| 20th of January 2021 |
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| ASKAP observations of a new X-Ray Binary |
| by Chauhan et al. |
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On 2019 January 26, MAXI (the Monitor of All-sky X-ray Image)
discovered an uncatalogued X-ray Binary system, now known as MAXI
J1348–630. ASKAP observed MAXI J1348–630 on 2019 February 13 over 10
hours using the full array of 36 dishes, with 36 overlapping
beams. ASKAP's large field of view and high angular resolution (∼25
arcseconds) allowed the simultaneous detection of HI absorption
towards both MAXI J1348–630 and a set of nearby extragalactic sources.
At the time of the ASKAP observation, MAXI J1348–630 was transiting from the hard to the soft X-ray spectral state, where many black hole XRBs undergo transient jet ejection events. To characterize the short-timescale variability in MAXI J1348–630 during the ASKAP observation, a continuum image was generated for each of ten hour-long time bins. The time-resolved 1.34-GHz light curve of MAXI J1348–630 for beam 20, shown above, reveals a short-duration flare, peaking at 252 ± 13 mJy at 15:51:32 (UTC), and then gradually decreasing to 111 ± 6 mJy by 22:53:16 (UTC). The radio flux density of the extragalactic sources in the same ASKAP beam remained constant within error bars during the observation, verifying that the variation seen from MAXI J1348–630 is intrinsic to the source. More details are given in the paper, published in Monthly Notices of the Royal Astronomical Society. |