For years, astronomers have been trying to see as far as they can into the deep Universe. By observing the cosmos since it had been right after the Big Bang, astrophysicists and cosmologists aspire to learn all they can about early formation of the Universe and its subsequent development. As a result of instruments like the Hubble Space Telescope, astronomers have been able to observe elements of the Universe that were previously inaccessible.
However, the Hubble is not capable of seeing all that was occurring during early Universe. But, with the joint power of some of the modern astronomical observatories from across the Earth, a group of international astronomers directed by Tokyo University’s Institute of Astronomy observed 3 9 previously-undiscovered ancient galaxies, a find that could have major consequences for astronomy and cosmology.
The group behind the discovery comprised members from Tokyo University’s Institute of Astronomy, the French National Center for Scientific Research (CNRS), the Anhui Normal University in China, the University of Medicine Ludwig-Maximilians at Munich, the National Astronomical Observatories of China, and the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA) at Taiwan. Their research appeared in the Aug. 7th issue of Nature.
To put it simply, the oldest potential galaxies from the Universe have stayed imperceptible until now due to their light is very faint and occurs at long wave lengths that are undetectable by Hubble. The team looked into the Atacama Big Millimeter/submillimeter Array (ALMA), whose telescopes are optimized for viewing this kind of light.
The discovery that led wasn’t just unprecedented, however the discovery of this many galaxies of this type interrupts present cosmological models. Since Tao Wang, a researcher by the AISAA and also a Co Author on the analysis, explained:
“This really is the first time that this kind of huge population of massive galaxies was supported during the first two billion years of their 13.7-billion-year lifetime of their universe. These were invisible to us. This finding contravenes current models for that amount of cosmic development and will assist you add some detailsthat have been missing until now.”
These galaxies, though they’re the biggest in life at the moment, were very tricky to identify. Much of the main reason has to do with the degree to which their light is stretched by the expansion of the Universe. In regular astronomy, is known as red shift, where the expansion of distance (that the Hubble Constant) induces the wavelength of light to become elongated, changing it towards the red end of their spectrum.
This allows astronomers to not just tell how remote a thing is, but exactly what that object appeared as if in days gone by. But when trying to the very earliest epoch of the Universe (over 13 billion years ago) the enormous distance moves that the wavelength of visible light into the idea at which it is no longer at the domain of visible light and becomes more infrared.
Still another reason these galaxies are hard to see is that larger galaxies tend to be shrouded in dust, particularly if they are still in early sections of these formation. This tends to obscure them more than their smaller counterparts that are ancestral. For these factors, there was some suspicion that these galaxies were not as old as the team suggested. As Wang suggested:
“It was tough to convince that our peers those galaxies were as old as we all imagined them to become. Our initial suspicions about their presence stems out of the Spitzer Space Telescope’s infrared statistics. However, ALMA has sharp eyes and also shown details at submillimeter wavelengths, the best wavelength to peer through dust contained from early universe. Nevertheless, it took further data from the imaginatively named Very Large Telescope in Chile to really prove we were seeing ancient massive galaxies where no one was spotted before.”
As the discovery of these galaxies defies our current cosmological models, the team’s findings naturally have some substantial consequences for astronomers. Since Kotaro Kohno, a professor at the Institute of Astronomy and also a Co Author on the analysis, explained:
“The more massive a galaxy, the more massive the supermassive black hole at its heart. So that the analysis of these galaxies and their development will probably tell us more about the growth of supermassive black holes, too,” added Kohno. “Massive galaxies may also be intimately correlated with the distribution of invisible dark matter. This plays a role in shaping the arrangement and distribution of galaxies. Theoretical researchers will need to update their concepts now.”
Yet another interesting find was that the ways that these 3 9 ancient galaxies differ from our own. First of all, those galaxies had a high density of stars compared to the Milky Way does today; which means when our galaxy had been similar, stargazers would be seeing something completely different if they looked up at the night sky.
“For one thing, the night sky would appear a lot more royal. The larger density of celebrities means there would be a lot more celebrities nearby appearing brighter and larger,” said Wang. “But conversely, the large quantity of dust means farther-away stars would be far less visible, therefore the backdrop to those glowing close stars may possibly be a vast dark void.”
As that is the very first time that a galactic population of this kind was detected, astronomers are looking forward to what else they may find. As it stands, even ALMA isn’t complex enough to investigate the chemical compositions and stellar populations of these galaxies. But, nextgeneration observatories are going to have the resolution for astrnomers to conduct those research studies.
These are the James Webb Space Telescope, which is now slated for launching in 2021. Ground-based observatories just like the ESO’s Extremely Large Telescope (ELT), the Thirty Meter Telescope (TMT) and the Giant Magellan Telescope (GMT) will also be likely to play a crucial role.
It’s a fantastic time for astronomers and cosmologists. Very slowly, they have been peeling back the following layer of the Universe to see what secrets lurk beneath!