An enormous fanny of gas 300,000 light - years long has been observe get behind behind a galaxy . The hydrogen bum is three times the length of our own beetleweed and five times long than NGC 4569 , the Galax urceolata from which it come . The breakthrough explicate a whodunit – why is NGC 4569 so depleted in hydrogen gas ?
At 55 million light - years away , NGC 4569 ( Messier 90 ) is comparatively close by galactic standards , and is part of the famous Virgo cluster of galaxies . It is famed both because it is moving at 1,200 kilometers ( 745 miles ) per second relative to that huge cluster as a whole , and because it is extremely depleted in gas .
Astronomers suspected that the two fact were touch on , with NGC 4569 being strip down of gas in its travels . As a paper inAstronomy and Astrophysicsnoted,“Galaxies in rich environs are consistently dissimilar from those located in the field . ” One vernacular difference is reduced tightness of atomic number 1 gas , indicating that something in the clustering slip accelerator pedal from snuff it extragalactic nebula .
However , cobalt - authorDr . Luca Corteseof the University of Western Australia said in astatement : “ We did n’t have the smoke gunman , the clear grounds of direct remotion of gun from the galaxy . ”
Cortese and colleagues think they have changed this . “ Now , with these reflection , we ’ve seen a immense amount of flatulency that create a flow trailing behind the galaxy for the first time , ” hesaid . “ What ’s very nice is that if you measure the great deal of the stream , it ’s the same amount of gaseous state that is missing from the galaxy ’s magnetic disc . ”
notice the missing hydrogen gasoline was a challenge because , left behind from its galaxy , there is nothing to fire up it up . Nevertheless , Cortese and his colleagues were able-bodied to observe it using the Canada France Hawaii Telescope , equipped with a filter to detectH - alpha radiationfrom ionized atomic number 1 .
The ionised gun is estimated to have a mass adequate to 3.2 billion meter that of the Sun , but no superstar - forming regions have been detected . This eliminates eminent - energy radiation from stars as a mechanism for the gas ' ionisation . The author propose several other possible ionization processes , with some evidence in favour of powerful magnetic fields .
Onepopular theoryis that galaxies in clusters recede flatulence because the gravitational pulling of large galax steal material from those that get too nigh . In this eccentric , however , the authors favour the alternate explanation , blame gas concentrations between galaxies within the cluster .
“ We know that big clump of galaxies trap a flock of hot gas,”saidCortese . “ So when a galaxy enters the cluster it feel the pressure of all the gas , like when you feel the wind on your face , and that pressure is capable to strip weigh out from the galaxy . ” The faster a galaxy like NGC 4569 is move compared to the gas within the bunch , the more pressure it will experience , forcing unbound hydrogen to trail behind it .
