- 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.
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Search Results
- 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.
- 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)
- 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.
- ID:
- ivo://CDS.VizieR/J/ApJ/655/L33
- Title:
- High-resolution spectrum of OGLE-2006-BLG-265
- Short Name:
- J/ApJ/655/L33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an R=45000 Keck spectrum of the microlensed Galactic bulge G dwarf OGLE-2006-BLG-265, which has high (~60) signal-to-noise ratio despite its short (15 minute) exposure time, because the source was magnified by A~135. While it is very metal-rich ([Fe/H]=0.56), the higher temperature of this star compared with the luminous red giants usually measured in the bulge gives its spectrum many unblended atomic lines. We measure the abundances of 17 elements, including the first abundances for S and Cu in a bulge star. The [alpha/Fe] ratios are subsolar, while the odd-Z elements are slightly supersolar, trends that are also seen in the more metal-rich stars in the bulge and the local Galactic disk. Because the star is a dwarf, the [O/Fe], [Na/Fe], and [Al/Fe] ratios cannot be attributed to internal mixing, as is sometimes claimed for giants. Similar high-resolution spectra could be obtained for about a dozen bulge dwarf stars per year by means of well-designed target-of-opportunity observations.
- ID:
- ivo://CDS.VizieR/VI/120
- Title:
- High-resolution synthetic stellar library
- Short Name:
- VI/120
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Libraries of stellar spectra are fundamental tools for the study of stellar populations and both empirical and synthetic libraries have been used for this purpose. In this paper, a new library of high resolution synthetic spectra is presented, ranging from the near-ultraviolet (300nm) to the near-infrared (1.8{mu}m). The library spans all the stellar types that are relevant to the integrated light of old and intermediate-age stellar populations in the involved spectral region (spectral types F through M and all luminosity classes). The grid was computed for metallicities ranging from [Fe/H]=-2.5 to +0.5, including both solar and {alpha}-enhanced ([{alpha}/Fe]=0.4) chemical compositions. The synthetic spectra are a good match to observations of stars throughout the stellar parameter space encompassed by the library and over the whole spectral region covered by the computations.
- ID:
- ivo://CDS.VizieR/J/ApJ/848/18
- Title:
- High-res. spectroscopic obs. of 2 Herbig stars
- Short Name:
- J/ApJ/848/18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent observational work has indicated that mechanisms for accretion and outflow in Herbig Ae/Be star-disk systems may differ from magnetospheric accretion (MA) as it is thought to occur in T Tauri star-disk systems. In this work, we assess the temporal evolution of spectral lines probing accretion and mass loss in Herbig Ae/Be systems and test for consistency with the MA paradigm. For two Herbig Ae/Be stars, HD 98922 (B9e) and V1295 Aql (A2e), we have gathered multi-epoch (~years) and high-cadence (~minutes) high-resolution optical spectra to probe a wide range of kinematic processes. Employing a line equivalent width evolution correlation metric introduced here, we identify species co-evolving (indicative of common line origin) via novel visualization. We interferometrically constrain often problematically degenerate parameters, inclination and inner-disk radius, allowing us to focus on the structure of the wind, magnetosphere, and inner gaseous disk in radiative transfer models. Over all timescales sampled, the strongest variability occurs within the blueshifted absorption components of the Balmer series lines; the strength of variability increases with the cadence of the observations. Finally, high-resolution spectra allow us to probe substructure within the Balmer series' blueshifted absorption components: we observe static, low-velocity features and time-evolving features at higher velocities. Overall, we find the observed line morphologies and variability are inconsistent with a scaled-up T Tauri MA scenario. We suggest that as magnetic field structure and strength change dramatically with increasing stellar mass from T Tauri to Herbig Ae/Be stars, so too may accretion and outflow processes.
- ID:
- ivo://CDS.VizieR/J/ApJ/877/104
- Title:
- High-res. spectroscopy of LAMOST Li-rich giants
- Short Name:
- J/ApJ/877/104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The discovery of Li-rich giants has introduced a new challenge for standard stellar evolution models. To resolve this issue, the number of this type of object has been rapidly increased through the development of worldwide surveys. Taking advantage of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope survey, 44 new Li-rich giants are reported, which are confirmed with high-resolution observations. Based on the high-resolution and high signal-to-noise spectra, we derived the atmospheric parameters and elemental abundances with the spectral synthesis method. We performed a detailed analysis of their evolutionary stages, infrared excess, projected rotational velocity (vsini), and stellar population. We find that (1) the Li-rich giants concentrate at the evolutionary status of the red giant branch bump, red clump, and asymptotic giant branch; (2) three of them are fast rotators and none exhibit infrared excess. Our results imply that the origins of Li enrichment are most likely to be associated with the extra mixing in the stellar interior, and the external sources might only make a minor contribution. Moreover, various Li-rich episodes take place at different evolutionary stages.
- ID:
- ivo://CDS.VizieR/J/ApJ/727/73
- Title:
- High S/N composite spectrum of GRB afterglows
- Short Name:
- J/ApJ/727/73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a composite spectrum of 60 long duration gamma-ray burst (GRB) afterglows with redshifts in the range 0.35<z<6.7 observed with low-resolution optical spectra. The composite spectrum covers the wavelength range 700-6600{AA} in the rest frame and has a mean signal-to-noise ratio of 150 per 1{AA} pixel and reaches a maximum of ~300 in the range 2500-3500{AA}. Equivalent widths are measured from metal absorption lines from the Ly{alpha} line to ~5200{AA}, and associated metal and hydrogen lines are identified between the Lyman break and Ly{alpha} line. The average transmission within the Lyman forest is consistent with that found along quasar lines of sight.
- ID:
- ivo://CDS.VizieR/J/AJ/103/514
- Title:
- High-velocity stars toward South Galactic Cap
- Short Name:
- J/AJ/103/514
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present spectroscopic observations of stars identified in Murray's (1986) astrometric survey of the South Galactic Cap
