(ORDO NEWS) — An undergraduate student at the University of Massachusetts Amherst, USA, made a significant contribution to the development of ideas about the mechanism of growth of stars and black holes, establishing the nature of the relationship between these two processes.
The information obtained will make it possible to more effectively interpret the results of observations of galaxies using NASA’s James Webb Space Telescope.
Astronomers know that the evolution of galaxies proceeds under the influence of two processes: the growth of supermassive black holes lying at the centers of galaxies, and the formation of new stars.
How these processes relate to each other remains a mystery to this day, and the recently launched James Webb Space Telescope is set to help answer this question.
The work by Meredith Stone, who graduated with an undergraduate degree from the University of Massachusetts Amherst in May 2022, will help astronomers better understand this connection.
“We know that galaxies grow, merge and evolve throughout their life cycle,” says Stone, who did the research under the direction of Alexandra Pope, professor of astronomy at the University of Massachusetts Amherst, who is the lead author of this new study.
“And we know that black hole growth and star formation play the most important roles. We think that these two processes are interconnected and regulate each other, but so far we have remained unknown to the mechanism of such interaction.”
One of the reasons that the mechanism of interaction between black holes and stars is difficult to study is that we cannot really see these interactions, since they occur behind a curtain of giant clouds of galactic dust.
“For galaxies that are actively forming stars, more than 90 percent of all the visible light they emit can be absorbed by dust,” says Pope.
But the opportunity to observe the interaction between stars and black holes still remains. When dust absorbs visible light, it heats up, and although thermal radiation cannot be seen by the naked eye, infrared telescopes can.
“We used the Spitzer space telescope,” says Stone. “The data collected with it as part of the Great Observatories All-sky LIRG Survey (GOALS) observational campaign made it possible to study infrared radiation from some of the brightest galaxies located relatively close to Earth.”
In particular, Stone and her co-authors were looking for special signatures that point to actively developing processes of star and black hole formation.
The difficulty in searching for such spectral features is that they are often indistinguishable against the background of the general noise in the infrared spectrum of the galaxy. Stone’s merit was that she was able to isolate these signals from the general flow, Pope explained.
With this refined data, the team found that the growth of black holes and star formation in galaxies are competitive and influence each other. Stone was even able to calculate a relationship describing the relationship between the two processes.
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