dc.contributor.author | Hong, Jaesub | |
dc.contributor.author | Schlegel, Eric M. | |
dc.contributor.author | Grindlay, Jonathan E. | |
dc.date.accessioned | 2019-09-25T14:13:35Z | |
dc.date.issued | 2004 | |
dc.identifier.citation | Hong, 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.issn | 0004-637X | |
dc.identifier.issn | 1538-4357 | |
dc.identifier.uri | http://nrs.harvard.edu/urn-3:HUL.InstRepos:41399903 | * |
dc.description.abstract | We 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.iso | en_US | |
dc.publisher | American Astronomical Society | |
dash.license | LAA | |
dc.title | New Spectral Classification Technique for X‐Ray Sources: Quantile Analysis | |
dc.type | Journal Article | |
dc.description.version | Version of Record | |
dc.relation.journal | The Astrophysical Journal | |
dash.depositing.author | Grindlay, Jonathan E.::60a4e0fa703c94a1ad5c71189cf4844e::600 | |
dc.date.available | 2019-09-25T14:13:35Z | |
dash.workflow.comments | 1Science Serial ID 96768 | |
dc.identifier.doi | 10.1086/423445 | |
dash.source.volume | 614;1 | |
dash.source.page | 508-517 | |