European astronomers used a space station to investigate recently discovered hard x-ray transients known as IGR J17503-2636. This study, published on the arXiv print server on March 7th, suggests that this source may be a relatively fast super fast X-ray transient phenomenon.
Supergiant fast X-ray transients (SFXTs) are high-mass X-ray binary (HMXBs) classes with supergiant companions. It shows the active activity of X-rays, and experiences a typical uptime of several hours associated with explosions and supergiant stars with very fast rise times.
IGR J17503-2636, detected by ESA's INTEGRAL space telescope on August 11, 2018, is a solid X-ray transient. The researchers later found that it hosted a largely red OB giants star and was therefore classified as HMXB.
Almost immediately after its discovery, follow-up observations of IGR J17503-2636 began using NASA's Chandra, Swift and NuSTAR spacecraft and NICER equipment at the International Space Station. An astronomy team led by Carlo Ferrigno of the University of Geneva, Switzerland, analyzed the results of this observation campaign and found evidence suggesting that the system was SFXT.
"This article uses our interpretation of all available X-ray data collected during the X-ray emission episodes first reported in IGR J17503-2636 using instruments from INTEGRAL, NuSTAR, Swift, and NICER," astronomers I wrote in this paper.
IGR J17503-2636 was faded very quickly after being confirmed by INTEGRAL, but subsequent observations were able to detect faint X-ray emissions from the source. In particular, in IGR J17503-2636, the emission from soft to hard x-ray regions (between 0.5 keke and 80 keV) exhibited significant variability on a time scale between a few seconds and a few thousand seconds.
According to the authors of the paper, this variability is a typical feature of airway HMXB. This is because the massive companion winds can form a cocoon of dense material around the star attacked by the wind, and the wind change can produce the X-ray variability observed in that time system.
In general, considering all the data collected in subsequent campaigns, the researchers concluded that the results favor the HMXB scenario of IGR J17503-2636. However, more research is needed to confirm this assumption. They also suggested that the available data would host the neutron stars with strongly magnetized systems.
"IGR J17503-2636 is most likely based on the rapid variability of the X-ray region, the spectral energy distribution in the 0.5-80 keV energy range, and reported associations with the OB giant with very red shine at ~ 10 kpc. Supergiant fast X-ray A relatively dim new member of transients (…) The accreting object of IGR J17503-2636 is NS [neutron star] A magnetic field of ~ 2 x 10 is given.12 G is compatible with other measured NS field strengths of HMXB, "the scientists explained.
Astronomers observe ultra-fast, high-speed X-ray transient prototypes.
C. Ferrigno et al. IGR J17503-2636: candidate high-speed high-speed X-ray transient arXiv: 1903.03210 [astro-ph.HE]. arxiv.org/abs/1903.03210