We report the serendipitous detection of an X-ray source, AX J1749+684, with the ASCA Gas Imaging Spectrometer. AXJ1749+684 is identified with a LINER/starburst-type spiral galaxy KUG1750+683A at a redshift z = 0.05. It has a hard X-ray spectrum, consistent with that of the X-ray background (XRB) in the 1-10 keV band. Despite the optical classification, the X-ray luminosity cannot be explained by starburst activity. Combined with spatial variations in the optical emission-line ratios, this suggests the presence of an obscured Seyfert nucleus embedded within a star-forming galaxy. Similar behaviour could explain the ambiguous properties of the faint narrow-line X-ray galaxies (NLXGs) emerging from deep X-ray surveys.
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science