Gas around galaxy haloes – III: hydrogen absorption signatures around galaxies and QSOs in the Sherwood simulation suite. Issue 2 (23rd January 2017)

• Record Type: Journal Article
• Authors: Meiksin, Avery; Bolton, James S.; Puchwein, Ewald
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 468:Issue 2(2017)
• Page Start: 1893
• Page End: 1901
• Publication Date: 2017-01-23
• Subjects: galaxies: formation -- intergalactic medium -- quasars: absorption lines -- large-scale structure of Universe; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stx191
• Languages: English
• ISSNs: 0035-8711

Abstract

Abstract: Modern theories of galaxy formation predict that galaxies impact on their gaseous surroundings, playing the fundamental role of regulating the amount of gas converted into stars. While star-forming galaxies are believed to provide feedback through galactic winds, quasi-stellar objects (QSOs) are believed instead to provide feedback through the heat generated by accretion on to a central supermassive black hole. A quantitative difference in the impact of feedback on the gaseous environments of star-forming galaxies and QSOs has not been established through direct observations. Using the Sherwood cosmological simulations, we demonstrate that measurements of neutral hydrogen in the vicinity of star-forming galaxies and QSOs during the era of peak galaxy formation show excess Ly α absorption extending up to comoving radii of ∼150 kpc for star-forming galaxies and 300–700 kpc for QSOs. Simulations including supernovae-driven winds account for the absorption around star-forming galaxies but not QSOs.