Документ взят из кэша поисковой машины. Адрес оригинального документа : http://xmm.vilspa.esa.es/calibration/documentation/epic_cal_meetings/200904/molendi-ec-ma-09.pdf Дата изменения: Tue May 13 17:48:24 2014 Дата индексирования: Wed Apr 13 13:33:08 2016 Кодировка: Поисковые слова: hst

EPIC Chandra Cross Calibration with the Perseus Cluster
S. Molendi, F. Gastaldello & A.Tiengo (IASF-MI)


Cross Cal with Clusters
· · · · Has enjoyed some success Perseus is the brightest cluster in the Xray sky Lots of photons and no pile-up! In the past used to check pn/MOS cross calibration


Example of old vs new pn/mos
Residuals in the form of ratio data/model for PN data on MOS best fitting model


Example of old vs new pn/mos
Residuals in the form of ratio data/model for PN data on MOS best fitting model


ACIS S3 vs EPIC pn
· · Same thing, only now we compare Chandra ACIS S3 with EPIC pn About 3в106 events for each spectrum
extracted from annulus with bounding radii of 1' and 2 `

·
·

Used old and new Chandra calibrations
(CALDB 4.1.1 with hrmaD1996-12-20axeffaN0008.fits)

Multi T spectral model (Molendi & Gastaldello 09)


ACIS S3 vs EPIC pn
Residuals in the form of and ACIS data on pn Renorm applied to match ratio data/model for pn best fitting model. spectra at 1.5 keV

ACIS S3

pn


ACIS S3 vs EPIC pn
Residuals in the form of and ACIS data on pn Renorm applied to match ratio data/model for pn best fitting model. spectra at 1.5 keV

ACIS S3

pn


Cross Cal
pn and ACIS S3 spectral shapes are now in much better agreement!

Congratulations calibrators!


Flux cross-cal
· Both figures have renorm factors: 5% for the first; 15% for the second: let's take them out.


Flux cross-cal
· Both figures have renorm factors: 5% for the first; 15% for the second: let's take them out.


Flux cross-cal
· Both figures have renorm factors: 5% for the first; 15% for the second: let's take them out.



Flux cross-cal
· · The new HRMA calibration impacts on the ACIS/EPIC flux cross calibration. Our analysis indicates that the flux cross calibration below ~ 2 keV will be shifted by about 10%. Although comparing spectra extracted from a given region of a cluster may not be the best way to go, our data indicates that the flux cross calibration change is not for the better.

·


Summary
· The new HRMA effective area limits ACIS S3 vs pn residual calibration errors to less than 5%

this is no small achievement!
· The new spectral calibration modifies by about 10% Chandra fluxes below 2 keV, ACIS vs EPIC flux cross calibration will be affected