相关论文: Disentangling microlensing and differential extinc…
We use spectroscopic observations of the gravitationally lensed systems SDSS0924+0219(BC), Q1355-2257(AB), and SDSS1029+2623(BC) to analyze microlensing and dust extinction in the observed components. We detect chromatic microlensing…
We present the first spatially resolved spectroscopic observations of the recently discovered quadruple QSO and gravitational lens HE0435-1223. Using the Potsdam Multi-Aperture Spectrophotometer (PMAS), we show that all four QSO components…
We present a survey of the extinction properties of ten lensing galaxies, in the redshift range z = 0.04 - 1.01, using multiply lensed quasars imaged with the ESO VLT in the optical and near infrared. The multiple images act as 'standard…
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…
Using infrared spectra of the z = 1.693 quadruply lensed quasar HE0435-1223 acquired in 2009 with the spectrograph SINFONI at the ESO Very Large Telescope, we have detected a clear microlensing effect in images A and D. While microlensing…
We present Hubble Space Telescope (HST) infrared images of four gravitational lens systems from the JVAS/CLASS gravitational lens survey and compare the new infrared HST pictures with previously published WFPC2 HST optical images and radio…
We critique the method of constructing extinction curves of lensing galaxies using multiply imaged QSOs. If one of the two QSO images is lightly reddened or if the dust along both sightlines has the same properties then the method works…
In the course of a Cycle 8 snapshot survey, we have discovered that the z=1.565 quasar HE 0512-3329 is a double with image separation 0.644", almost certainly due to gravitational lensing. The two components differ in brightness by only 0.4…
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…
SDSS J0924+0219 is the most glaring example of a gravitational lens with anomalous flux ratios: optical broad-band photometry shows image D to be a factor of 12 fainter than expected for smooth lens potentials. We report spectroscopy…
Similar to the magnification of the galaxies' fluxes by gravitational lensing, the extinction of the fluxes by comic dust, whose existence is recently detected by Menard et al (2009), also modify the distribution of a flux-selected galaxy…
Quadruple gravitational lens systems offer the possibility of measuring time delays for image pairs, microlensing effects, and extinction in distant galaxies. Observations of these systems may be used to obtain estimates of H_o and to study…
Strong gravitational lensing has significantly advanced the study of high-redshift galaxies, but the differential magnification effect inevitably introduces biases in the spectral analysis of source galaxies. This work investigates these…
The near-infrared emission lines of Fe$^{+}$ at 1.257, 1.321, and 1.644 $\mu$m share the same upper level; their ratios can then be exploited to derive the extinction to a line emitting region once the relevant spontaneous emission…
On the basis of 16 years of spectroscopic observations of the four components of the gravitationally lensed broad absorption line (BAL) quasar H1413+117, covering the ultraviolet to visible rest-frame spectral range, we analyze the spectral…
Light rays from a multiply imaged quasar usually sample different path lengths across the deflector. Extinction in the lensing galaxy may thus lead to a differential obscuration and reddening between the observed macro-lensed QSO images.…
The spectroscopy of microlensed sources towards the Galactic bulge provides a unique opportunity to study (i) the kinematics of the Galactic bulge, particularly its far-side, (ii) the effects of extinction on the microlensed sources, and…
We use observations from the CASTLES survey of gravitational lenses to study extinction in 23 lens galaxies with $0 < z_l < 1$. The median differential extinction between lensed images is $\Delta E(\bv) = 0.05$ mag, and the directly…
We estimate the dust extinction laws in two intermediate redshift galaxies. The dust in the lens galaxy of LBQS1009-0252, which has an estimated lens redshift of zl~0.88, appears to be similar to that of the SMC with no significant feature…
Context. Observations of quasars shining through foreground galaxies, offer a way to probe the dust extinction curves of distant galaxies. Interesting objects for this study are found in strong gravitational lensing systems, where the…