Neil Gehrels Swift Observatory monitoring of the X-ray transient IGR 17494-3030

ATel #14126; Devraj Pawar (R. J. College, Mumbai-86, India)
on 28 Oct 2020; 19:09 UT
Credential Certification: Devraj Pawar (devrajdp@gmail.com)

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ATel # 14119 reported the INTEGRAL detection of renewed activity in the X-ray transient IGR J17494-3030. Since the source is known to be a rapidly fading transient (ATel # 4886, Armas Padilla et al. 2013 MNRAS 436, 89) we proposed Swift ToO monitoring observations to find the state of the source and evolution of the outburst.

A ~1 ks Swift/XRT observation in the photon counting mode was performed on October 27, 2020 (00032318005). We extracted X-ray spectrum following Evans et al. (2009, MNRAS, 397, 1177). The spectrum was fit it using XSPEC (Arnaud et al.) with model tbabs*powerlaw. The unabsorbed flux for IGR 17494-3030 was found to be 2.09+/-0.3 X 10^{-11} erg cm^{-2} s^{-1} in the 2-10 keV energy band. The spectral fit estimates a photon index of 2.84+/-0.36 for neutral hydrogen column density 2.7+/-0.5E22 cm^{-2} using abundance Wilm. Further analysis is ongoing.

Swift monitoring is planned for three more days tentatively between October 29th, 2020 and November 2nd, 2020 with Target ID 32318. As the source is known to fade rapidly any further monitoring will be based on the observed evolution.

Rapid variability has been observed during this outburst (ATel # 14124), such spectral and temporal variability can lead to confirmation of the nature of the source which is so far assumed to be a neutron star binary (Armas Padilla et al. 2013 MNRAS 436, 89), hence further observations in all wavelengths are encouraged.

We thank the duty scientists of The Neil Gehrels Swift Observatory for the discussions and rapid scheduling of the observations.