2001/01/08 by W. Coburn, W. A. Heindl, D. E. Gruber +4 · 1 citation
Earth and Planetary Sciences · Physics and Astronomy · #Accretion (finance) #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Binary pulsar #Black-body radiation #Cyclotron #Cyclotron resonance #High-pressure geophysics and materials #Luminosity #Millisecond pulsar #Neutron star #Nuclear physics #Physics #Plasma #Pulsar #Pulsars and Gravitational Waves Research #Scattering #X-ray binary #astro-ph
paper · pdf · doi:10.1086/320565
34 pages, 6 figures, 3 tables, Accepted by ApJ
arxiv created 2001/01/08 · openalex publication_date 2001/05/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
We have discovered a ~29 keV cyclotron resonance scattering feature (CRSF) in the X-ray spectrum of 4U 0352+309 (X Per) using observations taken with the Rossi X-Ray Timing Explorer . The source 4U 0352+309 is a persistent low-luminosity ( L X = 4.2 × 10 34 ergs s -1 ) X-ray pulsar with a 837 s period, which accretes material from the Be star X Per. The X-ray spectrum, unusual when compared to brighter accreting pulsars, may be due to the low mass accretion rate and could be typical of the new class of persistent low-luminosity Be/X-ray binary pulsars. We attempted spectral fits with continuum models used historically for 4U 0352+309 and found that all were improved by the addition of a CRSF at ~29 keV. The model that best fitted the observations is a combination of a 1.45 ± 0.02 keV blackbody with a 5.4 × 10 8 cm 2 area and a power law with a 1.83 ± 0.03 photon index modified by the CRSF. In these fits the CRSF energy is 28.6 keV, implying a magnetic field strength of 2.5(1 + z ) × 10 12 G in the scattering region (where z is the gravitational redshift). Phase-resolved analysis shows that the blackbody and cyclotron line energies are consistent with being constant through the pulse.