NIHAO - XI. Formation of ultra-diffuse galaxies by outflows

Arianna Di Cintio, Chris B. Brook, Aaron A. Dutton, Andrea Maccio, Aura Obreja, Avishai Dekel

    Research output: Contribution to journalArticle

    Abstract

    We address the origin of ultra-diffuse galaxies (UDGs), which have stellar masses typical of dwarf galaxies but effective radii of Milky Way-sized objects. Their formation mechanism, and whether they are failed L* galaxies or diffuse dwarfs, are challenging issues. Using zoomin cosmological simulations from the Numerical Investigation of a Hundred Astrophysical Objects (NIHAO) project, we show that UDG analogues form naturally in dwarf-sized haloes due to episodes of gas outflows associated with star formation. The simulated UDGs live in isolated haloes of masses 1010-11 M⊙, have stellar masses of 107-8.5 M⊙, effective radii larger than 1 kpc and dark matter cores. They show a broad range of colours, an average Sérsic index of 0.83, a typical distribution of halo spin and concentration, and a non-negligible HI gas mass of 107-9 M⊙, which correlates with the extent of the galaxy. Gas availability is crucial to the internal processes which form UDGs: feedback-driven gas outflows, and subsequent dark matter 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 should exist in the field. The largest isolated UDGs should contain more HI gas than less extended dwarfs of similar M*.

    Original languageEnglish (US)
    Pages (from-to)L1-L6
    JournalMonthly Notices of the Royal Astronomical Society: Letters
    Volume466
    Issue number1
    DOIs
    StatePublished - Jan 1 2017

    Fingerprint

    astrophysics
    outflow
    galaxies
    gas
    halos
    gases
    formation mechanism
    stellar mass
    dark matter
    radii
    dwarf galaxies
    simulation
    availability
    star formation
    brightness
    analogs
    color
    expansion

    Keywords

    • Galaxies: dwarf
    • Galaxies: evolution
    • Galaxies: formation
    • Galaxies: haloes

    ASJC Scopus subject areas

    • Astronomy and Astrophysics
    • Space and Planetary Science

    Cite this

    Di Cintio, A., Brook, C. B., Dutton, A. A., Maccio, A., Obreja, A., & Dekel, A. (2017). NIHAO - XI. Formation of ultra-diffuse galaxies by outflows. Monthly Notices of the Royal Astronomical Society: Letters, 466(1), L1-L6. https://doi.org/10.1093/mnrasl/slw210

    NIHAO - XI. Formation of ultra-diffuse galaxies by outflows. / Di Cintio, Arianna; Brook, Chris B.; Dutton, Aaron A.; Maccio, Andrea; Obreja, Aura; Dekel, Avishai.

    In: Monthly Notices of the Royal Astronomical Society: Letters, Vol. 466, No. 1, 01.01.2017, p. L1-L6.

    Research output: Contribution to journalArticle

    Di Cintio, A, Brook, CB, Dutton, AA, Maccio, A, Obreja, A & Dekel, A 2017, 'NIHAO - XI. Formation of ultra-diffuse galaxies by outflows', Monthly Notices of the Royal Astronomical Society: Letters, vol. 466, no. 1, pp. L1-L6. https://doi.org/10.1093/mnrasl/slw210
    Di Cintio, Arianna ; Brook, Chris B. ; Dutton, Aaron A. ; Maccio, Andrea ; Obreja, Aura ; Dekel, Avishai. / NIHAO - XI. Formation of ultra-diffuse galaxies by outflows. In: Monthly Notices of the Royal Astronomical Society: Letters. 2017 ; Vol. 466, No. 1. pp. L1-L6.
    @article{b94504d674a546899793081aaa6a6227,
    title = "NIHAO - XI. Formation of ultra-diffuse galaxies by outflows",
    abstract = "We address the origin of ultra-diffuse galaxies (UDGs), which have stellar masses typical of dwarf galaxies but effective radii of Milky Way-sized objects. Their formation mechanism, and whether they are failed L* galaxies or diffuse dwarfs, are challenging issues. Using zoomin cosmological simulations from the Numerical Investigation of a Hundred Astrophysical Objects (NIHAO) project, we show that UDG analogues form naturally in dwarf-sized haloes due to episodes of gas outflows associated with star formation. The simulated UDGs live in isolated haloes of masses 1010-11 M⊙, have stellar masses of 107-8.5 M⊙, effective radii larger than 1 kpc and dark matter cores. They show a broad range of colours, an average S{\'e}rsic index of 0.83, a typical distribution of halo spin and concentration, and a non-negligible HI gas mass of 107-9 M⊙, which correlates with the extent of the galaxy. Gas availability is crucial to the internal processes which form UDGs: feedback-driven gas outflows, and subsequent dark matter 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 should exist in the field. The largest isolated UDGs should contain more HI gas than less extended dwarfs of similar M*.",
    keywords = "Galaxies: dwarf, Galaxies: evolution, Galaxies: formation, Galaxies: haloes",
    author = "{Di Cintio}, Arianna and Brook, {Chris B.} and Dutton, {Aaron A.} and Andrea Maccio and Aura Obreja and Avishai Dekel",
    year = "2017",
    month = "1",
    day = "1",
    doi = "10.1093/mnrasl/slw210",
    language = "English (US)",
    volume = "466",
    pages = "L1--L6",
    journal = "Monthly Notices of the Royal Astronomical Society: Letters",
    issn = "1745-3925",
    publisher = "Oxford University Press",
    number = "1",

    }

    TY - JOUR

    T1 - NIHAO - XI. Formation of ultra-diffuse galaxies by outflows

    AU - Di Cintio, Arianna

    AU - Brook, Chris B.

    AU - Dutton, Aaron A.

    AU - Maccio, Andrea

    AU - Obreja, Aura

    AU - Dekel, Avishai

    PY - 2017/1/1

    Y1 - 2017/1/1

    N2 - We address the origin of ultra-diffuse galaxies (UDGs), which have stellar masses typical of dwarf galaxies but effective radii of Milky Way-sized objects. Their formation mechanism, and whether they are failed L* galaxies or diffuse dwarfs, are challenging issues. Using zoomin cosmological simulations from the Numerical Investigation of a Hundred Astrophysical Objects (NIHAO) project, we show that UDG analogues form naturally in dwarf-sized haloes due to episodes of gas outflows associated with star formation. The simulated UDGs live in isolated haloes of masses 1010-11 M⊙, have stellar masses of 107-8.5 M⊙, effective radii larger than 1 kpc and dark matter cores. They show a broad range of colours, an average Sérsic index of 0.83, a typical distribution of halo spin and concentration, and a non-negligible HI gas mass of 107-9 M⊙, which correlates with the extent of the galaxy. Gas availability is crucial to the internal processes which form UDGs: feedback-driven gas outflows, and subsequent dark matter 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 should exist in the field. The largest isolated UDGs should contain more HI gas than less extended dwarfs of similar M*.

    AB - We address the origin of ultra-diffuse galaxies (UDGs), which have stellar masses typical of dwarf galaxies but effective radii of Milky Way-sized objects. Their formation mechanism, and whether they are failed L* galaxies or diffuse dwarfs, are challenging issues. Using zoomin cosmological simulations from the Numerical Investigation of a Hundred Astrophysical Objects (NIHAO) project, we show that UDG analogues form naturally in dwarf-sized haloes due to episodes of gas outflows associated with star formation. The simulated UDGs live in isolated haloes of masses 1010-11 M⊙, have stellar masses of 107-8.5 M⊙, effective radii larger than 1 kpc and dark matter cores. They show a broad range of colours, an average Sérsic index of 0.83, a typical distribution of halo spin and concentration, and a non-negligible HI gas mass of 107-9 M⊙, which correlates with the extent of the galaxy. Gas availability is crucial to the internal processes which form UDGs: feedback-driven gas outflows, and subsequent dark matter 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 should exist in the field. The largest isolated UDGs should contain more HI gas than less extended dwarfs of similar M*.

    KW - Galaxies: dwarf

    KW - Galaxies: evolution

    KW - Galaxies: formation

    KW - Galaxies: haloes

    UR - http://www.scopus.com/inward/record.url?scp=85018241359&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=85018241359&partnerID=8YFLogxK

    U2 - 10.1093/mnrasl/slw210

    DO - 10.1093/mnrasl/slw210

    M3 - Article

    VL - 466

    SP - L1-L6

    JO - Monthly Notices of the Royal Astronomical Society: Letters

    JF - Monthly Notices of the Royal Astronomical Society: Letters

    SN - 1745-3925

    IS - 1

    ER -