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arXiv · 2410.21788

Tracing Outflows from Stellar Feedback in the Early Universe with Lyman-$\alpha$

James Nianias·Jeremy Lim·Yik Lok Wong·Gordon Wong·Ishika Kaur·Wenjun Chen
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Abstract

Blind spectroscopy of massive lensing galaxy clusters with MUSE has revealed large numbers of gravitationally-lensed Lyman-$ \alpha $ emitters exhibiting asymmetric profiles at $ 2.9 \leq z \leq 6.7 $, suggesting abundant outflows from low-mass star-forming galaxies in the early universe. Are these primaeval galaxies experiencing their first bursts of star formation, or established galaxies experiencing rejuvenation? With JWST rest-frame optical/NIR continuum imaging now available for many of these objects, we can search for older stellar populations. Here, we search for spectroscopic confirmation of outflows from these galaxies, finding a few high-signal-to-noise cases in which blueshifted interstellar absorption lines are detected. Next, we analyse the star formation histories with combined HST + JWST photometry. We find most them to be well characterised by very young, low metallicity stellar populations. However, despite the rest-frame optical/NIR coverage of JWST, we cannot place strict upper bounds on the mass in old stars (age $ > 100\,\text{Myr} $).

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James Nianias, Jeremy Lim, Yik Lok Wong, Gordon Wong, Ishika Kaur, Wenjun Chen. 2024-10-29. Tracing Outflows from Stellar Feedback in the Early Universe with Lyman-$\alpha$. https://arxiv.org/abs/2410.21788

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