Discovery of a prominent cyclotron absorption feature from the transient X-ray pulsar X0331 + 53

Journal Article · Sat Dec 01 04:00:00 EST 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/185888· OSTI ID:5995558

Makishima, K; Mihara, T; Ishida, M; Ohashi, T; Sakao, T ^[1]

---

1. Tokyo Univ. (Japan)

A remarkable absorption feature at 28.5 keV, attributable to electron cyclotron resonance, has been discovered in the 1.9-60-keV X-ray spectrum of the recurrent transient X-ray pulsar X0331 + 53. The observed resonance energy implies a neutron star surface magnetic field of 2.5(1 + z) x 10 to the 12th G, where z is the gravitational redshift. The detection was made with the Ginga observatory in October 1989, during an outburst of this transient with a flux level of about 0.3 Crab. The feature is very deep and has been resolved with excellent statistics. This is the fourth unambiguous detection of cyclotron resonant scattering features from X-ray pulsars, suggesting that these features are a common phenomenon among these objects. An empirical relation found between the cyclotron resonance energy and the spectral cutoff energy suggests that the magnetic field strengths of the known X-ray pulsars are clustered in a range (1-4) x 10 to the 12th G. 30 refs.

• OSTI ID: 5995558
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 365; 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
COSMIC RADIO SOURCES
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
CYCLOTRON RESONANCE
MAGNETIC FIELDS
NEUTRON STARS
PULSARS
RED SHIFT
RESONANCE
SPECTRA
STARS
TRANSIENTS
X-RAY SPECTRA