An X-ray View of Star Formation in the Central 3 kpc of NGC 2403

TL;DR

This study uses Chandra X-ray data to analyze hot gas associated with star formation in NGC 2403, revealing diffuse hot gas linked to star-forming regions and past outflows, with implications for galaxy evolution.

Contribution

It provides the first detailed analysis of diffuse X-ray emission in NGC 2403's central region, linking hot gas to star formation and feedback processes.

Findings

Diffuse hot gas (kT ~ 0.2 keV) is associated with star-forming regions.

Less than 20% of X-ray emission comes from unresolved point sources.

Hot gas may be remnants of past outflows or lingering disk components.

Abstract

Archival Chandra observations are used to study the X-ray emission associated with star formation in the central region of the nearby SAB(s)cd galaxy NGC 2403. The distribution of X-ray emission is compared to the morphology visible at other wavelengths using complementary Spitzer, GALEX, and ground-based Halpha imagery. In general, the brightest extended X-ray emission is associated with HII regions and to other star-forming structures but is more pervasive; existing also in regions devoid of strong Halpha and UV emission. This X-ray emission has the spectral properties of diffuse hot gas (kT ~ 0.2keV) whose likely origin is in gas shock-heated by stellar winds and supernovae with < 20% coming from faint unresolved X-ray point sources. This hot gas may be slowly-cooling extra-planar remnants of past outflow events, or a disk component that either lingers after local star formation activity has ended or that has vented from active star-forming regions into a porous interstellar medium.