2011/12/08 by Shin’ya Yamada, Shin'ya Yamada, Hideki Uchiyama +12 · 48 citations
Physics and Astronomy · #Advanced X-ray Imaging Techniques #Astrophysical Phenomena and Observations #Astrophysics and Cosmic Phenomena #Branching fraction #Brightness #Brightness temperature #Data reduction #Effective radius #Fraction (chemistry) #RADIUS #astro-ph.HE #astro-ph.IM
paper · pdf · doi:10.1093/pasj/64.3.53
published in Publications of the Astronomical Society of Japan 64(3) (Oxford University Press) · 13 pages, 8 figures, pileup issues on the Suzaku XIS
arxiv created 2011/12/08 · openalex publication_date 2012/06/25 · arxiv updated 2015/06/03 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Abstract We present the results of a systematic study of pileup phenomena seen in the X-ray Imaging Spectrometer, an X-ray CCD instrument, onboard the Suzaku observatory. Using a data set of observed sources in a wide range of brightness and spectral hardness, we characterized the pileup fraction, spectral hardening, and grade migration as a function of the observed count rate in a frame per pixel. Using the pileup fraction as a measure of the degree of pileup, we found that the relative spectral hardening (the hardness ratio normalized to the intrinsic spectral hardness), branching ratio of split events, and that of detached events increase monotonically as the pileup fraction increases, despite the variety of brightness and hardness of the sample sources. We derived the pileup fraction as a function of radius used for event extraction. Upon practical considerations, we found that events outside of the radius with a pileup fraction of 1% or 3% are useful for spectral analysis. We present relevant figures, tables, and software for the convenience of users who wish to apply our method for their data reduction of piled-up sources.