Quasi-Periodic Oscillation Frequency-Color Radius Connection in GRS 1915+105: A Possible Turnover Supporting Accretion-Ejection Instability Predictions
Abstract
It is widely believed that the low-frequency quasi-periodic X-ray oscillations observed in microquasars are correlated to, but do not originate at, the physical radius of the inner edge of the accretion disk. Models relating the quasi-periodic oscillation (QPO) frequency and color radius are hindered by observations showing contradicting trend correlations between the microquasars GRO 1655-40, XTE J1550-564, and GRS 1915+105. The first shows a negative correlation and the latter two a positive one. By taking into account relativistic rotation in the accretion disk, the accretion-ejection instability (AEI) model predicts a turnover in the frequency-radius relationship, and has been successfully compared with observations of GRO J1655-40 and GRS 1915+105. We present further evidence supporting the AEI model prediction by using observations of the microquasar GRS 1915+105. By combining a data set including θ-, β-, and α-class X-ray light curves, we observe positive, negative, and null correlations in the frequency-radius relationship. This is the first time a single source has shown a possible inversion in the QPO frequency-color radius curve predicted by the AEI model.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 2009
- DOI:
- 10.1088/0004-637X/694/2/L132
- arXiv:
- arXiv:0903.2680
- Bibcode:
- 2009ApJ...694L.132M
- Keywords:
-
- accretion;
- accretion disks;
- black hole physics;
- stars: individual: GRS 1915+105;
- stars: oscillations;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- Astrophys.J.694:L132-L135,2009