_version_ 1866911452176056320
author Giménez-Alcázar, A.
Amorín, R.
Vílchez, J. M.
Hernán-Caballero, A.
González-Otero, M.
Arroyo-Polonio, A.
Iglesias-Páramo, J.
Lumbreras-Calle, A.
Fernández-Ontiveros, J. A.
Bonatto, L.
Delgado, R. M. González
Kehrig, C.
Torralba, A.
Rahna, P. T.
Jiménez-Teja, Y.
Márquez, I.
Breda, I.
Álvarez-Candal, A.
Abramo, R.
Alcaniz, J.
Benitez, N.
Bonoli, S.
Carneiro, S.
Cenarro, J.
Cristóbal-Hornillos, D.
Dupke, R.
Ederoclite, A.
Hernández-Monteagudo, C.
Marín-Franch, A.
de Oliveira, C. Mendes
Moles, M.
Sodré Jr., L.
Taylor, K.
Varela, J.
Ramió, H. Vázquez
author_facet Giménez-Alcázar, A.
Amorín, R.
Vílchez, J. M.
Hernán-Caballero, A.
González-Otero, M.
Arroyo-Polonio, A.
Iglesias-Páramo, J.
Lumbreras-Calle, A.
Fernández-Ontiveros, J. A.
Bonatto, L.
Delgado, R. M. González
Kehrig, C.
Torralba, A.
Rahna, P. T.
Jiménez-Teja, Y.
Márquez, I.
Breda, I.
Álvarez-Candal, A.
Abramo, R.
Alcaniz, J.
Benitez, N.
Bonoli, S.
Carneiro, S.
Cenarro, J.
Cristóbal-Hornillos, D.
Dupke, R.
Ederoclite, A.
Hernández-Monteagudo, C.
Marín-Franch, A.
de Oliveira, C. Mendes
Moles, M.
Sodré Jr., L.
Taylor, K.
Varela, J.
Ramió, H. Vázquez
contents Extreme emission line galaxies (EELGs) are key tracers of intense star formation and potential analogues of the sources that reionized the early Universe. Their low-redshift counterparts offer a unique opportunity to study the physical conditions that enable high ionizing-photon escape fractions. We present a robust method to photometrically identify EELGs in the J-PAS survey, which provides 56 optical bands over 8500 deg^2. Using data from a fully observed 30 deg^2 region, we combine narrow-band equivalent widths with machine-learning techniques to select galaxies with emission lines above 300 Å. The method achieves 95% purity and 96% completeness for $i_\mathrm{SDSS}<22.5$ mag. We identify 917 EELGs up to $z=0.8$; spectroscopic cross-matching with DESI/DR1 confirms the reliability of our redshifts and emission-line measurements. The selected galaxies show strong correlations between $ξ_\mathrm{ion}$ and EW([OIII]), consistent with previous low- and high-z studies. Most sources exceed the ionizing efficiency threshold required for reionization, reinforcing their role as local analogues of early-Universe galaxies.
format Preprint
id arxiv_https___arxiv_org_abs_2512_08484
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle J-PAS: First Identification, Physical Properties and Ionization Efficiency of Extreme Emission Line Galaxies
Giménez-Alcázar, A.
Amorín, R.
Vílchez, J. M.
Hernán-Caballero, A.
González-Otero, M.
Arroyo-Polonio, A.
Iglesias-Páramo, J.
Lumbreras-Calle, A.
Fernández-Ontiveros, J. A.
Bonatto, L.
Delgado, R. M. González
Kehrig, C.
Torralba, A.
Rahna, P. T.
Jiménez-Teja, Y.
Márquez, I.
Breda, I.
Álvarez-Candal, A.
Abramo, R.
Alcaniz, J.
Benitez, N.
Bonoli, S.
Carneiro, S.
Cenarro, J.
Cristóbal-Hornillos, D.
Dupke, R.
Ederoclite, A.
Hernández-Monteagudo, C.
Marín-Franch, A.
de Oliveira, C. Mendes
Moles, M.
Sodré Jr., L.
Taylor, K.
Varela, J.
Ramió, H. Vázquez
Astrophysics of Galaxies
Extreme emission line galaxies (EELGs) are key tracers of intense star formation and potential analogues of the sources that reionized the early Universe. Their low-redshift counterparts offer a unique opportunity to study the physical conditions that enable high ionizing-photon escape fractions. We present a robust method to photometrically identify EELGs in the J-PAS survey, which provides 56 optical bands over 8500 deg^2. Using data from a fully observed 30 deg^2 region, we combine narrow-band equivalent widths with machine-learning techniques to select galaxies with emission lines above 300 Å. The method achieves 95% purity and 96% completeness for $i_\mathrm{SDSS}<22.5$ mag. We identify 917 EELGs up to $z=0.8$; spectroscopic cross-matching with DESI/DR1 confirms the reliability of our redshifts and emission-line measurements. The selected galaxies show strong correlations between $ξ_\mathrm{ion}$ and EW([OIII]), consistent with previous low- and high-z studies. Most sources exceed the ionizing efficiency threshold required for reionization, reinforcing their role as local analogues of early-Universe galaxies.
title J-PAS: First Identification, Physical Properties and Ionization Efficiency of Extreme Emission Line Galaxies
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2512.08484