Weekly Report 15Apr2011

RHESSI Albedo Imaging Test

RHESSI Clean Imaging techniques were used to image a large number of flares. For each flare three different detector combinations and two different energy bands were used. The following parameters were used: The flares used were decided upon by the RHESSI response in the 25keV-50keV bands.

• Time: Decided by the peak of the 25keV-50keV energy band for each flare
• Energy: 12keV to 25keV, or 25keV to 50keV
• Detectors: 1 to 9, or 1 to 5,or 6 to 9
• Pixel Size: 2 arcsec by 2 arcsec
• Image Size: 128 pixels by 128 pixels
• Clean Beam Width Factor = 2

Clean images were made with each for each energy band with each detector combination. For each image the centroid of the source was measured, the total flux in the image was measured, and the standard deviation in the x and y direction for each source was measured. Using these measurements the plots below were made.

12keV - 25keV

The following are the plots for the 12keV - 25keV energy band.

The difference in the centroid location for an image with detectors 1 to 9 and an image with detectors 1 to 5 in the 12keV - 25keV energy band.

The difference in the centroid location for an image with detectors 6 to 9 and an image with detectors 1 to 5 in the 12keV - 25keV energy band.

The difference in the centroid location for an image with detectors 6 to 9 and an image with detectors 1 to 9 in the 12keV - 25keV energy band.

The ratio of the standard deviation in y to the standard deviation in x for images made with detectors 1 to 9.

The ratio of the standard deviation in y to the standard deviation in x for images made with detectors 1 to 5.

The ratio of the standard deviation in y to the standard deviation in x for images made with detectors 6 to 9.

The ratio of the flux in the coarse detectors to fine detectors for the 12keV-25keV energy band.

25keV - 50keV

The difference in the centroid location for an image with detectors 1 to 9 and an image with detectors 1 to 5 in the 25keV - 50keV energy band.

The difference in the centroid location for an image with detectors 6 to 9 and an image with detectors 1 to 5 in the 25keV - 50keV energy band.

The difference in the centroid location for an image with detectors 6 to 9 and an image with detectors 1 to 9 in the 25keV - 50keV energy band.

The ratio of the standard deviation in y to the standard deviation in x for images made with detectors 1 to 9.

The ratio of the standard deviation in y to the standard deviation in x for images made with detectors 1 to 5.

The ratio of the standard deviation in y to the standard deviation in x for images made with detectors 6 to 9.

The ratio of the flux in the coarse detectors to fine detectors for the 25keV - 50keV energy band.