Published : Tuesday, July 17, 2018 | 5:38 AM
A scientist at the Observatories of the Carnegie Institution for Science in Pasadena has been recognized for leading a team that recently found a quasar – an extremely remote celestial object that emits exceptionally large amounts of energy – with the brightest radio emission ever seen from the early universe.
Quasars typically have a starlike image in a telescope and have been suggested to contain massive black holes, possibly representing a stage in the evolution of some galaxies.
Dr. Eduardo Bañados, a fellow at both Pasadena’s Carnegie and the Department of Astrophysical Sciences of Princeton University, said the newly discovered quasar, called PSO J352.4034–15.3373, is one of a rare breed that doesn’t just swallow matter into the black hole but also emits a jet of plasma traveling at speeds approaching that of light.
The jet makes it extremely bright in the frequencies detected by radio telescopes. Although quasars were identified more than 50 years ago by their strong radio emissions, it is known that only about 10 percent of them are strong radio emitters.
What’s more, this newly discovered quasar’s light has been traveling nearly 13 billion of the universe’s 13.7 billion years to reach Earth. P352-15 is the first quasar with clear evidence of radio jets seen within the first billion years of the universe’s history.
“There is a dearth of known strong radio emitters from the universe’s youth and this is the brightest radio quasar at that epoch by an order of magnitude,” Bañados said in a Carnegie Institution press release.
Bañados’ discovery was followed up by Emmanuel Momjian of the National Radio Astronomy Observatory (NRAO) in Charlottesville, Virginia, which allowed the team to see with unprecedented detail the jet shooting out of a quasar that formed within the universe’s first billion years of existence.
The findings, published in two papers in The Astrophysical Journal, will allow astronomers to better probe the universe’s youth during an important period of transition to its current state.
“This is the most-detailed image yet of such a bright galaxy at this great distance,” Momjian added.
According to the Big Bang theory, the universe started as a hot soup of extremely energetic particles that were rapidly expanding. As it expanded, it cooled and coalesced into neutral hydrogen gas, which left the universe dark, without any luminous sources, until gravity condensed matter into the first stars and galaxies.
About 800 million years after the Big Bang, the energy released by these first galaxies caused the neutral hydrogen that was scattered throughout the universe to get excited and lose an electron, or ionize, a state that the gas has remained in since that time.
It’s highly unusual to find radio jet-emitting quasars such as this one from the period just after the universe’s lights came back on.
“The jet from this quasar could serve as an important calibration tool to help future projects penetrate the dark ages and perhaps reveal how the earliest galaxies came into being,” Bañados concluded in the paper.
Bañados and his team’s research was funded in part by the European Research Council. Data gathered with Carnegie’s 6.5-meter Magellan Telescopes located at Las Campanas Observatory in Chile contributed to the research.
According to the Carnegie Institution website, Bañados is involved in several follow-up projects related to distant quasars by mining various large sky surveys including Pan-STARRS1 and WISE.
“To characterize these quasars, their environments, and their host galaxies, a multiwavelength approach is mandatory,” Bañados said. “I am participating in a number of follow-up programs using data from various 6-10m class telescopes, the Hubble Space Telescope, the Spitzer Space Telescope, the Karl G. Jansky Very Large Array, the NOEMA Interferometer, and the Atacama Large Millimeter Array.”
Team member Chris Carilli, of the NRAO, said the team is seeing P352-15 as it was “when the Universe was less than a billion years old, or only about seven percent of its current age.”
“This is near the end of a period when the first stars and galaxies were re-ionizing the neutral hydrogen atoms that pervaded intergalactic space,” Carilli said. “Further observations may allow us to use this quasar as a background ‘lamp’ to measure the amount of neutral hydrogen remaining at that time.”
On this paper, Bañados, Momjian, and Carilli worked with Fabian Walter of the Max Planck Institute for Astronomy in Heidelberg, Germany; and Bram Venemans, also of the Max Planck Institute.
Bañados obtained his BS in Astronomy degree at the La Pontificia Universidad Católica de Chile (Pontifical Catholic University of Chile) and his PhD in Astronomy, Summa Cum Laude, at the Max Planck Institute of the University of Heidelberg in Germany.