The Earliest Stage of Galactic Star Formation

Autor: Charles L. Steinhardt, Vadim Rusakov, Thomas H. Clark, Andrei Diaconu, John Forbes, Conor McPartland, Albert Sneppen, John Weaver
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: The Astrophysical Journal Letters, Vol 949, Iss 2, p L38 (2023)
Druh dokumentu: article
ISSN: 2041-8213
2041-8205
DOI: 10.3847/2041-8213/acd447
Popis: Using a recently developed technique to estimate gas temperatures ( T _SF ) in star-forming regions from large photometric surveys, we propose a diagram, analogous to the Hertzsprung–Russell diagram for individual stars, to probe the evolution of individual galaxies. On this T _SF -sSFR (specific star formation rate) diagram, a small fraction of star-forming galaxies appear to be dominated by different feedback mechanisms than typical star-forming galaxies. These galaxies generically have younger stellar populations and lower stellar masses and increase in relative abundance toward higher redshifts, so we argue that these objects are in an earlier stage of galactic star formation. Further, Hubble observations find that these “core-forming” galaxies also exhibit distinct morphology and that tracks on the T _SF -sSFR diagram are also a morphological sequence. Thus, unlike starburst phases which can be triggered environmentally, these earliest core-forming galaxies appear to be a stage that typical galaxies go through early in their star formation history. We therefore argue that most galaxies first go through a core formation stage, then subsequently disk formation, and finally become quiescent.
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