Unusual Galaxy M87

M87 and its blue Relativistic jet imaged by Author using a Celestron C14 equipped with a QHY183c camera. The galaxy itself is the diffuse warm glow and is the combined light of a trillion stars which are too faint to be individually resolved here. 284 individual 6 second exposures were added together for the view (a total of 1704 seconds exposure)

One aspect I find interesting with astronomy is there is no end of unusual and weird objects out there to observe, even from the convenience of your suburban home observatory. One such unusual object is a galaxy called M87, a large elliptic galaxy in the constellation of Virgo. It turns out that the constellation of Virgo is full of galaxies. When viewing through a telescope there are some parts of the constellation where you can see 3 or 4 galaxies or more in the same view. The reason for this is there is a concentration of galaxies in that direction of sky called the Virgo cluster, of which M87 is one of the largest members.

M87 is estimated to have a mass that could be as high as 200 times more than our own Milky Way (which is itself a large galaxy). But the most intriguing feature of M87 is the prominent blue “Relativistic” jet that points away from the core of the galaxy. Recently, I tried to image this jet, and I was pleasantly surprised to not only image it but also see some detail in the jet. You can clearly see the jet in the picture above.

Relativistic jet

Artist Impression of a large Accretion disk surrounding a black hole, as well as an associated Astrophysical Jet. Image credit: Caltech/Nasa

In astronomy matter falling into a large massive body will often arrange itself into a flattened spinning disk, known as an accretion disk. Complex magnetic interactions created from the spinning accretion disk are thought to transfer momentum away from material in the disk to material in collimated jets directed outwards along to the axis of rotation. This class of phenomena is called an Astrophysical Jet. From the research I have done there still appears to be a lot of differing opinion on the exact nature of these jets and considerable more research needs to be done.

The grandest type of Astrophysical Jet is those associated with Active Galactic Nuclei (AGN’s) and Quasars, where there is believed to be a massive accretion disk feeding into a large black hole at the center of the galaxy. These objects are so energetic that their jets can accelerate large amounts of material to close to the speed of light. When this happens the jet will show Relativistic effects such as blue-shifting and Doppler Effect brightening and as such are called Relativistic Jets. M87 pictured above is a fine example of an AGN galaxy with a prominent Relativistic Jet.

So, has Hubble managed to get an image of the M87 jet? The answer is yes and here it is (amazing isn’t it!).

M87's Relativistic jet imaged by Hubble. Image Credit : STScI/NASA