TY - JOUR
T1 - The proximity effect around high-redshift galaxies
AU - Maselli, A.
AU - Ferrara, A.
AU - Bruscoli, M.
AU - Marri, S.
AU - Schneider, R.
PY - 2004/5/11
Y1 - 2004/5/11
N2 - Recent observations have shown that the intergalactic medium (IGM) is more transparent to Lyα photons close to Lyman break galaxies (LBGs) than at large distance from them, i.e. there is a proximity effect. Cosmological simulations including winds from LBGs have been so far unable to explain this trend. By coupling such simulations with the radiative transfer code CRASH, we investigate whether the addition of the ionizing radiation emitted by LBGs can increase the transmissivity by decreasing the neutral hydrogen fraction in the inner Mpc of the galaxy halo. The transmissivity as a function of distance is roughly reproduced only if LBGs are identified with dwarf galaxies (with masses ≲ 109 M⊙) which are undergoing a vigorous (50 M⊙ yr-1) burst of star formation. Similar star formation rates in larger galaxies are not sufficient to overwhelm the large recombination rates associated with their denser environment. If so, photoionization partly reconciles theory with observations, although we discuss a number of uncertainties affecting both approaches.
AB - Recent observations have shown that the intergalactic medium (IGM) is more transparent to Lyα photons close to Lyman break galaxies (LBGs) than at large distance from them, i.e. there is a proximity effect. Cosmological simulations including winds from LBGs have been so far unable to explain this trend. By coupling such simulations with the radiative transfer code CRASH, we investigate whether the addition of the ionizing radiation emitted by LBGs can increase the transmissivity by decreasing the neutral hydrogen fraction in the inner Mpc of the galaxy halo. The transmissivity as a function of distance is roughly reproduced only if LBGs are identified with dwarf galaxies (with masses ≲ 109 M⊙) which are undergoing a vigorous (50 M⊙ yr-1) burst of star formation. Similar star formation rates in larger galaxies are not sufficient to overwhelm the large recombination rates associated with their denser environment. If so, photoionization partly reconciles theory with observations, although we discuss a number of uncertainties affecting both approaches.
KW - Cosmology: theory
KW - Galaxies: high-Redshift
KW - Intergalactic medium
KW - Methods: numerical
KW - Radiative transfer
UR - http://www.scopus.com/inward/record.url?scp=2542588679&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=2542588679&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2966.2004.07810.x
DO - 10.1111/j.1365-2966.2004.07810.x
M3 - Article
AN - SCOPUS:2542588679
VL - 350
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 2
ER -