single stars in the field. About 83% of the sample stars exhibit the Mg/Si ratios greater than 1.0 and may potentially harbor rocky planets in their systems.
1069. High-resolution spectroscopy of V348 Sgr
ID:
ivo://CDS.VizieR/J/A+AS/103/445
Title:
High-resolution spectroscopy of V348 Sgr
Short Name:
J/A+AS/103/445
Date:
21 Oct 2021
Publisher:
CDS
Description:
(no description available)
1070. High-resolution spectrum of La and Ar
ID:
ivo://CDS.VizieR/J/ApJS/208/18
Title:
High-resolution spectrum of La and Ar
Short Name:
J/ApJS/208/18
Date:
21 Oct 2021
Publisher:
CDS
Description:
A high-resolution spectrum of lanthanum has been recorded by a Fourier Transform spectrometer in the wavelength range from 833nm to 1666nm (6000/cm to 12000/cm) using as light source a hollow cathode lamp operated with argon as the discharge carrier gas. In total, 2386 spectral lines were detected in this region, of which 555 lines could be classified as La I transitions and 10 lines as La II transitions. All La II transitions and 534 of these La I transitions were classified for the first time, and 6 of the La II transitions and 433 of the classified La I transitions appear to be new lines, which could not be found in the literature. The corresponding energy level data of classified lines are given. Additionally, 430 lines are assigned as Ar I lines and 394 as Ar II lines, of which 179 and 77, respectively, were classified for the first time. All 77 classified Ar II transitions as well as 159 of the classified Ar I transitions are new lines. Furthermore, the wavenumbers of 997 unclassified spectral lines were determined, 235 of which could be assigned as La lines, because of their hyperfine pattern. The remaining 762 lines may be either unclassified Ar lines or unresolved and unclassified La lines with only one symmetrical peak with an FWHM in the same order of magnitude as the Ar lines. The accuracy of the wavenumber for the classified lines with signal-to-noise-ratio higher than four is better than 0.006/cm which corresponds to an accuracy of 0.0004nm at 830nm and 0.0017nm at 1660nm, respectively.

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