Credit: Illustration: NASA/CXC/M. Weiss; X-ray (inset): NASA/CXC/SAO/D. Schwartz et al. Schwartz et al.
Astronomers captured unprecedented views of X-rays coming from a black hole in the early universe by using a space lens.
This magnifying lens was used to sharpen X-ray images using NASA's Chandra X-ray Observatory. It captured details about black hole that are impossible to see with existing X-ray telescopes.
Astronomers used a phenomenon called "gravitational lensesing". This occurs when light from distant objects bends the path of light, such as from a galaxy. This lensing can magnify or amplify light and create duplicate images of an object. These duplicate images can be used for decoding the object's complexity and sharpening images.
The gravitationally-lensed system in the new study is called MG B2016+112. Chandra discovered that the X-rays emitted by this system were emitted when the universe was just 2 billion years old. This is a far cry from its current age of 14 billion years.
The study was led by Dan Schwartz, Center for Astrophysics, Harvard & Smithsonian (CfA).
This research is a continuation of earlier work by Cristiana Spingola (INAF), currently based in Bologna, Italy. Her team discovered evidence of two supermassive black hole explosions separated by just 650 light-years using radio observations from MG B2016+112. Both black hole candidates could have jets, they discovered.
Schwartz and his collaborators concluded that the three Xray sources detected by the MG B2016+112 systems were the result of the lensing from two distinct objects using a gravitational lensesing model based upon radio data. These two Xray-emitting objects could be either a pair growing supermassive dark holes or an expanding supermassive dark hole and its jet. These two objects are consistent with radio work.
Previous Chandra measurements of supermassive black hole pairs and trios have typically involved objects closer to Earth or had greater separations. A previously observed X-ray jet located at a greater distance from Earth was also seen. The light emitted by the jet was emitted in a time when the universe was just 7% old. The jet's emission is however separated from the black hole by approximately 160,000 light-years.
This result is crucial because it gives important information about the growth rate of black holes in early universes and the possibility of a double black hole system. These far-flung objects are easier to detect thanks to the gravitational lens. The X-ray light detected from one of the objects in MG B2016+112 could be 300 times brighter without the lensing.
Spingola stated that black holes with masses billions times larger than the Sun were discovered by astronomers. They were formed only hundreds of millions years after the big bang when the universe was just a fraction of its current age. We want to find out how supermassive black hole mass was gained so quickly.
Researchers may be able to use gravitational lensing to determine how many supermassive black hole systems have enough separation to produce gravitational waves that can be detected in the future using space-based detectors.
This result is an exciting proof of concept of how the'magnifying glasses' can be used to reveal the physics of distant supermassive dark holes. Chandra would have to look at it for hundreds of times more without this effect, and that would not reveal complex structures," Anna Barnacka (CfA) and Jagiellonian University co-authors. They developed techniques to turn gravitational lenses into high resolution telescopes to sharpen images.
"Gravitational lensing may make it possible to distinguish between the black holes pair and black holes plus jet explanations thanks to Chandra observations that are much longer. Schwartz concluded that we also look forward to using this technique in future, particularly as major new radio and optical facilities will soon be available for surveys. This will allow us to supply thousands of targets."
The uncertainty in the Xray position of one object in MG B2016+112 measures 130 light years in one dimension, and 2,000 light year in the other, perpendicular dimension. This means that the likely source area is 100 times smaller than that of a Chandra source that isn't lensed. This precision in positioning determination is unmatched in X-ray Astronomy for sources at this distance.
These results are described in a paper published in The Astrophysical Journal's August issue.
Further Black hole seeds are key to galaxies behemoths.
Further information: Daniel Schwartz et. al., Resolving Complex Inner Xray Structure of the Gravitationally Led AGN MG b2016+112, The Astrophysical Journal (2021). Daniel Schwartz et. al., Resolving Complex Inner Xray Structure of the Gravitationally Leashed AGN MG BR2016+112 (2021). DOI: 10.3847/1538-4357/ac0909 Preprint: arxiv.org/abs/2103.08537 Journal information: Astrophysical Journal
