2023 111 P

Giant Radio Galaxies in MeerKAT Legacy Surveys

By: Preet Agnihotri

Department: Physics & Astronomy

Faculty Advisor: Dr. Bill Cotton (National Radio Astronomy Observatory)

This study makes use of data close to the Galactic center taken by the MeerKAT radio telescope. The study makes use of SAOImage DS9 software to pick out the largest 288 radio sources in terms of angular size from the data by hand. The measurement of their angular sizes were then done using the Obit software using the "position logging" feature. Assuming the hosts of the radio sources in our sample are of similar type and stellar mass, as suggested by Merloni (2010), we then assumed that the luminosities and hence the absolute K-band magnitudes for the hosts galaxies in our sample are similar. In absence of redshift data for all the hosts identified in the 2MASS and allWISE surveys using the Astroquery python library, the method of assuming the distances to the radio sources in our sample was then based on the assumption that we knew their absolute magnitudes and their distance modulus could then be calculated based on their apparent magnitudes obtained from the K-band of 2MASS survey. The data was corrected for dust reddening and redshift corrections using DUST catalog from IRSA and a template spectrum for a giant elliptical obtained from Mannucci (2001) respectively. A color-color plot of the sources detected in both 2MASS and WISE catalogs helps convert WISE magnitudes to 2MASS K-band magnitudes where sources were not detected in 2MASS surveys. More calculations were made based on the calculation of the total area of the sky covered by the data which was calculated from a mosaic of the data made using the Reproject python library. Applying a Monte-Carlo analysis on the sample and the distance and size calculations made, we found 40.9 ± 0.9 GRGs in our sample.