Suzaku Observations of the Galactic Center Microquasar 1E 1740.7-2942
Abstract
We present two Suzaku observations of the Galactic center microquasar 1E 1740.7-2942 separated by approximately 900 days. The source was observed on both occasions after a transition to the spectrally hard state (Lx~0.01 LEdd). Significant emission from 1E 1740.7-2942 is detected out to an energy of at least 300 keV, with no spectral break or turnover evident in the data.
The high energy emission is consistent with a hard power-law (Γ~1.8) with a significant contribution from an accretion disc with a temperature of ~0.4 keV at soft X-ray energies. The measured value for the inner radius of the accretion disc is found to be inconsistent with the picture whereby the disc is truncated at large radii in the low-hard state and instead favours a radius close to the ISCO (Rin~10-20 Rg)- Publication:
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X-ray Astronomy 2009; Present Status, Multi-Wavelength Approach and Future Perspectives
- Pub Date:
- July 2010
- DOI:
- 10.1063/1.3475198
- Bibcode:
- 2010AIPC.1248..189R
- Keywords:
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- Galactic centre;
- quasars;
- astronomical observations;
- brightness;
- 98.35.Jk;
- 98.54.Aj;
- 95.85.Ry;
- 97.10.Xq;
- Galactic center bar circumnuclear matter and bulge;
- Quasars;
- Neutrino muon pion and other elementary particles;
- cosmic rays;
- Luminosity and mass functions