CGCS 6306, another X-ray-emitting asymptotic giant branch star confirmed to be a symbiotic binary

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F25%3A10511304" target="_blank" >RIV/00216208:11320/25:10511304 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=72DXvN526z" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=72DXvN526z</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/202554671" target="_blank" >10.1051/0004-6361/202554671</a>

Jazyk výsledku

angličtina

Název v původním jazyce

CGCS 6306, another X-ray-emitting asymptotic giant branch star confirmed to be a symbiotic binary

Popis výsledku v původním jazyce

Context. A number of asymptotic giant branch (AGB) stars are known to exhibit UV excess and/or X-ray emission. These have been considered signposts of a hot white dwarf (WD) companion in a symbiotic system (SySt), but AGB stars are so bright that they easily outshine these companions, thus hampering their detection at optical wavelengths. A recent multi-wavelength investigation on the X-ray-emitting AGB (X-AGB) star Y Gem has confirmed the presence of a WD companion and therefore its SySt nature. Aims. Our goal is to explore the true nature of another X-AGB star, namely CGCS 6306, to investigate whether some objects from this group may in fact be unnoticed SySts with AGB donors. Methods. We analyzed optical spectra and photometric data together with X-ray observations to investigate the properties of the stellar components and accretion process in CGCS 6306. Results. CGCS 6306 is a carbon Mira with a pulsation period of 362 days. Its optical spectrum exhibits the typical saw-shaped features of molecular absorptions in addition to H I and He I recombination and [O I] and [O III] forbidden emission lines. The H alpha line profile is broad, which can be interpreted as evidence for an accretion disk. The X-ray spectrum is hard, which is typical of highly extincted hot plasma emission, and the X-ray luminosity is approximate to 10(32) erg s(-1). Conclusions. The detection of high-excitation optical emission lines and the X-ray properties of CGCS 6306 confirm the presence of a WD companion, making it a bona fide delta-type X-SySt. Its X-ray luminosity is comparable to that of Y Gem, the other X-AGB star confirmed to be a SySt, which was found to exhibit a high accretion rate. The lack of suitable information on the UV and blue optical properties of CGCS 6306, however, precludes a definitive estimate of the accretion rate in this system. Since CGCS 6306 is a carbon Mira, our work adds it to the small group of Galactic carbon SySts.

Název v anglickém jazyce

CGCS 6306, another X-ray-emitting asymptotic giant branch star confirmed to be a symbiotic binary

Popis výsledku anglicky

Context. A number of asymptotic giant branch (AGB) stars are known to exhibit UV excess and/or X-ray emission. These have been considered signposts of a hot white dwarf (WD) companion in a symbiotic system (SySt), but AGB stars are so bright that they easily outshine these companions, thus hampering their detection at optical wavelengths. A recent multi-wavelength investigation on the X-ray-emitting AGB (X-AGB) star Y Gem has confirmed the presence of a WD companion and therefore its SySt nature. Aims. Our goal is to explore the true nature of another X-AGB star, namely CGCS 6306, to investigate whether some objects from this group may in fact be unnoticed SySts with AGB donors. Methods. We analyzed optical spectra and photometric data together with X-ray observations to investigate the properties of the stellar components and accretion process in CGCS 6306. Results. CGCS 6306 is a carbon Mira with a pulsation period of 362 days. Its optical spectrum exhibits the typical saw-shaped features of molecular absorptions in addition to H I and He I recombination and [O I] and [O III] forbidden emission lines. The H alpha line profile is broad, which can be interpreted as evidence for an accretion disk. The X-ray spectrum is hard, which is typical of highly extincted hot plasma emission, and the X-ray luminosity is approximate to 10(32) erg s(-1). Conclusions. The detection of high-excitation optical emission lines and the X-ray properties of CGCS 6306 confirm the presence of a WD companion, making it a bona fide delta-type X-SySt. Its X-ray luminosity is comparable to that of Y Gem, the other X-AGB star confirmed to be a SySt, which was found to exhibit a high accretion rate. The lack of suitable information on the UV and blue optical properties of CGCS 6306, however, precludes a definitive estimate of the accretion rate in this system. Since CGCS 6306 is a carbon Mira, our work adds it to the small group of Galactic carbon SySts.

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/GN24-10608O" target="_blank" >GN24-10608O: Výzkum populací symbiotických systémů a příbuzných dvojhvězd s červenými obry</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2025

Kód důvěrnosti údajů

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

Název periodika

Astronomy &amp; Astrophysics

ISSN

0004-6361

e-ISSN

1432-0746

Svazek periodika

699

Číslo periodika v rámci svazku

cervenec

Stát vydavatele periodika

FR - Francouzská republika

Počet stran výsledku

8

Strana od-do

A117

Kód UT WoS článku

001522098000013

EID výsledku v databázi Scopus

2-s2.0-105009902612