Andromeda Galaxy in X-rays
This image shows the Andromeda galaxy, also known as M31, the nearest major galaxy to the Milky Way, as observed by ESA's X-ray observatory, XMM-Newton.
By targeting radiation in the X-ray portion of the spectrum, XMM-Newton is sensitive to highly energetic phenomena typical of the latest evolutionary stages of stellar life. The XMM-Newton data have been gathered by the EPIC camera in the 0.3–7.0 keV energy range, corresponding to wavelengths of 1.8–41.3 Ångstroms. This deep map of M31 is the result of a few tens of observations performed between 2000 and 2010, with a total observing time of more than 2 million seconds, equivalent to over 20 days; different amounts of time were spent observing different regions of the galaxy.
Visible in this XMM-Newton image are hundreds of sources of X-rays, which mostly belong to two classes: supernova remnants (SNR), remains of the powerful explosions through which massive stars end their life; and binary systems, pairs of objects consisting of a compact stellar remnant - a white dwarf, neutron star or black hole - exerting an intense gravitational pull onto a companion star, from which it strips material via an accretion disc.
By probing the latest stages of stellar evolution, which have also a major impact on the birth of future generations of stars via the mass and energy released by supernovae in their surroundings, XMM-Newton offer us an exceptional view of the evolution of stars in the Andromeda galaxy.