Simultaneous optical and x-ray bursts from 4U/MXB 1636-53

Journal Article · Wed Dec 01 04:00:00 EST 1982 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/160507· OSTI ID:5637765

Pedersen, H; Lub, J; Inoue, H; Koyama, K; Makishima, K; Matsuoka, M; Mitsuda, K; Murakami, T; Oda, M; Ogawara, Y; Ohashi, T; Shibazaki, N; Tanaka, Y; Hayakawa, S; Kunieda, H; Makino, F; Masai, K; Nagase, F; Tawara, Y; Miyamoto, S ; Tsunemi, H; Yamashita, K; Kondo, I; Jernigan, J G; Paradijs, J V; Beardsley, A; Cominsky, L; Doty, J; Lewin, W H.G.

We report the detection of five coincident optical/X-ray bursts from 4U/MXB 1636-53. The optical observations were made with the Danish 1.5 m telescope at the European Southern Observatory (E.S.O.) and the X-ray observations were made with the Hakucho X-ray observatory. We have analyzed these bursts in terms of a simple general mathematical model, in which the optical emission (both during and between the bursts) is that of a blackbody and the result of thermally reprocessed X-ray. One expects that the optical burst is a delayed and sneared verison of the X-ray burst. We estimate that the optical radiative delay is smaller than the observed values, which we believe are therefore mainly due to the geometry of the system. For the delay and smearing of the optical burst and the maximum temperature of the reprocessing region, we find values of approx.2.5 s, <4 s, and approx.75 x 10/sup 3/ K, respectively. The reprocessing region surrounding the X-ray source has a projected area of approx.6 x 10/sup 21/ cm/sup 2/ corresponding to a linear size of approx.1.5 lt-sec independent of any assumption about its geometry. An accretion disk around a compact object is one plausible model for the reprocessing region. The derived restrictions on the parameters of a consistent low-mass close binary system containing an approx.1.4 M/sub sun/ neutron star. The radius of the accretion disk is >1.5 1t-sec, the mass of the Roche lobe filling companion star is <2.0 M/sub sun/ corresponding to a binary period between approx.1 hour and approx.10 hours.

• Research Organization: European Southern Observatory
• OSTI ID: 5637765
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 263:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640103* -- Astrophysics &amp; Cosmology-- Quasi-Stellar
Radio
&amp; X-Ray Sources-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BINARY STARS
COSMIC RAY SOURCES
COSMIC X-RAY BURSTS
COSMIC X-RAY SOURCES
DATA ANALYSIS
ELECTROMAGNETIC RADIATION
IONIZING RADIATIONS
PHOTOMETRY
RADIATION FLUX
RADIATIONS
SPECTRA
STAR ACCRETION
STAR EVOLUTION
STARS
VISIBLE SPECTRA
X RADIATION
X-RAY SPECTRA