Details

Autor(en) / Beteiligte

• Russell, T D
• Del Santo, M
• Marino, A
• Segreto, A
• Motta, S E
• Bahramian, A
• Corbel, S
• D’Aì, A
• Salvo, T Di
• Miller-Jones, J C A
• Pinto, C
• Pintore, F
• Tzioumis, A

Titel

Investigating the nature and properties of MAXI J1810−222 with radio and X-ray observations

Ist Teil von

• Monthly notices of the Royal Astronomical Society, 2022-06, Vol.513 (4), p.6196-6209

Ort / Verlag

Oxford University Press

Erscheinungsjahr

2022

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• ABSTRACT We present results from radio and X-ray observations of the X-ray transient MAXI J1810−222. The nature of the accretor in this source has not been identified. In this paper, we show results from a quasi-simultaneous radio and X-ray monitoring campaign taken with the Australia Telescope Compact Array, the Neil Gehrels Swift Observatory X-ray Telescope (XRT), and the Swift Burst Alert Telescope. We also analyse the X-ray temporal behaviour using observations from the Neutron star Interior Composition Explorer. Results show a seemingly peculiar X-ray spectral evolution of MAXI J1810−222 during this outburst, where the source was initially only detected in the soft X-ray band for the early part of the outburst. Then, ∼200 d after MAXI J1810−222 was first detected the hard X-ray emission increased and the source transitioned to a long-lived (∼1.5 yr) bright, harder X-ray state. After this hard state, MAXI J1810−222 returned back to a softer state, before fading and transitioning again to a harder state and then appearing to follow a more typical outburst decay. From the X-ray spectral and timing properties, and the source’s radio behaviour, we argue that the results from this study are most consistent with MAXI J1810−222 being a relatively distant (≳6 kpc) black hole X-ray binary. A sufficiently large distance to source can simply explain the seemingly odd outburst evolution that was observed, where only the brightest portion of the outburst was detectable by the all-sky XRTs.