A 500 pc volume-limited sample of hot subluminous stars: I. Space density, scale height, and population properties

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F24%3A00587668" target="_blank" >RIV/67985815:_____/24:00587668 - isvavai.cz</a>

Výsledek na webu

<a href="https://hdl.handle.net/11104/0354880" target="_blank" >https://hdl.handle.net/11104/0354880</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/202348319" target="_blank" >10.1051/0004-6361/202348319</a>

Jazyk výsledku

angličtina

Název v původním jazyce

A 500 pc volume-limited sample of hot subluminous stars: I. Space density, scale height, and population properties

Popis výsledku v původním jazyce

We present the first volume-limited sample of spectroscopically confirmed hot subluminous stars out to 500 pc, defined using the accurate parallax measurements from the Gaia space mission data release 3 (DR3). The sample comprises a total of 397 members, with 305 (similar to 77%) identified as hot subdwarf stars, including 83 newly discovered systems. Of these, we observe that 178 (similar to 58%) are hydrogen-rich sdBs, 65 are sdOBs (similar to 21%), 32 are sdOs (similar to 11%), and 30 are He-sdO/Bs (similar to 10%). Among them, 48 (similar to 16%) exhibit an infrared excess in their spectral energy distribution fits, suggesting a composite binary system. The hot subdwarf population is estimated to be 90% complete, assuming that most missing systems are these composite binaries located within the main sequence (MS) in the Gaia colour-magnitude diagram. The remaining sources in the sample include cataclysmic variables, blue horizontal branch stars, hot white dwarfs, and MS stars. We derived the mid-plane density rho(0) and scale height h(z) for the non-composite hot subdwarf star population using a hyperbolic sechant profile (sech(2)). The best-fit values are rho(0) = 5.17 +/- 0.33 x 10(-7) stars pc(-3) and h(z) = 281 +/- 62 pc. When accounting for the composite-colour hot subdwarfs and their estimated completeness, the mid-plane density increases to rho(0) = 6.15(-0.53)(+1.16) x 10(-7) stars pc(-3). This corrected space density is an order of magnitude lower than predicted by population synthesis studies, supporting previous observational estimates.

Název v anglickém jazyce

A 500 pc volume-limited sample of hot subluminous stars: I. Space density, scale height, and population properties

Popis výsledku anglicky

We present the first volume-limited sample of spectroscopically confirmed hot subluminous stars out to 500 pc, defined using the accurate parallax measurements from the Gaia space mission data release 3 (DR3). The sample comprises a total of 397 members, with 305 (similar to 77%) identified as hot subdwarf stars, including 83 newly discovered systems. Of these, we observe that 178 (similar to 58%) are hydrogen-rich sdBs, 65 are sdOBs (similar to 21%), 32 are sdOs (similar to 11%), and 30 are He-sdO/Bs (similar to 10%). Among them, 48 (similar to 16%) exhibit an infrared excess in their spectral energy distribution fits, suggesting a composite binary system. The hot subdwarf population is estimated to be 90% complete, assuming that most missing systems are these composite binaries located within the main sequence (MS) in the Gaia colour-magnitude diagram. The remaining sources in the sample include cataclysmic variables, blue horizontal branch stars, hot white dwarfs, and MS stars. We derived the mid-plane density rho(0) and scale height h(z) for the non-composite hot subdwarf star population using a hyperbolic sechant profile (sech(2)). The best-fit values are rho(0) = 5.17 +/- 0.33 x 10(-7) stars pc(-3) and h(z) = 281 +/- 62 pc. When accounting for the composite-colour hot subdwarfs and their estimated completeness, the mid-plane density increases to rho(0) = 6.15(-0.53)(+1.16) x 10(-7) stars pc(-3). This corrected space density is an order of magnitude lower than predicted by population synthesis studies, supporting previous observational estimates.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

<a href="/cs/project/GA22-34467S" target="_blank" >GA22-34467S: Interakce dvojhvězd na větvi červených obrů: horcí podtrpaslíci jako testovací případ.</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2024

Kód důvěrnosti údajů

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

Název periodika

Astronomy & Astrophysics

ISSN

0004-6361

e-ISSN

1432-0746

Svazek periodika

686

Číslo periodika v rámci svazku

June

Stát vydavatele periodika

FR - Francouzská republika

Počet stran výsledku

21

Strana od-do

A25

Kód UT WoS článku

001231909000010

EID výsledku v databázi Scopus

2-s2.0-85190330949