Probing ~100 AU Intergalactic MgII Absorbing "Cloudlets" with Quasar Microlensing
arXiv:astro-ph/0612403 · doi:10.1086/513099
Abstract
Intergalactic MgII absorbers are known to have structures down to scales ~ 10^{2.5} pc, and there are now indications that they may be fragmented on scales <~ 10^{-2.5} pc (Hao et al., astro-ph/0612409). When a lensed quasar is microlensed, the micro-images of the quasar experience creation, destruction, distortion, and drastic astrometric changes during caustic-crossing. I show that quasar microlensing can effectively probe MgII and other absorption "cloudlets" with sizes ~ 10^{-4.0} - 10^{-2.0} pc by inducing significant spectral variability on the timescales of months to years. With numerical simulations, I demonstrate the feasibility of applying this method to Q2237+0305, and I show that high-resolution spectra of this quasar in the near future would provide a clear test of the existence of such metal-line absorption "cloudlets" along the quasar sight line.
13 pages, 2 figures, ApJ, submitted; for PDF file with high-res figures, see http://www.astronomy.ohio-state.edu/~dong/mg2/mg2.pdf
References in corpus (11)
- Quantitative Interpretation of Quasar Microlensing Light Curves
- Size is Everything: Universal Features of Quasar Microlensing with Extended Sources
- On the Incidence of Strong MgII Absorbers Along GRB Sightlines
- The Sizes and Kinematic Structure of Absorption Systems Towards the Lensed Quasar APM08279+5255
- Gravitational Microlensing
- Small Scale Structure at High Redshift: IV. Low Ionization Gas Intersecting Three Lines of Sight to Q2237+0305
- Astrometric Microlensing of Quasars : Dependence on surface mass density and external shear
- Strongly Variable z=1.48 FeII and MgII Absorption in the Spectra of z=4.05 GRB 060206
- Disparate MgII Absorption Statistics towards Quasars and Gamma-Ray Bursts : A Possible Explanation
- Constraining the photometric properties of MgII absorbing galaxies with the SDSS
- Probing Sub-parsec Structure in the Lyman Alpha Forest with Gravitational Microlensing