X-ray Sources Population in NGC 1559

This paper presents the detected X-ray sources in the spiral galaxy NGC 1559, observed by the Chandra's Advanced CCD Imaging Spectrometer (ACIS). Twenty-four Xray sources are detected within this galaxy, and all sources information such as positions, count rates, fluxes and luminosities are cataloged. Among the twenty-four sources detected, none of them are located at the nuclear position of the galaxy, suggesting that NGC 1559 does not host an active galactic nucleus. We therefore classify all of the detected sources as ultra-luminous X-ray source (ULX) and X-ray binary (XRB) candidates, according to their luminosities. We find that six out of twenty-four sources have luminosity exceeding 1 x 10³⁹ erg s^-1, indicating that they are ULXs. The further eighteen sources detected have luminosity less than 1 x 10³⁹ erg s^-1, suggesting that they are X-ray binaries. The number of X-ray sources we found in the NGC 1559 is relatively high as compared to most galaxies. This is likely due to the high star formation activity and number of supernova explosions in the galaxy. The number of X-ray sources we detect is also much higher than that detected by previous X-ray study of the galaxy using ROSAT satellite. This can be attributed to the better sensitivity and resolving power of Chandra as compared to ROSAT.