Astronomers have uncovered greater than 400 beforehand hidden black holes feeding on stars and mud within the heart of galaxies. It seems that lots of the new black holes, found utilizing NASA’s Chandra X-ray Observatory, remained unknown till now as a result of they’re buried beneath cocoons of mud.
Supermassive black holes, which may be thousands and thousands of instances heavier than the solar, reside within the heart of just about each galaxy within the universe. These colossal objects produce vibrant beams of power as they feed on gasoline, mud, and stars of their speedy neighborhood, creating what are generally known as Energetic Galactic Nuclei (AGN), according to NASA (opens in new tab).
AGN are notably vibrant within the X-ray portion of the electromagnetic spectrum, mentioned astronomer Dong-Woo Kim (opens in new tab) of the Harvard and Smithsonian Middle for Astrophysics throughout a information convention Jan. 11 on the 241st assembly of the American Astronomical Society in Seattle.
Additionally they go away telltale seen patterns in optical mild, which determine them as AGN, he added.
However sure objects have been noticed giving off tons of X-rays with out the precise optical signatures related to AGN, Kim mentioned, and these have been named “X-ray vibrant optically regular galaxies” or “XBONGs.”
In an effort to examine these mysterious entities additional, he and his colleagues checked out a catalog of greater than 300,000 vibrant X-ray objects captured by Chandra.
They then grabbed optical photos of the night time sky from the Sloan Digital Sky Survey (SDSS) and mixed the 2 datasets to pick for X-ray vibrant, however optically regular objects. The researchers recognized 820 XBONGs situated between 550 million and seven.8 billion light-years from Earth, the biggest such pattern ever constructed, mentioned Kim.
“The speedy query is: ‘What are they?'” he added.
X-rays penetrate mud, whereas optical mild will get obscured by it, so Kim and his colleagues tried to determine if these 820 XBONGs is perhaps black holes surrounded by giant quantities of mud.
If that had been the case, the bottom power X-ray mild would get barely absorbed by the mud, whereas essentially the most highly effective X-ray mild would proceed to shine brightly by it, mentioned Kim. His group noticed precisely this sample in round 50% of the XBONGs, suggesting that they’re AGNs buried in dusty cocoons.
“What are the opposite half?” Kim requested. One risk is that Chandra is seeing extraordinarily distant clusters of galaxies, which might shine vibrant in X-rays however lack the attribute optical signature figuring out them as AGN, he mentioned. This might clarify round 20% of the remaining XBONGs, Kim added.
The ultimate 30%, he thinks, are galaxies whose optical mild is especially highly effective, vibrant sufficient to clean out the optical AGN signature, which might occur when such galaxies are notably far-off.
Kim hopes that additional Chandra investigations will assist reply remaining questions on these unusual entities.
Source link
