Detection of 125.5-day optical periodic modulation of the neutron star M51 ULX-8
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Tarih
2022
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Oxford Univ Press
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Studying Ultraluminous X-ray sources (ULXs) in the optical wavelengths provides important clues about the accretion mechanisms and the evolutionary processes of X-ray binary systems. In this study, three (C1, C2, and C3) possible optical counterparts were identified for well-known neutron star (NS) candidate M51 ULX-8 through advanced astrometry based on the Chandra and Hubble Space Telescope (HST) observations, as well as the GAIA optical source catalogue. Optical periodic modulation of 125.5 d with an amplitude of 0.14 mag was determined for C3, which has evidence to represent the optical nature of ULX-8 using one-year (2016-2017) 34 HST Advanced Camera for Surveys (ACS)/Wide Field Camera (WFC) observations. Moreover, surprisingly, the observed optical fluxes of C3 exhibit a bi-modal distribution. This could mean that there is a possible correlation between the optical and the X-ray flux variabilities of the ULX-8. The possible scenarios which are frequently mentioned in the literature proposed for the nature of optical emission and optical super-orbital period. The most probable scenario is that the optical emission could have originated from the accretion disc of the ULX-8.
Açıklama
Anahtar Kelimeler
astrometry, galaxies: individual: M51 ULX-8, X-rays: binaries: Optical counterparts of M51 ULX-8
Kaynak
Monthly Notices of The Royal Astronomical Society
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
517
Sayı
3
