A&A 621, A25 (2019) Astronomy https://doi.org/10.1051/0004-6361/201834159 & c ESO 2018 Astrophysics Kinematics and dynamics of the luminous infrared galaxy pair NGC 5257/58 (Arp 240)? I. Fuentes-Carrera1, M. Rosado2, P. Amram3, E. Laurikainen4, H. Salo4, J. A. Gómez-López3, H. O. Castañeda1, A. Bernal2, and C. Balkowski5 1 Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional (ESFM-IPN), U.P. Adolfo López Mateos, edificio 9, Zacatenco, 07730 Mexico City, Mexico e-mail:
[email protected],
[email protected] 2 Instituto de Astronomía, Universidad Nacional Autónoma de México (UNAM), Apdo. Postal 70-264, 04510 Mexico City, Mexico 3 Aix-Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille), 13388 Marseille, France 4 Department of Physical Sciences, Division of Astronomy, University of Oulu, 90570 Oulu, Finland 5 GEPI, Observatoire de Paris, CNRS, Université Paris Diderot, 5 Place Jules Janssen, 92190 Meudon, France Received 29 August 2018 / Accepted 19 October 2018 ABSTRACT Context. Encounters between galaxies modify their morphology, kinematics, and star formation history. The relation between these changes and external perturbations is not straightforward. The great number of parameters involved requires both the study of large samples and individual encounters where particular features, motions, and perturbations can be traced and analysed in detail. Aims. We analysed the morphology, kinematics, and dynamics of two luminous infrared spiral galaxies of almost equal mass, NGC 5257 and NGC 5258, in which star formation is mostly confined to the spiral arms, in order to understand interactions be- tween galaxies of equivalent masses and star-forming processes during the encounter.