A machine learning approach for identification and classification of symbiotic stars using 2MASS and WISE

Akras, S.; Leal-Ferreira, M. L.; Guzmán-Ramírez, L.; Ramos-Larios, G.

doi:10.1093/mnras/sty3359

Cited by 50 publications

(64 citation statements)

References 83 publications

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“…S-type symbiotic stars (Akras et al 2019;Corradi et al 2008). The properties of these systems, which we identify as symbiotic systems in Draco dSph are discussed in the following.…”

Section: Symbiotic Stars In the Draco Dsphmentioning

confidence: 99%

Classification of low-luminosity stellar X-ray sources in the field of the Draco dwarf spheroidal galaxy

Saeedi

Sasaki

Stelzer

et al. 2019

A&A

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Aims.A previous study of the X-ray luminosity function of the X-ray sources in the field of the Draco dwarf spheroidal (dSph) galaxy indicated the presence of a population of unknown X-ray sources in the soft energy range of 0.5-2 keV. In 2015, Draco dSph was observed again in twenty-six deep XMM-Newton observations providing an opportunity for a new study of the yet unclassified sources. Methods. We apply the classification criteria presented in our previous multi-wavelength study of the X-ray sources of the Draco dSph to the sources detected in the combined 2009 and 2015 XMM-Newton data set. These criteria are based on X-ray studies and properties of the optical, near-infrared, and mid-infrared counterparts and allows us to distinguish background active galactic nuclei (AGNs) and galaxies from other types of X-ray sources. In this work we perform X-ray spectral and timing analyses for fifteen sources in the field of Draco dSph with stellar counterparts. Results. We present the classification of X-ray sources, for which the counterpart is identified as a stellar object based on our criteria from multi-wavelength data. We identify three new symbiotic stars in the Draco dSph with X-ray luminosities between ∼3.5×10 34 erg s −1 and 5.5×10 34 erg s −1 . The X-ray spectral analysis shows that two of the classified symbiotic stars are β-type. This is the first identification of this class of symbiotic stars in a nearby galaxy. Eight sources are classified as Galactic M dwarfs in the field of the Draco dSph. The distances of these M dwarfs are between∼140-800 pc, their X-ray luminosities are between 10 28 − 10 29 erg s −1 and the logarithmic ratio of X-ray to bolometric luminosity, log( L X L bol ), is between −3.4 to −2.1. The multiple observations allowed us to investigate flare activity of the M dwarfs. For 5 M dwarfs flare(s) are observed with a significance of >3σ level of confidence. Moreover, we classified three foreground sources, located at distances of the order of ∼1-3 kpc in the field of the Draco dSph. Based on both the X-ray luminosities of these foreground sources (>10 30 erg s −1 ) and their optical counterparts (late type G or K stars), these X-ray sources were classified as candidates of contact binary systems. Conclusions. Our study of X-ray sources of the Draco dSph shows that accreting white dwarfs are the most promising X-ray population of dSphs, which is in line with theoretical expectations. The number of Galactic M dwarfs detected at our X-ray sensitivity limit is consistent with the expectation based on the space density of M dwarfs.

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“…S-type symbiotic stars (Akras et al 2019;Corradi et al 2008). The properties of these systems, which we identify as symbiotic systems in Draco dSph are discussed in the following.…”

Section: Symbiotic Stars In the Draco Dsphmentioning

confidence: 99%

Classification of low-luminosity stellar X-ray sources in the field of the Draco dwarf spheroidal galaxy

Saeedi

Sasaki

Stelzer

et al. 2019

A&A

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“…Following Mukai et al (), as the SySts without shell burning do not have prominent emission lines, all SySt catalogues could preferentially consist of the shell‐burning systems because most surveys are still based on spectroscopic methods. Just recently, new approaches and techniques are explored in order to identify new systems (e.g., machine‐learning algorithms; Akras et al ).…”

Section: X‐ray Emission Of Symbiotic Variable Starsmentioning

confidence: 99%

New online database of symbiotic variables: Symbiotics in X‐rays

2019

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Symbiotic variable stars belong to an interesting class of interacting binary systems.Since the beginning of this century, the systematic search for these objects has begun, and such surveys have led to discoveries of many new objects and dozens of candidates in the Milky Way and the Local Group. As the latest catalogue of symbiotic binaries is almost two decades old, we decided to prepare a new, online database of the galactic and extragalactic symbiotic systems. These objects are also known for their X-ray emission. For the purpose of this work, we have prepared a census of symbiotic binaries and their properties based on observations obtained by X-ray satellites in the previous decades. As our review has shown, the X-ray emission seems to be a common feature of symbiotic systems, preferentially detected from nearby sources.

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“…-see, e.g., Figs. 1 & 2 in Corradi et al 2008;Akras et al 2019b), no photometric diagnostic tool has so far demonstrated the power to unambiguously identify a SySt, thus making the recourse to costly spectroscopic follow-up still inescapable.…”

Section: Introductionmentioning

confidence: 99%

RAMSES II: RAMan Search for Extragalactic Symbiotic Stars Project Concept, Commissioning, and Early Results from the Science Verification Phase

Angeloni

Gonçalves

Akras

et al. 2019

Self Cite

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Symbiotic stars (SySts) are long-period interacting binaries composed of a hot compact star, an evolved giant star, and a tangled network of gas and dust nebulae. They represent unique laboratories for studying a variety of important astrophysical problems, and have also been proposed as possible progenitors of SNIa. Presently, we know 257 SySts in the Milky Way and 69 in external galaxies. However, these numbers are still in striking contrast with the predicted population of SySts in our Galaxy. Because of other astrophysical sources that mimic SySt colors, no photometric diagnostic tool has so far demonstrated the power to unambiguously identify a SySt, thus making the recourse to costly spectroscopic follow-up still inescapable. In this paper we present the concept, commissioning, and science verification phases, as well as the first scientific results, of RAMSES II -a Gemini Observatory Instrument Upgrade Project that has provided each GMOS instrument at both Gemini telescopes with a set of narrow-band filters centered on the Raman OVI 6830Å band. Continuum-subtracted images using these new filters clearly revealed known SySts with a range of Raman OVI line strengths, even in crowded fields. RAMSES II observations also produced the first detection of Raman OVI emission from the SySt LMC 1 and confirmed Hen 3-1768 as a new SySt -the first photometric confirmation of a SySt. Via Raman OVI narrow-band imaging, RAMSES II provides the astronomical community with the first purely photometric tool for hunting SySts in the local Universe.

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A machine learning approach for identification and classification of symbiotic stars using 2MASS and WISE

Cited by 50 publications

References 83 publications

Classification of low-luminosity stellar X-ray sources in the field of the Draco dwarf spheroidal galaxy

Classification of low-luminosity stellar X-ray sources in the field of the Draco dwarf spheroidal galaxy

New online database of symbiotic variables: Symbiotics in X‐rays

RAMSES II: RAMan Search for Extragalactic Symbiotic Stars Project Concept, Commissioning, and Early Results from the Science Verification Phase

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