2004/01/01 by W. A. Heindl, R. E. Rothschild, W. Coburn +4
Physics and Astronomy · #Accretion (finance) #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Cyclotron #Cyclotron resonance #Line (geometry) #Neutron star #Pulsar #Pulsars and Gravitational Waves Research #Spectral line #Spectroscopy #astro-ph
paper · pdf · doi:10.1063/1.1781049
8 pages, 13 figures. to appear in the proceedings of "X-Ray Timing 2003: Rossi and Beyond", eds. P. Kaaret, F.K. Lamb, & J.H. Swank (Melville, NY: AIP)
openalex publication_date 2004/01/01 · arxiv created 2004/03/09 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A great deal of emphasis on timing in the RXTE era has been on pushing toward higher and higher frequency phenomena, particularly kHz QPOs. However, the large areas of the RXTE pointed instruments provide another capability which is key for the understanding of accreting X‐ray pulsars — the ability to accumulate high quality spectra in a limited observing time. For the accreting X‐ray pulsars, with their relatively modest spin frequencies, this translates into an ability to study broad band spectra as a function of pulse phase. This is a critical tool, as pulsar spectra are strong functions of the geometry of the “accretion mound” and the observers’ viewing angle to the ∼1012 G magnetic field. In particular, the appearance of “cyclotron lines” is sensitively dependent on the viewing geometry, which must change with the rotation of the star. These spectral features, seen in only a handful of objects, are quite important, as they give us our only direct measure of neutron star magnetic fields. Furthermore, they carry a great deal of information as to the geometry and physical conditions in the accretion mound. In this paper, we review the status of cyclotron line studies with the RXTE. We present an overview of phase‐averaged results and give examples of observations which illustrate the power of phase‐resolved spectroscopy.