Dusty-wind-clear JWST Super-early Galaxies
F. Fiore, Andrea Ferrara, M. Bischetti, C. Feruglio, A. Travascio
Abstract
Abstract The JWST discovery of a number of super-early (redshift z > 10) blue galaxies requires these systems to be essentially dust free in spite of their large stellar masses. A possible explanation is that dust is evacuated by radiatively driven outflows. We test this hypothesis by deriving the Eddington ratio λ E = L bol / L E , where L bol is the bolometric luminosity produced by star formation and possible black hole accretion, for 134 galaxies at 6.5 < z < 16. We find a strong anticorrelation between λ E and dust UV optical depth, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>τ</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>1500</mml:mn> </mml:mrow> </mml:msub> <mml:mo>∝</mml:mo> <mml:msubsup> <mml:mrow> <mml:mi>λ</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>E</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.63</mml:mn> </mml:mrow> </mml:msubsup> <mml:mo>;</mml:mo> </mml:math> also, λ E increases with redshift. We confirm that galaxies exceeding a specific star formation rate sSFR > 13 Gyr −1 develop powerful outflows clearing the galaxy from its dust. This result is supported by ALMA dust continuum nondetections in three super-early systems.