Chandra observation of the edge-on spiral NGC 5775: probing the hot galactic disc/halo connection

We study the edge-on galaxy NGC 5775, utilizing a 58.2 ks Chandra ACIS-S observation together with complementary Hubble Space Telescope (HST) ACS, Spitzer IRAC and other multi-wavelength data sets. This edge-on galaxy, with its disc-wide active star formation, is particularly well suited for studying the disc/halo interaction on subgalactic scales. We detect 27 discrete X-ray sources within the D-25 region of the galaxy, including an ultra-luminous source with a 0.3-7 keV luminosity of similar to 7 x 10(40) erg s(-1). The source-removed diffuse X-ray emission shows several prominent extraplanar features, including a similar to 10 kpc diameter 'shell-like' feature and a 'blob' reaching a projected distance of similar to 25 kpc from the galactic disc. The bulk of the X-ray emission in the halo has a scale height of similar to 1.5 kpc and can be characterized by a two-temperature optically thin thermal plasma with temperatures of similar to 0.2 and 0.6 keV and a total 0.3-2 keV luminosity of similar to 3.5 x 10(39) erg s(-1). The high-resolution, multi-wavelength data reveal the presence of several extraplanar features around the disc, which appear to be associated with the in-disc star formation. We suggest that hot gas produced with different levels of mass loading can have different temperatures, which may explain the characteristic temperatures of hot gas in the halo. We have obtained a subgalactic scale X-ray-intensity-star-formation relation, which is consistent with the integrated version in other star-forming galaxies.