4U 1909+07: a well-hidden pearl
Loading...
Author/Creator ORCID
Date
2010-12-02
Type of Work
Department
Program
Citation of Original Publication
Fürst, F., I. Kreykenbohm, S. Suchy, L. Barragán, J. Wilms, R. E. Rothschild, and K. Pottschmidt. “4U 1909+07: A Well-Hidden Pearl.” Astronomy & Astrophysics 525 (January 1, 2011): A73. https://doi.org/10.1051/0004-6361/201015636.
Rights
This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.
Attribution 4.0 International (CC BY 4.0)
Attribution 4.0 International (CC BY 4.0)
Subjects
Abstract
We present the first detailed spectral and timing analysis of the high mass X-ray binary (HMXB) 4U 1909+07 with INTEGRAL and RXTE. 4U 1909+07 is detected in the ISGRI 20–40 keV energy band with an average countrate of 2.6 cts s⁻¹. The pulse period of ~604 s is not stable, but changing erratically on timescales of years. The pulse profile is strongly energy dependent: it shows a double peaked structure at low energies, the secondary pulse decreases rapidly with increasing energy and above 20 keV only the primary pulse is visible. This evolution is consistent between PCA, HEXTE, and ISGRI. The phase averaged spectrum can be well described by the sum of a photoabsorbed power law with a cutoff at high energies and a blackbody component. To investigate the pulse profile, we performed phase resolved spectral analysis. We find that the changing spectrum can be best described with a variation of the folding energy. We rule out a correlation between the black body component and the continuum variation and discuss possible accretion geometries.