EXO 2030+375 Restarts in Reverse
Abstract
The Be X-ray binary pulsar EXO 2030+375, first detected in 1985, has shown a significant detected X-ray outburst at nearly every periastron passage of its 46-day orbit for the past ~25 years, with one low state accompanied by a torque reversal in the 1990s. In early 2015 the outbursts progressively became fainter and less regular while the monotonic spin-up flattened. At the same time a decrease in the H$\alpha$ line equivalent width was reported, indicating a change in the disk surrounding the mass donor. In order to explore the source behaviour in the poorly explored low-flux state with a possible transition to a state of centrifugal inhibition of accretion we have undertaken an observing campaign with Swift/XRT, NuSTAR and the Nordic Optical Telescope (NOT). This conference contribution reports the preliminary results obtained from our campaign.
- Publication:
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arXiv e-prints
- Pub Date:
- June 2017
- DOI:
- 10.48550/arXiv.1706.03969
- arXiv:
- arXiv:1706.03969
- Bibcode:
- 2017arXiv170603969K
- Keywords:
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- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 11th INTEGRAL Conference Gamma-Ray Astrophysics in Multi-Wavelength Perspective, 10-14 October 2016, Amsterdam, The Netherlands. 7 pages