Related papers: Measuring Microlensing using Spectra of Multiply L…
Quasar microlensing serves as a unique probe of discrete objects within galaxies and galaxy clusters. Recent advancement of the technique shows that it can constrain planet-scale objects beyond our native galaxy by studying their induced…
The magnification induced by gravitational microlensing is sensitive to the size of a source relative to the Einstein radius, the natural microlensing scale length. This paper investigates the effect of source size in the case where the…
The light curves of the two images of the double quasar Q0957+561 as obtained by Kundic et al. (1997) are almost identical, except for an overall time delay and scaling factor. This allows us to put limits on the amount of microlensing that…
We present results from Chandra observations of SDSS J1004+4112, a strongly lensed quasar system with a maximum image separation of 15". All four bright images of the quasar, as well as resolved X-ray emission originating from the lensing…
We use the high magnification event seen in the 1999 OGLE campaign light curve of image C of the quadruply imaged gravitational lens Q2237+0305 to study the structure of the quasar engine. We have obtained g'- and r'-band photometry at the…
Recent studies have shown that line profile distortions are commonly observed in gravitationally lensed quasar spectra. We investigate the effect of gravitational microlensing on quasar broad emission line profiles and their underlying…
We present results from monitoring of the distant (z = 2.64), gravitationally lensed quasar MG J0414+0534 with the Chandra X-ray Observatory. An Fe Ka line at 6.49 +/- 0.09 keV (rest-frame) with an equivalent width of ~ 190eV consistent…
Optical and X-ray observations of the quadruply imaged quasar 1RXS J1131-1231 show flux ratio anomalies among the images factors of ~2 in the optical and \~3-9 in X-rays. Temporal variability of the quasar seems an unlikely explanation for…
Gravitational microlensing of planetary-mass objects (or "nanolensing", as it has been termed) can be used to probe the distribution of mass in a galaxy that is acting as a gravitational lens. Microlensing and nanolensing light curve…
We analyze the optical, UV, and X-ray microlensing variability of the lensed quasar SDSS J0924+0219 using six epochs of Chandra data in two energy bands (spanning 0.4-8.0 keV, or 1-20 keV in the quasar rest frame), 10 epochs of F275W…
We investigate the spectro-photometric variability of quasars due to lensing of small mass substructure (from several tens to several hundreds solar masses). The aim of this paper is to explore the milli/microlensing influence on the flux…
Microlensing observations of the Q0957+561 A,B have consistently shown evidence for structure in the quasar that has not been evident in available microlensing models, where the luminous source has been consistently modeled as a single…
Due to the finite size of the disk and the temperature fluctuations producing the variability, microlensing changes the actual time delays between images of strongly lensed AGN on the $\sim$day(s) light-crossing time scale of the emission…
We predict the effects of gravitational lensing on the color-selected flux-limited samples of z~4.3 and z>5.8 quasars, recently published by the Sloan Digital Sky Survey (SDSS). Our main findings are: (i) The lensing probability should be…
We consider a contribution of microlensing to the X-ray variability of high-redshifted QSOs. Such an effect could be caused by stellar mass objects (SMO) located in a bulge or/and in a halo of this quasar as well as at cosmological…
A small fraction of all quasars are strongly lensed and multiply imaged, with usually a galaxy acting as the main lens. Some, maybe all of these quasars are also affected by microlensing, the effects of stellar mass objects in the lensing…
Observations of the effect of microlensing in gravitationally lensed quasars can be used to study the structure of active galactic nuclei on distance scales down to the sizes of the supermassive black holes powering source activity. We…
We present new HST WFPC3 imaging of four gravitationally lensed quasars: MG 0414+0534; RXJ 0911+0551; B 1422+231; WFI J2026-4536. In three of these systems we detect wavelength-dependent microlensing, which we use to place constraints on…
We present new spectroscopic and polarimetric observations of the gravitational lens SDSS J1004+4112 taken with the 6m telescope of the Special Astrophysical Observatory (SAO, Russia). In order to explain the variability that is observed…
We present our long term Chandra X-ray monitoring data for the gravitationally lensed quasar Q2237+0305 with 20 epochs spanning 10 years. We easily detect microlensing variability between the images in the full (0.2--8 keV), soft (0.2--2…