The accretion disc in the quasar SDSS J0924+0219
Abstract
We present single-epoch multiwavelength optical-near-infrared observations of the `anomalous' lensed quasar SDSS J0924+0219, made using the Magellan 6.5-m Baade Telescope at Las Campanas Observatory, Chile. The data clearly resolve the anomalous bright image pair in the lensed system, and exhibit a strong decrease in the anomalous flux ratio with decreasing wavelength. This is interpreted as a result of microlensing of a source of decreasing size in the core of the lensed quasar. We model the radius of the continuum emission region, σ, as a power law in wavelength, σ ~ λζ. We place an upper limit on the Gaussian radius of the u'-band emission region of 3.04 × 1016h-1/270 (<M>/Msolar)1/2 cm, and constrain the size-wavelength power-law index to ζ < 1.34 at 95 per cent confidence. These observations rule out an alpha-disc prescription for the accretion disc in SDSS J0924+0219 with 94 per cent confidence.
This paper includes data gathered with the 6.5-m Magellan Telescopes located at Las Campanas Observatory, Chile. E-mail: dfloyd@lco.cl (DJEF); nbate@physics.unimelb.edu.au (NFB); rwebster@unimelb.edu.au (RLW)- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- September 2009
- DOI:
- 10.1111/j.1365-2966.2009.15045.x
- arXiv:
- arXiv:0905.2651
- Bibcode:
- 2009MNRAS.398..233F
- Keywords:
-
- accretion;
- accretion discs;
- gravitational lensing;
- quasars: individual: SDSS J0924+0219;
- Astrophysics - High Energy Astrophysical Phenomena;
- Astrophysics - Cosmology and Extragalactic Astrophysics
- E-Print:
- 8 pages, 5 figures. Accepted for publication in MNRAS