We report the discovery of a “ super-damped ” Lyman-alpha absorber at z _ { abs } = 2.2068 toward QSO Q1135-0010 in the Sloan Digital Sky Survey , and follow-up VLT UVES spectroscopy .
Voigt profile fit to the DLA line indicates log N _ { HI } = 22.05 \pm 0.1 .
This is the second QSO DLA discovered to date with such high N _ { HI } .
We derive element abundances [ Si/H ] = -1.10 \pm 0.10 , [ Zn/H ] = -1.06 \pm 0.10 , [ Cr/H ] = -1.55 \pm 0.10 , [ Ni/H ] = -1.60 \pm 0.10 , [ Fe/H ] = -1.76 \pm 0.10 , [ Ti/H ] = -1.69 \pm 0.11 , [ P/H ] = -0.93 \pm 0.23 , and [ Cu/H ] = -0.75 \pm 0.14 .
Our data indicate detection of Ly- \alpha emission in the DLA trough , implying a star formation rate of \sim 10 M _ { \odot } yr ^ { -1 } in the absence of dust attenuation .
CÂ II ^ { * } \lambda 1336 absorption is also detected , suggesting SFR surface density -2 < { log } \dot { \psi _ { * } } < 0 M _ { \odot } yr ^ { -1 } kpc ^ { -2 } .
We estimate electron density in the range 3.5 \times 10 ^ { -4 } to 24.7 cm ^ { -3 } from C II ^ { * } /CÂ II , and \sim 0.5-0.9 cm ^ { -3 } from Si II ^ { * } /Si II .
Overall , this is a robustly star-forming , moderately enriched absorber , but with relatively low dust depletion .
Fitting of the SDSS spectrum yields low reddening for Milky Way , LMC , or SMC extinction curves .
No CO absorption is detected , and C I absorption is weak .
The low dust and molecular content , reminiscent of some SMC sight-lines , may result from the lower metallicity , and a stronger radiation field ( due to higher SFR ) .
Finally , we compare this absorber with other QSO and GRB DLAs .