Redshift evolution of Lyman continuum escape fraction after JWST
Andrea Ferrara, M. Giavalisco, L. Pentericci, E. Vanzella, A. Calabrò, Mario Llerena
Abstract
The LyC escape fraction from galaxies, , is strongly boosted by galactic outflows. In the Attenuation-Free Model (AFM) accounting for the properties of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:mi>z</mml:mi> <mml:mo>></mml:mo> <mml:mn>10</mml:mn> </mml:mrow> </mml:math> galaxies, radiation-driven outflows develop once the galaxy specific star formation rate, . As the cosmic sSFR increases with redshift, so does , which, when globally averaged, grows from 0.007 to 0.6 in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:mn>0</mml:mn> <mml:mo><</mml:mo> <mml:mi>z</mml:mi> <mml:mo><</mml:mo> <mml:mn>20</mml:mn> </mml:mrow> </mml:math> . We successfully tested the model on specific data sub-samples. Our predictions are consistent with measurements of , and provide a physical explanation for the observed decreasing trend of the mean UV galaxy spectral slope, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>β</mml:mi> </mml:math> , towards high- <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>z</mml:mi> </mml:math> .