MTA Science Instrument Background Report: ACIS Nov 2009

Updated on: 2009-11-23 / DAY OF YEAR: 327 / DAY OF MISSION: 3778

This page shows scientific instrument background data based on Acis observations. A source region file is generated using get_srcregions and then the input event file is filtered using the regions in that file to remove the sources. Details on these tools can be using ahelp.

The plot above is data of the background photon count rates of the entire energy range of ccd6 from Sept 1999 to this week.

If you select a ccd from the table below, it brings up seven plots of that month. The top plot is for the entire energy range. Smaller plots are for super soft, soft, moderate, hard, very hard, and beyond 10 KeV.

Before computing SIB, most extended sources, such as clusters of galaxies, were removed manually to avoid confusion. All point sources were removed automatically by scripts. (NOTE: extended sources were currently removed only for 2003, and 2004.)

The fitted line for the entire period is 4th order polynomials, and it is extended to two years beyond the current time to show a possible SIB level in future. For all others, the fitted line is a linear, and for one year plots, the line is extended 6 months beyond the current date.

If you are interested in checking the scientific instrument background computed with Level 2 data set, please to go to level 2 SIB page.