Abstract Details
| Name: Katherine Rawlins Affiliation: UM-DAE Centre for Excellence in Basic Sciences Conference ID: ASI2015_463 Title : Physical conditions for two high redshifted damped Lyman alpha systems, DLAs at zabs = 2.3377 and zabs = 2.41837 Authors and Co-Authors : Gargi Shaw, UM-DAE Centre for Excellence in Basic Sciences, Mumbai Abstract Type : Poster Abstract Category : Extragalactic astronomy Abstract : Damped Lyman alpha systems (DLAs) are quasar absorption systems with neutral hydrogen column density greater than 2×1020 cm-2. They are considered to be star-forming regions which are the progenitors of present-day disk galaxies. Studying the physical conditions in DLAs is significant towards our understanding of galaxy formation and evolution. We have modelled two DLAs at zabs = 2.3377 and zabs = 2.41837, using the spectral synthesis code CLOUDY (http://www.nublado.org). These DLAs have been observed in absorption along the sightline towards the quasars LBQS 1232+0815 and SDSS J143912.04+111740.5 respectively. H2 has been detected in both DLAs, and the DLA at zabs = 2.41837 also has CO. We have predicted the density, radiation field, metallicity, dust grain size, composition and abundances of the DLAs self-consistently based on the observed column densities of various atomic and molecular lines. Our simulations suggest grain sizes smaller than the ISM dust grains for these two DLAs. |