During school days we were all very inquisitive about how the universe was formed. Now we all know and it is widely accepted that the hydrogen in the universe was once neutral but was “reionized” — split into its component protons and electrons. It was around this time when the first generation of stars, galaxies and supermassive black holes were born, in the first few hundred million years after the Big Bang.
Experiments have been going on in order to understand the evolution of the universe that is to know, how many billion years back the first black hole was created which lead to the formation of the universe and also to understand if there would be any other universe like us and what was the energy that lead to the cause of reionization.
A group of Astronomers from Japan, Taiwan and Princeton University has discovered that there are about 83 quasars that are powered by supermassive black holes in the distant universe along with 17 quasars already known in the survey region. Supermassive black holes are ones that are found at the centers of the galaxies and have masses millions or even billions of times that of the Sun.
Michael Strauss professor of astrophysical sciences at Princeton University, who is one of the co-authors of the study said, “It is remarkable that such massive dense objects were able to form soon after the big bang”. The most distant quasar observed so far by the team is 13.05 billion light years away.
We cannot observe black holes directly, but when a large quantity of matter falls into an SMBH (Supermassive Black Holes), it releases energy as a bright light that can be seen across the Universe. Therefore initially the research team has taken data from the used data taken with a cutting-edge instrument, “Hyper Suprime-Cam” (HSC) mounted on the Subaru Telescope of the National Astronomical Observatory of Japan, which is located on the summit of Maunakea in Hawaii. This research reveals that the occurrence of a black hole is not a rare phenomenon but how common they really are in the universe.
The team selected distant quasar candidates from the sensitive HSC survey data. They then carried out an intensive observational campaign to obtain spectra of those candidates, using three telescopes: the Subaru Telescope; the Gran Telescopio Canarias on the island of La Palma in the Canaries, Spain; and the Gemini South Telescope in Chile.
Robert Lupton a 1985 Princeton Ph.D. alumnus who is a senior research scientist in astrophysical sciences states that “The number of quasars seen is significantly less than needed to explain the reionization.”
Yoshiki Matsuoka, a former Princeton postdoctoral researcher now at Ehime University in Japan, adds to the discovery that “The quasars we discovered will be an interesting subject for further follow-up observations with current and future facilities. We will also learn about the formation and early evolution of SMBHs by comparing the measured number density and luminosity distribution with predictions from theoretical models.”
Based on the results achieved so far, the team is looking forward to finding yet more distant black holes and discovering when the first supermassive black hole appeared in the universe.