NRL researchers capture supermassive black holes that launch newborn radio jets

WASHINGTON – Researchers from the US Naval Research Laboratory have led a team of scientists who have discovered some of the youngest known radio jets launched from supermassive black holes growing in the centers of distant galaxies.

Observing and recording jets, believed to be only decades old, in their infancy allows researchers to observe their formation and growth and to study how they affect their environments.

“Time and navigation are a key part of the Navy’s mission and form part of the key infrastructure on which the DOD is based,” said NRL astronomer Henrique Schmitt, Ph.D. “Understanding the evolution of jets in active galaxies is important for everyday tools such as GPS. Such active galaxies define the celestial reference system from which timing and precision positioning are derived.”

The team discovered the jets after examining images from the Very Large Array Sky Survey (VLASS) that contained unusually bright radio sources compared to previous studies with the Karl G. Jansky Very Large Array (VLA) in Socorro, New Mexico. The document was accepted for publication by Astrophysical Journal.

“This is a new topic that has yet to be fully explored,” said Kristina Nyland, Ph.D., a National Research Council postdoctoral fellow in residency at NRL. “Studying the launch of powerful jets is important for us to understand how galaxies and supermassive black holes grow in tandem over billions of years.”

According to Nyland, older jets glow for millions of years and can extend far beyond the confines of their host galaxies, while newborn jets remain within the confines of their hosts. Known as the interstellar medium, this area contains the raw materials that give rise to new stars and planetary systems. Newborn jets are hypothesized to interact with these dense gas clouds and play an important role in the formation and evolution of galaxies.

“When you have compact, powerful jets of radio plasma colliding with a reservoir of gas that forms stars, the jets can alter the efficiency of new stellar births and the future appearance and properties of the galaxy,” Nyland said. “Studying young jets in particular is essential to understanding our cosmic origins. It is important for us to measure the rate at which new jets are launched from supermassive black holes to ultimately understand how they affect the life of the galaxies in which they reside.”

The US Naval Observatory (USNO) maintains a celestial frame of reference used to provide a reference of the skies and space. That celestial frame of reference appears in the form of a grid and includes more than 4,000 known radio sources. New radio sources, such as newborn jets, can add landmarks to the grid.

The reference points on the grids can change their appearance over time. Researchers are trying to fill scattered areas of the grid by coupling an optical frame to the celestial frame. However, the physics of optical and radio energy emissions from supermassive black holes are not fully understood. These emissions look different over time, and researchers find that when the optical and celestial grids are superimposed they don’t always match perfectly.

“Without understanding the physics of those radio sources, what you see is that those two reference frames are not always aligned,” said Tracy Clarke, Ph.D., a radio astronomer in the NRL’s remote sensing division. “This is because we are looking at a different part of the radio source than the optical host galaxy – they are slightly shifted.”

“Understanding the source of radio emissions from AGN is a key area of ​​interest for USNO and the Navy, and helps us better understand the nature of the quasar sources that make up the International Celestial Reference Frame,” said Megan Johnson. Ph.D. at USNO.

Numerous studies are underway to gain a better understanding of physics. Such information could be used to build a more comprehensive and predictive framework. Navy resources can use the frame of reference in a GPS-restricted environment. To do this, the researchers want to provide operators with bias sources in a fixed grid (such as a brightness shift in one of the jet sources) to compensate for the reference frame.

“The physics of what Kristina Nyland is doing helps us understand how to tie these two frames of reference tightly, and this will give the Navy a fantastic multi-wavelength frame of reference,” Clarke said.

Clarke is currently co-chair of the Survey Science Group for the VLA Sky Survey (VLASS). This group played a key role in the development of the VLASS survey and currently serves as an interface to the scientific community.

VLASS is building a richer understanding of space by combining images and data of the entire visible sky from a telescope taken multiple times over several years. NRL is supporting VLASS through commensal observations with the VLA Low Band Ionosphere and Transient Experiment (VLITE), operated by NRL. VLITE is a powerful addition to the survey, providing complementary information on the properties of the radio source over a different range of frequencies and spatial scales.

“While the VLASS data has enabled the discovery of these newly formed jets, understanding the history of the galaxy’s evolution may require additional radio data,” Clarke said. “This is where VLITE comes in. VLITE operates at longer observation wavelengths and observes in parallel to VLASS.”

Clarke believes VLITE is a powerful addition to the survey as it provides complementary information on the properties of the radio source that allows NRL researchers to better understand the evolution of the supermassive black hole that powers each newborn radio jet.

Nyland is leading the research project in NRL’s remote sensing division through the NRC postdoctoral fellowship program. Keep studying newborn shoots and watching how they change over time.

“This research contributes to human exploration in general,” Nyland said. “It contributes to a richer understanding of fundamental physics and the fascinating link between supermassive black holes and the evolution of galaxies.”

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The remote sensing division conducts basic research, science and applications aimed at developing new concepts for passive sensors and imaging systems for objects and targets on Earth, in the near-Earth environment and in deep space.

NRL is a dedicated research science and engineering command that drives innovative advances for the Navy and Marine Corps from the seafloor to space and in the information domain. NRL is located in Washington, DC, with major field sites in Stennis Space Center, Mississippi; Key West, Florida; and Monterey, Calif., and employs approximately 2,500 civil scientists, engineers and support personnel.