Related papers: Microlensing Induced Spectral Variability In Q2237…
Recent estimates of the scale of structures at the heart of quasars suggest that the region responsible for the broad line emission are smaller than previously thought. With this revision of scale, the broad line region is amenable to the…
We consider the influence of (milli/micro)lensing on the spectra of lensed QSOs. We propose a method for the observational detection of microlensing in the spectra of lensed QSOs and apply it to the spectra of the three lensed QSOs (PG…
We report on a program of spectroscopic observations of gravitationally-lensed QSOs with multiple images. We seek to establish whether microlensing is occurring in each QSO image using only single-epoch observations. We calculate flux…
We present an extended optical monitoring of the quadruply-imaged gravitationally lensed quasar QSO 2237+0305, the Einstein Cross, including observations from different observatories in both hemispheres and using a new photometric…
The observed enhancement of the Fe K$\alpha$ line in three gravitationally lensed QSOs (MG J0414+0534, QSO 2237+0305, H1413+117) is interpreted in terms of microlensing, even when equivalent X-ray continuum amplification is not observed. In…
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…
It is demonstrated that the 1988-90 microlensing events in image A of Q2237+0305 reported by Racine (1992) do not exclude microlensing models with very low average mass, making the source radius larger than the projected Einstein radius…
Selective amplification of the line and continuum source by microlensing in a lensed quasar can lead to changes of continuum spectral slopes and line shapes in the spectra of the quasar components. Comparing the spectra of different…
The physical nature of the material responsible for the high--velocity, broad-absorption line features seen in a small fraction of quasar spectra has been the subject of debate since their discovery. This has been especially compounded by…
Lensed quasars are powerful cosmic laboratories; they are used to simultaneously probe various astrophysical phenomena. Microlensing by stars within distant galaxies acts as strong gravitational lenses of multiply imaged quasars, and…
We aim to unveil the structure of the continuum and broad-emission line (BEL) emitting regions in the gravitationally lensed quasar SDSS J1339+1310 by examining the distinct signatures of microlensing present in this system. Our study…
Owing to the advent of large area photometric surveys, the possibility to use broad band photometric data, instead of spectra, to measure the size of the broad line region of active galactic nuclei, has raised a large interest. We describe…
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…
The passage of stars through the beam of a lensed quasar can induce violent fluctuations in its apparent brightness. The fluctuations observed in the Huchra lens, (2237+0305), are taken to be the first evidence of this ``microlensing''…
Line profile distortions are commonly observed in gravitationally lensed quasar spectra. These distortions are caused by microlensing from the stars in the lensing galaxy, which produce differential magnification of spatially and…
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…
Flux ratio `anomalies' in quadruply-imaged gravitational lenses can be explained with galactic substructure of the sort predicted by CDM, but the strength and uniqueness of that hypothesis needs to be further assessed. A good way to do that…
Strong gravitational lensing leads to an occurrence of multiple images, with different magnifications, of a lensed source. Those magnifications can in turn be modified by microlensing on smaller mass scales within the lens. Recently,…
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…
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…