Multivariate Predictors of Lyman Continuum Escape. I. A Survival Analysis of the Low-redshift Lyman Continuum Survey

Autor: Anne E. Jaskot, Anneliese C. Silveyra, Anna Plantinga, Sophia R. Flury, Matthew Hayes, John Chisholm, Timothy Heckman, Laura Pentericci, Daniel Schaerer, Maxime Trebitsch, Anne Verhamme, Cody Carr, Henry C. Ferguson, Zhiyuan Ji, Mauro Giavalisco, Alaina Henry, Rui Marques-Chaves, Göran Östlin, Alberto Saldana-Lopez, Claudia Scarlata, Gábor Worseck, Xinfeng Xu
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: The Astrophysical Journal, Vol 972, Iss 1, p 92 (2024)
Druh dokumentu: article
ISSN: 1538-4357
DOI: 10.3847/1538-4357/ad58b9
Popis: To understand how galaxies reionized the Universe, we must determine how the escape fraction of Lyman continuum (LyC) photons ( f _esc ) depends on galaxy properties. Using the z ∼ 0.3 Low-redshift Lyman Continuum Survey (LzLCS), we develop and analyze new multivariate predictors of f _esc . These predictions use the Cox proportional hazards model, a survival analysis technique that incorporates both detections and upper limits. Our best model predicts the LzLCS f _esc detections with an rms scatter of 0.31 dex, better than single-variable correlations. According to ranking techniques, the most important predictors of f _esc are the equivalent width (EW) of Lyman-series absorption lines and the UV dust attenuation, which track line-of-sight absorption due to H i and dust. The H i absorption EW is uniquely crucial for predicting f _esc for the strongest LyC emitters, which show properties similar to weaker LyC emitters and whose high f _esc may therefore result from favorable orientation. In the absence of H i information, star formation rate surface density (Σ _SFR ) and [O iii ]/[O ii ] ratio are the most predictive variables and highlight the connection between feedback and f _esc . We generate a model suitable for z > 6, which uses only the UV slope, Σ _SFR , and [O iii ]/[O ii ]. We find that Σ _SFR is more important in predicting f _esc at higher stellar masses, whereas [O iii ]/[O ii ] plays a greater role at lower masses. We also analyze predictions for other parameters, such as the ionizing-to-nonionizing flux ratio and Ly α escape fraction. These multivariate models represent a promising tool for predicting f _esc at high redshift.
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