Aql X-1: Neil Gehrels Swift Observatory XRT observations
ATel #16174; Devraj Pawar (R. J. College, Mumbai-400086, India)
on 5 Aug 2023; 12:00 UT
Credential Certification: Devraj Pawar (devrajdp@gmail.com)
Subjects: X-ray, Binary, Black Hole, Neutron Star, Transient
A new outburst of the recurrent X-ray transient neutron star LMXB was reported by MAXI and XB-NEWS on 25 July 2023 (ATel #16147). We requested for Neil Gehrels Swift Observatory data for Aql X-1 to monitor this outburst.
Following Evans et al. (2009, MNRAS, 397, 1177) we analyzed the data and find that the unabsorbed source flux in the 0.3 to 10 keV energy range increases from (4.26+/-0.05)E-9 erg/cm2/s on 30 July 2023 to (2.55+/-0.02)E-8 erg/cm2/s on 2 August 2023. The photon index evolves to 1.47(+/-0.02) indicating that Aql X-1 is in a hard state.
This outburst also shows the characteristic rapid brightening of Aql X-1.
Date, Time, Rate, +Err, -Err
2023-07-30 06:48:00 63.3795 0.349 -0.349
2023-07-31 17:52:00 259.528 8.285 -1.915
2023-08-01 06:13:00 278.772 11.955 -2.749
2023-08-02 10:44:00 325.948 12.449 -1.239
ATel #16153, ATel #16158, ATel #16169, ATel #16170 have also reported increase in the optical as well as X-ray flux of Aql X-1.
Link to Lightcurve
Link to Photon Index
We thank Neil Gehrels Swift Observatory for scheduling these observations. We will request for further monitoring of Aql X-1.
