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arXiv · 2309.06813

A Strong Blend in the Morning: Studying the Circumgalactic Medium Before Cosmic Noon with Strong, Blended Lyman-$\alpha$ Forest Systems

Sean Morrison·Debopam Som·Matthew M. Pieri·Ignasi Pérez-Ràfols·Michael Blomqvist
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Abstract

We study of the properties of a new class of circumgalactic medium absorbers identified in the Lyman-$\alpha$ forest: "Strong, Blended Lyman-$\alpha$" (or SBLA) absorption systems. We study SBLAs at $2.4 -2.40$ for $T=10^{3.5}$K and show gas clumping on $<210$ parsec scales. We fit multiphase models to this strong sub-population and find a low ionization phase with $n_H=1$cm$^{-3}$, $T=10^{3.5}$K and $[X/H]=0.8$, an intermediate ionization phase with $\log(n_H / $cm$^{-3}) = -3.05$, $T=10^{3.5}$K and $[X/H]=-0.8$, and a poorly constrained higher ionization phase. We find that the low ionization phase favours cold, dense super-solar metallicity gas with a clumping scale of just 0.009 parsecs.

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Sean Morrison, Debopam Som, Matthew M. Pieri, Ignasi Pérez-Ràfols, Michael Blomqvist. 2023-09-13. A Strong Blend in the Morning: Studying the Circumgalactic Medium Before Cosmic Noon with Strong, Blended Lyman-$\alpha$ Forest Systems. https://arxiv.org/abs/2309.06813

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