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Ultradiffuse galaxies: the high-spin tail of the abundant dwarf galaxy population
- Source :
- Monthly Notices of the Royal Astronomical Society: Letters. 459:L51-L55
- Publication Year :
- 2016
- Publisher :
- Oxford University Press (OUP), 2016.
-
Abstract
- Recent observations have revealed the existence of an abundant population of faint, low surface brightness (SB) galaxies, which appear to be numerous and ubiquitous in nearby galaxy clusters, including the Virgo, Coma and Fornax clusters. With median stellar masses of dwarf galaxies, these ultra-diffuse galaxies (UDGs) have unexpectedly large sizes, corresponding to a mean SB of $24\lesssim\langle\mu_e\rangle_r\ {\rm mag}^{-1} {\rm arcsec}^2\lesssim27$ within the effective radius. We show that the UDG population represents the tail of galaxies formed in dwarf-sized haloes with higher-than-average angular momentum. By adopting the standard model of disk formation -- in which the size of galaxies is set by the spin of the halo -- we recover both the abundance of UDGs as a function of the host cluster mass and the distribution of sizes within the UDG population. According to this model, UDGs are not failed $L_*$ galaxies, but genuine dwarfs, and their low SB is not uniquely connected to the harsh cluster environment. We therefore expect a correspondingly abundant population of UDGs in the field, with likely different morphologies and colours.<br />Comment: MNRAS Letters, accepted version
- Subjects :
- Physics
Luminous infrared galaxy
010308 nuclear & particles physics
FOS: Physical sciences
Astronomy
Astronomy and Astrophysics
Astrophysics::Cosmology and Extragalactic Astrophysics
Astrophysics
Computer Science::Computational Geometry
Astrophysics - Astrophysics of Galaxies
01 natural sciences
Peculiar galaxy
Dwarf spheroidal galaxy
Space and Planetary Science
Astrophysics of Galaxies (astro-ph.GA)
Galaxy group
0103 physical sciences
Elliptical galaxy
Astrophysics::Solar and Stellar Astrophysics
Astrophysics::Earth and Planetary Astrophysics
Brightest cluster galaxy
010303 astronomy & astrophysics
Astrophysics::Galaxy Astrophysics
Galaxy cluster
Dwarf galaxy
Subjects
Details
- ISSN :
- 17453933 and 17453925
- Volume :
- 459
- Database :
- OpenAIRE
- Journal :
- Monthly Notices of the Royal Astronomical Society: Letters
- Accession number :
- edsair.doi.dedup.....534c7a41941e7c2a90e16d238905c7cf