Abstract Details
| Name: Abhisek Mohapatra Affiliation: Dept. Of Physics, NIT Rourkela Conference ID: ASI2018_805 Title : Implication of ultraviolet background on physical properties of intervening {\CIII} absorbers in the redshift range 2 $<$ z $<$ 3. Authors and Co-Authors : Prof. R. Srianand (IUCAA, INDIA), Dr. V. Khaire (UCSB, USA) Abstract Type : Poster Abstract Category : Extragalactic astronomy Abstract : We present the evolution of 132 intervening CIII + CIV absorbers at 2.1 $<$ z $<$ 3.4 associated with optically-thin {\HI} absorbers in 19 high-quality spectra. We find a negligible evolution of CIV / CIII in this redshift range. For 32 CIV components tied (aligned) with HI, the gas temperature (log $T_b$) estimated from photoionization model is 4.4 $\pm$ 0.3 K,with a negligible non-thermal contribution. We use both photoionization equilibrium (PIE) and non-PIE (using a fixed temperature $T_b$) Cloudy models for the Haardt-Madau QSO+galaxy 2012 \& Khaire-Srianand 2016 UV backgrounds. From our fiducial model, we find that most of the absorbers do not follow Jean's stability and line-of-sight thickness for such absorbers are below 1 kpc. High-metallicity branch absorbers in our sample seem to be originated from extended disks, inner halos or outflowing gas of intervening galaxies, while low-metallicity absorbers are produced by galactic halos or the surrounding IGM filament. Finally, We show pressure-density (P - $\Delta$) relation with power-law index $\gamma$ = 1.3 which supports adiabatic expansion for these absorbers and provides evidence to one of the major reheating events i.e. {\HeII} reionization during the epoch, 2.4 $<$ z $<$ 3.0. |