Black Hole

A black hole is a mathematically defined region of spacetime exhibiting such a strong gravitational pull that no particle or electromagnetic radiation can escape from it. The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole. The boundary of the region from which no escape is possible is called the event horizon. Although crossing the event horizon has enormous effect on the fate of the object crossing it, it appears to have no locally detectable features. In many ways a black hole acts like an ideal black body, as it reflects no light.

Objects whose gravitational fields are too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace. The first modern solution of general relativity that would characterize a black hole was found by Karl Schwarzschild in 1916, although its interpretation as a region of space from which nothing can escape was first published by David Finkelstein in 1958. Long considered a mathematical curiosity, it was during the 1960s that theoretical work showed black holes were a generic prediction of general relativity. The discovery of neutron stars sparked interest in gravitationally collapsed compact objects as a possible astrophysical reality.

Black holes of stellar mass are expected to form when very massive stars collapse at the end of their life cycle. After a black hole has formed, it can continue to grow by absorbing mass from its surroundings. By absorbing other stars and merging with other black holes, supermassive black holes of millions of solar masses (M☉) may form. There is general consensus that supermassive black holes exist in the centers of most galaxies. (Wikipedia)


 

A stellar-mass black hole

A stellar-mass black hole

#1: A stellar-mass black hole
GRS 1915+105 : A stellar-mass black hole with about 14 times the Sun’s mass in the Milky Way.

Image credit: X-ray (NASA/CXC/Harvard/J.Neilsen); Optical & IR (Palomar DSS2)
Source and Reference: chandra.harvard.edu

GRS 1915+105 Animations   GRS 1915+105 Animations
Click here for Animations.   Click here for Animations.

Click here for more information.
GRS 1915+105 Animations
GRS 1915+105 Animations
GRS 1915+105: Erratic Black Hole Regulates Itself

Spiral Galaxy M81 - A supermassive black hole

A supermassive black hole

#2: Spiral Galaxy M81 - A supermassive black hole
M81 is a spiral galaxy about 12 million light years away that is both relatively large in the sky and bright, making it a frequent target for both amateur and professional astronomers.

Image credit: X-ray: NASA/CXC/SAO; Optical: Detlef Hartmann; Infrared: NASA/JPL-Caltech
Source and Reference: chandra.harvard.edu

M81 Animations chandra.harvard.edu

Black hole animation

Black hole animation

#3: Black hole animation

Image source:

Black Hole Gobbles a Star

Black Hole Gobbles a Star

Black Hole Gobbles a Star(25.3 MB)

Source: Go to source for more information


Simulation of gravitational lensing by a black hole, which distorts the image of a galaxy in the background

Simulation of gravitational lensing by a black hole, which distorts the image of a galaxy in the background

#5: Simulation of gravitational lensing by a black hole, which distorts the image of a galaxy in the background
Animated simulation of gravitational lensing caused by a black hole going past a background galaxy. A secondary image of the galaxy can be seen within the black hole Einstein ring on the opposite direction of that of the galaxy. The secondary image grows (remaining within the Einstein ring) as the primary image approaches the black hole. The surface brightness of the two images remains constant, but their angular size varies, hence producing an amplification of the galaxy luminosity as seen from a distant observer. The maximum amplification occurs when the background galaxy (or in the present case a bright part of it) is exactly behind the black hole.

Image source: commons.wikimedia.org

Simulated view of a black hole (center) in front of the Large Magellanic Cloud.

Simulated view of a black hole (center) in front of the Large Magellanic Cloud.

#6: Simulated view of a black hole (center) in front of the Large Magellanic Cloud.
Note the gravitational lensing effect, which produces two enlarged but highly distorted views of the Cloud. Across the top, the Milky Way disk appears distorted into an arc.

Simulated view of a black hole in front of the Large Magellanic Cloud. The ratio between the black hole Schwarzschild radius and the observer distance to it is 1:9. Of note is the gravitational lensing effect known as an Einstein ring, which produces a set of two fairly bright and large but highly distorted images of the Cloud as compared to its actual angular size.

Image source: commons.wikimedia.org

Black Holes: Monsters in Space (Artist's Concept)

Black Holes: Monsters in Space (Artist's Concept)

#7: Black Holes: Monsters in Space (Artist's Concept)
This artist's concept illustrates a supermassive black hole with millions to billions times the mass of our sun. Supermassive black holes are enormously dense objects buried at the hearts of galaxies. (Smaller black holes also exist throughout galaxies.) In this illustration, the supermassive black hole at the center is surrounded by matter flowing onto the black hole in what is termed an accretion disk. This disk forms as the dust and gas in the galaxy falls onto the hole, attracted by its gravity.

Also shown is an outflowing jet of energetic particles, believed to be powered by the black hole's spin. The regions near black holes contain compact sources of high energy X-ray radiation thought, in some scenarios, to originate from the base of these jets. This high energy X-radiation lights up the disk, which reflects it, making the disk a source of X-rays. The reflected light enables astronomers to see how fast matter is swirling in the inner region of the disk, and ultimately to measure the black hole's spin rate.

Image source: commons.wikimedia.org

Supermassive black hole at the center of the Milky Way galaxy

Supermassive black hole at the center of the Milky Way galaxy

Supermassive black hole at the center of the Milky Way galaxy
Astronomers have observed the largest X-ray flare ever detected from the supermassive black hole at the center of the Milky Way galaxy. This event, detected by NASA’s Chandra X-ray Observatory, raises questions about the behavior of this giant black hole and its surrounding environment.

The supermassive black hole at the center of our galaxy, called Sagittarius A*, or Sgr A*, is estimated to contain about 4.5 million times the mass of our sun.

Source: Go to source for more information


 

A supermassive black hole - A composite image

Spiral Galaxy M81 - A supermassive black hole

A supermassive black hole

#2: Spiral Galaxy M81 - A supermassive black hole
M81 is a spiral galaxy about 12 million light years away that is both relatively large in the sky and bright, making it a frequent target for both amateur and professional astronomers.

Image credit: X-ray: NASA/CXC/SAO; Optical: Detlef Hartmann; Infrared: NASA/JPL-Caltech
Source and Reference: chandra.harvard.edu

M81 Animations chandra.harvard.edu

A composite NASA image of the spiral galaxy M81

A composite NASA image of the spiral galaxy M81

#2: A composite NASA image of the spiral galaxy M81, located about 12 million light years away. This composite NASA image of the spiral galaxy M81, located about 12 million light years away, includes X-ray data from the Chandra X-ray Observatory (blue), optical data from the Hubble Space Telescope (green), infrared data from the Spitzer Space Telescope (pink) and ultraviolet data from GALEX (purple). The inset shows a close-up of the Chandra image. At the center of M81 is a supermassive black hole that is about 70 million times more massive than the Sun.

Image credit: X-ray: NASA/CXC/Wisconsin/D.Pooley & CfA/A.Zezas; Optical: NASA/ESA/CfA/A.Zezas; UV: NASA/JPL-Caltech/CfA/J.Huchra et al.; IR: NASA/JPL-Caltech/CfA
Source and Reference: chandra.harvard.edu
More images of M81

Chandra X-ray Image of M81

Chandra X-ray Image of M81

Chandra X-ray Image of M81
The biggest black holes may feed just like the smallest ones, according to data from NASA's Chandra X-ray Observatory and ground-based telescopes. This discovery supports the implication of Einstein's relativity theory that black holes of all sizes have similar properties,

Image source: chandra.harvard.edu

Optical Image of M81

optical

Optical Image of M81
show optical data from the Hubble Space Telescope (green).

Image source: chandra.harvard.edu


 

Infra-red Image of M81

Infra-red

Infra-red Image of M81
show infrared data from the Spitzer Space Telescope (pink).

Image source: chandra.harvard.edu

UV Image of M81

UV

UV Image of M81
show ultraviolet data from GALEX (purple).

Image source: chandra.harvard.edu

 

 

Gravitational Waves Detected

Gravitational Waves Detected

Gravitational Waves Detected, Confirming Einstein’s Theory.

Gravitational Waves Detected (Video)

 

Where does Physics go from here now that we’ve found gravitational waves?

Einstein's gravitational waves found.

LIGO team’s visualization of gravitational waves caused by two rapidly orbiting black holes in a binary system.

Einstein's gravitational waves 'seen' from black holes

Einstein's gravitational waves 'seen' from black holes

Scientists have observed the warping of space-time generated by the collision of two black holes more than a billion light-years from Earth.
Scientists are claiming a stunning discovery in their quest to fully understand gravity. For the first time, scientists detect tiny, rhythmic distortions in space and time - gravitational waves - predicted by Einstein 100 years ago..

 

 

Why every picture of a black hole is an illustration


Read the article at www.vox.com Most images of black holes are illustrations. Here’s what our telescopes actually capture.   Copy

What Hawking meant when he said ‘there are no black holes’

Illustration of the supermassive black holes

Illustration of the supermassive black holes.
This artist’s concept shows a supermassive black hole with millions to billions times the mass of our sun. Supermassive black holes are enormously dense objects buried at the hearts of galaxies, and fundamental aspects of their behavior have baffled scientists. Image by NASA/JPL-Caltech (www.pbs.org/)
In this illustration, the supermassive black hole at the center is surrounded by matter flowing onto the black hole in what is termed an accretion disk. This disk forms as the dust and gas in the galaxy falls onto the hole, attracted by its gravity. Also shown is an outflowing jet of energetic particles, believed to be powered by the black hole's spin. NASA/JPL-Caltech (www.vox.com)

Read the article at www.pbs.org What Hawking meant when he said ‘there are no black holes’   Copy

 

 

 

https://www.nasa.gov/mission_pages/chandra/cosmic-winter-wonderland.html