Two new efforts have taken a famous supernova remnant from the static to the dynamic. A new movie of data from NASA's Chandra X-ray Observatory shows changes in time never seen before in this type of object. A separate team will also release a dramatic three-dimensional visualization of the same remnant.
Nearly ten years ago, Chandra's "First Light" image of Cassiopeia A (Cas A) revealed previously unseen structures and detail. Now, after eight years of observation, scientists have been able to construct a movie that tracks the remnant's expansion and changes over time.
"With Chandra, we have watched Cas A over a relatively small amount of its life, but so far the show has been amazing," said Daniel Patnaude of the Smithsonian Astrophysical Observatory in Cambridge, Mass. "And, we can use this to learn more about the aftermath of the star's explosion."
This movie of X-ray data from Chandra was made by combining observations taken in January 2000, February 2002, February 2004 and December 2007. In these images, the lowest-energy X-rays Chandra detects are shown in red, intermediate energies in green and the highest energies in blue. Scientists have used the movie to measure the expansion velocity of the leading edge of the explosion's outer blast wave (shown in blue). The researchers find that the velocity is 11 million miles per hour, which is significantly slower than expected for an explosion with the energy estimated to have been released in Cas A. Credit: NASA/CXC/SAO/D. Patnaude et al.
A separate, but equally fascinating visualization featuring Cas A was presented, along with the Patnaude team's results, at a press conference at the American Astronomical Society meeting in Long Beach, Calif. Based on data from Chandra, NASA's Spitzer Space Telescope, and ground-based optical telescopes, Tracey DeLaney and her colleagues have created the first three-dimensional fly-through of a supernova remnant.
"We have always wanted to know how the pieces we see in two dimensions fit together with each other in real life," said DeLaney of the Massachusetts Institute of Technology. "Now we can see for ourselves with this 'hologram' of supernova debris."
This ground-breaking visualization of Cas A was made possible through a collaboration with the Astronomical Medicine project based at Harvard. The goal of this project is to bring together the best techniques from two very different fields, astronomy and medical imaging.
"Right now, we are focusing on improving three-dimensional visualization in both astronomy and medicine," said Harvard's Alyssa Goodman who heads the Astronomical Medicine project. "This project with Cas A is exactly what we have hoped would come out of it."
While these are stunning visuals, both the data movie from Patnaude and the 3-D model from DeLaney are, more importantly, rich resources for science. The two teams are trying to get a much more complete understanding of how this famous supernova explosion and its remnant work.
Patnaude and his team have measured the expansion velocity of features in Cas A from motions in the movie, and find it is slower than expected based on current theoretical models. Patnaude thinks the explanation for this mysterious loss of energy is cosmic ray acceleration.
Using estimates of the properties of the supernova explosion, including its energy and dynamics, Patnaude's group show that about 30% of the energy in this supernova has gone into accelerating cosmic rays, energetic particles that are generated, in part, by supernova remnants and constantly bombard the Earth's atmosphere. The flickering in the movie provides valuable new information about where the acceleration of these particles occurs.
This visualization is a 3-D model constructed from data from Chandra, Spitzer and ground-based optical telescopes. Scientists determined the positions of the different telescopes, represented by the various colors, using the Doppler effect. That information was then put into a medical imaging program adapted for astronomical use before commercial software was used to create the final visualization. This is the first time such a multiwavelength 3-D model of a supernova remnant has been created. Credit: NASA/CXC/MIT/T. Delaney et al.
Likewise, the new 3-D model of Cas A provides researchers with unique ability to study this remnant. With this new tool, Delaney and colleagues found two components to the explosion, a spherical component from the outer layers of the star and a flattened component from the inner layers of the star.
Notable features of the model are high-velocity plumes from this internal material that are shooting out from the explosion. Plumes, or jets, of silicon appear in the northeast and southwest, while plumes of iron are seen in the southeast and north. Astronomers had known about the plumes and jets before, but did not know that they all came out in a broad, disk-like structure.
The implication of this work is that astronomers who build models of supernova explosions must now consider that the outer layers of the star come off spherically, but the inner layers come out more disk like with high-velocity jets in multiple directions.
Cassiopeia A is the remains of a star thought to have exploded about 330 years ago, and is one of the youngest remnants in the Milky Way galaxy. The study of Cas A and remnants like it help astronomers better understand how the explosions that generate them seed interstellar gas with heavy elements, heat it with the energy of their radiation, and trigger shock waves from which new stars form.
Lawrence Rudnick of the University of Minnesota led the Spitzer part of the Delaney study. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- Women,This Is Your Brain On Junk Food
- ATLAS Higgs Challenge Results
- Epidemics: A Sleaze-Bag Payday?
- Ebola Virus And Protein Secrets
- Betavoltaics: Water-Based Nuclear Battery Developed
- The Chicxulub Meteorite Killed The Dinosaurs But Made Forests Great
- Life After The 125 GeV Higgs: What Is Left Of Two-Higgs Doublet Models
- "Hi Anon,it is not an issue of beauty versus performance. It is a question of of machine learning..."
- "Yeah, that's what is called the intraocular traumatic test: if the signal hits you between the..."
- " Contrary to popular belief, all atheists believe in God! Ask any atheists how the universe began..."
- " If the latter were true he would not be selling unapproved drugs, that not only don't work..."
- "У меня иммунитет против многих инфекционных заболеваний..."
- Phthalates heighten risk for childhood asthma
- New study examines the impact of socioeconomic position & maternal morbidity in Australia
- A greater focus on socially disadvantaged women is needed to improve maternity care in England
- NAMS issues first comprehensive recommendations on care of women at menopause and beyond
- Sharks' skin has teeth in the fight against hospital superbugs