Distance: 35,000,000 light-years (10.7 kpc) Image Size = 9.6 x 9.6 arcmin Visual Magnitude = 9.3

Ultraviolet Image
Not Available
X-Ray: ROSAT   Visible: DSS Visible: Color © AAO
Near-Infrared: 2MASS Mid-Infrared: IRAS Far-Infrared: IRAS Radio: NVSS


Messier 65 is a type Sa spiral galaxy and a member of the Leo Triplet of galaxies (neither of its companions, one of which is Messier 66, is seen in these images). Galaxies are often bound by gravity into small groups and larger clusters. Note that M65 is seen from an oblique (nearly edge-on) angle.


Visible: DSS and Visible Color: AAO

The DSS visible-light photograph (left) is over-exposed in the central regions, and most of the galaxy's structural details are lost in the saturated light. Nonetheless, you can see a vertical lane of dust in the eastern (left-side) edge of the galaxy. The dust lane is much more prominent in the color image from the Anglo-Australian Observatory (right). In this photograph, dust can easily be seen throughout the entire disk of the galaxy.

Note that type Sa spiral galaxies have pronounced central bulges, with relatively weak arm structures (unlike Messier 33, for example). Moreover, Messier 65 has less gas and dust content than a type Sc spiral like M33, and its stellar population is characterized by a higher ratio of older-to-newer stars.


Near-Infrared: 2MASS (left), Mid-Infrared: IRAS (center) and Far-Infrared: IRAS (right)

Near-infrared light is ideal for tracing the old stellar population in galaxies, and hence the 2MASS image (left) reveals an impressive degree of structure within the galaxy disk, despite its short exposure time of 7.8 seconds. [Contrast this finding with M33, which is dominated by young stars and where the disk structure is more pronounced in the optical images rather then the near-IR pictures.] Note the dark lane of dust running north-south along the left edge of the galaxy.

Messier 65 is barely seen at a wavelength of 25 microns (above, center). Newborn stars normally appear bright at this mid-infrared wavelength, and we are left to conclude that the rate of star formation in M65 is rather low.

The far-infrared image (above, right) is of relatively poor spatial resolution and the target galaxy is smeared along one the major axis of the rectangular IRAS detectors used to create this image. The central core of M65 is clearly the brightest region in the far-infrared, corresponding to the region of highest stellar density. Overall, the long-wavelength IR emission from M65 is rather modest, due to relatively low rates of ongoing star formation.


Radio: NVSS (left) and X-Ray: ROSAT (right)

The radio image (above left) reveals emission along the vertical extent of the galaxy. Curiously, the brightest source of radio emission near the galaxy is not at the center, but is located (yellow/orange peak) about 2 arcminutes to the south-southeast, at approximately the 7 o'clock position. What is the source of this emission? That's a good question! A search of the exhaustive NASA Extragalactic Database (NED) fails to find any cataloged astronomical object outside our Galaxy corresponding to the position of the modest radio peak. A similar search of the SIMBAD database of stellar objects fails to reveal the source of the emission. For now, the identity of the radio peak remains a mystery! Meanwhile, the bright source of radio emission to the northwest (upper right corner) is probably associated with a background object, such as a distant and uncataloged quasar.


X-Ray: ROSAT

The x-ray image reveals very little emission. The core of M65 is faintly seen, but there is no significant x-ray emission from the rest of the galaxy disk.

NED technical data for M65
Multiwavelength Astronomy | Multiwavelength Gallery | Solar System | Open Star Clusters| Globular Clusters| Emission Nebulae| Planetary Nebulae| Supernova Remnants| Sa Spiral Galaxies| Sb Spiral Galaxies| Sc Spiral Galaxies| Elliptical Galaxies| Irregular Galaxies| Active Galaxies|