Simultaneous ASCA, RXTE and BeppoSAX Observations of 3C 273
(ASCA GOF Calibration Memo [ASCA-CAL-00-06-02, v1.0 (06/07/00): T. Yaqoob & ASCATEAM])
This document describes the results of two multimission calibration
campaigns on 3C 273 with simultaneous observations by ASCA,
RXTE and BeppoSAX (in July 1996 and June 1998).
A thorough comparison of the ASCA and BeppoSAX results
have been dicussed in detail in a
by Grandi and Guainazzi.
That report discusses both the soft and hard X-ray cross-calibrattion.
All results from BeppoSAX which are quoted here in this
ASCA/RXTE report have been taken from the Grandi and Guainazzi
report with kind permission.
This report concerns the comparison of the PCA and ASCA SIS and GIS
instruments. Since the PCA does not have a useful repsonse below 3 keV the
comparison is necessarily restricted to the hard 3-10 keV X-ray band.
1. Bottom Line
2. Spectral Fits
3. Observation Log & Lightcurves
4. Data Analysis Details
For those interested in only a summary and "bottom line"
of the analysis, here it is. Full details are given on separate pages.
Power-law Slope: The ASCA and PCA slopes are
in excellent agreement, within the (small) statistical
errors. The BeppoSAXASCA but still in good agreement with both
PCA and ASCA within the errors.
The MECS slope from July 1996 is smaller than ASCA by ~0.06. BUT
BeppoSAX was not truly simultaneous with ASCA and
RXTE in the July 1996 campaign so the slope
may have varied. In summary, the slope differences between
ASCA/PCA/MECS are not worse than 0.06.
Flux: PCA is more than 20% higher than ASCA.
BeppoSAX and ASCA agreement is better than 3%.
In the July 1996 campaign the 3-10 keV power-law slope for the
PCA (1.65 +/- 0.01) is compatible with the ASCA SIS+GIS 4-instrument
value (1.65 -0.02,+0.03).
In the June 1998 campaign the 3-10 keV power-law slope for the
PCA (1.68 +/- 0.01) is just compatible with the ASCA
SIS+GIS 4-instrument value (1.66 -0.03,+0.01).
In the July 1996 campaign the 4-instrument ASCA 1.5-10 keV slope is
steeper than the corresponding BeppoSAX MECS value by about 0.06 but
the SIS1 value is in good agreement.
BUT, note that the July 1996 ASCA and BeppoSAX observations
were not truly simulateous so the slope could have varied.
In the June 1998 campaign the
4-instrument ASCA and SIS1 slopes are both in good agreement with
the MECS slope in the 1.5-10 keV band and are compatible at the 90%
The 4-10 keV fluxes from the PCA are 23% and 28% higher than those
for ASCA in the July 1996 and June 1998 campaigns respectively.
These values are obtained using 4-instrument ASCA averages but
approximately the same discrepancy is present no matter which ASCA
instrument is used.
The 4-10 keV fluxes from the 4-instrument ASCA average and
the BeppoSAX MECS agree with each other to better than 3%.
This file was last modified on Monday, 30-Jul-2001 18:17:24 EDT
Michael Arida (SP Sys); firstname.lastname@example.org
HEASARC Guest Observer Facility
If you have any questions concerning ASCA, visit
our Feedback form.