A artificial satellite galaxy of the milklike Way seems to possess the with child denseness of dark matter in the local universe . The object , called Triangulum II , is made up of only 1,000 wiz and is located117,000 ignitor - yearsfrom the centre of the Milky Way .
Astronomers canvass the speed of six star near the beetleweed center , a feature dictated by the gravitational force-out exerted on them . After using this to calculate the sizing of the forcefulness , the team was able to estimate that the mass of the small galaxy was the combining weight of 1.6 million solar masses , significantly big than what one would wait from a coltsfoot housing just 1,000 wiz .
The surplus mass is likely due todark matter , a hypothetical type of matter which interacts gravitationally with normal matter , helping keep extragalactic nebula together . Because it does not absorb or reflect illumination , it can not be seen using telescope . Galaxies tend to have 10 times more coloured matter particles than normal matter , but in Triangulum II disconsolate matter is about 3,600 fourth dimension more abundant .
" The full spate I measured was much , much peachy than the batch of the full number of stars – imply that there ’s a gross ton of densely packed dark matter contribute to the entire mass , " Professor Evan Kirby said in astatement . " The proportion of dark matter to luminous subject is the highest of any galaxy we know . After I had made my measurements , I was just thinking – wow . "
If the approximation is confirmed , Triangulum II could be a perfect place to observe indirect evidence of dark matter . When dismal matter wipe out itself , it give out hefty gamma shaft of light . Often those signals are drowned out by the rest of the light emitted by galaxies , but since Triangulum II has only a small turn of stars our telescope should be able to detect the gamma sign from obscure affair .
A group of research worker from the University of Strasbourg in France , havemeasuredthe stars on the border of the beetleweed and found that those stars are move faster than the key group . If that were to be the case , it would designate that the minor galaxy is being pulled aside by the Milky Way , and that the dark thing estimate is not as accurate . " My next steps are to make measurements to confirm that other group ’s finding , " Kirby say . " If it turns out that those outer stars are n’t actually be active faster than the interior ones , then the galaxy could be in what ’s call dynamic equilibrium . That would make it the most excellent candidate for detecting drear matter with gamma electron beam . " The paper was release in theAstrophysics Journal Letters .
