Abstract Details
| Name: Rajeshwari Dutta Affiliation: IUCAA Conference ID: ASI2015_435 Title : Cold HI 21-cm Absorption Line Survey Authors and Co-Authors : R. Srianand (IUCAA), N. Gupta (IUCAA) Abstract Type : Poster Abstract Category : Extragalactic astronomy Abstract : We are carrying out a systematic survey for 21-cm absorption in a sample of quasar sight lines passing through disks/halos of nearby galaxies (quasar galaxy pairs or QGPs) using 200 hours of GMRT time. Using SDSS and FIRST catalogs we have built a sample of 105 QGPs with small projected separation in the sky, b <= 30 kpc. Our galaxy sample spans a wide range of luminosity, morphology, impact parameter and environment. Thus, it will provide an important resource for understanding high-z galaxy evolution based on absorption line studies. From this parent sample, we have constructed a sub-sample of 36 QGPs for which we have the optical spectra from SDSS and our spectroscopic observations using SALT. Optical spectra of these quasars and galaxies are being utilised to measure the redshifts for conducting radio spectral line observations and to derive the galaxy properties. From our ongoing survey, we report 21-cm detection from two new QGPs. We wish to present these and upcoming results from our GMRT survey, which will allow us to infer correlations between properties of the absorbing gas and those of the host galaxies. Further, these results would be extremely relevant for interpreting on-going and future blind 21-cm searches at z > 2 where it is difficult to detect the associated galaxies. |