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arXiv · 2306.14334

The luminosity-area relation of $z>2$ quasars' Ly$\alpha$ nebulae

Fabrizio Arrigoni Battaia·Aura Obreja·Tiago Costa·Emanuele P. Farina·Zheng Cai
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Abstract

Cool ($T\sim10^4$~K) gas is commonly observed around $z>2$ quasars as traced by extended Ly$\alpha$ emission. These large-scale nebulae are usually studied using circularly averaged surface brightness profiles, which suppress information on morphological differences. Here, we revisit the Ly$\alpha$ nebulae around 78 $z\sim2-3$ quasars to obtain a novel estimate of their area and asymmetry using a common redshift-corrected surface-brightness threshold. We find a luminosity-area relation of the form ${{\rm log}(L_{\rm Ly\alpha}^{\rm Neb})=a_1 log({\rm Area^{Neb})+a_0}}$. Most nebulae are symmetric and bright, the most lopsided ones being the faintest and the less extended. The Enormous Lyman-Alpha Nebulae, asymmetric due to the presence of active companions, are the exceptions to this trend. By using simulations able to reproduce $z\sim6$ quasar's nebulae, we show that the observed relation should not vary with redshift. Finally, we discuss possible mechanisms that drive the relation and future work needed to constrain them.

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Fabrizio Arrigoni Battaia, Aura Obreja, Tiago Costa, Emanuele P. Farina, Zheng Cai. 2023-06-25. The luminosity-area relation of $z>2$ quasars' Ly$\alpha$ nebulae. https://doi.org/10.3847/2041-8213%2Face42b

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