Spectroscopic and photometric periods of six ultracompact accreting binaries
| Autor: | Danny Steeghs, Madelon C. P. Bours, A. F. Pala, D. I. Sahman, Philip J. Carter, S. P. Littlefair, Sabrina Outmani, Boris T. Gänsicke, P. Kerry, Nicola P Gentile Fusillo, Elmé Breedt, Chuangwit Pattama, Boonchoo Sukaum, Tom Marsh, Tim Cunningham, Martin J. Dyer, Jim M. Wild, Paula Izquierdo, Richard Ashley, Steven G. Parsons, M. J. Green, V. S. Dhillon |
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| Jazyk: | angličtina |
| Předmět: |
Astrophysics::High Energy Astrophysical Phenomena
Binary number Cataclysmic variable star FOS: Physical sciences Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics 01 natural sciences Photometry (optics) 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics Spectroscopy 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) Astrophysics::Galaxy Astrophysics Physics High Energy Astrophysical Phenomena (astro-ph.HE) Infrared excess 010308 nuclear & particles physics White dwarf Astronomy and Astrophysics Mass ratio Orbital period Astrophysics - Solar and Stellar Astrophysics 13. Climate action Space and Planetary Science Astrophysics::Earth and Planetary Astrophysics Astrophysics - High Energy Astrophysical Phenomena |
| Zdroj: | arXiv |
| Popis: | Ultracompact accreting binary systems each consist of a stellar remnant accreting helium-enriched material from a compact donor star. Such binaries include two related sub-classes, AM CVn-type binaries and helium cataclysmic variables, in both of which the central star is a white dwarf. We present a spectroscopic and photometric study of six accreting binaries with orbital periods in the range of 40--70 min, including phase-resolved VLT spectroscopy and high-speed ULTRACAM photometry. Four of these are AM CVn systems and two are helium cataclysmic variables. For four of these binaries we are able to identify orbital periods (of which three are spectroscopic). SDSS J1505+0659 has an orbital period of 67.8 min, significantly longer than previously believed, and longer than any other known AM CVn binary. We identify a WISE infrared excess in SDSS J1505+0659 that we believe to be the first direct detection of an AM CVn donor star in a non-direct impacting binary. The mass ratio of SDSS J1505+0659 is consistent with a white dwarf donor. CRTS J1028-0819 has an orbital period of 52.1 min, the shortest period of any helium cataclysmic variable. MOA 2010-BLG-087 is co-aligned with a K-class star that dominates its spectrum. ASASSN-14ei and ASASSN-14mv both show a remarkable number of echo outbursts following superoutbursts (13 and 10 echo outbursts respectively). ASASSN-14ei shows an increased outburst rate over the years following its superoutburst, perhaps resulting from an increased accretion rate. Comment: 22 pages, 21 figures. Accepted for publication by MNRAS |
| Databáze: | OpenAIRE |
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