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Angular momentum of dwarf galaxies

2018/05/24 by Sushma Kurapati, Jayaram N. Chengalur, S. A. Pustilnik +3 · 35 citations
Physics and Astronomy · #Accretion (finance) #Angular momentum #Angular momentum coupling #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Classical mechanics #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy formation and evolution #Physics #Specific relative angular momentum #Stellar, planetary, and galactic studies #Total angular momentum quantum number #Void (composites) #astro-ph.GA

paper · pdf · doi:10.1093/mnras/sty1397

published in Monthly Notices of the Royal Astronomical Society 479(1), 228-239 (Oxford University Press) · Accepted for publication in MNRAS

arxiv created 2018/05/24 · openalex publication_date 2018/05/25 · arxiv updated 2018/06/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

Mass and specific angular momentum are two fundamental physical parameters of galaxies. We present measurements of the baryonic mass and specific angular momentum of 11 void dwarf galaxies derived from neutral hydrogen (H i) synthesis data. Rotation curves were measured using 3D and 2D tilted-ring fitting routines, and the derived curves generally overlap within the error bars, except in the central regions where, as expected, the 3D routines give steeper curves. The specific angular momentum of void dwarfs is found to be high compared to an extrapolation of the trends seen for higher mass bulge-less spirals but comparable to that of other dwarf irregular galaxies that lie outside voids. As such, our data show no evidence for a dependence of the specific angular momentum on the large-scale environment. Combining our data with the data from the literature, we find a baryonic threshold of ∼109.1M⊙ for this increase in specific angular momentum. Interestingly, this threshold is very similar to the mass threshold below which the galaxy discs start to become systematically thicker. This provides qualitative support to the suggestion that the thickening of the discs as well as the increase in specific angular momentum is the result of a common physical mechanism, such as feedback from star formation. Quantitatively, however, the amount of star formation observed in our dwarfs appears insufficient to produce the observed increase in specific angular momentum. It is hence likely that other processes, such as cold accretion of high-angular-momentum gas, also play a role in increasing the specific angular momentum..

Citations