JimD
01-21-2011, 10:00 AM
--------- #1240 - Stephen’s Quintet Merging Galaxies.
- The picture below is a “composite” image of the five merging galaxies in the Constellation Pegasus, The Winged Horse. The galaxies are called the Stephen’s Quintet. They are 280 million lightyears from Earth, but, they are showing us how galaxies evolved and merged in the early Universe as well as what is going on today.
- Attachments - Stephen’s Quintet Galaxies.
- One of the major breakthroughs in astronomy in recent decades is to have telescopes that can “see” the full range of the electromagnetic spectrum. No one telescope sees everything, but several telescopes, each specializing in a specific part of the spectrum can record images and those images can be overlaid to give a “composite” image covering many wavelengths of “light” in one picture.
- The image below is the merging of 5 galaxies in Stephen’s Quintet. Astronomers can see what happens as these galaxies collide. They can study how spiral galaxy mergers can occur to form larger elliptical galaxies. In this image of 5 merging galaxies the infrared wavelengths that we normally can not see are translated to the wavelength of red light that we can see. The visible spectrum is translated from pink light to blue colored light corresponding to wavelengths from 700 nanometers to 400 nanometers. The green color is selected to correspond to X-ray emissions that again we could not normally see. All the separate images from different space telescopes are overlaid into a composite that reveals surprising new details.
- The magnificent green arch in the center of the group is the glow of ionized atomic hydrogen. The arch is a giant intergalactic shockwave that is the size of the Milky Way Galaxy and traveling at 500 miles per second into the group of four galaxies. The one spiral galaxy plunging into the intergalactic medium between the other galaxies creates a wave of ionized hydrogen as the electrons are stripped from the hydrogen gas atoms. The shockwave becomes a wave of positively charged protons. When this gigantic wave hit’s the other gas in the intergalactic medium the gas heats up to millions of degrees. This intense temperature creates X-rays that are detected by the Chandra X-ray Space telescope.
- The more amazing discovery was made by the Spitzer Space telescope that detected infrared radiation coming from molecular hydrogen. Hydrogen molecules of gas somehow survived in the turbulence behind the shockwave. Molecular hydrogen are two hydrogen atoms bound together to form hydrogen gas. These molecules are the seeds of new stars but are very fragile and can be easily pulled apart with little energy. However, they somehow held together as the shockwave passed. Detailed study of the turbulence in the infrared showed that the massive shockwave created many smaller shockwaves that churned in the turbulence like the waves behind a speed boat. Inside the turbulence there were more neutral pressures and temperatures that allowed the neutral hydrogen to survive. This cooler hydrogen is the seeds for new star formation. Here is the picture the astronomers came away with:
- When the spiral galaxies merge individual stars rarely collide because of the vast distances separating them. Even in the most crowded centers of these galaxies the stars are several trillion miles apart. However, the interstellar clouds of gas and dust do crash into each other like giant ocean waves. These collisions create shockwaves which in turn create the gravitational collapse of dense pockets of star making material. At the centers of this denser material new stars are born. These young, hot, new borne stars shine in intense ultraviolet light. This intense ultraviolet light hit’s the gas and dust that surrounds the new stars. This interstellar medium absorbs the ultraviolet energy and re-emits radiation in the infrared wavelengths. It is this infrared image that the Spitzer Space telescope receives.
- This 5 galaxy merger is occurring 280 million years ago as we see it. However, we are experiencing a galaxy merger today in our own Milky Way Galaxy. The giant Milky Way 120,000 lightyears across is merging with the Sagittarius Dwarf Galaxy at its outer edges. Sagittarius Dwarf is only one of several dwarf galaxies that are circling the Milky Way and the Andromeda Galaxies like bees swarming around a hive. Bigger galaxies are swallowing up smaller galaxies. And, in 5 billion years from now the two biggest galaxies in our Local Group of galaxies will begin to merge. The Milky Way and Andromeda galaxies will collide and begin their own merging dance in the Cosmos.
- When 2 spiral galaxies like the Milky Way and Andromeda collide they form a giant elliptical galaxy. The tremendous tidal forces of the collision tear apart the spiral disks. Stars collectively are thrown into random orbits. Gravitationally much of the gas and material sinks to the center of the collision. This increased density creates a star burst of many new star formations. Supernovae of the largest and short-lived stars and their stellar winds blow away the rest of the gas and dust. When the “ dust settles” what is left is one giant elliptical galaxy where two spiral galaxies were before. No disk remains and stars are like a swarm of bees in random orbits throughout the new galaxy.
- So, 10 billion years from now things will look a lot different around here.
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RSVP, please reply with a number to rate this review: #1- learned something new. #2 - Didn’t read it. #3- very interesting. #4- Send another review #___ from the index. #5- Keep em coming. #6- I forwarded copy to some friends. #7- Don‘t send me these anymore! #8- I am forwarding you some questions? Index is available with email. Please send feedback, corrections, or recommended improvements to: [email protected] ([email protected]). or, use www.facebook.com (https://www.facebook.com/), or , www.twitter.com (https://www.twitter.com/).
707-536-3272, [email protected] ([email protected]) Friday, January 21, 2011
- The picture below is a “composite” image of the five merging galaxies in the Constellation Pegasus, The Winged Horse. The galaxies are called the Stephen’s Quintet. They are 280 million lightyears from Earth, but, they are showing us how galaxies evolved and merged in the early Universe as well as what is going on today.
- Attachments - Stephen’s Quintet Galaxies.
- One of the major breakthroughs in astronomy in recent decades is to have telescopes that can “see” the full range of the electromagnetic spectrum. No one telescope sees everything, but several telescopes, each specializing in a specific part of the spectrum can record images and those images can be overlaid to give a “composite” image covering many wavelengths of “light” in one picture.
- The image below is the merging of 5 galaxies in Stephen’s Quintet. Astronomers can see what happens as these galaxies collide. They can study how spiral galaxy mergers can occur to form larger elliptical galaxies. In this image of 5 merging galaxies the infrared wavelengths that we normally can not see are translated to the wavelength of red light that we can see. The visible spectrum is translated from pink light to blue colored light corresponding to wavelengths from 700 nanometers to 400 nanometers. The green color is selected to correspond to X-ray emissions that again we could not normally see. All the separate images from different space telescopes are overlaid into a composite that reveals surprising new details.
- The magnificent green arch in the center of the group is the glow of ionized atomic hydrogen. The arch is a giant intergalactic shockwave that is the size of the Milky Way Galaxy and traveling at 500 miles per second into the group of four galaxies. The one spiral galaxy plunging into the intergalactic medium between the other galaxies creates a wave of ionized hydrogen as the electrons are stripped from the hydrogen gas atoms. The shockwave becomes a wave of positively charged protons. When this gigantic wave hit’s the other gas in the intergalactic medium the gas heats up to millions of degrees. This intense temperature creates X-rays that are detected by the Chandra X-ray Space telescope.
- The more amazing discovery was made by the Spitzer Space telescope that detected infrared radiation coming from molecular hydrogen. Hydrogen molecules of gas somehow survived in the turbulence behind the shockwave. Molecular hydrogen are two hydrogen atoms bound together to form hydrogen gas. These molecules are the seeds of new stars but are very fragile and can be easily pulled apart with little energy. However, they somehow held together as the shockwave passed. Detailed study of the turbulence in the infrared showed that the massive shockwave created many smaller shockwaves that churned in the turbulence like the waves behind a speed boat. Inside the turbulence there were more neutral pressures and temperatures that allowed the neutral hydrogen to survive. This cooler hydrogen is the seeds for new star formation. Here is the picture the astronomers came away with:
- When the spiral galaxies merge individual stars rarely collide because of the vast distances separating them. Even in the most crowded centers of these galaxies the stars are several trillion miles apart. However, the interstellar clouds of gas and dust do crash into each other like giant ocean waves. These collisions create shockwaves which in turn create the gravitational collapse of dense pockets of star making material. At the centers of this denser material new stars are born. These young, hot, new borne stars shine in intense ultraviolet light. This intense ultraviolet light hit’s the gas and dust that surrounds the new stars. This interstellar medium absorbs the ultraviolet energy and re-emits radiation in the infrared wavelengths. It is this infrared image that the Spitzer Space telescope receives.
- This 5 galaxy merger is occurring 280 million years ago as we see it. However, we are experiencing a galaxy merger today in our own Milky Way Galaxy. The giant Milky Way 120,000 lightyears across is merging with the Sagittarius Dwarf Galaxy at its outer edges. Sagittarius Dwarf is only one of several dwarf galaxies that are circling the Milky Way and the Andromeda Galaxies like bees swarming around a hive. Bigger galaxies are swallowing up smaller galaxies. And, in 5 billion years from now the two biggest galaxies in our Local Group of galaxies will begin to merge. The Milky Way and Andromeda galaxies will collide and begin their own merging dance in the Cosmos.
- When 2 spiral galaxies like the Milky Way and Andromeda collide they form a giant elliptical galaxy. The tremendous tidal forces of the collision tear apart the spiral disks. Stars collectively are thrown into random orbits. Gravitationally much of the gas and material sinks to the center of the collision. This increased density creates a star burst of many new star formations. Supernovae of the largest and short-lived stars and their stellar winds blow away the rest of the gas and dust. When the “ dust settles” what is left is one giant elliptical galaxy where two spiral galaxies were before. No disk remains and stars are like a swarm of bees in random orbits throughout the new galaxy.
- So, 10 billion years from now things will look a lot different around here.
---------------------- -----------------------------------------------------------------------------------
RSVP, please reply with a number to rate this review: #1- learned something new. #2 - Didn’t read it. #3- very interesting. #4- Send another review #___ from the index. #5- Keep em coming. #6- I forwarded copy to some friends. #7- Don‘t send me these anymore! #8- I am forwarding you some questions? Index is available with email. Please send feedback, corrections, or recommended improvements to: [email protected] ([email protected]). or, use www.facebook.com (https://www.facebook.com/), or , www.twitter.com (https://www.twitter.com/).
707-536-3272, [email protected] ([email protected]) Friday, January 21, 2011