X-rays from the barred galaxy NGC 4303

The late-type galaxy NGC 4303 (M61) is one of the most intensively studied barred galaxies in the Virgo Cluster. Its prominent enhanced star formation throughout large areas of the disk can be nicely studied due to its low in clination of about 27 degrees. We present observations of NGC 4303 with the ROSAT PSPC and HRI in the soft X-ray (0.1-2.4 keV). The bulk of, the X-ray emission is located at the nuc lear region. It contributes more than 80% to the total observed soft X-ray flux. The extension of the central X-ray source and the L-X/L-H alpha ratio point to a low luminous AGN (LINER) with a circumnuclear star-forming regi on. Several separate disk sources can be distinguished with the HRI, coinci ding spatially with some of the most luminous H II regions outside the nucl eus of NGC 4303. The total star formation rate amounts to 1-2 M. yr(-1). Th e X-ray structure follows the distribution of star formation with enhanceme nt at the bar-typical patterns. The best spectral fit consists of a power-law component (AGN and HMXBs) and a thermal plasma component of hot gas from supernova remnants and superbub bles. The total 0.1-2.4 keV luminosity of NGC 4303 amounts to 5 x 10(40) er g s(-1) consistent with comparable galaxies, like e.g. NGC 4569.