Discovery of 10 mHz quasi-periodic oscillations likely from IGR J17091-3624

Altamirano, D.; Linares, M.; van der Klis, M.; Wijnands, R.; Kalamkar, M.; Casella, P.; Watts, A.; Patruno, A.; Armas-Padilla, M.; Cavecchi, Y.; Degenaar, N.; Kaur, R.; Yang, Y.; Rea, N.
Bibliographical reference

The Astronomer's Telegram, #3225

Advertised on:
3
2011
Number of authors
14
IAC number of authors
0
Citations
18
Refereed citations
18
Description
We report the discovery of ~10 mHz quasi-periodic oscillations (QPOs) in a 3.5 ks RXTE observation of the black hole candidate IGR J17091-3624 (ATELs #3144, #3159, #3167, #3203) on March 14th 2011 (MJD 55634.66). Only PCU2 was active, with an average 2-60 keV background-corrected count rate of 110 counts/s. The QPO is visible by eye in the light curve during the first ~1000 seconds and the last ~1500 seconds, with an average 2-60 keV fractional rms amplitude of 5.3+-0.4% and a mean frequency of ~10 mHz.