Extended Lyman α haloes around individual high-redshift galaxies revealed by MUSE

By L. Wisotzki, R. Bacon, Jérémy Blaizot, J. Brinchmann, E. C. Herenz, Joop Schaye, N. Bouché, S. Cantalupo, Thierry Contini, C. Carollo and 15 more. 2015

220 citations recorded by the source corpus.

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 (1sigma) of ~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 >~ 27) galaxies. In most objects the Ly alpha emission is considerably more extended than the UV continuum light. While 5 of the faintest galaxies in the sample show no significantly detected Ly alpha haloes, the derived upper limits suggest that this is just due to insufficient S/N. Ly alpha haloes therefore appear to be (nearly) ubiquitous even for low-mass (~10^8-10^9 M_sun) star-forming galaxies at z>3. We decompose the Ly alpha emission of each object into a compact `continuum-like' 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 ~5, than Ly alpha haloes around low-redshift star-forming galaxies. Between ~40% and >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.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/5c59d7611780a736f24147ce5f7526a13562acf4

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. Naveen A. Reddy
2. A. Shapley
3. C. Steidel
4. R. Dav'e
5. M. Pettini
6. P. Hopkins
7. D. Erb
8. C. Conroy

In Instrumentation

1. Naveen A. Reddy
2. A. Shapley
3. C. Steidel
4. M. Pettini
5. D. Erb
6. G. Rudie
7. C. Conroy
8. P. V. van Dokkum

Citations in the corpus

• The Keck Lyman Continuum Spectroscopic Survey (KLCS): The Emergent Ionizing Spectrum of Galaxies at z ∼ 3 (2018, background): “Conversely, if a galaxy spectrum’s low-ionization IS lines are black over a considerable range in velocity, one would expect no significant LyC photon leakage in our direction (e.g., Steidel et al. 2001; Pettini et al. 2002; Shapley et al. 2003, 2006; Quider et al. 2009; Steidel et al. 2010; Heckman”
• UBIQUITOUS GIANT Lyα NEBULAE AROUND THE BRIGHTEST QUASARS AT z ∼ 3.5 REVEALED WITH MUSE (2016, background): “This profile is very different from the results of other surveys targeting Lyα emitting galaxies both in large areas and using deep integrations (e.g., Wisotzki et al. 2016).”