Distant Galaxy Steals Building Blocks of Stars and Galaxies

Surprising new observations from NASA's infrared Spitzer Space Telescope are catching a thieving galaxy in the middle of a hydrogen heist. The energy equivalent of one billion suns is being stolen by distant radio galaxy 3C 326 North from its diminutive neighbor 3C 326 South. Hydrogen gas is common among galaxies, but if a particular galaxy is not actively in the process of forming new stars and planets, it is unusual for it to have vast reservoirs of hydrogen. Yet the radio galaxy 3C326 North, which has a black hole (area with such intense gravity that it is impermeable to light) at its center, is swimming in hydrogen.

The mystery was discovered and decoded by Patrick Ogle of NASA's Spitzer Science Center at the California Institute of Technology. He and his team were using Spitzer's infrared data to study distant radio galaxies about a billion light years away and found that the 3C 326 duo were not acting according to expectations. Upon closer examination the team made two discoveries.

First, upon noticing that 3C 326 North was acquiring huge amounts of highly heated hydrogen gas--730 degrees Celsius, or 1,34 degrees Fahrenheit--they then detected a "tail of stars" called a tidal tail. This tidal tail was part of the hydrogen flow and established an interaction between 3C 326 North and the smaller near neighbor 3C 326 South: they are connected in a dynamic interaction as 3C 326 North siphons hydrogen from its neighboring radio galaxy 3C 326 South.

The form of hydrogen being pulled from 3C 326 South is hydrogen Cgas and is called molecular hydrogen gas. Hydrogen Cgas comprises two hydrogen atoms instead of one hydrogen atom. When molecular hydrogen is heated, as it is during the process of being pulled from one radio galaxy to the other, it becomes visible in infrared. Spitzer's infrared telescopes made the molecular hydrogen visible, whereas with optical telescopes, molecular hydrogen is invisible. As a side note, this same hydrogen Cgas is being developed as an alternative automobile fuel.

Radio galaxies have black holes at their centers, but the 3C 326 black holes are not the most energetic that have been found. However they do have very energetic jets of radio waves emitting from their centers, the jets are said to be "screaming out" of the black hole centers.

3C 326 North and 3C 326 South provide the best evidence to date of molecular hydrogen making the stolen passage from one galaxy to its neighboring galaxy and the best display of the extraordinarily high heat that is produced-the infrared waves of which can be picked up by Spitzer. The duo of 3C 326 is close enough that they perturb (effect the movement) of each other gravitationally and the possibility exists that one day they may collide and and eventually produce on seamless galaxy from the galactic tangle of cosmic gas and galactic stars.

"To Catch a Galactic Thief," NASA's Spitzer Space Telescope.