A Search for Hard X-ray Nebulae in Star-forming Galaxies with Chandra

Recently, diffuse, hard (>2 keV) X-ray, kpc-scale nebulae have been reported in several nearby star-forming galaxies, such as M82, NGC 891, and NGC 3079. However, the origin of these nebulae is still unknown. This hard emission may be interpreted as superheated gas, which may drive galactic outflows from regions of intense star formation. If this is the case, the hard diffuse X-ray emission may help understand how the superheated gas connects to the surrounding kpc-scale winds seen from radio through the X-rays. We are conducting the Chandra archival survey to quantify the frequency and properties of diffuse, hard emission in starbursts and star-forming galaxies. Our sample consists of 20 galaxies, ranging from 3 - 12 Mpc in distance and with SFR ranging from 0.2 − 43 M_sun/yr. We present our preliminary results.