Spiral inflow feeding the nuclear starburst in M83, observed in H-alpha emission with the GHAFAS Fabry-Perot interferometer

TL;DR

This study uses high-resolution H-alpha observations with GHAFAS to reveal gas inflow feeding the nuclear starburst in M83, showing a nuclear disk and multiple star formation events within the central 100 pc.

Contribution

First high-resolution Fabry-Perot observations of M83's central region demonstrating gas inflow feeding nuclear starburst activity.

Findings

Detection of gas inflow from kpc scales to the nucleus

Formation of a nuclear rotating disk of ~60 pc scale

Multiple star formation episodes within 100 pc of the nucleus

Abstract

We present observations of the nearby barred starburst galaxy, M83 (NGC5236), with the new Fabry-Perot interferometer GHAFAS mounted on the 4.2 meter William Herschel Telescope on La Palma. The unprecedented high resolution observations, of 16 pc/FWHM, of the H-alpha-emitting gas cover the central two kpc of the galaxy. The velocity field displays the dominant disk rotation with signatures of gas inflow from kpc scales down to the nuclear regions. At the inner Inner Lindblad Resonance radius of the main bar and centerd at the dynamical center of the main galaxy disk, a nuclear $5.5 (\pm 0.9) \times 10^8 M_\odot$ rapidly rotating disk with scale length of $60 \pm 20$ pc has formed. The nuclear starburst is found in the vicinity as well as inside this nuclear disk, and our observations confirm that gas spirals in from the outer parts to feed the nuclear starburst, giving rise to several star formation events at different epochs, within the central 100 pc radius of M83.