Ultra-Diffuse Galaxies: A formation scenario

Arianna Di Cintio, Christopher B.A. Brook, Aaron A. Dutton, Andrea V. Macciò, Aura Obreja, Avishai Dekel

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

: feedback driven gas outflows, and subsequent dark mattA large number of Ultra-Diffuse Galaxies (UDGs) has been detected over the past few years, both in clusters and in isolation. UDGs have stellar masses typical of dwarf galaxies but effective radii of Milky Way-sized objects, and their origin remains puzzling. Using hydrodynamical zoom-in simulations from the NIHAO project we show that UDGs form naturally in dwarf-mass haloes, as a result of episodic gas outflows associated with star formation. The simulated UDGs live in isolated haloes of masses 1010-11M, have stellar masses of 107-8.5M, effective radii larger than 1 kpc and dark matter cores. Remarkably, they have a non-negligible HI gas mass of 107-9M, which correlates with the extent of the galaxy. Gas availability is crucial to the internal processes that form UDGser and stellar expansion, are the key to reproduce faint, yet unusually extended, galaxies. This scenario implies that UDGs represent a dwarf population of low surface brightness galaxies and that they should exist in the field. Several predictions and comparisons with stat-of-the-art observational data will be presented. Amongst other, we will show that the largest isolated UDGs sistematically contain more HI gas than less extended dwarfs of similar M?, corroborating our proposed formation scenario.

Original languageEnglish (US)
Title of host publicationProceedings of the 13th Scientific Meeting of the Spanish Astronomical Society - Highlights of Spanish Astrophysics X, SEA 2018
EditorsB. Montesinos, A. Asensio Ramos, F. Buitrago, R. Schodel, E. Villaver, S. Perez-Hoyos, I. Ordonez-Etxeberria
PublisherSEA
Pages116-121
Number of pages6
ISBN (Electronic)9788409093311
StatePublished - 2018
Event13th Scientific Meeting of the Spanish Astronomical Society - Highlights of Spanish Astrophysics X, SEA 2018 - Salamanca, Spain
Duration: Jul 16 2018Jul 20 2018

Publication series

NameProceedings of the 13th Scientific Meeting of the Spanish Astronomical Society - Highlights of Spanish Astrophysics X, SEA 2018

Conference

Conference13th Scientific Meeting of the Spanish Astronomical Society - Highlights of Spanish Astrophysics X, SEA 2018
CountrySpain
CitySalamanca
Period7/16/187/20/18

ASJC Scopus subject areas

  • Astronomy and Astrophysics

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