MOSEL Survey: Extremely weak outflows in EoR analogues at z=3-4 [GA]

http://arxiv.org/abs/2211.13763


This paper presents deep K-band spectroscopic observations of galaxies at z=3-4 with composite photometric rest-frame Hb+[OIII] equivalent widths EW_0>600A, comparable to the EW of galaxies observed during the epoch of reionisation (EoR, z>6). The typical spectroscopic [OIII] EW_0 and stellar mass of our targets is ~ 700A and log(M_star/M_sun)=8.98. By stacking the [OIII] emission profiles, we find evidence of a weak broad component with F_broad/F_narrow ~ 0.2 and velocity width sigma_{broad} ~ 170 km/s. The strength and velocity width of the broad component does not change significantly with stellar mass and [OIII] EW_0 of the stacked sample. Assuming similar broad component profiles for [OIII] and Halpha emission, we estimate a mass loading factor ~0.2, similar to low stellar mass galaxies at z>1 even if the star formation rates of our sample is 10 times higher. We hypothesize that either the multi-phase nature of supernovae driven outflows or the suppression of winds in the extreme star-forming regime is responsible for the weak signature of outflows in the EoR analogues.

Read this paper on arXiv…

A. Gupta, K. Tran, T. Mendel, et. al.
Mon, 28 Nov 22
85/93

Comments: 14 pages, 9 figures, accepted for publication in MNRAS