CTC Seminar: CANCELLED -- Cosima Eibensteiner (NRAO), Observations of the Atomic–Molecular Gas Balance and Star Formation in Nearby Galaxies

Observations of the Atomic–Molecular Gas Balance and Star Formation in Nearby Galaxies

Cosima Eibensteiner 
Jansky Postdoctoral Fellow

Abstract: Star formation in galaxies is fueled by cold gas, but the balance between atomic and molecular phases and the efficiency with which gas forms stars vary strongly with environment. In this talk I use new radio and multi-wavelength observations to ask what regulates this fuel cycle from neutral atomic (HI) to molecular (H_2) to stars. I will first summarize results from my 2024 PHANGS–MeerKAT and MHONGOOSE study of nearby spirals, where high-sensitivity HI from MeerKAT and CO maps from ALMA are combined to measure the molecular-to-atomic gas ratio R_mol and the dynamical equilibrium pressure P_DE across entire disks. I will then present new results from the Local Group L-band Survey (LGLBS), which extends this framework to ∼100 pc scales in six nearby, largely HI-dominated galaxies. Using uniform HI and multi-wavelength SFR maps (and CO where available), we measure pressure–SFR and gas–SFR relations in low-density, low-metallicity environments and compare them to the higher-mass spirals, providing new observational constraints on how pressure and environment shape star formation in HI-dominated gas.

Host: Ankita Bera