English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We present the first detailed spectral and timing analysis of the High MassX-ray Binary (HMXB) 4U 1909+07 with INTEGRAL and RXTE. 4U 1909+07 is detectedin the ISGRI 20-40 keV energy band with an average countrate of 2.6 cps. Thepulse period of ~604 sec is not stable, but changing erratically on timescalesof years. The pulse profile is strongly energy dependent: it shows a doublepeaked structure at low energies, the secondary pulse decreases rapidly withincreasing energy and above 20 keV only the primary pulse is visible. Thisevolution is consistent between PCA, HEXTE, and ISGRI. The phase averagedspectrum can be well described by the sum of a photoabsorbed power law with acutoff at high energies and a blackbody component. To investigate the pulseprofile, we performed phase resolved spectral analysis. We find that thechanging spectrum can be best described with a variation of the folding energy.We rule out a correlation between the black body component and the continuumvariation and discuss possible accretion geometries.

4U 1909+07: a well-hidden pearl