Luminosity dependence of the electron temperature in the bright hard state of the black hole candidate GX 339--4

Details Luminosity dependence of the electron temperature in the bright hard state of the black hole candidate GX 339--4 Luminosity dependence of the electron temperature in the bright hard state of the black hole candidate GX 339--4

2008-06-30

arxiv.org/abs/0806.4796v1

Astronomy and Astrophysics

Astrophysics

Accepted by PASJ. 15 pages, 8 figures

Scientific paper

We have analyzed 200 Rossi X-ray Timing Explorer observations of the black hole candidate GX 339--4, all from the bright hard state periods between 1996 and 2005. Purpose of our study is to investigate the radiation mechanisms in the hard state of GX 339--4. The broadband 3--200 keV spectra were successfully modeled by a simple analytic model, power--law with an exponential cut-off modified with a smeared edge. The obtained energy cut-off ($E_{\rm{cut}}$) was distributed over 50--200 keV, and the photon index over 1.4--1.7. We found a clear anti-correlation ($E_{\rm{cut}} \propto L^{-0.70\pm0.06}$) between the X-ray luminosity ($L$) in 2--200 keV and $E_{\rm{cut}}$, when $L$ is larger than $7 \times 10^{37}$ erg s$^{-1}$ (assuming a distance of 8 kpc), while $E_{\rm{cut}}$ is roughly constant at around 200 keV when $L$ is smaller than $7 \times 10^{37}$ erg s$^{-1}$. This anti-correlation remained unchanged by adopting a more physical thermal Comptonization model, which resulted in the anti-correlation that can be expressed as $kT_{\rm{e}} \propto L^{-0.24\pm0.06}$. These anti-correlations can be quantitatively explained by a picture in which the energy-flow rate from protons to electrons balances with the inverse Compton cooling.

Affiliated with

Also associated with

No associations

Rating

Luminosity dependence of the electron temperature in the bright hard state of the black hole candidate GX 339--4 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Luminosity dependence of the electron temperature in the bright hard state of the black hole candidate GX 339--4, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Luminosity dependence of the electron temperature in the bright hard state of the black hole candidate GX 339--4 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-154391