Date: 08.04.2025

Subhrata Dey (NCBJ,PL)

Bridging the Gap: From UV/IR to Radio via SED Modeling of Infrared Bright Galaxies

Abstract:
Luminous and Ultra-luminous Infrared Galaxies (U/LIRGs) are extreme star-forming galaxies, typically triggered by interactions or mergers of gas-rich galaxies. Their infrared emission is dominated by warm dust heated by active galactic nuclei (AGN) and starbursts, positioning them as a transitional phase between gas-rich galaxies and red, dead ellipticals. U/LIRGs offer a unique laboratory for studying the evolution from star-forming galaxies to elliptical galaxies. In this seminar, I will discuss the global astrophysical properties of a sample of 25 infrared-bright galaxies, combining the spectral energy distribution (SED) modeling results of 11 nearby LIRGs (z < 0.04) and 14 ULIRGs (z < 0.5) across ultraviolet (UV), infrared (IR), and radio wavelengths. The focus will be on bridging UV-IR and radio-only SED modeling, which have traditionally been studied independently. By integrating these regimes, I aim to gain deeper insights into the physical processes driving galaxy evolution. Additionally, I will introduce a physically motivated approach to radio-only SED modeling that accounts for low-frequency absorption and the complex nature of radio continuum emission originating from multiple star-forming regions with varying compositions or geometric orientations. I will also present efforts to calibrate radio continuum emission for deriving the radio star formation rate (SFR), an extinction-free diagnostic of star formation activity.