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arXiv · 2303.16234

Probing the Star Formation Main Sequence down to $10^{8}$ M$_\odot$ at $1.0<z<3.0$

Rosa M. Mérida·Pablo G. Pérez-González·Patricia Sánchez-Blázquez·Ángela García-Argumánez·Marianna Annunziatella·Luca Costantin·Alejandro Lumbreras-Calle·Belén Alcalde-Pampliega·Guillermo Barro·Néstor Espino-Briones·Anton M. Koekemoer
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Abstract

We investigate the star formation main sequence (MS) (SFR-M$_{\star}$) down to 10$^{8-9}\mathrm{M}_\odot$ using a sample of 34,061 newly-discovered ultra-faint ($27\lesssim i \lesssim 30$ mag) galaxies at $1 \sim28.2$ mag, $ \sim27.9$ mag), blue (UV-slope $<\beta>\sim-1.9$), star-forming (rest-frame colors $ \sim0.10$ mag, $ \sim0.17$ mag) galaxies. These observational characteristics are identified with young (mass-weighted age $<\mathrm{t_{M-w}}>\sim0.014$ Gyr) stellar populations subject to low attenuations ($<\mathrm{A(V)}>\sim0.30$ mag). Our sample allows us to probe the MS down to $10^{8.0}\,\mathrm{M}_\odot$ at $z=1$ and $10^{8.5}\,\mathrm{M}_\odot$ at $z=3$, around 0.6 dex deeper than previous analysis. In the low-mass galaxy regime, we find an average value for the slope of 0.97 at $1<z<2$ and 1.12 at $2<z<3$. Nearly $\sim$60% of our sample presents stellar masses in the range $10^{6-8}$ M$_\odot$ between $1<z<3$. If the slope of the MS remained constant in this regime, the sources populating the low-mass tail of our sample would qualify as starburst galaxies.

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Rosa M. Mérida, Pablo G. Pérez-González, Patricia Sánchez-Blázquez, Ángela García-Argumánez, Marianna Annunziatella, Luca Costantin, Alejandro Lumbreras-Calle, Belén Alcalde-Pampliega, Guillermo Barro, Néstor Espino-Briones, Anton M. Koekemoer. 2023-03-28. Probing the Star Formation Main Sequence down to $10^{8}$ M$_\odot$ at $1.0<z<3.0$. https://doi.org/10.3847/1538-4357%2Facc7a3

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