Astronomy and Astrophysics – Astronomy
Scientific paper
Sep 2009
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009cfdd.confe.107g&link_type=abstract
Chandra's First Decade of Discovery, Proceedings of the conference held 22-25 September, 2009 in Boston, MA. Edited by Scott Wo
Astronomy and Astrophysics
Astronomy
Source Catalogs, Software
Scientific paper
X-ray sources with very few counts can be identified with low-noise X-ray detectors such as the Advanced CCD Imaging Spectrometer onboard the Chandra X-ray Observatory. These sources are often too faint for parametric spectral modeling using well-established methods such as spectral fitting with XSPEC. We discuss the estimation of apparent and intrinsic broad-band X-ray fluxes and soft X-ray absorption from gas along the line-of-sight to these sources, using nonparametric methods. Apparent flux is estimated from the ratio of the source count number to the instrumental effective area averaged over the chosen band. Absorption and intrinsic flux are estimated from the comparison of the apparent median energy of the source photons and apparent source flux with those of high signal-to-noise spectra that were simulated using spectral models characteristic of much brighter sources of similar class previously studied in detail. The concept of this method is similar to the long-standing use of color-magnitude diagrams in optical and infrared astronomy. Our nonparametric method is tested against the apparent spectra of faint sources. We show that the intrinsic X-ray properties can be determined with little bias and reasonable accuracy using these observable photometric quantities without employing often uncertain methods of non-linear parametric spectral modeling. Our results are obtained for thermal spectra characteristic of stars in young stellar clusters, but similar results should hold for other classes of faint X-ray sources.
Broos Patrick
Feigelson Eric
Garmire Gordon
Getman Konstantin
Townsley Leisa
No associations
LandOfFree
Nonparametric Estimation of Intrinsic Properties of Faint X-ray Sources does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Nonparametric Estimation of Intrinsic Properties of Faint X-ray Sources, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nonparametric Estimation of Intrinsic Properties of Faint X-ray Sources will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-837221