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Session: Extragalactic Astronomy and Astrophysics

Name: Dr. Konstantinos Kouroumpatzakis (Astronomical Institute, Czech Academy of Sciences)
Coauthors: No coauthors were included.
Type: Oral
Title: Infrared star-formation rate and stellar mass calibrations and their dependence on stellar population age and extinction
Abstract:

The stellar mass (M⋆) and the star formation rate (SFR) are among the most important features of galaxies. Measuring these fundamental properties accurately is critical for understanding the present state of galaxies, their history, and future evolution. Infrared (IR) photometry is widely used to measure the M⋆ and SFR of galaxies because of its wide all-sky coverage and the fact that the near-IR traces the continuum emission of the majority of their stellar populations (SPs), and the mid/far-IR traces the dust emission powered by star-forming activity. This work uses an MCMC and a machine learning framework to explore the dependence of the IR emission of galaxies on their extinction, and the age of their SPs. It provides accurate and precise IR-photometry SFR and M⋆ calibrations that account for both effects and it quantifies the scatter of these and other IR-based calibrations. The calibrations for the SFR are using a combination of the WISE bands 1 and 3, or the JWST NIR-F200W and MIRI-F2100W. The M⋆ calibrations are based on the WISE band-1, or the JWST NIR-F200W, and the optical u−r or g−r colors. The proposed calibrations show robust estimations while minimizing the scatter and biases throughout a wide range of SFRs and stellar masses. The SFR calibration offers better results, especially in dust-free or passive galaxies where the contributions of old SPs or biases from the lack of dust are significant. Similarly, the M⋆ calibration yields significantly better results for dusty and high-SFR galaxies where dust emission can otherwise bias the estimations.