After spending old age searching the cosmos , a enquiry team from CalTech may have found the oldest andmost distant galaxy yet . As part of its search , the team combed through information pile up by the Hubble Space Telescope and the Spitzer Space scope , and finally identify the galaxy EGS8p7 as a target to investigate further .
The team then performed a spectrographic depth psychology of EGS8p7 using the Keck Observatory ’s multi - object mass spectrometer for infrared exploration ( MOSFIRE ) to forecast its red shift . Redshiftis a result of the Doppler effect – like when an ambulance drives by and the siren fades as it passes . In astronomy , rather of levelheaded waves , light from the galaxy is elongate and shift towards the ruddy end of the spectrum as it moves far aside . Based on the data collected , the squad gauge that EGS8p7 is over 13.2 billion years old , meaning it was formed only around 600 million years after the Big Bang .
A galaxy ’s redshift is normally used to determine its age . However , when looking at very distant objects , it ’s difficult to calculate . Right after the Big Bang , the universe of discourse was like a hot , mawkish mixture of charged particles , ineffectual to transmit any brightness level . roughly 380,000 year afterwards , theuniverse cooledjust enough to allow the proton and electron earn up the speck soup to combine , take shape neutral hydrogen and permitting igniter to travel through the universe .
The first galaxies started cranking out young whizz when the world was just half a billion years previous , thusreionizing the creation . Before the reionization started , the achromatic hydrogen atoms would have absorbed certain Light Within emitted by other galaxies . Typically , when stars form they give off bang of ultraviolet light . This UV expelling wake up fence atomic number 1 petrol , producing a traceable spiritual signature have sex as a Lyman - alpha air . Astronomers look for this signature when they are looking for novel star formation . Theoretically , due to the immersion , the squad should not have been able to honor a Lyman - alpha telephone line for EGS8p7 .
" If you bet at the galaxies in the other cosmos , there is a lot of neutral hydrogen that is not transparent to this emission , " said Adi Zitrin , a NASA Hubble postdoctoral scholar in astatement . " We expect that most of the radiation sickness from this galax would be absorbed by the hydrogen in the intervene place . Yet still we see Lyman - alpha from this coltsfoot . "
Keck ’s MOSFIRE mass spectrometer records chemic signatures of stars and aloof galaxies in nearly - infrared wavelengths . Prior to EGS8p7 , the farthest galaxy on record had a redshift of 7.73 . Based on the MOSFIRE reflexion , the squad find a Lyman - alpha line within EGS8p7 with a red shift of 8.68 . One potential explanation for this surprising discovery is that the reionization process could be patchy , meaning it does n’t happen uniformly .
" The Galax urceolata we have observed , EGS8p7 , which is outstandingly luminous , may be powered by a population of remarkably hot stars , and it may have especial properties that enable it to create a declamatory house of cards of ionize hydrogen much earlier than is potential for more typical galaxies at these time , " said Sirio Belli , a Caltech graduate student who worked on the project .
The squad is presently contemplate this discovery in greater detail to determine exactly what the chances are for discover early coltsfoot such as EGS8p7 and their emissions to easily understand the reionization timeline .
The finding are published in theAstrophysical Journal Letters .
