EGS8p7 – Possibly the Farthest Galaxy in the Universe

One of the recently found galaxies identified by the scientists at the Institution of Technology in California could be the farthest galaxy in the universe discovered until now. In their researches published in the Astrophysical Journal Letters, the astronomers as Caltech provided this extremely distant galaxy named EGS8p7, and its extremely old age might offer us a few clues about the formation of the universe and the earliest object in space.

The scientists think that this galaxy might be 13.2 billion years old, while the age of the entire universe is estimated to be around 13.8 billion years. NASA researchers believe that EGS8p7 is the oldest galaxy in the known space, based on the data collected by the famous Hubble Space Telescope. To measure the enormous distances up to those far away galaxies, astronomers use multi-object spectrometers for infrared exploration, or MOSFIRE, at the Keck Observatory in Hawaii in order to measure the galaxy’s red shift.

A red shift is generally a result of the Doppler Effect, similar to the sounds produced by a passing vehicle and these sound waves are stretched and sound different depending if the car is coming to or going from us. In space, the light produced by stars and galaxies suffers the same transformation, shifting into the red specter, as they are moving further into the universe. However, the red shift phenomenon cannot be very accurate when there have to be measured the most distant objects in space.

The first galaxies ionized massive amounts of hydrogen in the early universe at almost 1 billion years after the Big Bang, and this ionization process is present until the present day. Due to its extremely old age, EGS8p7 should lack even the Lyman-alpha line, a phenomenon produced by the ionized hydrogen and a marker used to determine the age of space objects. The earliest galaxies contain large quantities of unionized or neutral hydrogen that blocks ultraviolet emissions, but EGS8p7 shows a faint line of Lyman-alpha line.

Other theories of the scientists regarding the presence of this line are related to the possible intermittence of the ionization process, so this is not probably a continuous phenomenon. Another idea refers to the luminosity of EGS8p7, a sign that might be due to the presence of many hot stars inside it. Whatever is the case, this unusual state of things could change the perspective of the specialists on the ionization processes in the universe.

Image source: Daily Times Gazette