High-Speed Optical Photometry of the Ultracompact X-ray Binary 4U 1626-67

Details High-Speed Optical Photometry of the Ultracompact X-ray Binary 4U 1626-67 High-Speed Optical Photometry of the Ultracompact X-ray Binary 4U 1626-67

1997-06-05

arxiv.org/abs/astro-ph/9706049v1

ApJ 492 (1998) 342

Astronomy and Astrophysics

Astrophysics

26 pages including 6 PS figures. Submitted to ApJ

Scientific paper

10.1086/305035

Rapid UBVRI photometry of this ultracompact LMXB pulsar has detected 7.67 s optical pulsations in all five bands. The optical pulsations, which are at the same frequency as the X-ray pulsations, are understood as reprocessing of pulsed X-rays in the accretion disk or on the companion surface. The optical pulsed fraction is 6%, independent of wavelength, indicating that the optical emission is dominated by X-ray reprocessing. A weaker (1.5%) sideband, shifted down 0.395(15) mHz from the main optical pulsation, is also present. This is consistent with a previously reported sideband and corroborating the 42-min binary period proposed earlier by Middleditch et al. (1981). A 0.048 Hz optical QPO, corresponding to a known X-ray feature, was also detected in some of the observations. This is the first measurement of an optical QPO in an X-ray binary pulsar. I discuss constraints on the nature of the mass donor and show that mass transfer via a radiatively-driven wind is inconsistent with the data. I also review the basic theory of X-ray-heated accretion disks and show that such models provide a good fit to the optical photometry. If the X-ray albedo of LMXB accretion disks is as high as recently reported, then the optical data imply a distance of 8 kpc and an X-ray luminosity of 10^37 erg/s.

Affiliated with

Also associated with

No associations

Rating

High-Speed Optical Photometry of the Ultracompact X-ray Binary 4U 1626-67 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with High-Speed Optical Photometry of the Ultracompact X-ray Binary 4U 1626-67, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High-Speed Optical Photometry of the Ultracompact X-ray Binary 4U 1626-67 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-483296