Related papers: Constraining quasar structure using high-frequency…
Microlensing perturbations to the flux ratios of gravitationally lensed quasar images can vary with wavelength because of the chromatic dependence of the accretion disk's apparent size. Multiwavelength observations of microlensed quasars…
We aim to reveal the sizes of the continuum and broad emission line (BEL) emitting regions in the gravitationally lensed quasar SDSS J1004+4112 by analyzing the unique signatures of microlensing in this system. Through a comprehensive…
Cosmological gravitational microlensing is a useful technique for understanding the structure of the inner parts of a quasar, especially the accretion disk and the central supermassive black hole. So far, most of the cosmological…
Context. The gravitational lens system SDSS J1004+4112 was the first known example of a quasar lensed by a galaxy cluster. The interest in this system has been renewed following the publication of r-band light curves spanning 14.5 years and…
The physical origins of quasar components, such as the broad line region (BLR) and dust torus, remain under debate. To gain insights into them, we focused on Changing-State Quasars (CSQs) which provide a unique perspective through…
We discuss the effects of microlensing on the broad emission lines (BELs) of QSOs in the light of recent determinations of the size of the broad line region (BLR) and its scaling with QSO luminosity. Microlensing by star-sized objects can…
We analyzed the CIV line profile distortions due to microlensing in two quasars, J1339 and J1138. J1339 shows a strong, asymmetric line profile deformation, while J1138 shows a more modest, symmetric deformation. To probe the CIV broad line…
We study three high magnification microlensing events, generally recognized as probable caustic crossings, in the optical light curves of the multiply imaged quasar Q 2237+0305. We model the light curve of each event as the convolution of a…
Recent models for the emission clouds within the Broad Line Region of quasars suggest that they are due to transient overdensities within an overall turbulent medium. If this were the case, the broad line emission would spatially appear…
Assuming a two-component quasar structure model consisting of a central compact source and an extended outer feature, we produce microlensing simulations for a population of star-like objects in the lens galaxy. Such a model is a simplified…
MgII or H$\alpha$ line profile distortions observed in five gravitationally lensed quasars have been compared with simulated ones. The simulations are based on three BLR models, a Keplerian disk (KD), an equatorial wind (EW), and a polar…
Optical and X-ray observations of strongly gravitationally lensed quasars (especially when four separate images of the quasar are produced) determine not only the amount of matter in the lensing galaxy but also how much is in a smooth…
Gravitational microlensing is a powerful tool for probing the inner structure of distant quasars. In this context, we have obtained spectropolarimetric observations of the two images of the broad absorption line (BAL) quasar…
Gravitational microlensing is a powerful tool for probing the physical properties of quasar accretion disks and properties of the lens galaxy such as its dark matter fraction and mean stellar mass. Unfortunately the number of lensed quasars…
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…
We estimate the fraction of mass that is composed of compact objects in gravitational lens galaxies. This study is based on microlensing measurements (obtained from the literature) of a sample of 29 quasar image pairs seen through 20 lens…
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…
A 7.5 years spectrophotometric monitoring program of 28 Palomar-Green quasars to determine the size of their broad emission line region (BLR) is reviewed. We find both the continuum and the emission line fluxes of all quasars to vary during…
We use archival data of NASA's Chandra X-ray telescope to compile an X-ray light curve of all four images of the quadruply lensed quasar Q2237+0305 (z=1.695) from January 2006 to January 2007. We fit simulated point spread functions to the…
The first investigations of the response of the microlensing magnification pattern (at an optical depth of order unity) to the mass function of the microlenses found that the resulting statistics depend only on the mean microlens mass <m>.…