Comparison of XMM-Newton EPIC, Chandra ACIS-S3, ASCA SIS and GIS, and ROSAT PSPC Results for G21.5-0.9, 1E0102.2-7219, and MS1-54.4-0321

TL;DR

This study compares spectral calibration results across XMM-Newton, Chandra, ASCA, and ROSAT instruments using three different astronomical sources, finding flux agreement within 10% and generally consistent spectral parameters.

Contribution

It provides a cross-calibration assessment of major X-ray observatories using real data, highlighting their relative agreement and limitations.

Findings

Flux measurements agree within 10% across instruments.

XMM-Newton and Chandra show better flux agreement.

Spectral parameters are relatively consistent across instruments.

Abstract

This paper presents a ``man on the street'' view of the current status of the spectral cross calibration between the XMM-Newton EPIC, Chandra ACIS-S3, ASCA SIS and GIS, and ROSAT PSPC instruments. Using publicly released software for the extraction of spectra and the production of spectral redistribution response matrices and effective areas, the spectral fits of data from three astronomical objects are compared. The three sources are G21.5-0.9 (a heavily absorbed Galactic SNR with a power law spectrum), 1E0102.2-7219 (a SNR in the SMC with a line-dominated spectrum), and MS1054.4-0321 (a high redshift cluster with a thermal spectrum). The agreement between the measured fluxes of the various instruments is within the 10% range, and is better when just XMM-Newton and Chandra are compared. Fitted spectral parameters are also in relatively good agreement although the results are more limited.