Bibcode
Fian, C.; Guerras, Eduardo; Mediavilla, E.; Jiménez-Vicente, J.; Muñoz, J. A.; Falco, E. E.; Motta, V.; Hanslmeier, A.
Bibliographical reference
The Astrophysical Journal, Volume 859, Issue 1, article id. 50, 26 pp. (2018).
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5
2018
Journal
Citations
33
Refereed citations
29
Description
We study the broad emission lines in a sample of 11 gravitationally
lensed quasars with at least two epochs of observation to identify
intrinsic variability and to disentangle it from microlensing. To
improve our statistical significance and emphasize trends, we also
include 15 lens systems with single-epoch spectra. Mg II and C III]
emission lines are only weakly affected by microlensing, but C IV shows
strong microlensing in some cases, even for regions of the line core,
presumably associated with small projected velocities. However,
excluding the strongly microlensed cases, there is a strikingly good
match, on average, between the red wings of the C IV and C III]
profiles. Analysis of these results supports the existence of two
regions in the broad-line region (BLR), one that is insensitive to
microlensing (of size ≳50 lt-day and kinematics not confined to a
plane) and another that shows up only when it is magnified by
microlensing (of size of a few light-days, comparable to the accretion
disk). Both regions can contribute in different proportions to the
emission lines of different species and, within each line profile, to
different velocity bins, all of which complicates detailed studies of
the BLR based on microlensing size estimates. The strength of the
microlensing indicates that some spectral features that make up the
pseudo-continuum, such as the shelf-like feature at λ1610 or
several Fe III blends, may in part arise from an inner region of the
accretion disk. In the case of Fe II, microlensing is strong in some
blends but not in others. This opens up interesting possibilities to
study quasar accretion disk kinematics. Intrinsic variability seems to
affect the same features prone to microlensing, with similar frequency
and amplitude, but does not induce outstanding profile asymmetries. We
measure intrinsic variability (≲20%) of the wings with respect to
the cores in the C IV, C III], and Mg II lines consistent with
reverberation mapping studies.
Related projects
Relativistic and Theoretical Astrophysics
Introduction Gravitational lenses are a powerful tool for Astrophysics and Cosmology. The goals of this project are: i) to obtain a robust determination of the Hubble constant from the time delay measured between the images of a lensed quasar; ii) to study the individual and statistical properties of dark matter condensations in lens galaxies from
Evencio
Mediavilla Gradolph