The massive unseen companion of X Persei - Emission contamination in the Balmer lines

Abstract

view Abstract Citations (26) References (20) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The massive unseen companion of X Persei : emission contamination in the Balmer lines. Penrod, G. D. ; Vogt, S. S. Abstract X Per is the optical counterpart of the pulsating X-ray source 4U 0352 + 30. Although nearly all observations of this system are consistent with a relatively simple model consisting of a normal O93-B0e star with a neutron star companion in a distant orbit, Hutchings et al. (1974) reported large-amplitude radial velocity variations with a 580-day period in the high-order Balmer absorption lines, which, if interpreted as orbital motion, imply the existence of a massive (more than 30 solar mass) unseen compansion, probably a black hole. High-quality Reticon spectra of the high-order Balmer lines have been obtained which show that the 'radial velocity' variations reported by Hutchings et al. are spurious and are caused by asymmetric and variable emission components hiding in the absorption profiles. This result eliminates the necessity for postulating a massive, unseen secondary or tertiary star. All observed aspects of X Per now seem consistent with the Be + neutron star binary scenario. A previously reported 22.4-hr periodicity in the X-ray flux is explained in terms of nonradial g-mode pulsations of the Be star, which modulate the star's wind, and, hence, the accretion rate onto the neutron star. Publication: The Astrophysical Journal Pub Date: December 1985 DOI: 10.1086/163730 Bibcode: 1985ApJ...299..653P Keywords: Astronomical Spectroscopy; B Stars; Balmer Series; Black Holes (Astronomy); Companion Stars; Neutron Stars; X Ray Sources; Radial Velocity; Spectrum Analysis; Stellar Spectra; Astrophysics full text sources ADS | data products SIMBAD (1)