Discarding piled-up events in ACIS

P. S. Broos, L. K. Townsley, J. A. Nousek

Research output: Contribution to journalConference articlepeer-review

4 Scopus citations


The coincidence of multiple x-rays in a detection cell within one CCD frame - an effect known as pile-up - is a significant source of spectral contamination for bright sources observed with the AXAF CCD Imaging Spectrometer (ACIS). Investigation of algorithms for correcting contaminated spectra is underway. In cases where such algorithms fail, the observer may wish to discard events from the core of the AXAF point spread function (PSF), computing spectra using only events from the PSF wings, where pile-up effects are reduced. This work investigates the effectiveness of this technique for an isolated on-axis point source, using event lists produced by a Monte-Carlo simulation of the ACIS instrument.

Original languageEnglish (US)
Pages (from-to)30-35
Number of pages6
JournalProceedings of SPIE - The International Society for Optical Engineering
StatePublished - 1998
EventProceedings of the 1998 Conference on X-Ray Optics, Instruments, and Missions - San Diego, CA, USA
Duration: Jul 19 1998Jul 22 1998

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


Dive into the research topics of 'Discarding piled-up events in ACIS'. Together they form a unique fingerprint.

Cite this