| Name: | Rashmi Sagar |
| Affiliation: | Indian Institute of Technology Indore |
| Conference ID : | ASI2024_723 |
| Title : | Unveiling the ELAIS-N1 Field: uGMRT Band-2 Observations, Catalogue, Source Count, and Insights into Galactic Diffuse Synchrotron |
| Authors : | Rashmi Sagar , Abhirup Datta, Arnab Chakraborty |
| Authors Affiliation: | Rashmi Sagar , Abhirup Datta (Indian Institute of Technology Indore, Indore-452020, India)
Arnab Chakraborty ( McGill University, Montreal, QC-H3A 2T8, Canada) |
| Mode of Presentation: | Poster |
| Abstract Category : | Galaxies and Cosmology |
| Abstract : | In the quest to unveil the mysteries of the Epoch of Reionization, detecting the elusive redshifted 21-cm signal of neutral hydrogen emerges as a formidable challenge. This faint signal grapples with foreground complexities, particularly emanating from galactic and extragalactic sources, especially at lower frequencies. The advent of uGMRT has ushered in a new era, enabling observations at these crucial frequencies, and offering a deeper understanding of the foreground sky. This study presents uGMRT observations of the ELAIS-N1 field within the band-2 (120 - 250 MHz). A significant feat is achieved with a substantial 32-hour observations and an operational bandwidth of approximately 100 MHz. Impressively, this effort culminates in a local RMS noise level of 236 ðJy/beam in the final single-pointing image, a noteworthy accomplishment facilitated by uGMRT. The resulting image boasts a commendable resolution of approximately 11.45 arcseconds, housing a comprehensive radio catalogue with 1029 sources, all surpassing the 5ð detection threshold. A meticulous cross-matching and comparison exercise with extant radio catalogues of the same field adds credence to the precision of both flux density and positional offset. Moreover, a well-grounded normalized source count derived from this radio catalogue underscores its consistency with source counts from prior catalogues in different fields. This count aligns seamlessly with the LOFAR catalogue for the same field at 150 MHz. Delving deeper, this work scrutinizes the statistical fluctuations in Galactic Diffuse Synchrotron Emission (GDSE) via power spectrum estimators. Two techniques are meticulously compared: an image-based estimator and a visibility-based estimator. Intriguingly, the results posit
the image-based estimator as a more effective approach for investigating low-frequency GDSE. Unlike its counterpart, the visibility estimator, this method considers the entire field of view, eschewing the need for tapering. This study advances fresh insights into the nuanced nature of GDSE and its pivotal role in low-frequency radio observations. |
