TY  - JOUR
A1  - Wisotzki, Lutz
A1  - Bacon, Roland
A1  - Blaizot, J.
A1  - Brinchmann, Jarle
A1  - Herenz, Edmund Christian
A1  - Schaye, Joop
A1  - Bouche, Nicolas
A1  - Cantalupo, Sebastiano
A1  - Contini, Thierry
A1  - Carollo, C. M.
A1  - Caruana, Joseph
A1  - Courbot, J. -B.
A1  - Emsellem, E.
A1  - Kamann, S.
A1  - Kerutt, Josephine Victoria
A1  - Leclercq, F.
A1  - Lilly, S. J.
A1  - Patricio, V.
A1  - Sandin, C.
A1  - Steinmetz, Matthias
A1  - Straka, Lorrie A.
A1  - Urrutia, Tanya
A1  - Verhamme, A.
A1  - Weilbacher, Peter Michael
A1  - Wendt, Martin
T1  - Extended Lyman alpha haloes around individual high-redshift galaxies revealed by MUSE
JF  - Science
N2  - We report the detection of extended Ly alpha emission around individual star-forming galaxies at redshifts z = 3-6 in an ultradeep exposure of the Hubble Deep Field South obtained with MUSE on the ESO-VLT. The data reach a limiting surface brightness (1 sigma) of similar to 1 x 10(-19) erg s(-1) cm(-2) arcsec(-2) in azimuthally averaged radial profiles, an order of magnitude improvement over previous narrowband imaging. Our sample consists of 26 spectroscopically confirmed Ly alpha-emitting, but mostly continuum-faint (m(AB) greater than or similar to 27) galaxies. In most objects the Ly alpha emission is considerably more extended than the UV continuum light. While five of the faintest galaxies in the sample show no significantly detected Ly alpha haloes, the derived upper limits suggest that this is due to insufficient S/N. Ly alpha haloes therefore appear to be ubiquitous even for low-mass (similar to 10(8)-10(9) M-circle dot) star-forming galaxies at z > 3. We decompose the Ly alpha emission of each object into a compact component tracing the UV continuum and an extended halo component, and infer sizes and luminosities of the haloes. The extended Ly alpha emission approximately follows an exponential surface brightness distribution with a scale length of a few kpc. While these haloes are thus quite modest in terms of their absolute sizes, they are larger by a factor of 5-15 than the corresponding rest-frame UV continuum sources as seen by HST. They are also much more extended, by a factor similar to 5, than Ly alpha haloes around low-redshift star-forming galaxies. Between similar to 40% and greater than or similar to 90% of the observed Ly alpha flux comes from the extended halo component, with no obvious correlation of this fraction with either the absolute or the relative size of the Ly alpha halo. Our observations provide direct insights into the spatial distribution of at least partly neutral gas residing in the circumgalactic medium of low to intermediate mass galaxies at z > 3.
KW  - galaxies: high-redshift
KW  - galaxies: evolution
KW  - galaxies: formation
KW  - cosmology: observations
KW  - intergalactic medium
Y1  - 2016
U6  - https://doi.org/10.1051/0004-6361/201527384
SN  - 1432-0746
VL  - 587
PB  - EDP Sciences
CY  - Les Ulis
ER  -