Aperture corrections for disk galaxy properties derived from the CALIFA survey

Balmer emission lines in spiral galaxies

¹ Instituto de Astrofísica de Andalucía – CSIC, 18008 Granada, Spain
e-mail: jiglesias@iaa.es
² Centro Astronómico Hispano Alemán, 04004 Almería, Spain
³ CENTRA Centro Multidisciplinar de Astrofísica, Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal
⁴ Instituto Nacional de Astrofísica, Óptica y Electrónica, Luis E. Erro 1, 72840 Tonantzintla, Puebla, Mexico
⁵ Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany
⁶ Instituto de Astrofísica de Canarias, vía Láctea s/n, La Laguna, Tenerife, Spain
⁷ Departamento de Astrofísica, Universidad de La Laguna, 38205 La Laguna, Tenerife, Spain
⁸ University of Vienna, Department of Astrophysics, Türkenschanzstr. 17, 1180 Vienna, Austria
⁹ Sydney Institute for Astronomy, School of Physics A28, University of Sydney, NSW 2006, Australia
¹⁰ Departamento de Astrofísica y CC. de la Atmósfera, Universidad Complutense de Madrid, 28040 Madrid, Spain
¹¹ Departamento de Física, Universidade Federal de Santa Catarina, PO Box 476, 88040-900 Florianpolis, SC, Brazil
¹² Australian Astronomical Observatory, 105 Delhi Rd., North Ryde, NSW 1670, Australia
¹³ GEPI, Observatoire de Paris, CNRS-UMR8111, Univ. Paris-Diderot, 5 place Janssen, 92195 Meudon, France
¹⁴ Departamento de Física Teórica y del Cosmos, University of Granada, Facultad de Ciencias (Edificio Mecenas), 18071 Granada, Spain
¹⁵ Instituto Carlos I de Física Teórica y Computación, 18071 Granada, Spain
¹⁶ Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Mariesvej 30, 2100 Copenhagen, Denmark
¹⁷ INAF–Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, 50125 Firenze, Italy
¹⁸ Centro de Astrofísica and Faculdade de Ciências, Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal
¹⁹ Department of Physics and Astronomy, University of Missouri Kansas City, Kansas City, MO 64110, USA
²⁰ Departamento de Astronomia do Instituto de Astronomia, Geofísica e Ciências Atmosféricas da USP, Rua do Matão 1226, Cidade Universitária, 05508-090 São Paulo, Brasil
²¹ Department of Physics and Astronomy, Macquarie University, NSW 2109, Australia
²² Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
²³ CEI Campus Moncloa, UCM-UPM, Departamento de Astrofísica y CC. de la Atmósfera, Facultad de CC. Físicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid, Spain
²⁴ Departamento de Investigación Básica, CIEMAT, Avda. Complutense 22, 28040 Madrid, Spain
²⁵ Departamento de Física Teórica, Universidad Autónoma de Madrid, 28049 Madrid, Spain
²⁶ Department ofPhysics, Royal Military College of Canada, PO Box 17000, Station Forces, Kingston, Ontario, K7K 7B4, Canada
²⁷ European Southern Observatory, Alonso de Cordova 3107, Casilla 19001, Vitacura, Santiago, Chile

Received: 13 March 2013
Accepted: 4 April 2013

Abstract

This work investigates the effect of the aperture size on derived galaxy properties for which we have spatially-resolved optical spectra. We focus on some indicators of star formation activity and dust attenuation for spiral galaxies that have been widely used in previous work on galaxy evolution. We investigated 104 spiral galaxies from the CALIFA survey for which 2D spectroscopy with complete spatial coverage is available. From the 3D cubes we derived growth curves of the most conspicuous Balmer emission lines (Hα, Hβ) for circular apertures of different radii centered at the galaxy’s nucleus after removing the underlying stellar continuum. We find that the Hα flux (f(Hα)) growth curve follows a well-defined sequence with aperture radius that shows a low dispersion around the median value. From this analysis, we derived aperture corrections for galaxies in different magnitude and redshift intervals. Once stellar absorption is properly accounted for, the f(Hα)/f(Hβ) ratio growth curve shows a smooth decline, pointing toward the absence of differential dust attenuation as a function of radius. Aperture corrections as a function of the radius are provided in the interval [0.3, 2.5]R₅₀. Finally, the Hα equivalent-width (EW(Hα)) growth curve increases with the size of the aperture and shows a very high dispersion for small apertures. This prevents us from using reliable aperture corrections for this quantity. In addition, this result suggests that separating star-forming and quiescent galaxies based on observed EW(Hα) through small apertures will probably result in low EW(Hα) star-forming galaxies begin classified as quiescent.