Abstract Details
| Name: Raghunath Ghara Affiliation: NCRA-TIFR Conference ID: ASI2016_509 Title : 21-cm signature of the first sources in the Universe: Prospects of detection with SKA Authors and Co-Authors : Tirthankar Roy Choudhury (NCRA-TIFR, Pune), Kanan K. Datta (Presidency University, Kolkata) Abstract Type : Poster Abstract Category : General Relativity and Cosmology Abstract : Currently several low-frequency experiments are being planned to study the nature of the first stars using the redshifted 21-cm signal from the cosmic dawn and epoch of reionization. Using a one-dimensional radiative transfer code, we model the 21-cm signal pattern around the early sources for different source models, i.e., the metal-free Population III (PopIII) stars, primordial galaxies consisting of Population II (PopII) stars, mini-QSOs and high-mass X-ray binaries (HMXBs). We investigate the detectability of these sources by comparing the 21-cm visibility signal with the system noise appropriate for a telescope like the SKA1-low. Upon integrating the vis- ibility around a typical source over all baselines and over a frequency interval of 16 MHz, we find that it will be possible make a ∼ 9 − σ detection of the isolated sources like PopII galaxies, mini-QSOs and HMXBs at z ∼ 15 with the SKA1-low in 1000 hours. The exact value of the signal to noise ratio (SNR) will depend on the source properties, in particular on the mass and age of the source and the escape fraction of ionizing photons. The predicted SNR decreases with increasing redshift. We provide simple scaling laws to estimate the SNR for different values of the parameters which characterize the source and the surrounding medium. These calculations will be useful in planning 21-cm observations to detect the first sources. |