Author ORCID Identifier
Document Type
Article
Publication Date
12-7-2017
Abstract
We explore the star-forming properties of late-type, low surface brightness (LSB) galaxies. The star-forming main sequence (SFR-M∗) of LSB dwarfs has a steep slope, indistinguishable from unity (1.04 ± 0.06). They form a distinct sequence from more massive spirals, which exhibit a shallower slope. The break occurs around M∗ ≈ 1010 Mo , and can also be seen in the gas mass-stellar mass plane. The global Kennicutt-Schmidt law (SFR-Mg) has a slope of 1.47 ± 0.11 without the break seen in the main sequence. There is an ample supply of gas in LSB galaxies, which have gas depletion times well in excess of a Hubble time, and often tens of Hubble times. Only ∼3% of this cold gas needs be in the form of molecular gas to sustain the observed star formation. In analogy with the faint, long-lived stars of the lower stellar main sequence, it may be appropriate to consider the main sequence of star-forming galaxies to be defined by thriving dwarfs (with M∗ > 1010 Mo), while massive spirals (with M∗ > 1010Mo) are weary giants that constitute more of a turn-off population.
Keywords
galaxies: dwarf, galaxies: evolution, galaxies: formation, galaxies: irregular, galaxies: spiral, galaxies: star formation
Language
English
Publication Title
Astrophysical Journal
Rights
© The American Astronomical Society. All rights reserved. This content is free to access, download, and share. For all other uses, you must obtain permission to reuse content: https://journals.aas.org/article-charges-and-copyright/#AAS_material
Recommended Citation
Stacy S. McGaugh et al 2017. The Star-Forming Main Sequence of Dwarf Low Surface Brightness Galaxies. ApJ 851 22
Manuscript Version
Final Publisher Version