Physics – Optics
Scientific paper
Jan 2009
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009aas...21341104d&link_type=abstract
American Astronomical Society, AAS Meeting #213, #411.04; Bulletin of the American Astronomical Society, Vol. 41, p.216
Physics
Optics
Scientific paper
We present the results of near-infrared (2 and 3 \micron) monitoring of Sgr A*-IR with 1 min time sampling using the natural and laser guide star adaptive optics (LGS AO) system at the Keck II telescope. Sgr A*-IR was observed continuously for up to three hours on each of seven nights, between 2005 July and 2007 August. Sgr A*-IR is detected at all times and is continuously variable, with a median observed 2 $\micron$ flux density of 0.192 mJy, corresponding to 16.3 magnitude at $K^{\prime}$. These observations allow us to investigate Nyquist sampled periods ranging from about 2 minutes to an hour. Using Monte Carlo simulations, we find that the variability of Sgr A* in this data set is consistent with models based on correlated noise with power spectra having frequency dependent power law slopes between 2.0 to 3.0, consistent with those reported for AGN light curves. Of particular interest are periods of $\sim 20$ min, corresponding to a quasi-periodic signal claimed based upon previous near-infrared observations and interpreted as the orbit of a `hot spot' at or near the last stable orbit of a spinning black hole. We find no significant periodicity at any time scale probed in these new observations for periodic signals. This study is sensitive to periodic signals with amplitudes greater than 20\% of the maximum amplitude of the underlying red noise component for light curves with duration greater than $\sim 2$ hours at a 98\% confidence limit.
Do Tuan
Ghez Andrea
Hornstein Seth D.
Lu Jianhua
Matthews Keith
No associations
LandOfFree
A Near-IR Variability Study of the Galactic Black Hole: A Red Noise Source with No Detected Periodicity 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 A Near-IR Variability Study of the Galactic Black Hole: A Red Noise Source with No Detected Periodicity, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Near-IR Variability Study of the Galactic Black Hole: A Red Noise Source with No Detected Periodicity will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1701809