Thermonuclear X-ray bursts in rapid succession in 4U 1636–536 with AstroSat-LAXPC

Aru Beri , Biswajit Paul , J.S. Yadav , H.M. Antia , P.C. Agrawal , R.K. Manchanda , Dhiraj Dedhia , Jai Verdhan Chauhan , Mayukh Pahari , Ranjeev Misra , Tilak Katoch , P. Madhwani , Parag Shah , M. Varun , Sujay Mate (1)

1 IRAP - Institut de recherche en astrophysique et planétologie

We present results from an observation of the low-mass X-ray binary 4U 1636–536 obtained with the LAXPC instrument aboard AstroSat. The observations of 4U 1636–536 made during the performance verification phase of AstroSat showed seven thermonuclear X-ray bursts in a total exposure of ∼65 ks over a period of about two consecutive days. Moreover, the light curve of 4U 1636–536 revealed the presence of a rare triplet of X-ray bursts, having a wait time of about 5.5 min between the second and the third bursts. We also present results from time-resolved spectroscopy performed during these seven X-ray bursts. In addition, we have also detected a transient quasi-periodic oscillation  at ∼5 Hz. However, we did not find any evidence of kilo-hertz quasi-periodic oscillations and/or X-ray burst oscillations, perhaps due to the hard spectral state of the source during this observation.

Mots clés: accretion discs; stars: neutron; X-rays: binaries; X-rays: bursts; X-rays: individual: 4U 1636—536; accretion

Domaines: Astrophysique [astro-ph]

Aru Beri, Biswajit Paul, J.S. Yadav, H.M. Antia, P.C. Agrawal, et al.. Thermonuclear X-ray bursts in rapid succession in 4U 1636–536 with AstroSat-LAXPC. Monthly Notices of the Royal Astronomical Society, 2019, 482 (4), pp.4397-4407. ⟨10.1093/mnras/sty2975⟩. ⟨hal-03186430⟩