some chandra basics. chandra x-ray observatory
Post on 19-Dec-2015
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Some Chandra Basics
Chandra X-Ray Observatory
Chandra X-ray Observatory
• Chandra has the most precise X-ray mirrors ever flown
• Grazing incidence paraboloid -hyperboloid mirror pairs give 0.5” spatial resolution
• Transmission gratings (HETG, LETG): dispersive high resolution spectrometers (for compact sources)
• Advanced CCD Imaging Spectrometer (ACIS): CCDs with moderate spectral resolution
8’ field of view
120 eV FWHM at 1 keV
Si He Forbidden 1.840 keV Intercombination 1.855 keV Resonance 1.865 keV
Si Ly (H-like ion) 2.006 keV
blended
Image Event File Information
• All astronomical data now in FITS format• Each detected event: pixel ID, time, pulse height• Differential exposure corrections can be made• Correlation with sky can be made, so that pixel
map in “corrected” image removes jitter• For HRC, best timing and position (bad spectrum)• For ACIS (CCD), better spectrum (120 eV FWHM)