Bibcode
Jiménez-Vicente, J.; Mediavilla, E.; Kochanek, C. S.; Muñoz, J. A.
Bibliographical reference
The Astrophysical Journal, Volume 806, Issue 2, article id. 251, 7 pp. (2015).
Advertised on:
6
2015
Journal
Citations
38
Refereed citations
35
Description
We use X-ray and optical microlensing measurements to study the shape of
the dark matter density profile in the lens galaxies and the size of the
(soft) X-ray emission region. We show that single epoch X-ray
microlensing is sensitive to the source size. Our results, in good
agreement with previous estimates, show that the size of the X-ray
emission region scales roughly linearly with the black hole mass, with a
half-light radius of {{R}}1/2≃ (24+/-
14){{r}}{\boldsymbol{g}} where
{r}g={{GM}}{BH}/{c}2. This corresponds
to a size of
{log}({{R}}1/2/{cm})={15.6}-0.3+0.3 or
∼1 lt-day for a black hole mass of
{M}{BH}={10}9 {M}ȯ . We
simultaneously estimated the fraction of the local surface mass density
in stars, finding that the stellar mass fraction is α = 0.20
± 0.05 at an average radius of ∼ 1.9{R}e, where
Re is the effective radius of the lens. This stellar mass
fraction is insensitive to the X-ray source size and in excellent
agreement with our earlier results based on optical data. By combining
X-ray and optical microlensing data, we can divide this larger sample
into two radial bins. We find that the surface mass density in the form
of stars is α = 0.31 ± 0.15 and α = 0.13 ±
0.05 at (1.3+/- 0.3){R}e and (2.3+/- 0.3){R}e,
respectively, in good agreement with expectations and some previous
results.
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