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arXiv · 2309.05513

Median Surface Brightness Profiles of Lyman-$α$ Haloes in the MUSE Extremely Deep Field

Yucheng Guo·Roland Bacon·Lutz Wisotzki·Thibault Garel·Jérémy Blaizot·Joop Schaye·Johan Richard·Yohana Herrero Alonso·Floriane Leclercq·Leindert Boogaard·Haruka Kusakabe·John Pharo·Eloïse Vitte
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Abstract

We present the median surface brightness profiles of diffuse Ly$α$ haloes (LAHs) around star-forming galaxies by stacking 155 spectroscopically confirmed Ly$α$ emitters (LAEs) at 3<z<4 in the MUSE Extremely Deep Field (MXDF), with median Ly$α$ luminosity $\mathrm{L_{Lyα} \approx 10^{41.1} erg\,s^{-1}}$. After correcting for a systematic surface brightness offset we identified in the datacube, we detect extended Ly$α$ emission out to a distance of 270 kpc. The median Ly$α$ surface brightness profile shows a power-law decrease in the inner 20 kpc, and a possible flattening trend at larger distance. This shape is similar for LAEs with different Ly$α$ luminosities, but the normalisation of the surface brightness profile increases with luminosity. At distances over 50 kpc, we observe strong overlap of adjacent LAHs, and the Ly$α$ surface brightness is dominated by the LAHs of nearby LAEs. We find no clear evidence of redshift evolution of the observed Ly$α$ profiles when comparing with samples at 4<z<5 and 5<z<6. Our results are consistent with a scenario in which the inner 20 kpc of the LAH is powered by star formation in the central galaxy, while the LAH beyond a radius of 50 kpc is dominated by photons from surrounding galaxies.

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Yucheng Guo, Roland Bacon, Lutz Wisotzki, Thibault Garel, Jérémy Blaizot, Joop Schaye, Johan Richard, Yohana Herrero Alonso, Floriane Leclercq, Leindert Boogaard, Haruka Kusakabe, John Pharo, Eloïse Vitte. 2024-07-14. Median Surface Brightness Profiles of Lyman-$α$ Haloes in the MUSE Extremely Deep Field. https://doi.org/10.1051/0004-6361%2F202347658

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