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Quasars, among the universe's oldest and most luminous entities, are formed by active galactic nuclei (AGN) powered by supermassive black holes drawing in surrounding matter. These celestial objects emit electromagnetic radiation detectable across a broad spectrum, including radio, infrared, visible, ultraviolet, X-ray, and gamma-ray wavelengths. Their wide-ranging visibility makes them valuable by Jim Shelton for Yale News
New Haven CT (SPX) Jan 15, 2025
Quasars, among the universe's oldest and most luminous entities, are formed by active galactic nuclei (AGN) powered by supermassive black holes drawing in surrounding matter. These celestial objects emit electromagnetic radiation detectable across a broad spectrum, including radio, infrared, visible, ultraviolet, X-ray, and gamma-ray wavelengths. Their wide-ranging visibility makes them valuable tools for exploring the cosmos' structure and evolution.
One of their critical roles lies in aiding astronomers to study the epoch of reionization, a transformative era less than a billion years after the Big Bang. During this period, electrically neutral hydrogen atoms became ionized, marking the emergence of the universe's first generation of stars.
"The epoch of reionization is considered the end of the universe's dark ages," said Thomas Connor, an astronomer at the Chandra X-Ray Center and co-corresponding author of the study. "The precise timeline and source class responsible for reionization are still debated, and actively accreting supermassive black holes are one proposed culprit."
Researchers conducted a detailed analysis of the quasar designated J1429+5447. They compared data from the NuSTAR telescope to observations made four months earlier by the Chandra X-ray telescope. The findings revealed that the quasar's X-ray emissions doubled in intensity over this brief period, equivalent to just two weeks for the quasar due to relativistic time effects.
"This level of X-ray variability, in terms of intensity and rapidity, is extreme," explained Meg Urry, the Israel Munson Professor of Physics and Astronomy in Yale's Faculty of Arts and Sciences and a co-author of the study. "It is almost certainly explained by a jet pointing toward us - a cone in which particles are transported up to a million light years away from the central, supermassive black hole. Because the jet moves at nearly the speed of light, effects of Einstein's theory of special relativity speed up and amplify the variability."
The study provides vital insights for astronomers investigating the reionization epoch and raises further questions about the growth mechanisms of supermassive black holes in the early universe. "Finding more supermassive black holes that are potentially hosting jets raises the question as to how these black holes grew so big in such a short timescale, and what the connection may be to jet triggering mechanisms," said researcher Marcotulli.
Research Report:NuSTAR Observations of a Varying-flux Quasar in the Epoch of Reionization
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