Detailed Information on Publication Record
2019
Hot subdwarf wind models with accurate abundances I. Hydrogen dominated stars HD 49798 and BD+18 degrees 2647
KRTIČKA, Jiří, Jan JANÍK, Iva KRTIČKOVÁ, S. MEREGHETTI, F. PINTORE et. al.Basic information
Original name
Hot subdwarf wind models with accurate abundances I. Hydrogen dominated stars HD 49798 and BD+18 degrees 2647
Authors
KRTIČKA, Jiří (203 Czech Republic, guarantor, belonging to the institution), Jan JANÍK (203 Czech Republic, belonging to the institution), Iva KRTIČKOVÁ (203 Czech Republic, belonging to the institution), S. MEREGHETTI (380 Italy), F. PINTORE (380 Italy), P. NEMETH (348 Hungary), Jiří KUBÁT (203 Czech Republic) and M. VUCKOVIC (191 Croatia)
Edition
ASTRONOMY & ASTROPHYSICS, LES ULIS CEDEX A, EDP SCIENCES S A, 2019, 0004-6361
Other information
Language
English
Type of outcome
Článek v odborném periodiku
Field of Study
10308 Astronomy
Country of publisher
France
Confidentiality degree
není předmětem státního či obchodního tajemství
References:
Impact factor
Impact factor: 5.636
RIV identification code
RIV/00216224:14310/19:00108216
Organization unit
Faculty of Science
UT WoS
000515090700003
Keywords in English
stars: winds; outflows stars; mass-loss; stars: early-type; subdwarfs; X-rays: binaries
Tags
Tags
International impact, Reviewed
Změněno: 17/4/2020 14:30, Mgr. Marie Šípková, DiS.
Abstract
V originále
Context. Hot subdwarfs are helium burning objects in late stages of their evolution. These subluminous stars can develop winds driven by light absorption in the lines of heavier elements. The wind strength depends on chemical composition which can significantly vary from star to star. Aims. We aim to understand the influence of metallicity on the strength of the winds of the hot hydrogen-rich subdwarfs HD 49798 and BD+18 2647. Methods. We used high -resolution UV and optical spectra to derive stellar parameters and abundances using the TLUSTY and SYNSPEC codes. For derived stellar parameters, we predicted wind structure (including mass -loss rates and terminal velocities) with our METUJE code. Results. We derived effective temperature Teff = 45 900 K and mass M = 1.46 M for HD 49798 and Teff = 73 000 K and M = 0.38 M for BD+18 2647. The derived surface abundances can be interpreted as a result of interplay between stellar evolution and diffusion. The subdwarf HD 49798 has a strong wind that does not allow for chemical separation and consequently the star shows solar chemical composition modified by hydrogen burning. On the other hand, we did not find any wind in BD+18 2647 and its abundances are therefore most likely affected by radiative diffusion. Accurate abundances do not lead to a significant modification of wind mass -loss rate for HD 49798, because the increase of the contribution of iron and nickel to the radiative force is compensated by the decrease of the radiative force due to other elements. The resulting wind mass -loss rate M = 2.1 x 10-9 M. yr1 predicts an X-ray light curve during the eclipse which closely agrees with observations. On the other hand, the absence of the wind in BD+18 2647 for accurate abundances is a result of its peculiar chemical composition. Conclusions. Wind models with accurate abundances provide more reliable wind parameters, but the influence of abundances on the wind parameters is limited in many cases.
Links
| GA18-05665S, research and development project |
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