CALIFA spectroscopy of the interacting galaxy NGC 5394 (Arp 84): starbursts, enhanced [N ii]6584 and signs of outflows and shocks
N. Roche, A. Humphrey, J. M. Gomes, P. Papaderos, P. Lagos, S. F. Sánchez
Abstract
We investigate the spiral galaxy NGC 5394, which is strongly interacting with the larger spiral NGC 5395 (the pair is Arp 84), using optical integral-field spectroscopy from the CALIFA (Calar Alto Legacy Integral Field Area) survey. Spatially resolved equivalent widths, emission-line ratios and kinematics reveal many features related to the interaction, which has reshaped the galaxy. H α maps (with other diagnostic emission lines) show a concentrated central (r < 1 kpc) starburst and three less luminous star-forming regions (one knot far out in the northern arm), and we estimate the dust-corrected total star-formation rate as 3.39 M⊙ yr− 1. However, much of the galaxy, especially the outer tidal arms, has a post-starburst spectrum, evidence of a more extensive episode of star formation a few ×108 yr ago, triggered by the previous perigalacticon. The
Keywords
galaxies: evolution, galaxies: individual: NGC 5394, galaxies: interactions, galaxies: starburst
Monthly Notices of the Royal Astronomical Society
Volume 453, Page 2349
November 2015
DOI: 10.1093/mnras/stv1669
ADS Bibliographic code: 2015MNRAS.453.2349R