Looking into the cradle of the grave: J22564-5910, a potential young post-merger hot subdwarf

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F21%3A00552680" target="_blank" >RIV/67985815:_____/21:00552680 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1051/0004-6361/202140391" target="_blank" >https://doi.org/10.1051/0004-6361/202140391</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/202140391" target="_blank" >10.1051/0004-6361/202140391</a>

Result language

angličtina

Original language name

Looking into the cradle of the grave: J22564-5910, a potential young post-merger hot subdwarf

Original language description

Using high-resolution, high signal-to-noise spectroscopy, combined with multi-band photometry, Gaia astrometry, and TESS light curves, we aim to interpret these unusual spectral features. The photometry, spectra, and light curves were all analysed, and their results were combined in order to support our interpretation of the observations: the likely presence of a magnetic field combined with gas features around the sdB. Based on the triple-peaked H lines, the magnetic field strength was estimated and, by using the SHELLSPEC code, qualitative models of gas configurations were fitted to the observations. All observations can either be explained by a magnetic field of similar to 650 kG, which enables the formation of a centrifugal magnetosphere, or a non-magnetic hot subdwarf surrounded by a circumstellar gas disc or torus. Both scenarios are not mutually exclusive and both can be explained by a recent merger. Conclusions. J22564-5910 is the first object of its kind. It is a rapidly spinning sdB with gas still present in the system. It is the first post-merger star observed this early after the merger event, and as such it is very valuable system to test merger theories. If the magnetic field can be confirmed, it is not only the first magnetic sdB, but it hosts the strongest magnetic field ever found in a pre-white dwarf object. Thus, it could represent the long sought-after immediate ancestor of strongly magnetic white dwarfs.

Czech name

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Czech description

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Type

J_imp - 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)

Project

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Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2021

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Astronomy & Astrophysics

ISSN

0004-6361

e-ISSN

1432-0746

Volume of the periodical

655

Issue of the periodical within the volume

November

Country of publishing house

FR - FRANCE

Number of pages

15

Pages from-to

A43

UT code for WoS article

000717212300001

EID of the result in the Scopus database

2-s2.0-85119498257