Journal article · Preprint article
RX J0529.8−6556: a BeXRB pulsar with an evolving optical period and out of phase X-ray outbursts
Yale University1
University of Cape Town2
South African Astronomical Observatory3
Max Planck Institute for Extraterrestrial Physics4
NASA Goddard Space Flight Center5
U.S. Naval Research Laboratory6
Université de Strasbourg7
Astrophysics and Atmospheric Physics, National Space Institute, Technical University of Denmark8
National Space Institute, Technical University of Denmark9
University of Warsaw10
Erlangen Centre for Astroparticle Physics11
...and 1 moreWe report the results of eROSITA and NICER observations of the June 2020 outburst of the Be/X-ray binary pulsar RX J0529.8−6556 in the Large Magellanic Cloud, along with the analysis of archival X-ray and optical data from this source. We find two anomalous features in the system’s behavior. First, the pulse profile observed by NICER during maximum luminosity is similar to that observed by XMM-Newton in 2000, despite the fact that the X-ray luminosity was different by two orders of magnitude.
By contrast, a modest decrease in luminosity in the 2020 observations generated a significant change in pulse profile. Second, we find that the historical optical outbursts are not strictly periodic, as would be expected if the outbursts were triggered by periastron passage, as is generally assumed.
The optical peaks are also not coincident with the X-ray outbursts. We suggest that this behavior may result from a misalignment of the Be star disc and the orbital plane, which might cause changes in the timing of the passage of the neutron star through the disc as it precesses. We conclude that the orbital period of the source remains unclear.
Language: | English |
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Year: | 2021 |
Pages: | 6187-6201 |
ISSN: | 13652966 , 00358711 and 13658711 |
Types: | Journal article and Preprint article |
DOI: | 10.1093/mnras/stab807 |
ORCIDs: | 0000-0003-0660-9776 , 0000-0003-3902-3915 , 0000-0002-0107-5237 , 0000-0002-5297-5278 , 0000-0002-0766-7313 , 0000-0001-5612-5185 , Jaisawal, G. K. , 0000-0001-5207-5619 , 0000-0002-4754-3526 and 0000-0002-7004-9956 |