arXiv subjects

Timea O. Kovacs

Publications and source records attributed to Timea O. Kovacs.

3 recordsLinked to original sources

arXiv2026

Probing Magnetic Fields In and Around Galaxies Near and Far

In order to understand the magnetization of galaxies and the role of magnetic fields in feedback processes that govern star formation and galaxy evolution, it is essential to have a comprehensive census of magnetic fields in and around galaxies from the nearby Universe to high redshifts. In this chapter, we outline the science goals, strategies, techniques, and observational requirements with SKA AA4 for (1) a homogeneous polarimetric survey of nearby galaxies - mapping both the diffuse polarized emission as well as producing a dense RM grid within the virial radius; (2) a survey of the interstellar magnetic fields in distant galaxies targeting strong lensing systems with polarized lensed quasars, as well as a general statistical back-illumination survey to probe the redshift evolution of magnetic fields in the CGM. These proposed observations will serve as a major step towards understanding the co-evolution of galaxies and their magnetic fields over cosmic time and provide constraints on galactic dynamo theories.

astro-ph.GA↗

arXiv2026

Small-scale Magnetic Fields in the Milky Way and Nearby Galaxies

Magnetic fields in galaxies span decades in physical scale, from the coherent magnetic fields on galactic scales (> kpc) to the random magnetic fields from 100 pc to the resistive scale of the galactic plasma (i.e. ~1e6 cm). While many radio studies to date have placed more emphasis on the large-scale galactic magnetic fields than the small-scale counterparts, the emerging SKA will greatly facilitate accurate, detailed studies of the small-scale (< 100 pc) galactic magnetic fields. In this Chapter, we highlight the importance of understanding the small-scale galactic magnetic fields in furthering our understanding of star formation, galaxy evolution, and the fundamental physics of magnetohydrodynamics. Furthermore, we discuss some open questions in the research field and outline several possible large observation programmes with the SKA Array Assembly 4 (AA4).

astro-ph.GA↗

arXiv2025

The Karl G. Jansky Very Large Array Local Group L-band Survey (LGLBS)

We present the Local Group L-Band Survey (LGLBS), a Karl G. Jansky Very Large Array (VLA) survey producing the highest quality 21-cm and 1-2 GHz radio continuum images to date for the six VLA-accessible, star-forming, Local Group galaxies. Leveraging the VLA's spectral multiplexing power, we simultaneously survey the 21-cm line at high 0.4 km/s velocity resolution, the 1-2 GHz polarized continuum, and four OH lines. For the massive spiral M31, the dwarf spiral M33, and the dwarf irregular galaxies NGC6822, IC10, IC1613, and the Wolf-Lundmark-Melotte Galaxy (WLM), we use all four VLA configurations and the Green Bank Telescope to reach angular resolutions of $< 5''$ ($10{-}20$~pc) for the 21-cm line with $<10^{20}$~cm$^{-2}$ column density sensitivity, and even sharper views ($< 2''$; $5{-}10$~pc) of the continuum. Targeting these nearby galaxies ($D\lesssim1$ Mpc) reveals a sharp, resolved view of the atomic gas, including 21-cm absorption, and continuum emission from supernova remnants and HII regions. These datasets can be used to test theories of the abundance and formation of cold clouds, the driving and dissipation of interstellar turbulence, and the impact of feedback from massive stars and supernovae. Here, we describe the survey design and execution, scientific motivation, data processing, and quality assurance. We provide a first look at and publicly release the wide-field 21-cm HI data products for M31, M33, and four dwarf irregular targets in the survey, which represent some of the highest physical resolution 21-cm observations of any external galaxies beyond the LMC and SMC.

astro-ph.GA↗