Galaxy formation in pre-heated intergalactic media

H. J. Mo, Shude Mao

    Research output: Contribution to journalArticlepeer-review

    Abstract

    We outline a scenario of galaxy formation in which the gas in galaxy-forming regions was pre-heated to high entropy by vigorous energy feedback associated with the formation of stars in old ellipticals and bulges and with active galactic nuclei activity. Such pre-heating probably occurred at redshifts of z ∼ 2-3, and can produce the entropy excess observed .today in low-mass clusters of galaxies without destroying the bulk of the Lyα forest. Subsequent galaxy formation is affected by the pre-heating, because the gas no longer follows the dark matter on galaxy scales. The hot gas around galaxy haloes has very shallow profiles and emits only weakly in the X-ray range. Cooling in a pre-heated halo is not inside-out, because the cooling efficiency does not change significantly with radius. Only part of the gas in a protogalaxy region can cool and be accreted into the final galaxy halo by the present time. The accreted gas is probably in diffuse clouds and so does not lose angular momentum to the dark matter. Cluster ellipticals are produced by mergers of stellar systems formed prior to the pre-heating, while large galaxy discs form in low-density environments where gas accretion can continue to the present time.
    Original languageEnglish
    Pages (from-to)768-778
    Number of pages10
    JournalMonthly Notices of the Royal Astronomical Society
    Volume333
    Issue number4
    DOIs
    Publication statusPublished - 11 Jul 2002

    Keywords

    • Galaxies: clusters: general
    • Galaxies: elliptical and lenticular, cD
    • Galaxies: formation
    • Galaxies: spiral
    • Galaxies: structure

    Fingerprint

    Dive into the research topics of 'Galaxy formation in pre-heated intergalactic media'. Together they form a unique fingerprint.

    Cite this