2016/06/22 by D. M. Christodoulou, Dimitris M. Christodoulou, Christodoulou, D. M. +5
Engineering · Physics and Astronomy · #Astrophysical Phenomena and Observations #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #Mechanics and Biomechanics Studies #astro-ph.HE
paper · pdf · doi:10.48550/arxiv.1606.07096
7 pages, submitted to MNRAS. This is a new calculation of the magnetic field of M82 X-2 based on the latest observations from the Chandra archive
arxiv created 2016/06/22 · openalex publication_date 2016/06/22 · arxiv updated 2016/06/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
\it NuSTAR has detected pulsations from the ultraluminous X-ray source X-2 in M82 and archival \it Chandra observations have given us a good idea of its duty cycle. The newly discovered pulsar exhibited at least 4 super-Eddington outbursts in the past 15 years but, in its lowest-power state, it radiates just below the Eddington limit and its properties appear to be typical of high-mass X-ray binaries. M82 X-2 has been described as a common neutron star with a 1~TG magnetic field that occasionally accretes above the Eddington rate and as a magnetar-like pulsar with a 10-100~TG magnetic field that reaches above the quantum limit. We argue in favor of the former interpretation. Using standard accretion theory and the available observations, we calculate the stellar magnetic field of this pulsar in two independent ways and we show that it cannot exceed 3~TG in either case. We discuss the implications of our results for other ultraluminous X-ray sources that occasionally exhibit similar powerful outbursts.