Multi-wavelength Observations of AT2019wey: a New Candidate Black Hole Low-mass X-ray Binary
| Autor: | Jesper Sollerman, Stephen Kaye, Jan van Roestel, Frank J. Masci, Reed Riddle, S. R. Kulkarni, Dillon Dong, Maayane T. Soumagnac, Matthew J. Graham, Dmitry A. Duev, Mansi M. Kasliwal, S. Bradley Cenko, Andrew J. Drake, Kaushik De, N. Miranda, Thomas A. Prince, Kevin B. Burdge, Ben Rusholme, Thomas Kupfer, Ashot Bagdasaryan, Ilaria Caiazzo, Christoffer Fremling, Yuhan Yao, Eric C. Bellm |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
High Energy Astrophysical Phenomena (astro-ph.HE)
Physics education.field_of_study 010308 nuclear & particles physics media_common.quotation_subject Population X-ray binary FOS: Physical sciences Astronomy and Astrophysics Astrophysics medicine.disease_cause 01 natural sciences Accretion (astrophysics) Luminosity Black hole Space and Planetary Science Sky 0103 physical sciences medicine education Low Mass Astrophysics - High Energy Astrophysical Phenomena 010303 astronomy & astrophysics Ultraviolet media_common |
| Popis: | AT2019wey (SRGA J043520.9+552226, SRGE J043523.3+552234) is a transient first reported by the ATLAS optical survey in 2019 December. It rose to prominence upon detection, three months later, by the Spektrum-Roentgen-Gamma (SRG) mission in its first all-sky survey. X-ray observations reported in Yao et al. suggest that AT2019wey is a Galactic low-mass X-ray binary (LMXB) with a black hole (BH) or neutron star (NS) accretor. Here we present ultraviolet, optical, near-infrared, and radio observations of this object. We show that the companion is a short-period (P < 16 hr) low-mass (< 1 Msun) star. We consider AT2019wey to be a candidate BH system since its locations on the L_radio--L_X and L_opt--L_X diagrams are closer to BH binaries than NS binaries. We demonstrate that from 2020 June to August, despite the more than 10 times brightening at radio and X-ray wavelengths, the optical luminosity of AT2019wey only increased by 1.3--1.4 times. We interpret the UV/optical emission before the brightening as thermal emission from a truncated disk in a hot accretion flow and the UV/optical emission after the brightening as reprocessing of the X-ray emission in the outer accretion disk. AT2019wey demonstrates that combining current wide-field optical surveys and SRG provides a way to discover the emerging population of short-period BH LMXB systems with faint X-ray outbursts. Accepted by ApJ |
| Databáze: | OpenAIRE |
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