Symbiotic stars in X-rays

Until recently, symbiotic binary systems in which a white dwarf accretes from a red giant were thought to be mainly a soft X-ray population. Here we describe the detection with the X-ray Telescope (XRT) on the Swift satellite of nine white dwarf symbiotics that were not previously known to be X-ray...

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Detalles Bibliográficos
Publicado:	2013
Materias:	Accretion, accretion disks Binaries: symbiotic X-rays: binaries Accretion , accretion disks Brightness variations Classification scheme Hard x-ray emission Physical interpretation Spectral components X-rays: Binaries Accretion Accretion disks Electromagnetic wave emission Electron sources Flickering Stars Telescopes X ray analysis X ray apparatus X ray optics X ray scattering X ray spectrographs Bins Boundary layers Giant stars Mass transfer Stochastic systems Supernovae X rays White dwarfs
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00046361_v559_n_p_Luna http://hdl.handle.net/20.500.12110/paper_00046361_v559_n_p_Luna
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_00046361_v559_n_p_Luna
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spelling	paper:paper_00046361_v559_n_p_Luna2023-06-08T14:28:05Z Symbiotic stars in X-rays Accretion, accretion disks Binaries: symbiotic X-rays: binaries Accretion , accretion disks Binaries: symbiotic Brightness variations Classification scheme Hard x-ray emission Physical interpretation Spectral components X-rays: Binaries Accretion Accretion disks Binaries: symbiotic Brightness variations Classification scheme Physical interpretation Spectral components X-rays: Binaries Electromagnetic wave emission Electron sources Flickering Stars Telescopes X ray analysis X ray apparatus X ray optics X ray scattering X ray spectrographs Bins Boundary layers Electromagnetic wave emission Electron sources Flickering Giant stars Mass transfer Stars Stochastic systems Supernovae Telescopes X ray analysis X ray apparatus X ray optics X ray scattering X ray spectrographs X rays White dwarfs Until recently, symbiotic binary systems in which a white dwarf accretes from a red giant were thought to be mainly a soft X-ray population. Here we describe the detection with the X-ray Telescope (XRT) on the Swift satellite of nine white dwarf symbiotics that were not previously known to be X-ray sources and one that had previously been detected as a supersoft X-ray source. The nine new X-ray detections were the result of a survey of 41 symbiotic stars, and they increase the number of symbiotic stars known to be X-ray sources by approximately 30%. The Swift/XRT telescope detected all of the new X-ray sources at energies greater than 2 keV. Their X-ray spectra are consistent with thermal emission and fall naturally into three distinct groups. The first group contains those sources with a single, highly absorbed hard component that we identify as probably coming from an accretion-disk boundary layer. The second group is composed of those sources with a single, soft X-ray spectral component that probably originates in a region where low-velocity shocks produce X-ray emission, i.e., a colliding-wind region. The third group consists of those sources with both hard and soft X-ray spectral components. We also find that unlike in the optical, where rapid, stochastic brightness variations from the accretion disk typically are not seen, detectable UV flickering is a common property of symbiotic stars. Supporting our physical interpretation of the two X-ray spectral components, simultaneous Swift UV photometry shows that symbiotic stars with harder X-ray emission tend to have stronger UV flickering, which is usually associated with accretion through a disk. To place these new observations in the context of previous work on X-ray emission from symbiotic stars, we modified and extended the α/β/γ classification scheme for symbiotic-star X-ray spectra that was introduced by Muerset et al. based upon observations with the ROSAT satellite, to include a new δ classification for sources with hard X-ray emission from the innermost accretion region. Because we have identified the elusive accretion component in the emission from a sample of symbiotic stars, our results have implications for the understanding of wind-fed mass transfer in wide binaries, and the accretion rate in one class of candidate progenitors of type Ia supernovae. © 2013 ESO. 2013 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00046361_v559_n_p_Luna http://hdl.handle.net/20.500.12110/paper_00046361_v559_n_p_Luna
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Accretion, accretion disks Binaries: symbiotic X-rays: binaries Accretion , accretion disks Binaries: symbiotic Brightness variations Classification scheme Hard x-ray emission Physical interpretation Spectral components X-rays: Binaries Accretion Accretion disks Binaries: symbiotic Brightness variations Classification scheme Physical interpretation Spectral components X-rays: Binaries Electromagnetic wave emission Electron sources Flickering Stars Telescopes X ray analysis X ray apparatus X ray optics X ray scattering X ray spectrographs Bins Boundary layers Electromagnetic wave emission Electron sources Flickering Giant stars Mass transfer Stars Stochastic systems Supernovae Telescopes X ray analysis X ray apparatus X ray optics X ray scattering X ray spectrographs X rays White dwarfs
spellingShingle	Accretion, accretion disks Binaries: symbiotic X-rays: binaries Accretion , accretion disks Binaries: symbiotic Brightness variations Classification scheme Hard x-ray emission Physical interpretation Spectral components X-rays: Binaries Accretion Accretion disks Binaries: symbiotic Brightness variations Classification scheme Physical interpretation Spectral components X-rays: Binaries Electromagnetic wave emission Electron sources Flickering Stars Telescopes X ray analysis X ray apparatus X ray optics X ray scattering X ray spectrographs Bins Boundary layers Electromagnetic wave emission Electron sources Flickering Giant stars Mass transfer Stars Stochastic systems Supernovae Telescopes X ray analysis X ray apparatus X ray optics X ray scattering X ray spectrographs X rays White dwarfs Symbiotic stars in X-rays
topic_facet	Accretion, accretion disks Binaries: symbiotic X-rays: binaries Accretion , accretion disks Binaries: symbiotic Brightness variations Classification scheme Hard x-ray emission Physical interpretation Spectral components X-rays: Binaries Accretion Accretion disks Binaries: symbiotic Brightness variations Classification scheme Physical interpretation Spectral components X-rays: Binaries Electromagnetic wave emission Electron sources Flickering Stars Telescopes X ray analysis X ray apparatus X ray optics X ray scattering X ray spectrographs Bins Boundary layers Electromagnetic wave emission Electron sources Flickering Giant stars Mass transfer Stars Stochastic systems Supernovae Telescopes X ray analysis X ray apparatus X ray optics X ray scattering X ray spectrographs X rays White dwarfs
description	Until recently, symbiotic binary systems in which a white dwarf accretes from a red giant were thought to be mainly a soft X-ray population. Here we describe the detection with the X-ray Telescope (XRT) on the Swift satellite of nine white dwarf symbiotics that were not previously known to be X-ray sources and one that had previously been detected as a supersoft X-ray source. The nine new X-ray detections were the result of a survey of 41 symbiotic stars, and they increase the number of symbiotic stars known to be X-ray sources by approximately 30%. The Swift/XRT telescope detected all of the new X-ray sources at energies greater than 2 keV. Their X-ray spectra are consistent with thermal emission and fall naturally into three distinct groups. The first group contains those sources with a single, highly absorbed hard component that we identify as probably coming from an accretion-disk boundary layer. The second group is composed of those sources with a single, soft X-ray spectral component that probably originates in a region where low-velocity shocks produce X-ray emission, i.e., a colliding-wind region. The third group consists of those sources with both hard and soft X-ray spectral components. We also find that unlike in the optical, where rapid, stochastic brightness variations from the accretion disk typically are not seen, detectable UV flickering is a common property of symbiotic stars. Supporting our physical interpretation of the two X-ray spectral components, simultaneous Swift UV photometry shows that symbiotic stars with harder X-ray emission tend to have stronger UV flickering, which is usually associated with accretion through a disk. To place these new observations in the context of previous work on X-ray emission from symbiotic stars, we modified and extended the α/β/γ classification scheme for symbiotic-star X-ray spectra that was introduced by Muerset et al. based upon observations with the ROSAT satellite, to include a new δ classification for sources with hard X-ray emission from the innermost accretion region. Because we have identified the elusive accretion component in the emission from a sample of symbiotic stars, our results have implications for the understanding of wind-fed mass transfer in wide binaries, and the accretion rate in one class of candidate progenitors of type Ia supernovae. © 2013 ESO.
title	Symbiotic stars in X-rays
title_short	Symbiotic stars in X-rays
title_full	Symbiotic stars in X-rays
title_fullStr	Symbiotic stars in X-rays
title_full_unstemmed	Symbiotic stars in X-rays
title_sort	symbiotic stars in x-rays
publishDate	2013
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00046361_v559_n_p_Luna http://hdl.handle.net/20.500.12110/paper_00046361_v559_n_p_Luna
_version_	1768545030726746112

Symbiotic stars in X-rays

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