Abstract Details
| Name: Aditya Manuwal Affiliation: Indian Institute of Space Science and Technology Conference ID: ASI2018_1596 Title : A Survey of Intervening C IV Absorbers at Low Redshifts Authors and Co-Authors : Dr. Anand Narayanan Abstract Type : Poster Abstract Category : Extragalactic astronomy Abstract : We are presenting results from a blind survey for C IV absorbers in intergalactic and circumgalactic medium at low redshifts, with archival UV spectra from HST/Cosmic Origins Spectrograph along 232 QSO sightlines. This is currently the largest survey of such absorbers at low redshifts. This survey of intergalactic medium at different redshifts can be used to examine its chemical evolution across time. We do this by determining statistical constraints on the cosmic distribution and mass density of heavy elements. For some absorption systems, these values might be dominated by surrounding galaxies and have little correspondence to the enrichment of IGM. Such absorbers provide the opportunity to examine physical association of the enriched gas to galaxies. Distribution of absorbers with respect to redshift provides information about the influence of structure formation, galactic outflows and cosmological expansion. At low redshifts, there is still some discrepancy about the properties and distribution of absorption systems in IGM. According to simulations, most of the baryons at these redshifts are supposed to lie within the Warm Hot Intergalactic Medium (WHIM). Earlier studies of absorbers have indicated a diffuse, ionized medium which can be probed using high-ion transitions like C IV, Si IV etc. C IV can be used to trace a large amount of gas present outside the galaxies, including some part of the WHIM. Hence, by assembling a sample of intervening C IV absorbers, we will address the aforementioned points of interest by probing IGM and diffuse galaxy halos. In addition to the derivation of statistical correlations using hydrogen, low ions and C IV, we are also investigating the physical conditions and metallicities of gas traced by this ion along with the possible influence from nearby galaxies on the absorbers to explain their chemical enrichment. |