Mighty Dons Of Science News

As­tro­no­mers have found a gi­ant gal­axy sur­round­ing what they de­scribe as the old­est and most dis­tant black hole known.

The gal­axy is as large as the Milky Way gal­axy and har­bors a “su­per­mas­sive,” or giant, black hole es­ti­mat­ed to weigh the equiv­a­lent of at least a bil­lion Suns.

A black hole is an ob­ject so com­pact that its gra­vity drags in any­thing that pass­es too close by, in­clud­ing light rays. Some black holes are formed from burned-out stars, but others are too large to be ex­plained in this way and their ori­gin is some­what mys­ter­ious.

The newfound black hole and galaxy are meas­ured as lying 12.8 bil­lion light years from Earth. Since a light-year is the dis­tance light trav­els in a year, that would mean that from Earth we see the gal­axy as it was that many bil­lion years ago.

It’s “sur­pris­ing that such a gi­ant gal­axy ex­isted when the Un­iverse was only one six­teenth of its pre­s­ent age, and that it hosted a black hole one bil­lion times more mas­sive than the Sun. The gal­axy and black hole must have formed very rap­idly in the early un­iverse,” said Un­ivers­ity of Ha­waii as­tron­o­mer To­mot­sugu Goto, one of the re­search­ers.

The find­ing is con­sid­ered im­por­tant in un­lock­ing the se­cret of how ga­lax­ies evolved to­geth­er with the super­mas­sive black holes that most of them con­tain at their cores.

Un­til now, stu­dy­ing black-hole-containing host ga­lax­ies in the dis­tant un­iverse has been ex­tremely dif­fi­cult be­cause the blind­ing bright light from near the black hole makes it harder to see the al­ready faint light from the host gal­axy.

Un­like smaller black holes, which form when a large star dies, the or­i­gin of super­mas­sive black holes re­mains an un­solved prob­lem. A cur­rently pop­u­lar mod­el re­quires sev­eral mid-sized black holes to merge to form the gi­ant black hole.

The newfound gal­axy pro­vides a res­er­voir of such in­ter­me­diate black holes, ac­cord­ing to Goto and col­leagues. Af­ter form­ing, super­mas­sive black holes of­ten con­tin­ue to grow be­cause their gra­vity draws in mat­ter from sur­round­ing ob­jects. The en­er­gy re­leased in this pro­cess ac­counts for the bright light that these black holes pro­duce.

To see the super­mas­sive black hole, the team of sci­en­tists used new cam­era equip­ment in­stalled in the Sub­aru tel­e­scope on Mauna Kea, Ha­waii, and de­vel­oped by Satoshi Miyazaki of the Na­tional As­tron­o­my Ob­serv­a­to­ry of Ja­pan and col­leagues.

“We have wit­nessed a super­mas­sive black hole and its host gal­axy form­ing to­geth­er. This discovery has opened a new win­dow for in­ves­ti­gat­ing gal­ax­y-black hole co-evolution at the dawn of the un­iverse,” said You­suke Ut­sumi, al­so of the Na­tional As­tron­o­my Ob­serv­a­to­ry.