The miniJPAS survey: A search for extreme emission-line galaxies

Journal Article · Wed Sep 14 00:00:00 EDT 2022 · Astronomy and Astrophysics

DOI:https://doi.org/10.1051/0004-6361/202243931· OSTI ID:1982343

Iglesias-Páramo, J. ^[1]; Arroyo, A. ^[1]; Kehrig, C. ^[1]; Vílchez, J. M. ^[1]; Duarte Puertas, S. ^[2]; Pérez-Montero, E. ^[1]; Breda, I. ^[1]; Jiménez-Teja, Y. ^[1]; López Sanjuan, C. ^[3]; Lumbreras-Calle, A. ^[3]; Coelho, P. ^[4]; Gurung-López, S. ^[5]; Queiroz, C. ^[6]; Márquez, I. ^[1]; Pović, M. ^[7]; González Delgado, R. ^[1]; Chaves-Montero, J. ^[8]; Sobral, D. ^[9]; Hernán-Caballero, A. ^[3]; Fernández-Ontiveros, J. A. ^[3] ; Díaz-García, L. A. ^[1]; Alvarez-Candal, A. ^[10]; Abramo, R. ^[4]; Alcaniz, J. ^[11]; Benítez, N. ^[1]; Bonoli, S. ^[12]; Cenarro, A. J. ^[3]; Cristóbal-Hornillos, D. ^[3]; Dupke, R. ^[11]; Ederoclite, A. ^[3]; Marín-Franch, A. ^[3]; Mendes de Oliveira, C. ^[4]; Moles, M. ^[3]; Sodré, Jr., L. ^[4]; Taylor, K. ^[13]; Varela, J. ^[3]; Vázquez-Ramió, H. ^[3]

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1. Instituto de Astrofísica de Andalucía – CSIC, Granada (Spain)
2. Centre de Recherche en Astrophysique du Québec (CRAQ) (Canada); Instituto de Astrofísica de Andalucía – CSIC, Granada (Spain)
3. Centro de Estudios de Física del Cosmos de Aragón (CEFCA), Teruel (Spain)
4. University of São Paulo (Brazil)
5. University of Valencia (Spain)
6. Universidade Federal do Rio Grande do Sul (UFRGS), RS (Brazil)
7. Ethiopian Space Science and Technology Institute (ESSTI), Addis Ababa (Ethiopia); Instituto de Astrofísica de Andalucía – CSIC, Granada (Spain)
8. Donostia International Physics Center (DIPC), San Sebastian (Spain)
9. Lancaster University (United Kingdom); Universidade de Lisboa, Lisbon (Portugal)
10. Instituto de Astrofísica de Andalucía – CSIC, Granada (Spain); Universidad de Alicante (Spain); Ministerio da Ciencia, Tecnologia e Inovacao (MCTI), Rio de Janiero (Brazil)
11. Ministerio da Ciencia, Tecnologia e Inovacao (MCTI), Rio de Janiero (Brazil)
12. Donostia International Physics Center (DIPC), San Sebastian (Spain); Basque Foundation for Science, Bilbao (Spain); Centro de Estudios de Física del Cosmos de Aragón (CEFCA), Teruel (Spain)
13. Instruments4, La Cañada Flintridge, CA (United States)

Context. Galaxies with extreme emission lines (EELGs) may play a key role in the evolution of the Universe, as well as in our understanding of the star formation process itself. For this reason an accurate determination of their spatial density and fundamental properties in different epochs of the Universe will constitute a unique perspective towards a comprehensive picture of the interplay between star formation and mass assembly in galaxies. In addition to this, EELGs are also interesting in order to explain the reionization of the Universe, since their interstellar medium (ISM) could be leaking ionizing photons, and thus they could be low z, analogous of extreme galaxies at high z. Aims. This paper presents a method to obtain a census of EELGs over a large area of the sky by detecting galaxies with rest-frame equivalent widths ≥300 Å in the emission lines [O II]λλ3727,3729Å, [O III]λ5007Å, and Hα. For this, we aim to use the J-PAS survey, which will image an area of ≈8000 deg² with 56 narrow band filters in the optical. As a pilot study, we present a methodology designed to select EELGs on the miniJPAS images, which use the same filter dataset as J-PAS, and thus will be exportable to this larger survey. Methods. We make use of the miniJPAS survey data, conceived as a proof of concept of J-PAS, and covering an area of ≈1 deg². Objects were detected in the r_SDSS images and selected by imposing a condition on the flux in a given narrow-band J-PAS filter with respect to the contiguous ones, which is analogous to requiring an observed equivalent width larger than 300 Å in a certain emission line within the filter bandwidth. The selected sources were then classified as galaxies or quasi-stellar objects (QSOs) after a comparison of their miniJPAS fluxes with those of a spectral database of objects known to present strong emission lines. This comparison also provided a redshift for each source, which turned out to be consistent with the spectroscopic redshifts when available (|Δz/(1 + z_spec)| ≤ 0.01). Results. The selected candidates were found to show a compact appearance in the optical images, some of them even being classified as point-like sources according to their stellarity index. After discarding sources classified as QSOs, a total of 17 sources turned out to exhibit EW₀ ≥ 300 Å in at least one emission line, thus constituting our final list of EELGs. Our counts are fairly consistent with those of other samples of EELGs in the literature, although there are some differences, which were expected due to biases resulting from different selection criteria.

• Research Organization: US Department of Energy (USDOE), Washington, DC (United States). Office of Science, Sloan Digital Sky Survey (SDSS)
• Sponsoring Organization: National Science Foundation (NSF); USDOE Office of Science (SC)
• Contributing Organization: J-PAS team
• OSTI ID: 1982343
• Journal Information: Astronomy and Astrophysics, Journal Name: Astronomy and Astrophysics Vol. 665; ISSN 0004-6361
• Publisher: EDP Sciences
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
galaxies: evolution
galaxies: star formation
galaxies: starburst