The non-thermal radio source Sagittarius A East is a supernova remnant situated within parsecs of the Milky Way’s center. It has the smallest radio shell of any known mixed-morphology supernova remnant.
Sgr A East is around 25 light years across and is thought to have formed from a supernova between 35,000 and 100,000 BCE. However, the object’s size indicates that forming a remnant this large would have required 50 to 100 times more energy than a typical supernova event.
As a result of its close approach to the Milky Way’s center black hole, the star that went supernova is thought to have been gravitationally compressed.
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What is Sagittarius A made of?
From the perspective of the Earth, Sgr A West appears to be a three-arm spiral. It’s also known as the “Minispiral” because of this. The Minispiral’s appearance and nickname are deceiving, as its three-dimensional structure is not that of a spiral. It is made up of multiple dust and gas clouds that circle and fall at speeds of up to 1,000 kilometers per second onto Sagittarius A*. These clouds have an ionized surface layer. The population of big stars (about one hundred OB stars have been detected so far) that likewise inhabit the core parsec is the source of ionisation.
The Circumnuclear Disk, which surrounds Sgr A West, is a vast, clumpy torus of colder molecular gas (CND). The form and kinematics of Sgr A West’s Northern Arm cloud indicate that it was once a clump in the CND that dropped due to some perturbation, maybe the supernova explosion that caused Sgr A East. The Northern Arm appears as a bright North–South emission ridge, although it extends far to the East and can be seen as a dim extended source.
The ionized inner surface of the CND is interpreted as the Western Arc (outside the field of view of the figure displayed on the right). Although they do not share the same orbital plane as the Northern Arm, the Eastern Arm and the Bar appear to be two more huge clouds. They are thought to be worth around 20 solar masses each.
Many tiny cloudlets and holes inside the giant clouds may be observed on top of these massive scale formations (of the order of a few light-years in size). The Minicavity, which is regarded as a bubble blown inside the Northern Arm by the stellar wind of a massive star that has yet to be found, is the most visible of these perturbations.
How did we find Sagittarius A?
In August 1931, Karl Jansky, considered the founder of radio astronomy, discovered a radio signal emanating from a position in the direction of the constellation Sagittarius, near the Milky Way’s center. Sagittarius A was the name given to the radio source later on. His observations did not stretch exactly as far south as the Galactic Center, as we now know it. Observations by Jack Piddington and Harry Minnett using the CSIRO radio telescope at Potts Hill Reservoir in Sydney discovered a discrete and bright “Sagittarius-Scorpius” radio source, which was later identified in a letter to Nature as the probable Galactic Center after further observation with the 80-foot (24-metre) CSIRO radio telescope at Dover Heights.
Later investigations revealed that Sagittarius A is made up of numerous overlapping sub-components; astronomers Bruce Balick and Robert Brown identified Sgr A*, a bright and compact component, using the National Radio Astronomy Observatory’s baseline interferometer on February 13 and 15, 1974. Brown coined the moniker Sgr A* in a 1982 publication because the radio source was “exciting,” and asterisks denote excited states of atoms.
Is Sagittarius A The biggest black hole?
The list of (normal) gravitational suspects starts with black holes that are just the size of protons but have the mass of a large mountain. The comparison then ascends through black holes the size of the one that keeps V723 Mon in orbit, a star 24 times the mass of the Sun. However, as the narrator of the channel points out, that black hole is barely 17.2 kilometers (approximately 10 miles) across.
The comparison then progresses to black holes with hundreds of times the mass of the Sun. These appear to be enormous until the film progresses to black holes millions of times larger than the Sun. Sagittarius A*, the supermassive black hole at the center of the Milky Way Galaxy, is one of these monsters, although having a radius just 17 times that of the Sun.
The film concludes with an examination of ultramassive black holes, which follow the supermassive black holes. That is, after all, a technical term. Ultramassive black holes are “perhaps the largest single bodies that will ever exist,” putting all other black holes to shame. The mass of these huge physical manifestations is billions of times that of the Sun. They have the capacity to house several solar systems. With the very end of the video, Ton 618, the greatest ultramassive black hole, appears, which, at 66 billion times the mass of the Sun, will have a significant impact on how we daydream about the cosmos in the future.
How fast is Sagittarius A * spinning?
Using the durations of QPOs corresponding to K, we can now calculate the spin parameter of black holes. Sgr A*, for example, has a period of 31.4 minutes, while Galactic X-ray sources have periods of lower HF-QPOs. The frequency of single peak HF-QPOs is denoted by the letter K. The estimated mass of a supermassive black hole in Sgr A* is taken from recent studies to constrain the consequent spin parameter (
Is Sagittarius A * Active?
Sagittarius A*, the Milky Way’s very own supermassive black hole, is supposed to be tame. It’s not an active galactic nucleus and, unlike some other massive black holes that spin so quickly that they bend space, it mostly stays to itself.
How hot is Sagittarius A?
Naturally, “cold” gas is a relative phrase in this context. Around Sagittarius A*, the hot gasses reach around 18 million degrees Fahrenheit (10 million degrees Celsius), or two-thirds the temperature of the sun’s core. X-rays are emitted by this gas, which is one of the telltale indications of a black hole. By comparison, the cold hydrogen gas is only about 18,000 degrees Fahrenheit (10,000 degrees Celsius). The Atacama Large Millimeter/submillimeter Array (ALMA) was utilized by researchers to look for a faint radio frequency signal from this ring of colder gas.