Hα Dots: Direct-Method Metal Abundances of Low-Luminosity Star-Forming Systems [GA]

http://arxiv.org/abs/2112.02135


Utilizing low-luminosity star-forming systems discovered in the H$\alpha$ Dots survey, we present spectroscopic observations undertaken using the KPNO 4m telescope for twenty-six sources. With determinations of robust, “direct”-method metal abundances, we examine the properties of these dwarf systems, exploring their utility in characterizing starburst galaxies at low luminosities and stellar masses. We find that the H$\alpha$ Dots survey provides an effective new avenue for identifying star-forming galaxies in these regimes. In addition, we examine abundance characteristics and metallicity scaling relations with these sources, highlighting a flattening of both the luminosity-metallicity ($L$-$Z$) and stellar mass-metallicity ($M_{*}$-$Z$) relation slopes in these regimes as compared with those utilizing samples covering wider respective dynamic ranges. These local, accessible analogues to the kinds of star-forming dwarfs common at high redshift will help shed light on the building blocks which assembled into the massive galaxies common today.

Read this paper on arXiv…

A. Hirschauer, J. Salzer, N. Haurberg, et. al.
Tue, 7 Dec 21
57/91

Comments: Accepted for publication in The Astrophysical Journal; 27 pages, 7 figures, 5 tables