From new data assemble by NASA ’s Hubble Space Telescope , scientist have been able-bodied to count beyond the suave , settled “ brim ” of the Sombrero extragalactic nebula , and into its wilder past times . The surprising observations of alloy - rich principal in the galaxy ’s nimbus , normally only found in a coltsfoot ’s platter , indicate that its current state may peradventure be the result of major extragalactic nebula fusion . Although it ’s tidy appearing is not the common mussy scene feel after recent cosmic collision .
turn up in the constellation Virgo , 28 million easy - years away , the dear boundary - onM104 galaxygained its “ sombrero ” nickname due to its prominent central hump , encircle by thick , corkscrew dust lanes . Famed not just for its beauty , the unequalled morphology of the galaxy has also activate the curiosity of astronomers . Never quite meet the traditional definition of a spiral nor an elliptic beetleweed , observations of the “ hybrid ” Sombrero extend up an insight into how such galaxies may have make and gather .
" The Sombrero has always been a bit of a weird galaxy , which is what urinate it so interesting , " Paul Goudfrooij of the Space Telescope Science Institute ( STScI ) , Baltimore , said in astatement . " Hubble ’s metallicity measuring ( the abundance of heavy elements in the stars ) are another indication that the Sombrero has a destiny to teach us about coltsfoot assembly and organic evolution . "
Heavier element are formed through the stellar “ lifecycle ” process . Therefore , the longer a galaxy has contained headliner generating these component , the more “ metal - rich ” new ace forming in those environs will be . Typically , these younger gamey - metallicity stars are found in the dense starring populations in the main disk of the galaxy .
Out in the galaxy ’s halo , old alloy - miserable stars are expected to be found . Generated ahead of time on in a galaxy ’s history , when there were less heavy elements , these champion had been throw out into the halo from a larger companion star going supernova . Globular clusters , turn back old metal - hapless whiz , also contribute to the leading population in the doughnut , when they transmigrate out of the disc and into the anchor ring .
However , researchers cover in a paper published inThe Astrophysical Journalthe carry star metallicity dispersion was not observed in the Sombrero ’s halo . " The absence of metal - poor genius was a big surprisal , " said Goudfrooij , " and the copiousness of alloy - robust stars only added to the mystery . "
To taste and solve the mystery , the team used a computer plan to simulate events to discover the origin of the unexpected metallicity measurement . hold expectations once again , the squad found that the unperturbed Sombrero had in all probability undergone major accretion , or merger events billions of years ago . Colliding with one or more similarly massive galaxies that are full-bodied in higher - metallicity virtuoso could calculate for the measurements in Sombrero .
Although these monumental amalgamation event happen elsewhere in the universe , they ordinarily have a more distorted appearing for billion of years , unlike the politic disk of Sombrero . OurMilky Way galaxyis no alien to amalgamation as well , however , the small orbiter galaxy that it swallowed up in so - called “ minor ” accretions , are not on the same graduated table as Sombrero ’s surmise past fundamental interaction .
