Central star formation and metallicity in CALIFA interacting galaxies

¹ Instituto de Astrofísica de Canarias (IAC), 38205, La Laguna, Tenerife, Spain
e-mail: jkbb@iac.es
² Depto. Astrofísica, Universidad de La Laguna (ULL), 38206, La Laguna, Tenerife, Spain
³ Instituto de Astronomía,Universidad Nacional Autonóma de Mexico, A.P. 70-264, 04510, Mexico
⁴ Instituto de Cosmologia, Relatividade e Astrofísica – ICRA, Centro Brasileiro de Pesquisas Físicas, Rua Dr. Xavier Sigaud 150, CEP 22290-180, Rio de Janeiro, RJ, Brazil
⁵ Instituto de Astrofísica de Andalucía (CSIC), Glorieta de la Astronomía s/n, Aptdo. 3004, 18080 Granada, Spain
⁶ European Southern Observatory (ESO), Karl-Schwarzschild-Str. 2, 85748 Garching b. Muenchen, Germany
⁷ Max-Planck-Institut für Astronomie, 69117 Heidelberg, Germany
⁸ Estación Experimental de Zonas Aridas (CSIC), Ctra. de Sacramento s/n, La Cañada, Almería, Spain
⁹ Instituto Nacional de Astrofísica, Óptica y Electrónica, Luis E. Erro 1, 72840 Tonantzintla, Puebla, Mexico
¹⁰ Centro de Estudios de la Física del Cosmos de Aragón, 44001 Teruel, Spain
¹¹ 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
¹² Millennium Institute of Astrophysics, Universidad de Chile, 1058 Santiago, Chile
¹³ Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago, Chile
¹⁴ Australian Astronomical Observatory, PO Box 915, North Ryde, NSW 1670, Australia
¹⁵ Department of Physics and Astronomy, Macquarie University, NSW 2109, Australia
¹⁶ Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany

Received: 24 November 2014
Accepted: 16 April 2015

Abstract

We use optical integral-field spectroscopic (IFS) data from 103 nearby galaxies at different stages of the merging event, from close pairs to merger remnants provided by the CALIFA survey, to study the impact of the interaction in the specific star formation and oxygen abundance on different galactic scales. To disentangle the effect of the interaction and merger from internal processes, we compared our results with a control sample of 80 non-interacting galaxies. We confirm the moderate enhancement (×2–3 times) of specific star formation for interacting galaxies in central regions as reported by previous studies; however, the specific star formation is comparable when observed in extended regions. We find that control and interacting star-forming galaxies have similar oxygen abundances in their central regions, when normalized to their stellar masses. Oxygen abundances of these interacting galaxies seem to decrease compared to the control objects at the large aperture sizes measured in effective radius. Although the enhancement in central star formation and lower metallicities for interacting galaxies have been attributed to tidally induced inflows, our results suggest that other processes such as stellar feedback can contribute to the metal enrichment in interacting galaxies.