The proximity effect around high-redshift galaxies

被引:6
作者
Maselli, A
Ferrara, A
Bruscoli, M
Marri, S
Schneider, R
机构
[1] Univ Florence, Dipartimento Astron, I-50125 Florence, Italy
[2] SISSA, Int Sch Adv Studies, I-34014 Trieste, Italy
[3] Osserv Astrofis Arcetri, I-50125 Florence, Italy
关键词
radiative transfer; methods : numerical; galaxies : high-redshift; intergalactic medium; cosmology : theory;
D O I
10.1111/j.1365-2966.2004.07810.x
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Recent observations have shown that the intergalactic medium (IGM) is more transparent to Lyalpha 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 less than or similar to10(circle dot)(9 M)) which are undergoing a vigorous (50 M-circle dot 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.
引用
收藏
页码:L21 / L25
页数:5
相关论文
共 25 条
[1]   Galaxies and intergalactic matter at redshift z∼3:: Overview [J].
Adelberger, KL ;
Steidel, CC ;
Shapley, AE ;
Pettini, M .
ASTROPHYSICAL JOURNAL, 2003, 584 (01) :45-75
[2]   The contribution of galaxies to the UV ionising background and the evolution of the Lyman forest [J].
Bianchi, S ;
Cristiani, S ;
Kim, TS .
ASTRONOMY & ASTROPHYSICS, 2001, 376 (01) :1-9
[3]   The Lyα forest around high-redshift galaxies [J].
Bruscoli, M ;
Ferrara, A ;
Marri, S ;
Schneider, R ;
Maselli, A ;
Rollinde, E ;
Aracil, B .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2003, 343 (02) :L41-L45
[4]   The gaseous extent of galaxies and the origin of Lyα absorption systems.: III.: Hubble Space Telescope imaging of Lyα-absorbing galaxies at z<1 [J].
Chen, HW ;
Lanzetta, KM ;
Webb, JK ;
Barcons, X .
ASTROPHYSICAL JOURNAL, 1998, 498 (01) :77-94
[5]   Lyman continuum escape from an inhomogeneous interstellar medium [J].
Ciardi, B ;
Bianchi, S ;
Ferrara, A .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2002, 331 (02) :463-473
[6]   Evolution of the ionizing background at high redshifts [J].
Cooke, AJ ;
Espey, B ;
Carswell, RF .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1997, 284 (03) :552-568
[7]  
CROFT RAC, 2002, APJ, V570, P634
[8]  
CROFT RAC, 2003, UNPUB APJ
[9]  
DESJACQUES V, 2004, IN PRESS MNRAS
[10]   HOP: A new group-finding algorithm for N-body simulations [J].
Eisenstein, DJ ;
Hut, P .
ASTROPHYSICAL JOURNAL, 1998, 498 (01) :137-142