Discovery of a cyclotron absorption line in the spectrum of the binary X-ray pulsar 4U 1538 - 52 observed by Ginga

Journal Article · Sun Apr 01 04:00:00 EDT 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/168614· OSTI ID:7041795

Clark, G W; Woo, J W; Nagase, F; Makishima, K; Sakao, T ^[1]

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1. MIT, Cambridge, MA (USA) Institute of Space and Astronautical Science, Sagamihara (Japan) Tokyo, Univ. (Japan)

A cyclotron absorption line near 20 keV has been found in the spectrum of the massive eclipsing binary X-ray pulsar 4U 1538 - 52 in observations with the Ginga observatory. The line is detected throughout the 529 s pulse cycle with a variable equivalent width that has its maximum value during the smaller peak of the two-peak pulse profile. It is found that the profile of the pulse and the phase-dependence of the cyclotron line can be explained qualitatively by a pulsar model based on recent theoretical results on the properties of pencil beams emitted by accretion-heated slabs of magnetized plasma at the magnetic poles of a neutron star. The indicated field at the surface of the neutron star is 1.7 (1 + z) x 10 to the 12th G, where z is the gravitational redshift. 37 refs.

• OSTI ID: 7041795
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 353; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION SPECTRA
BINARY STARS
BREMSSTRAHLUNG
COSMIC RADIO SOURCES
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
CYCLOTRON RADIATION
ELECTROMAGNETIC RADIATION
LINE WIDTHS
LUMINOSITY
MAGNETIC STARS
NEUTRON STARS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
PULSARS
PULSES
RADIATIONS
SPECTRA
STARS