Transient X-ray sources in M 31
The X-ray monitoring of the central area of M 31 with XMM-Newton, Chandra and Swift continues to reveal new sources which brighten and fade on various time scales. These transient X-ray sources are of different nature, comprising nova and black hole systems.
X-ray images of the central area of M 31:
Left: Combined XMM-Newton EPIC PN, MOS1 and MOS2 low background image of the central area of M 31 (0.2-4.5 keV, Jun 2000 - Jan 2002, ~100 ks exposure, see Pietsch, Freyberg & Haberl 2005).
Middle: XMM-Newton EPIC PN 0.5-5 keV image from Aug 9, 2006 (~20 ks exposure), performed as one of the observations of the XMM-Newton/Chandra nova monitoring program of the central area of M31. The transient XMMU J004215.8+411924 is marked by a circle with 30 arcsec radius.
Right: Swift XRT 0.5-5 keV image from Sep 1, 2006 (~6 ks exposure). The transient SWIFT J004217.4+411532 is marked by a circle with 30 arcsec radius. XMMU J004215.8+411924 is also clearly visible.
Left: Combined XMM-Newton EPIC PN, MOS1 and MOS2 low background image of the central area of M 31 (0.2-4.5 keV, Jun 2000 - Jan 2002, ~100 ks exposure, see Pietsch, Freyberg & Haberl 2005).
Middle: XMM-Newton EPIC PN 0.5-5 keV image from Aug 9, 2006 (~20 ks exposure), performed as one of the observations of the XMM-Newton/Chandra nova monitoring program of the central area of M31. The transient XMMU J004215.8+411924 is marked by a circle with 30 arcsec radius.
Right: Swift XRT 0.5-5 keV image from Sep 1, 2006 (~6 ks exposure). The transient SWIFT J004217.4+411532 is marked by a circle with 30 arcsec radius. XMMU J004215.8+411924 is also clearly visible.
SWIFT UVOT image of the area around XMMU J004215.8+411924 obtained with the UW1 Filter. The circles mark the X-ray positions derived from the EPIC images (2 arcsec radius) and with the SWIFT XRT (6 arcsec radius).