A COMPREHENSIVE SPECTRAL ANALYSIS OF THE X-RAY PULSAR 4U 1907+09 FROM TWO OBSERVATIONS WITH THE SUZAKU X-RAY OBSERVATORY

Journal Article · Wed Jan 20 00:00:00 EST 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/709/1/179· OSTI ID:21392353

Rivers, Elizabeth; Markowitz, Alex; Suchy, Slawomir; Rothschild, Richard ^[1]; Pottschmidt, Katja ^[2]; Roth, Stefanie; Barragan, Laura; Fuerst, Felix; Kreykenbohm, Ingo; Wilms, Joern ^[3]

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1. Center for Astrophysics and Space Sciences, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0424 (United States)
2. CRESST and NASA Goddard Space Flight Center, Astrophysics Science Division, Code 661, Greenbelt, MD 20771 (United States)
3. Dr. Karl-Remeis-Sternwarte and Erlangen Centre for Astroparticle Physics, Sternwartstr. 7, 96049 Bamberg (Germany)

We present results from two observations of the wind-accreting X-ray pulsar 4U 1907+09 using the Suzaku Observatory. The broadband time-averaged spectrum allows us to examine the continuum emission of the source and the cyclotron resonance scattering feature at approx19 keV. Additionally, using the narrow CCD response of Suzaku near 6 keV allows us to study in detail the Fe K bandpass and to quantify the Fe Kbeta line for this source for the first time. The source is absorbed by fully covering material along the line of sight with a column density of N{sub H} approx 2 x 10{sup 22} cm{sup -2}, consistent with a wind-accreting geometry, and a high Fe abundance (approx3-4 times solar). Time- and phase-resolved analyses allow us to study variations in the source spectrum. In particular, dips found in the 2006 observation which are consistent with earlier observations occur in the hard X-ray bandpass, implying a variation of the whole continuum rather than occultation by intervening material, while a dip near the end of the 2007 observation occurs mainly in the lower energies implying an increase in N{sub H} along the line of sight, perhaps indicating clumpiness in the stellar wind.

• OSTI ID: 21392353
• Journal Information: Astrophysical Journal, Vol. 709, Issue 1; Other Information: DOI: 10.1088/0004-637X/709/1/179; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ABUNDANCE
CHARGE-COUPLED DEVICES
CYCLOTRON RESONANCE
ECLIPSE
EMISSION
HARD X RADIATION
MAGNETIC FIELDS
PULSARS
SCATTERING
STARS
STELLAR WINDS
COSMIC RADIO SOURCES
ELECTROMAGNETIC RADIATION
IONIZING RADIATIONS
RADIATIONS
RESONANCE
SEMICONDUCTOR DEVICES
STELLAR ACTIVITY
X RADIATION