Abstract Details
| Name: Abhisek Mohapatra Affiliation: NIT, Rourkela Conference ID: ASI2019_55 Title : Physical conditions in high-z triply ionized carbon: origin and evolution Authors and Co-Authors : Abhisek Mohapatra (NIT Rourkela), R. Srianand (IUCAA), Vikram Khaire (UCSB), Ananta C. Pradhan (NIT Rourkela) Abstract Type : Oral Abstract Category : Extragalactic Astronomy Abstract : We present detailed photoionization models of well-aligned optically thin triple ionized carbon (C III) absorption components at 2.1 < z < 3.4 analyzed by Kim et al. (2016). Using our models we estimate density (nH), metallicity ([C/H]), total hydrogen column density and line-of-sight thickness (L) in each C III components. From our fiducial model, we find that most of the absorbers do not follow hydrostatic equilibrium and line-of-sight thickness for such absorbers are below 1 kpc. Our inferred nH and overdensity (Δ) are much higher and favor the absorption originating from gas associated with circumgalactic medium (CGM). 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. We show L vs. [C/H] correlation can be well reproduced if L is governed by the product of gas cooling time and sound crossing speed as expected in the case of cloud fragmentation under thermal instabilities. Studying the optically thin C III absorbers over a large z range and probably correlating their z evolution with global star-formation rate density evolution can shed light into the physics of cold clump formation and their evolution in the CGM. |