Posts Tagged ‘AKARI’

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: