Black holes are thought to reside at the centre of most galaxies, including our Milky Way, holding important clues to the functioning of these giants. A group of researchers has now found a previously overlooked trove of massive black holes in dwarf galaxies. Black holes are usually detected when they actively grow by consuming gas around them, which makes them glow intensely. These black holes, the researchers believe, can offer insights into the journey of the supermassive black hole that sits at the centre of the Milky Way. [1]

Figure 1. Astronomers Discover Hidden Trove of Massive Black Holes, can help Understand the Milky Way’s Origin

Figure 1 shows the research, conducted by astronomers of the University of North Carolina (UNC)-Chapel Hill Department of Physics & Astronomy, US, is expected to shed light on the origin of our galaxy's supermassive black hole. [2]

Sending mixed messages

Black holes are typically detected when they are actively growing by ingesting gas and stardust swirling around them, which makes them glow intensely.

UNC-Chapel Hill Professor Sheila Kannappan, Polimera's Ph.D. advisor and coauthor of the study, compared black holes to fireflies.

The problem is, while growing black holes glow with distinctive high-energy radiation, young newborn stars can too. Traditionally, astronomers have differentiated growing black holes from new star formation using diagnostic tests that rely on detailed features of each galaxy's visible light when spread out into a spectrum like a rainbow.

The path to discovery began when undergraduate students working with Kannappan tried to apply these traditional tests to galaxy survey data. The team realized that some of the galaxies were sending mixed messages -- two tests would indicate growing black holes, but a third would indicate only star formation. [4]

A census of growing black holes

Polimera took on the challenge of constructing a new census of growing black holes, with attention to both traditional and mixed-message types. She obtained published measurements of visible light spectral features to test for black holes in thousands of galaxies found in two surveys led by Kannappan, RESOLVE and ECO. These surveys include ultraviolet and radio data ideal for studying star formation, and they have an unusual design: Whereas most astronomical surveys select samples that favor big and bright galaxies, RESOLVE and ECO are complete inventories of huge volumes of the present-day universe, in which dwarf galaxies are abundant. [3]

References:

1. https://gadgets360.com/science/news/astronomers-discover-hidden-treasure-trove-massive-black-holes-help-understand-milky-way-origin-3010752
2. https://newslogic.in/technology/astronomers-discover-hidden-trove-of-massive-black-holes-can-help-understand-the-milky-ways-origin/
3. https://scitechdaily.com/astronomers-discover-hidden-trove-of-massive-black-holes-we-all-got-nervous/
4. https://www.sciencedaily.com/releases/2022/05/220524100511.htm

Cite this article:

Thanusri swetha J (2022), Astronomers Discover Hidden Trove of Massive Black Holes, can help Understand the Milky Way’s Origin, Anatechmaz, pp. 320