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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We present results from the Suzaku observation of the microquasar GRS1915+105 performed during the 2005 October multiwavelength campaign. The datainclude both stable state (class \chi) and limit-cycle oscillation (class\theta). Correct interstellar absorption as well as effects of dust scatteringare fully taken into account in the spectral analysis. The energy spectra inthe 2-120 keV band in both states are all dominated by strong Comptonization ofdisk photons by an optically thick (\tau ~7-10) and low temperature (T_e ~2-3keV) hybrid plasmas containing non-thermal electrons produced with 10-60% ofthe total power input. Absorption lines of highly ionized Fe ions detectedduring the oscillation indicate that a strong disk wind is developed. Theionization stage of the wind correlates with the X-ray flux, supporting thephotoionization origin. The iron-K emission line shows a strong variabilityduring the oscillation; the reflection is strongest during the dip butdisappears during the flare. We interpret this as evidence for "self-shielding"that the Comptonizing corona becomes geometrically thick in the flare phase,preventing photons from irradiating the outer disk. The low-temperature andhigh luminosity disk emission suggests that the disk structure is similar tothat in the very high state of canonical black hole binaries. The spectralvariability during the oscillation is explained by the change of the diskgeometry and of the physical parameters of Comptonizing corona, particularlythe fractional power supplied to the acceleration of non-thermal particles.

Suzaku Observation of GRS 1915+105: Evolution of Accretion Disc Structure during Limit-Cycle Oscillation