Diagnostic of the spectral properties of Aquila X-1 by Insight-HXMT snapshots during the early propeller phase
Abstract
We study the 2018 outburst of Aql X-1 via the monitor of all sky X-ray image (MAXI) data. We show that the outburst starting in February 2018 is a member of short-low class in the frame of outburst duration and the peak count rate although the outburst morphology is slightly different from the other fast-rise-exponential-decay (FRED) type outbursts with a milder rising stage. We study the partial accretion in the weak propeller stage of Aql X-1 via the MAXI data of the 2018 outburst. We report on the spectral analysis of 3 observations of Aquila X-1 obtained by Insight - hard X-ray modulation telescope (Insight-HXMT) during the late decay stage of the 2018 outburst. We discuss that the data taken by Insight-HXMT is just after the transition to the weak propeller stage. Our analysis shows the necessity of a comptonization component to take into account the existence of an electron cloud resulting photons partly up-scattered.
- Publication:
-
Journal of High Energy Astrophysics
- Pub Date:
- March 2020
- DOI:
- 10.1016/j.jheap.2019.12.001
- arXiv:
- arXiv:1912.08542
- Bibcode:
- 2020JHEAp..25...10G
- Keywords:
-
- Accretion;
- Accretion disks;
- Stars: neutron;
- X-rays: binaries;
- X-rays: individuals;
- Aql X-1;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 8 pages, 4 figures, accepted for publication in JHEAp