Please use this identifier to cite or link to this item:
http://hdl.handle.net/20.500.12386/30507
Title: | Discovery of a 3 s Spinning Neutron Star in a 4.15 hr Orbit in the Brightest Hard X-Ray Source in M31 | Authors: | RODRIGUEZ CASTILLO, Guillermo Andres ISRAEL, Gian Luca ESPOSITO, PAOLO PAPITTO, ALESSANDRO STELLA, Luigi TIENGO, ANDREA DE LUCA, Andrea MARELLI, MARTINO |
Issue Date: | 2018 | Journal: | THE ASTROPHYSICAL JOURNAL LETTERS | Number: | 861 | Issue: | 2 | First Page: | L26 | Abstract: | We report the discovery with XMM-Newton of 3 s X-ray pulsations from 3XMM J004232.1+411314, a dipping source that dominates the hard X-ray emission of M31. This finding unambiguously assesses the neutron star (NS) nature of the compact object. We also measured an orbital period of 4.15 hr and a projected semi-axis at a_X sin i = 0.6 lt-s, which implies a low-mass companion of about 0.2-0.3 M_☉ assuming an NS of 1.5 M_☉ and an orbital inclination i = 60°-80°. The barycentric orbit-corrected pulse period decreased by ∼28 ms in about 16 year, corresponding to an average spin-up rate of \dot{P}∼ -6× {10}^-11 s s^-1 pulse period variations, probably caused by X-ray luminosity changes, were observed on shorter timescales. We identify two possible extreme scenarios for the source: a mildly magnetic NS with B _p ≃ few × 10^10 G if the pulsar is far from its equilibrium period P_eq and the disk is truncated at the value of the Alfvén radius corresponding to the observed luminosity, and a relatively young, highly magnetic NS with B_eq ≃ 2 × 10^13 G if spinning close to P_eq and the disk is truncated close to the co-rotation surface. | URI: | http://hdl.handle.net/20.500.12386/30507 | URL: | https://iopscience.iop.org/article/10.3847/2041-8213/aacf40 https://arxiv.org/abs/1804.10858 |
ISSN: | 2041-8205 | DOI: | 10.3847/2041-8213/aacf40 | Bibcode ADS: | 2018ApJ...861L..26R | Fulltext: | open |
Appears in Collections: | 1.01 Articoli in rivista |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
Rodríguez_Castillo_2018_ApJL_861_L26.pdf | Pdf editoriale | 857.54 kB | Adobe PDF | View/Open |
Page view(s)
71
checked on Apr 23, 2024
Download(s)
33
checked on Apr 23, 2024
Google ScholarTM
Check
Altmetric
Altmetric
Items in DSpace are published in Open Access, unless otherwise indicated.