Abstract Details
| Name: Jais Kumar Affiliation: IIT(BHU), Varanasi Conference ID: ASI2019_284 Title : Instrumental Calibration for EoR observations Authors and Co-Authors : Jais Kumar and Prasun Dutta Abstract Type : Oral Abstract Category : Extragalactic Astronomy Abstract : EoR is the epoch during which the universe became almost ionized from a completely neutral phase because of the radiation from the first luminous objects and galaxies. It holds the key to understand the structure formation in the early universe and its evolution, properties of first luminous objects and their properties. It has The major challenges in observing the HI 21-cm signal from the cosmic dawn, the Epoch of Reionization and Post Reionization era includes the presence of strong foreground emission from intervening compact sources like radio galaxies and strong synchrotron emission from the Milky Way. Presence of these three to four orders of magnitude larger foreground signals in the frequency of the redshifted 21-cm signal requires a high dynamic range calibration of the instrumental gain, leakage, and ionospheric phase errors. In this work, we are investigating the systematic effects of the instrumental response in estimating the power spectra of the redshifted 21-cm signal in presence of bright foregrounds. Our aim is to access and quantify the requirement for the instrumental gain stability with time and frequency and effectiveness of the contemporary calibration algorithms for the existing and upcoming low-frequency radio interferometers. In this regard, we shall present our results quantifying the requirement for gain variation and stability requirement for a GMRT and LOFAR like array. |