TY  - JOUR
A1  - Finley, Hayley
A1  - Bouche, Nicolas
A1  - Contini, Thierry
A1  - Epinat, Benoit
A1  - Bacon, Roland
A1  - Brinchmann, Jarle
A1  - Cantalupo, Sebastiano
A1  - Erroz-Ferrer, Santiago
A1  - Marino, Aella Anna
A1  - Maseda, Michael
A1  - Richard, Johan
A1  - Schroetter, Ilane
A1  - Verhamme, Anne
A1  - Weilbacher, Peter Michael
A1  - Wendt, Martin
A1  - Wisotzki, Lutz
T1  - Galactic winds with MUSE: A direct detection of Fe II* emission from a z=1.29 galaxy
JF  - Astronomy and astrophysics : an international weekly journal
N2  - Emission signatures from galactic winds provide an opportunity to directly map the outflowing gas, but this is traditionally challenging because of the low surface brightness. Using very deep observations (27 h) of the Hubble Deep Field South with the Multi Unit Spectroscopic Explorer (MUSE) instrument, we identify signatures of an outflow in both emission and absorption from a spatially resolved galaxy at z = 1.29 with a stellar mass M-star = 8 x 10(9) M-circle dot, star formation rate SFR = 77(-25)(+40) M-circle dot yr(-1), and star formation rate surface brightness Sigma(SFR) = 1.6 M-circle dot kpc(-2) within the [OII] lambda lambda 3727, 3729 half-light radius R-1/2, ([OII]) = 2.76 +/- 0.17 kpc. From a component of the strong resonant Mg II and Fe II absorptions at -350 km s(-1), we infer a mass outflow rate that is comparable to the star formation rate. We detect non-resonant Fe II* emission, at lambda 2365, lambda 2396, lambda 2612, and lambda 2626, at 1.2-2.4-1.5-2.7 x 10-(18) erg s(-1) cm(-2) respectively. The flux ratios are consistent with the expectations for optically thick gas. By combining the four non-resonant Fe II* emission lines, we spatially map the Fe II* emission from an individual galaxy for the first time. The Fe II* emission has an elliptical morphology that is roughly aligned with the galaxy minor kinematic axis, and its integrated half-light radius, R-1/2, (Fe II*) = 4.1 +/- 0.4 kpc, is 70% larger than the stellar continuum (R-1/2,(star) similar or equal to 2.34 +/- 0.17) or the [O II] nebular line. Moreover, the Fe II* emission shows a blue wing extending up to -400 km s(-1), which is more pronounced along the galaxy minor kinematic axis and reveals a C-shaped pattern in a p - v diagram along that axis. These features are consistent with a bi-conical outflow.
KW  - galaxies: evolution
KW  - galaxies: formation
KW  - galaxies: starburst
KW  - galaxies: ISM
KW  - ISM: jets and outflows
KW  - ultraviolet: ISM
Y1  - 2017
U6  - https://doi.org/10.1051/0004-6361/201730428
SN  - 1432-0746
VL  - 605
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Izotov, Y. I.
A1  - Schaerer, Daniel
A1  - Worseck, Gabor
A1  - Guseva, N. G.
A1  - Thuan, T. X.
A1  - Verhamme, A.
A1  - Orlitova, I.
A1  - Fricke, K. J.
T1  - J1154+2443: a low-redshift compact star-forming galaxy with a 46 per cent leakage of Lyman continuum photons
JF  - Monthly notices of the Royal Astronomical Society
N2  - We report the detection of the Lyman continuum (LyC) radiation of the compact star-forming galaxy (SFG) J1154+2443 observed with the Cosmic Origins Spectrograph (COS) onboard the Hubble Space Telescope. This galaxy, at a redshift of z = 0.3690, is characterized by a high emission-line flux ratio O-32 = [O III] lambda 5007/[O II] lambda 3727 = 11.5. The escape fraction of the LyC radiation f(esc)(LyC) in this galaxy is 46 per cent, the highest value found so far in low-redshift SFGs and one of the highest values found in galaxies at any redshift. The narrow double-peaked Ly alpha emission line is detected in the spectrum of J1154+2443 with a separation between the peaks V-sep of 199 km s(-1), one of the lowest known for Ly alpha-emitting galaxies, implying a high f(esc)(Ly alpha). Comparing the extinction-corrected Ly alpha/H beta flux ratio with the case B value, we find f(esc)(Ly alpha) = 98 per cent. Our observations, combined with previous detections in the literature, reveal an increase of O-32 with increasing f(esc)(LyC). We also find a tight anticorrelation between f(esc)(LyC) and V-sep. The surface brightness profile derived from the COS acquisition image reveals a bright star-forming region in the centre and an exponential disc in the outskirts with a disc scale length alpha = 1.09 kpc. J1154+2443, compared to other known low-redshift LyC leakers, is characterized by the lowest metallicity, 12+log O/H = 7.65 +/- 0.01, the lowest stellar mass M-star = 108.20 M-circle dot, a similar star formation rate SFR = 18.9 M-circle dot yr(-1), and a high specific SFR of 1.2 x 10(-7) yr(-1).
KW  - galaxies: abundances
KW  - galaxies: dwarf
KW  - galaxies: fundamental parameters
KW  - galaxies: ISM
KW  - galaxies: starburst
KW  - dark ages, reionization, first stars
Y1  - 2017
U6  - https://doi.org/10.1093/mnras/stx3115
SN  - 0035-8711
SN  - 1365-2966
VL  - 474
IS  - 4
SP  - 4514
EP  - 4527
PB  - Oxford Univ. Press
CY  - Oxford
ER  -