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dc.contributor.authorHong, Jaesub
dc.contributor.authorSchlegel, Eric M.
dc.contributor.authorGrindlay, Jonathan E.
dc.date.accessioned2019-09-25T14:13:35Z
dc.date.issued2004
dc.identifier.citationHong, Jaesub, Eric M. Schlegel, and Jonathan E. Grindlay. 2004. “New Spectral Classification Technique for X‐Ray Sources: Quantile Analysis.” The Astrophysical Journal 614 (1): 508–17. https://doi.org/10.1086/423445.
dc.identifier.issn0004-637X
dc.identifier.issn1538-4357
dc.identifier.urihttp://nrs.harvard.edu/urn-3:HUL.InstRepos:41399903*
dc.description.abstractWe present a new technique, quantile analysis, to classify the spectral properties of X-ray sources with limited statistics. Quantile analysis is superior to conventional approaches, such as X-ray hardness ratio or X-ray color analysis, for studying relatively faint sources or investigating a certain phase or state of a source in detail, where poor statistics do not allow spectral fitting using a model. Instead of working with predetermined energy bands, we determine the energy values that divide the detected photons into predetermined fractions of the total counts, such as the median (50%), terciles (33% and 67%), and quartiles (25% and 75%). We use these quantiles as an indicator of the X-ray hardness or color of the source. We show that the median is an improved substitute for the conventional X-ray hardness ratio. The median and other quantiles form a phase space, similar to the conventional X-ray color-color diagrams. The quantile-based phase space is more evenly sensitive over various spectral shapes than the conventional color-color diagrams, and it is naturally arranged to properly represent the statistical similarity of various spectral shapes. We demonstrate the new technique in the 0.3-8 keV energy range using the Chandra ACIS-S detector response function and a typical aperture photometry involving background subtraction. The technique can be applied in any energy band, provided the energy distribution of photons can be obtained.
dc.language.isoen_US
dc.publisherAmerican Astronomical Society
dash.licenseLAA
dc.titleNew Spectral Classification Technique for X‐Ray Sources: Quantile Analysis
dc.typeJournal Article
dc.description.versionVersion of Record
dc.relation.journalThe Astrophysical Journal
dash.depositing.authorGrindlay, Jonathan E.::60a4e0fa703c94a1ad5c71189cf4844e::600
dc.date.available2019-09-25T14:13:35Z
dash.workflow.comments1Science Serial ID 96768
dc.identifier.doi10.1086/423445
dash.source.volume614;1
dash.source.page508-517


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