Study of the X-ray pulsar IGR J19294+1816 with NuSTAR: Detection of cyclotron line and transition to accretion from the cold disk
Abstract
In the work we present the results of two deep broadband observations of the poorly studied X-ray pulsar IGR J19294+1816 obtained with the NuSTAR observatory. The source was observed during Type I outburst and in the quiescent state. In the bright state a cyclotron absorption line in the energy spectrum was discovered at Ecyc = 42.8 ± 0.7 keV. Spectral and timing analysis prove the ongoing accretion also during the quiescent state of the source. Based on the long-term flux evolution, particularly on the transition of the source to the bright quiescent state with luminosity around 1035 erg s-1, we conclude that IGR J19294+1816 switched to the accretion from the "cold" accretion disk between Type I outbursts. We also report the updated orbital period of the system.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- January 2019
- DOI:
- 10.1051/0004-6361/201833786
- arXiv:
- arXiv:1811.08912
- Bibcode:
- 2019A&A...621A.134T
- Keywords:
-
- accretion;
- accretion disks;
- magnetic fields;
- stars: individual: IGR J19294+1816;
- X-rays: binaries;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 7 pages, 8 figures, 2 tables