| Name: | Shivam Burman |
| Affiliation: | Indian Institute of Technology Delhi |
| Conference ID: | ASI2025_320 |
| Title: | Unveiling Galactic Magnetism: Probing Magnetic Field Profiles with Background Quasars |
| Authors: | Shivam Burman, Paras Sharma, Sunil Malik, Suprit Singh |
| Authors Affiliation: | Shivam Burman, Paras Sharma, Suprit Singh (Indian Institute of Technology Delhi, Delhi-110016, India)
Sunil Malik (Institute fur Physik und Astronomie Universitat Potsdam, D-14476 Potsdam, Germany) |
| Mode of Presentation: | Oral |
| Abstract Category: | Galaxies and Cosmology |
| Abstract: | Understanding the magnetic fields in distant galaxies is key to exploring how these galaxies evolve and interact with their surroundings. By utilizing the rotation measure (RM) of the background quasars, we have developed a radial profile of the magnetic field in a typical high redshift galaxy. We used Mg II absorption systems to identify these intervening galaxies by implementing redshift matching criteria in which the spectroscopic redshifts must lie within 3𝜎 of the photometric redshifts, followed by visual checks. We obtained a sample of 59 quasar-galaxy pairs. The quasar line-of-sights passes through various impact parameters (D) up to 160 kpc, covering the circumgalactic medium of a typical Milky-Way type galaxy. Utilizing the galactic RM removed residual rotation measure (RRM) of these sightlines, we estimated the excess in RRM dispersion, which translates to the magnetic fields by considering a typical electron density. Our findings showed that the magnetic fields are stronger closer to the galaxy's disk, averaging about 2.39 μG up to 50 kpc, and decreasing to 1.67 μG beyond 50 kpc. This observation fits well with the studies based on simulations and sheds light on how magnetic fields behave not just in the dense parts of galaxies, but also in their more diffuse outer regions. Our technique offers a promising approach for future surveys like LOFAR and the Square Kilometre Array (SKA), which could help us in understanding even more detailed structures of galactic magnetic fields in high redshift galaxies. |
