M81: GALEX image of M81

Credit: NASA/JPL-Caltech/J. Huchra (Harvard-Smithsonian CfA)

The Galaxy Evolution Explorer (GALEX) satellite has been used to obtain this spectacular false-color ultra-violet image of spiral galaxy M81, together with its companion Holmberg IX.

GALEX Press Release (May 1, 2007):
http://www.galex.caltech.edu/MEDIA/2007-02/

M81 and Holmberg IX page at SEDS:
http://www.seds.org/messier/more/m081_hom9.html

M31: XMM and Chandra investigate central region

Central part of M31 in X-rays

M31 central part, combined X-ray and optical image

Credit: NASA/CXC/MPE/W.Pietsch et.al.

In X-rays, hot gas is seen to envelop the central part of the Andromeda Galaxy, M31. The prominent point sources mostly belong to interacting double stars, many of them containing a White Dwarf companion pulling away matter from its partner star. When the matter gets compressed and heated, a thermonuclear explosion occurs near the White Dwarfs surface; this explosion is bright in X-rays and makes the star flash up as a nova.

Chandra Press Release (May 22, 2007):
http://chandra.harvard.edu/photo/2007/m31/

ESA XMM Newton Press Release (May 9, 2007):
http://www.esa.int/esaSC/SEM0C2V681F_index_0.html

Publication:
http://adsabs.harvard.edu/abs/2007A&A…465..375P

SEDS M31 page:
http://www.seds.org/messier/m/m031.html

M104: Chandra images the Sombrero Galaxy

The Sombrero Galaxy, M104 (NGC 4594), was imaged by NASA’s great observatories (Chandra, Hubble, and Spitzer) in the X-ray, optical, and infrared light. This is a false-color composite image showing M104 in great detail.

Credit: X-ray: NASA/UMass/Q.D.Wang et al.; Optical: NASA/STScI/AURA/Hubble Heritage; Infrared: NASA/JPL-Caltech/Univ. AZ/R.Kennicutt/SINGS Team

Chandra Press Release:
http://chandra.harvard.edu/photo/2007/sombrero/

SEDS M104 page:
http://www.seds.org/messier/m/m104.html