NGC 300 ULX1: A test case for accretion torque theory
Abstract
NGC 300 ULX1 is a newly identified ultra-luminous X-ray pulsar. The system is associated with the supernova impostor SN 2010da that was later classified as a possible supergiant Be X-ray binary. In this work we report on the spin period evolution of the neutron star based on all the currently available X-ray observations of the system. We argue that the X-ray luminosity of the system has remained almost constant since 2010, at a level above ten times the Eddington limit. Moreover, we find evidence that the spin period of the neutron star evolved from ∼126 s down to ∼18 s within a period of about 4 years. We explain this unprecedented spin evolution in terms of the standard accretion torque theory. An intriguing consequence for NGC 300 ULX1 is that a neutron star spin reversal should have occurred a few years after the SN 2010da event.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- December 2018
- DOI:
- arXiv:
- arXiv:1811.11907
- Bibcode:
- 2018A&A...620L..12V
- Keywords:
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- X-rays: binaries;
- galaxies: individual: NGC 300;
- stars: neutron;
- pulsars: individual: NGC 300 ULX1;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 10 pages with appendix, 9 figures, accepted to A&