The blazar—powered by an extremely bright black hole that can blast a hole through galaxies—is the most ancient ever discovered, sending radio signals from the early universe
By Becky Ferreira
Scientists have discovered the oldest and most distant “blazar,” a supermassive black hole that spews out mind-boggling amounts of light, at the edge of space and time. The object is nearly 13 billion years old, but scientists were able to detect it because it is so “radio-loud,” meaning it is incredibly luminous even from afar.
A team led by Silvia Belladitta, a graduate student at the University of Insubria in Italy, announced the discovery of the blazar on Friday in the journal Astronomy & Astrophysics. Named PSO J030947.49+271757.3 (or PSO J0309+27 for short), it is the first known blazar at such a high “redshift,” which is a scale that measures the distance of luminous objects based on the distorted color of their light.
Blazars are a special class of active galactic nuclei (AGN), which are galactic centers defined by supermassive black holes that feed on large volumes of infalling gas, dust, and stars. As this material falls into the black hole, it becomes extremely hot and energetic, sparking the release of luminous jets of matter and radiation that travel close to the speed of light. This transformation into an AGN can create explosive beams that are forcefulenough to punch holes clear through galaxy clusters.
What separates blazars from regular AGN is their orientation toward Earth: In order to be considered a blazar, the jets from these objects have to be pointed directly at us. As a result, they are among the brightest objects in the sky, and can be used to estimate the overall population of similarly radiant AGN.
“Observing a blazar is extremely important,” said Belladitta in a statement. “For every discovered source of this type, we know that there must be 100 similar, but most are oriented differently, and are therefore too weak to be seen directly.”
Belladitta and her colleagues were able to spot PSO J0309+27 by combining data from several different observatories. First, the team examined bright radio sources captured by the NRAO’s Very Large Array (VLA) in New Mexico, the Panoramic Survey Telescope and Rapid Response System in Hawaii (Pan-STARRS), and a space telescope called the Wide-field Infrared Survey Explorer (WISE).
Those results revealed the existence of PSO J0309+27, but it took measurements by the Large Binocular Telescope (LBT) in Arizona to confirm that this object is by far the most distant and ancient blazar ever observed. Further examination of its emissions, sourced from NASA’s Swift space telescope, showed that it is also “the most powerful radio-loud AGN ever discovered” at this distance, according to the study.
“The spectrum that appeared before our eyes confirmed first that PSO J0309+27 is actually an AGN,” Belladitta explained. “In addition, the data obtained by LBT also confirmed that PSO J0309+27 is really far away from us, according to the shift of the color of its light toward red or redshift with a record value of 6.1, never measured before for a similar object.”
The combined observations enabled the team to estimate that the supermassive black hole at the heart of PSO J0309+27 is about a billion times more massive than the Sun. By comparison, the supermassive black hole at the center of the Milky Way is puny, at only four million times the mass of the Sun.
The discovery of PSO J0309+27 sheds literal light on the origins of supermassive black holes, which are now abundant throughout the universe and influential to its evolution. “Thanks to our discovery, we are able to say that in the first billion years of life of the universe, there existed a large number of very massive black holes emitting powerful relativistic jets,” Belladitta said.
“This result places tight constraints on the theoretical models that try to explain the origin of these huge black holes in our universe,” she added.
What’s more, the team predicted that other ancient blazars are likely to be discovered as a hyper-sensitive generation of telescopes comes online in the coming years, especially the Vera C. Rubin Observatory in Chile. These facilities will put the distant universe into sharper focus, enabling unprecedented insights about how we ended up with our modern cosmic surroundings.
Source: Vice
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