OTELO survey: optimal emission-line flux determination with OSIRIS/GTC

Emission-line galaxies are important targets for understanding the chemical evolution of galaxies in the universe. Deep, narrow-band imaging surveys allow to detect and study the flux and the equivalent widths (EW) of the emission line studied. The present work has been developed within the context...

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Detalles Bibliográficos
Autor: Gallego Maestro, Jesús
Tipo de recurso: artículo
Fecha de publicación:2010
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/43022
Acceso en línea:https://hdl.handle.net/20.500.14352/43022
Access Level:acceso abierto
Palabra clave:52
Astrofísica
Astronomía (Física)
Descripción
Sumario:Emission-line galaxies are important targets for understanding the chemical evolution of galaxies in the universe. Deep, narrow-band imaging surveys allow to detect and study the flux and the equivalent widths (EW) of the emission line studied. The present work has been developed within the context of the OTELO project, an emission line survey using the Tunable Filters (TF) of OSIRIS, the first generation instrument on the GTC 10.4m telescope located in La Palma, Spain, that will observe through selected atmospheric windows relatively free of sky emission lines. With a total survey area of 0.1 square degrees distributed in different fields, reaching a 5 σ depth of 10^(−18) erg/cm^(2) /s and detecting objects of EW < 0.3 Å, OTELO will be the deepest emission line survey to date. As part of the OTELO preparatory activities, the objective of this study is to determine the best combination of sampling and full width at half maximum (FWHM) for the OSIRIS tunable filters for deblending Hα from [N ii] lines by analyzing the flux errors obtained. We simulated the OTELO data by convolving a complete set of synthetic H ii galaxies in EW with different widths of the OSIRIS TFs. We estimated relative flux errors of the recovered Hα and [N ii]λ6583 lines. We found that, for the red TF, a FWHM of 12 Å and a sampling of 5 Å is an optimal combination that allow deblending Hα from the [N ii]λ6583 line with a flux error lower than 20%. This combination will allow estimating SFRs and metallicities using the Hα flux and the N2 method, respectively.