Coffee talks
Friday 26/01/2024 @ 11:30, Sala riunioni quarto piano e on-line (meet.google.com/sue-bwvk-axf)
Lara Pantoni (Ghent University, Belgium), "Dust millimetre emission in Nearby Galaxies with NIKA2/IRAM-30m: major challenges and latest results of the IMEGIN Large Program."
The millimetre emission of galaxies is one of the least explored domain yet it contains emission from three fundamentally important physical processes: thermal emission from dust, free-free emission from ionized gas and synchrotron emission from relativistic charged particles moving in the galactic magnetic field. The NIKA2 camera (IRAM-30m telescope), observing at 1 mm and 2 mm, provides critical observations for input into comprehensive SED models and allows us to: 1) disentangle spatially resolved galaxy spectral energy distribution from dust contribution, free-free and synchrotron emission; 2) constrain the evolution of the dust-to-gas mass ratio within galaxies, which provides a direct link to the chemical evolution of galaxies and the reservoirs for dust production; 3) study the microscopic properties of dust, i.e. constraints on millimetric opacity; 4) study the sub-millimeter excess in galaxies, the origin of which is still unknown. These are some of the main objectives of the IMEGIN Large Program (Interpreting the Millimetre Emission of Galaxies with IRAM-NIKA2; PI S. Madden), targeting 22 nearby galaxies in the millimetre continuum regime with the NIKA2 camera. The NIKA2 millimetre data, combined with a suite of multi-wavelength observations from mid-infrared to radio, including CO and HI, allow us to model the IR-to-radio SED and put constraints on interstellar medium and dust grains properties of galaxies. Specifically, the dust SED analysis (performed globally and locally) makes use of the state-of-the-art hierarchical bayesian fitting code HerBIE with the prescriptions of the dust evolution model THEMIS, which is anchored to the laboratory-measured properties of interstellar dust analogues. During my talk, I will focus on the major challenges linked with data post-processing and uncertainty propagation, large-scale emission filtering in NIKA2 maps (due to atmosphere subtraction during the data reduction process) and I will present the latest results