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Posts Tagged ‘Cassiopeia’

AKARI Finds CO Molecules in 10,000,000-Degree Gas

February 9, 2012 Leave a comment

A scientific team using the Japanese AKARI infrared space observatory finds carbon monoxide (CO) molecules in the ten million degree gas associated with the young supernova remnant Cassiopeia A (Cas A). The team is led by Dr. Jeonghee Rho, who holds a joint appointment at the SETI Institute, and at the SOFIA Science Center at NASA Ames Research Center (both located in Mountain View California). Theoretically it was neither predicted nor expected to find the carbon monoxide molecule associated with a highly energetic supernova remnant. Energetic electrons and heavy-element atoms produced by nuclear processes in supernovae should have destroyed these molecules. This finding could change our current understanding of the cycle of carbon and molecules in the interstellar gas and dust clouds.

Infrared spectra obtained by AKARI have detected a broad feature with a double-peaked profile. A dozen spectra reveal CO features similar to this across the angular extent of Cas A. The CO emission is specially detected not only from the bright ring of shocked ejecta but also from the central region where unshocked ejecta are located. The CO at the center of Cas A contains material which has been relatively unchanged since a few years after the original supernova explosion. The spectral model applied to these spectra indicates that the broad feature is being composed of a few ten thousand spectral lines produced by CO. Cas A is 330 years old and located at a distance of approximately 11 thousand light years in the direction of the well-known W-shaped constellation of Cassiopeia.

Full Story: http://www.ir.isas.jaxa.jp/AKARI/Outreach/results/PR2012_CasA/casa_e.html

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NASA’s Fermi Shows That Tycho’s Star Shines in Gamma Rays

December 13, 2011 Leave a comment

Credit: Gamma ray, NASA/DOE/Fermi LAT Collaboration; X-ray, NASA/CXC/SAO; Infrared, NASA/JPL-Caltech; Optical, MPIA, Calar Alto, O. Krause et al. and DSS

Credit: Gamma ray, NASA/DOE/Fermi LAT Collaboration; X-ray, NASA/CXC/SAO; Infrared, NASA/JPL-Caltech; Optical, MPIA, Calar Alto, O. Krause et al. and DSS

In early November 1572, observers on Earth witnessed the appearance of a “new star” in the constellation Cassiopeia, an event now recognized as the brightest naked-eye supernova in more than 400 years. It’s often called “Tycho’s supernova” after the great Danish astronomer Tycho Brahe, who gained renown for his extensive study of the object. Now, years of data collected by NASA’s Fermi Gamma-Ray Space Telescope reveal that the shattered star’s remains shine in high-energy gamma rays.

The detection gives astronomers another clue in understanding the origin of cosmic rays, subatomic particles — mainly protons — that move through space at nearly the speed of light. Exactly where and how these particles attain such incredible energies has been a long-standing mystery because charged particles speeding through the galaxy are easily deflected by interstellar magnetic fields. This makes it impossible to track cosmic rays back to their sources.

Full Story: http://www.nasa.gov/mission_pages/GLAST/news/tycho-star.html

‘Pacman’ Nebula Gets Some Teeth

October 27, 2011 Leave a comment

 Image Credit: NASA/JPL-Caltech/UCLA

Image Credit: NASA/JPL-Caltech/UCLA

To visible-light telescopes, this star-forming cloud appears to be chomping through the cosmos, earning it the nickname the “Pacman” nebula, like the famous Pac-Man video game that debuted in 1980. When viewed in infrared light by NASA’s Wide-field Infrared Survey Explorer, or WISE, the Pacman takes on a new appearance. In place of its typical, triangle-shaped mouth is a new set of lower, sharp-looking teeth. The Pacman is located at the top of the picture, taking a bite in the direction of the upper left corner.

The teeth are actually pillars where new stars may be forming. These structures were formed when radiation and winds from massive stars in a central cluster blew gas and dust away, leaving only the densest of material. The red dots sprinkled throughout the picture are thought to be the youngest stars, still forming in cocoons of dust.

The Pacman nebula, also called NGC 281, is located 9,200 light years away in the constellation Cassiopeia.

Full Story: http://www.jpl.nasa.gov/news/news.cfm?release=2011-334