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arXiv · 0801.3729

Optical monitoring of the z=4.40 quasar Q 2203+292

E. P. Ovcharov·P. L. Nedialkov·A. T. Valcheva·V. D. Ivanov·N. A. Tikhonov·I. S. Stanev·A. B. Kostov·Ts. B. Georgiev
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Abstract

We report Cousins R-band monitoring of the high-redshift (z=4.40) radio quiet quasar Q 2203+292 from May 1999 to October 2007. The quasar shows maximum peak-to-peak light curve amplitude of ~0.3 mag during the time of our monitoring, and ~0.9 mag when combined with older literature data. The rms of a fit to the light curve with a constant is 0.08 mag and 0.2 mag, respectively. The detected changes are at ~3-sigma level. The quasar was in a stable state during the recent years and it might have undergone a brightening event in the past. The structure function analysis concluded that the object shows variability properties similar to those of the lower redshift quasars. We set a lower limit to the Q 2203+292 broad line region mass of 0.3-0.4 M_odot. Narrow-band imaging search for redshifted Ly_alpha from other emission line objects at the same redshift shows no emission line objects in the quasar vicinity.

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E. P. Ovcharov, P. L. Nedialkov, A. T. Valcheva, V. D. Ivanov, N. A. Tikhonov, I. S. Stanev, A. B. Kostov, Ts. B. Georgiev. 2008-01-24. Optical monitoring of the z=4.40 quasar Q 2203+292. https://doi.org/10.1111/j.1365-2966.2008.12990.x

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