First detection of Lyman continuum escape from a local starburst galaxy -: I.: Observations of the luminous blue compact galaxy Haro 11 with the Far Ultraviolet Spectroscopic Explorer (FUSE)

被引:136
作者
Bergvall, N
Zackrisson, E
Andersson, BG
Arnberg, D
Masegosa, J
Östlin, G
机构
[1] Dept Space Phys & Astron, S-75120 Uppsala, Sweden
[2] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA
[3] Inst Astrofis Andalucia, E-18080 Granada, Spain
[4] SCFAB, Stockholm Observ, S-10691 Stockholm, Sweden
关键词
galaxies : evolution; galaxies : formation; galaxies : starburst; galaxies : dwarfs; ultraviolet : galaxies; cosmology : diffuse radiation;
D O I
10.1051/0004-6361:20053788
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Context. The dominating reionization source in the young universe has not yet been identified. Possible candidates include metal poor dwarf galaxies with starburst properties. Aims. We selected an extreme starburst dwarf, the Blue Compact Galaxy Haro 11, with the aim of determining the Lyman continuum escape fraction from UV spectroscopy. Methods. Spectra of Haro 11 were obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE). A weak signal shortwards of the Lyman break is identified as Lyman continuum (LyC) emission escaping from the ongoing starburst. From profile fitting to weak metal lines we derive column densities of the low ionization species. Adopting a metallicity typical of the H II regions of Haro 11, these data correspond to a hydrogen column density of similar to 10(19) cm(-2). This relatively high value indicates that most of the LyC photons escape through transparent holes in the interstellar medium. We then use spectral evolutionary models to constrain the escape fraction of the produced LyC photons. Results. Assuming a normal Salpeter initial mass function we obtain a Lyman continuum escape fraction of f(esc) similar to 4-10%. We argue that in a hierarchical galaxy formation scenario, the upper limit we derive for the escape rate allows for a substantial contribution to cosmic reionization by starburst dwarf galaxies at high redshifts.
引用
收藏
页码:513 / 524
页数:12
相关论文
共 74 条
[1]  
[Anonymous], APJ
[2]   Line formation in solar granulation - IV. [O I], OI and OH lines and the photospheric O abundance [J].
Asplund, M ;
Grevesse, N ;
Sauval, AJ ;
Prieto, CA ;
Kiselman, D .
ASTRONOMY & ASTROPHYSICS, 2004, 417 (02) :751-768
[3]  
ASPLUND M, 2004, IN PRESS ASP C SER
[4]   Evidence for reionization at z ∼ 6:: Detection of a Gunn-Peterson trough in a z=6.28 quasar [J].
Becker, RH ;
Fan, XH ;
White, RL ;
Strauss, MA ;
Narayanan, VK ;
Lupton, RH ;
Gunn, JE ;
Annis, J ;
Bahcall, NA ;
Brinkmann, J ;
Connolly, AJ ;
Csabai, I ;
Czarapata, PC ;
Doi, M ;
Heckman, TM ;
Hennessy, GS ;
Ivezic, Z ;
Knapp, GR ;
Lamb, DQ ;
McKay, TA ;
Munn, JA ;
Nash, T ;
Nichol, R ;
Pier, JR ;
Richards, GT ;
Schneider, DP ;
Stoughton, C ;
Szalay, AS ;
Thakar, AR ;
York, DG .
ASTRONOMICAL JOURNAL, 2001, 122 (06) :2850-2857
[5]   A search for HI in some peculiar faint dwarf galaxies [J].
Begum, A ;
Chengalur, JN .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2005, 362 (02) :609-611
[6]  
BERGVALL N, 1986, ASTRON ASTROPHYS SUP, V64, P469
[7]   Massive (?) starburst hosts of blue compact galaxies (BCGs) -: Optical/near-IR observations of 4 BCGs and their companions [J].
Bergvall, N ;
Östlin, G .
ASTRONOMY & ASTROPHYSICS, 2002, 390 (03) :891-915
[8]  
BERGVALL N, 1985, ASTRON ASTROPHYS, V146, P269
[9]  
Bergvall N, 2000, ASTRON ASTROPHYS, V359, P41
[10]   The ionizing stars of extragalactic H II regions [J].
Bresolin, F ;
Kennicutt, RC ;
Garnett, DR .
ASTROPHYSICAL JOURNAL, 1999, 510 (01) :104-124