Orbital Decay in M82 X-2

Matteo Bachetti, Marianne Heida, Thomas Maccarone, Daniela Huppenkothen, Gian Luca Israel, Didier Barret, Murray Brightman, McKinley Brumback, Hannah P. Earnshaw, Karl Forster, Felix Fürst, Brian W. Grefenstette, Fiona A. Harrison, Amruta D. Jaodand, Kristin K. Madsen, Matthew Middleton, Sean N. Pike, Maura Pilia, Juri Poutanen, Daniel SternJohn A. Tomsick, Dominic J. Walton, Natalie Webb, Jörn Wilms

Research output: Contribution to journalArticlepeer-review

8 Downloads (Pure)

Abstract

M82 X-2 is the first pulsating ultraluminous X-ray source discovered. The luminosity of these extreme pulsars, if isotropic, implies an extreme mass transfer rate. An alternative is to assume a much lower mass transfer rate, but with an apparent luminosity boosted by geometrical beaming. Only an independent measurement of the mass transfer rate can help discriminate between these two scenarios. In this paper, we follow the orbit of the neutron star for 7 yr, measure the decay of the orbit ( Ṗorb/Porb≈−8·10−6yr−1 ), and argue that this orbital decay is driven by extreme mass transfer of more than 150 times the mass transfer limit set by the Eddington luminosity. If this is true, the mass available to the accretor is more than enough to justify its luminosity, with no need for beaming. This also strongly favors models where the accretor is a highly magnetized neutron star.
Original languageEnglish
Number of pages12
JournalThe Astrophysical Journal
Volume937
Issue number2
DOIs
Publication statusPublished - 5 Oct 2022

Keywords

  • 330
  • High-Energy Phenomena and Fundamental Physics

Fingerprint

Dive into the research topics of 'Orbital Decay in M82 X-2'. Together they form a unique fingerprint.

Cite this