Microlensing as a possible probe of event-horizon structure in quasars
- Univ. of Zurich, Zurich (Switzerland)
- Univ. of Zurich, Zurich (Switzerland); Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- Univ. of Zurich, Zurich (Switzerland); SwitzerlandZentrum fur Astronomie der Univ. Heidelberg, Heidelberg (Germany)
In quasars which are lensed by galaxies, the point-like images sometimes show sharp and uncorrelated brightness variations (microlensing). These brightness changes are associated with the innermost region of the quasar passing through a complicated pattern of caustics produced by the stars in the lensing galaxy. In this paper, we study whether the universal properties of optical caustics could enable extraction of shape information about the central engine of quasars. We present a toy model with a crescent-shaped source crossing a fold caustic. The silhouette of a black hole over an accretion disk tends to produce roughly crescent sources. When a crescent-shaped source crosses a fold caustic, the resulting light curve is noticeably different from the case of a circular luminosity profile or Gaussian source. Furthermore, with good enough monitoring data, the crescent parameters, apart from one degeneracy, can be recovered.
- Research Organization:
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), High Energy Physics (HEP)
- Grant/Contract Number:
- AC02-07CH11359
- OSTI ID:
- 1408334
- Report Number(s):
- arXiv:1604.01769; FERMILAB-PUB-16-724-A; 1444474
- Journal Information:
- Monthly Notices of the Royal Astronomical Society, Vol. 475, Issue 2; ISSN 0035-8711
- Publisher:
- Royal Astronomical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Lessons from a blind study of simulated lenses: image reconstructions do not always reproduce true convergence
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journal | January 2020 |
Lessons from a blind study of simulated lenses: image reconstructions do not always reproduce true convergence | text | January 2019 |
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