The Lyman Continuum escape fraction of faint galaxies at z~3.3 in the CANDELS/GOODS-North, EGS, and COSMOS fields with LBC. Grazian, A., Giallongo, E., Paris, D., Boutsia, K., Dickinson, M., Santini, P., Windhorst, R. A., Jansen, R. A., Cohen, S. H., Ashcraft, T. A., Scarlata, C., Rutkowski, M. J., Vanzella, E., Cusano, F., Cristiani, S., Giavalisco, M., Ferguson, H. C., Koekemoer, A., Grogin, N. A., Castellano, M., Fiore, F., Fontana, A., Marchi, F., Pedichini, F., Pentericci, L., Amorin, R., Barro, G., Bonchi, A., Bongiorno, A., Faber, S. M., Fumana, M., Galametz, A., Guaita, L., Kocevski, D. D., Merlin, E., Nonino, M., O'Connell, R. W., Pilo, S., Ryan, R. E., Sani, E., Speziali, R., Testa, V., Weiner, B., & Yan, H. 2017. cite arxiv:1703.00354Comment: Accepted for publication in A&A, 16 pages, 6 figures
The Lyman Continuum escape fraction of faint galaxies at z~3.3 in the CANDELS/GOODS-North, EGS, and COSMOS fields with LBC [link]Paper  abstract   bibtex   
The reionization of the Universe is one of the most important topics of present day astrophysical research. The most plausible candidates for the reionization process are star-forming galaxies, which according to the predictions of the majority of the theoretical and semi-analytical models should dominate the HI ionizing background at z~3. We aim at measuring the Lyman continuum escape fraction, which is one of the key parameters to compute the contribution of star-forming galaxies to the UV background. We have used ultra-deep U-band imaging (U=30.2mag at 1sigma) by LBC/LBT in the CANDELS/GOODS-North field, as well as deep imaging in COSMOS and EGS fields, in order to estimate the Lyman continuum escape fraction of 69 star-forming galaxies with secure spectroscopic redshifts at 3.27L*), while for the faint population (L=0.2L*) the limit to the escape fraction is ~10%. We have computed the contribution of star-forming galaxies to the observed UV background at z~3 and we have found that it is not enough to keep the Universe ionized at these redshifts, unless their escape fraction increases significantly (>10%) at low luminosities (M1500>-19). We compare our results on the Lyman continuum escape fraction of high-z galaxies with recent estimates in the literature and discuss future prospects to shed light on the end of the Dark Ages. In the future, strong gravitational lensing will be fundamental to measure the Lyman continuum escape fraction down to faint magnitudes (M1500~-16) which are inaccessible with the present instrumentation on blank fields.
@misc{grazian2017lyman,
  abstract = {The reionization of the Universe is one of the most important topics of
present day astrophysical research. The most plausible candidates for the
reionization process are star-forming galaxies, which according to the
predictions of the majority of the theoretical and semi-analytical models
should dominate the HI ionizing background at z~3. We aim at measuring the
Lyman continuum escape fraction, which is one of the key parameters to compute
the contribution of star-forming galaxies to the UV background. We have used
ultra-deep U-band imaging (U=30.2mag at 1sigma) by LBC/LBT in the
CANDELS/GOODS-North field, as well as deep imaging in COSMOS and EGS fields, in
order to estimate the Lyman continuum escape fraction of 69 star-forming
galaxies with secure spectroscopic redshifts at 3.27<z<3.40 to faint magnitude
limits (L=0.2L*, or equivalently M1500~-19). We have measured through stacks a
stringent upper limit (<1.7% at 1sigma) for the relative escape fraction of HI
ionizing photons from bright galaxies (L>L*), while for the faint population
(L=0.2L*) the limit to the escape fraction is ~10%. We have computed the
contribution of star-forming galaxies to the observed UV background at z~3 and
we have found that it is not enough to keep the Universe ionized at these
redshifts, unless their escape fraction increases significantly (>10%) at low
luminosities (M1500>-19). We compare our results on the Lyman continuum escape
fraction of high-z galaxies with recent estimates in the literature and discuss
future prospects to shed light on the end of the Dark Ages. In the future,
strong gravitational lensing will be fundamental to measure the Lyman continuum
escape fraction down to faint magnitudes (M1500~-16) which are inaccessible
with the present instrumentation on blank fields.},
  added-at = {2017-03-02T07:42:03.000+0100},
  author = {Grazian, A. and Giallongo, E. and Paris, D. and Boutsia, K. and Dickinson, M. and Santini, P. and Windhorst, R. A. and Jansen, R. A. and Cohen, S. H. and Ashcraft, T. A. and Scarlata, C. and Rutkowski, M. J. and Vanzella, E. and Cusano, F. and Cristiani, S. and Giavalisco, M. and Ferguson, H. C. and Koekemoer, A. and Grogin, N. A. and Castellano, M. and Fiore, F. and Fontana, A. and Marchi, F. and Pedichini, F. and Pentericci, L. and Amorin, R. and Barro, G. and Bonchi, A. and Bongiorno, A. and Faber, S. M. and Fumana, M. and Galametz, A. and Guaita, L. and Kocevski, D. D. and Merlin, E. and Nonino, M. and O'Connell, R. W. and Pilo, S. and Ryan, R. E. and Sani, E. and Speziali, R. and Testa, V. and Weiner, B. and Yan, H.},
  biburl = {https://www.bibsonomy.org/bibtex/2cb08137890beb292bb95347171c3af5c/miki},
  description = {[1703.00354] The Lyman Continuum escape fraction of faint galaxies at z~3.3 in the CANDELS/GOODS-North, EGS, and COSMOS fields with LBC},
  interhash = {c79bf94d99394d14629650d5cff48387},
  intrahash = {cb08137890beb292bb95347171c3af5c},
  keywords = {stacks Lyman escape fraction},
  note = {cite arxiv:1703.00354Comment: Accepted for publication in A&A, 16 pages, 6 figures},
  timestamp = {2017-03-02T07:42:03.000+0100},
  title = {The Lyman Continuum escape fraction of faint galaxies at z~3.3 in the
  CANDELS/GOODS-North, EGS, and COSMOS fields with LBC},
  url = {http://arxiv.org/abs/1703.00354},
  year = 2017
}

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