We report the detection of the host galaxy of a damped Ly$alpha$ system (DLA) with log N(HI) $ [rm cm^{-2}]$ = $21.0 pm 0.10$ at $z approx 3.0091$ towards the background quasar SDSS J011852+040644 using the Palomar Cosmic Web Imager (PCWI) at the Hale (P200) telescope. We detect Ly$alpha$ emission in the dark core of the DLA trough at a 3.3$sigma$ confidence level, with Ly$alpha$ luminosity of $L_{rm Lyalpha}$ $rm = (3.8 pm 0.8) times 10^{42} erg s^{-1}$, corresponding to a star formation rate of $gtrsim 2 rm M_{odot} yr^{-1}$ (considering a lower limit on Ly$alpha$ escape fraction $f_{esc}^{Ly{alpha}} sim 2%$) as typical for Lyman break galaxies at these redshifts. The Ly$alpha$ emission is blueshifted with respect to the systemic redshift derived from metal absorption lines by $281 pm 43$ km/s. The associated galaxy is at very small impact parameter of $lesssim 12 rm kpc$ from the background quasar, which is in line with the observed anticorrelation between column density and impact parameter in spectroscopic searches tracing the large-scale environments of DLA host galaxies.
تحميل البحث