A team of researchers at the California Institute of Technology (Caltech) has dedicated years to search for the earliest entities of the universe. Recently, the team reported that it has spotted a new galaxy, which might be the farthest to be discovered to date.
Two members of the research team Richard Ellis, a Caltech faculty who retired recently and now teaches astrophysics at the University College, London, and Adi Zitrin, a postdoctoral scholar from NASA, wrote about the event in the Astrophysical Journal Letters. The article was published in the journal on August 28, 2015.
In the article, the two researchers have presented evidence for the Galaxy EGS8p7, which was formed more than 13.2 billion years ago. This galaxy was spotted a few months back and was chosen as a candidate for further study based on information collected by the Spitzer Space Telescope and the Hubble Space Telescope of NASA.
The researchers at Hawaii’s W.M. Keck Observatory carried out a spectrographic analysis of EGS8p7 for determining its redshifts. They used the MOSFIRE (Multi-Object Spectrometer for Infrared Exploration) at the observatory for performing the analysis.
For those who don’t know: redshifts occur due to the Doppler effects. It’s the same theory due to which sirens on fire trucks drop in pitch when the truck passes.
However, in case of celestial objects the stretching occurs to light and not to sound. So, the audible drop gets replaced by a change in color. To put it more bluntly, the actual color gradually changes into shades with redder wavelengths, from where the name “redshift” comes.
Traditionally, redshifts are used for measuring distances from galaxies. However, the researchers said that things become quite difficult when redshifts are used for determining the distance between the Earth and the most distant and thus the earliest objects.
Another member of the research team Sirio Belli, who is a graduate student at Caltech informed that the EGS8p7 is unusually luminous. According to him, the galaxy might be excessively luminous as a result of being powered by some abnormally hot stars. He also assumes that the galaxy might boast some special qualities that allowed it to form a massive bubble of charged hydrogen ions much earlier than other galaxies would have managed to do so.