Hot Subdwarf Atmospheric Parameters, Kinematics, and Origins Based on 1587 Hot Subdwarf Stars Observed in Gaia DR2 and LAMOST DR7
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F21%3A00548302" target="_blank" >RIV/67985815:_____/21:00548302 - isvavai.cz</a>
Result on the web
<a href="https://doi.org/10.3847/1538-4365/ac11f6" target="_blank" >https://doi.org/10.3847/1538-4365/ac11f6</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.3847/1538-4365/ac11f6" target="_blank" >10.3847/1538-4365/ac11f6</a>
Alternative languages
Result language
angličtina
Original language name
Hot Subdwarf Atmospheric Parameters, Kinematics, and Origins Based on 1587 Hot Subdwarf Stars Observed in Gaia DR2 and LAMOST DR7
Original language description
Based on the Gaia DR2 catalog of hot subdwarf star candidates, we identified 1587 hot subdwarf stars with spectra in LAMOST DR7. We present atmospheric parameters for these stars by fitting the LAMOST spectra with Tlusty/Synspec non-LTE synthetic spectra. Combining LAMOST radial velocities and Gaia Early Data Release 3 (EDR3) parallaxes and proper motions, we also present the Galactic space positions, velocity vectors, orbital parameters and the Galactic population memberships of the stars. With our He classification scheme, we identify four groups of He rich hot subdwarf stars in the T (eff) - log g and T (eff) - log(nHe/nH) diagrams. We find two extreme He-rich groups (eHe-1 and eHe-2) for stars with log(nHe/nH) >= 0 and two intermediate He-rich groups (iHe-1 and iHe-2) for stars with -1 <= log(nHe/nH) < 0. We also find that over half of the stars in Group eHe-1 are thick-disk stars, while over half of the stars in Group eHe-2 correspond to thin-disk stars. The disk population fractions of Group iHe-1 are between those of Group eHe-1 and eHe-2. Almost all of the stars in Group iHe-2 belong to the thin disk. These differences indicate that the four groups probably have very different origins. Comparisons between hot subdwarf stars in the halo and in the Galactic globular cluster omega Cen show that only He-deficient stars with -2.2 <= log(nHe/nH) < -1 have similar fractions. Hot subdwarfs with log(nHe/nH) >= 0 in omega Cen have no counterparts in the thick-disk and halo populations, but they appear in the thin disk.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10308 - Astronomy (including astrophysics,space science)
Result continuities
Project
<a href="/en/project/GA18-20083S" target="_blank" >GA18-20083S: Gaia-GALEX survey of hot subdwarf stars</a><br>
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2021
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Astrophysical Journal. Supplement Series
ISSN
0067-0049
e-ISSN
1538-4365
Volume of the periodical
256
Issue of the periodical within the volume
2
Country of publishing house
US - UNITED STATES
Number of pages
22
Pages from-to
28
UT code for WoS article
000698466300001
EID of the result in the Scopus database
2-s2.0-85116542388