%0 Generic %1 vanzella2017direct %A Vanzella, E. %A Nonino, M. %A Cupani, G. %A Castellano, M. %A Sani, E. %A Mignoli, M. %A Calura, F. %A Meneghetti, M. %A Gilli, R. %A Comastri, A. %A Mercurio, A. %A Caminha, G. B. %A Caputi, K. %A Rosati, P. %A Grillo, C. %A Cristiani, S. %A Balestra, I. %A Fontana, A. %A Giavalisco, M. %D 2017 %K continuum escape lyman %T Direct Lyman continuum and Lyman-alpha escape observed at redshift 4 %U http://arxiv.org/abs/1712.07661 %X We report on the serendipitous discovery of a z=4.0, M1500=-22.20 star-forming galaxy (Ion3) showing copious Lyman continuum (LyC) leakage (~60% escaping), a remarkable multiple peaked Lya emission, and significant Lya radiation directly emerging at the resonance frequency. This is the highest redshift confirmed LyC emitter in which the ionising and Lya radiation possibly share a common ionised cavity (with N_HI<10^17.2 cm^-2). Ion3 is spatially resolved, it shows clear stellar winds signatures like the P-Cygni NV1240 profile, and has blue ultraviolet continuum (= -2.5 +/- 0.25, F_łambda~ łambda^\beta) with weak low-ionisation interstellar metal lines. Deep VLT/HAWKI Ks and Spitzer/IRAC 3.6um and 4.5um imaging show a clear photometric signature of the Halpha line with equivalent width of 1000A rest-frame emerging over a flat continuum (Ks-4.5um ~ 0). From the SED fitting we derive a stellar mass of 1.5x10^9 Msun, SFR of 140 Msun/yr and age of ~10 Myr, with a low dust extinction, E(B-V)< 0.1, placing the source in the starburst region of the SFR-M^* plane. Ion3 shows similar properties of another LyC emitter previously discovered (z=3.21, Ion2, Vanzella et al. 2016). Ion3 (and Ion2) represents ideal high-redshift reference cases to guide the search for reionising sources at z>6.5 with JWST.

@misc{vanzella2017direct, abstract = {We report on the serendipitous discovery of a z=4.0, M1500=-22.20 star-forming galaxy (Ion3) showing copious Lyman continuum (LyC) leakage (~60% escaping), a remarkable multiple peaked Lya emission, and significant Lya radiation directly emerging at the resonance frequency. This is the highest redshift confirmed LyC emitter in which the ionising and Lya radiation possibly share a common ionised cavity (with N_HI<10^17.2 cm^-2). Ion3 is spatially resolved, it shows clear stellar winds signatures like the P-Cygni NV1240 profile, and has blue ultraviolet continuum (\beta = -2.5 +/- 0.25, F_\lambda~ \lambda^\beta) with weak low-ionisation interstellar metal lines. Deep VLT/HAWKI Ks and Spitzer/IRAC 3.6um and 4.5um imaging show a clear photometric signature of the Halpha line with equivalent width of 1000A rest-frame emerging over a flat continuum (Ks-4.5um ~ 0). From the SED fitting we derive a stellar mass of 1.5x10^9 Msun, SFR of 140 Msun/yr and age of ~10 Myr, with a low dust extinction, E(B-V)< 0.1, placing the source in the starburst region of the SFR-M^* plane. Ion3 shows similar properties of another LyC emitter previously discovered (z=3.21, Ion2, Vanzella et al. 2016). Ion3 (and Ion2) represents ideal high-redshift reference cases to guide the search for reionising sources at z>6.5 with JWST.}, added-at = {2017-12-22T11:49:44.000+0100}, author = {Vanzella, E. and Nonino, M. and Cupani, G. and Castellano, M. and Sani, E. and Mignoli, M. and Calura, F. and Meneghetti, M. and Gilli, R. and Comastri, A. and Mercurio, A. and Caminha, G. B. and Caputi, K. and Rosati, P. and Grillo, C. and Cristiani, S. and Balestra, I. and Fontana, A. and Giavalisco, M.}, biburl = {https://www.bibsonomy.org/bibtex/29d3b13dc11a9329397d986606d650a6b/miki}, description = {[1712.07661] Direct Lyman continuum and Lyman-alpha escape observed at redshift 4}, interhash = {fcbb5cc8053daea1c65db5a1e7c3d20a}, intrahash = {9d3b13dc11a9329397d986606d650a6b}, keywords = {continuum escape lyman}, note = {cite arxiv:1712.07661Comment: 5 pages, 4 figures, 1 table, Submitted to MNRAS, Comments Welcome}, timestamp = {2017-12-22T11:49:44.000+0100}, title = {Direct Lyman continuum and Lyman-alpha escape observed at redshift 4}, url = {http://arxiv.org/abs/1712.07661}, year = 2017 }