2015/02/16 by P. Romano, E. Bozzo, V. Mangano +8
Engineering · Physics and Astronomy · #Accretion (finance) #Accretion disc #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Galaxy #Gamma-ray bursts and supernovae #High mass #Luminosity #Mechanics and Biomechanics Studies #Neutron star #Physics #Stars #Supergiant #Transient (computer programming) #X-ray transient #astro-ph.HE
paper · pdf · doi:10.1051/0004-6361/201525749
published as A&A 576, L4 (2015) · Accepted for publication in Astronomy and Astrophysics Letters. 5 pages, 5 figures, 2 tables
arxiv created 2015/02/16 · openalex publication_date 2015/02/18 · arxiv updated 2015/03/25 · openalex created_date 2019/06/27 · openalex updated_date 2026/08/05
Supergiant fast X-ray transients (SFXTs) are high mass X-ray binaries associated with OB supergiant companions and characterized by an X-ray flaring behaviour whose dynamical range reaches 5 orders of magnitude on time scales of a few hundred to thousands of seconds. Current investigations concentrate on finding possible mechanisms to inhibit accretion in SFXTs and to explain their unusually low average X-ray luminosity. We present the Swift observations of an exceptionally bright outburst displayed by the SFXT IGR J17544−2619 on 2014 October 10 when the source achieved a peak luminosity of 3 × 1038 erg s-1. This extends the total source dynamic range to ≳106, the largest (by a factor of 10) recorded so far from an SFXT. Tentative evidence for pulsations at a period of 11.6 s is also reported. We show that these observations challenge, for the first time, the maximum theoretical luminosity achievable by an SFXT and propose that this giant outburst was due to the formation of a transient accretion disc around the compact object.