Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 1 XMM-Newton ESAC Status of XMM-Newton cross-calibration with SAS-6.1 B.Altieri with inputs/support from whole cross-calibration team (XMM SOC, Leicester, MPE )

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 2 XMM-Newton ESAC Talk outline Response stability at low energies :Response stability at low energies : SNR (extended)SNR (extended) AGN view (trend analysis)AGN view (trend analysis) Low-energy problem: effect of the new pn redistribution in SAS-6.1Low-energy problem: effect of the new pn redistribution in SAS-6.1 Spectral fitting examples on various type of sourcesSpectral fitting examples on various type of sources Chandra/Newton cross-calibrationChandra/Newton cross-calibration Other cross-calibration problems:Other cross-calibration problems: MOS low-energy overestimated redistribution MOS low-energy overestimated redistribution EPIC high-energy discrepancy EPIC high-energy discrepancy Fudging RGS low-energy (<0.5 keV) effective area proposal Fudging RGS low-energy (<0.5 keV) effective area proposal ConclusionsConclusions

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 3 XMM-Newton ESAC EPIC-pn flux stability: N132D EPIC-pn is stable M.P. Esquej

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 4 XMM-Newton ESAC EPIC-pn Flux stability: RXJ1856 F. Haberl Confirmed by the Isolated Neutron star: EPIC-pn is extremely stable

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 5 XMM-Newton ESAC MOS flux stability: N132D Rev771: flux decrease in keV Redistributed below 0.4 keV Rev 828 : Less clear, especially MOS2, while at the same distance relative to low-E on-axis patch. Some changes at low energies (0.5-1keV) at ~5% level. spatial dependent time dependent Rev 771 Rev 828

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 6 XMM-Newton ESAC MOS flux stability: N132D (2) Why MOS’s see more flux deficit in keV band in rev.771 than rev.828 ? While it is relatively at the same distance from the on- axis patch.

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 7 XMM-Newton ESAC EPIC flux stability: N132D N132D keV band: EPIC-pn: pn flux is stable pn-LW lower fluxes than pn-SW due to pile-up MOSs : MOS1 lower than MOS2 by 5% Both MOSs have decreased by 6% since launch MOS2 lower than pn by 10% at launch up to 15% by rev.~800 MOS1 lower than pn by 15% at launch up to 20% by rev.~800 But MOS/pn normalisation TBD because of possible small pile-up for MOSs. M.P. Esquej

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 8 XMM-Newton ESAC MOS flux stability: 1ES0102 1ES keV band: MOS cameras seems stable in flux since launch but.. for off-axis positions also consistent with a 5% decrease. 10% lower flux observed on- axis where a spatially dependent degraded redistribution has developed (‘patch’) A.M.R. Read

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 9 XMM-Newton ESAC MOS on-axis low-E patch (1) A.M.R. Read When the SNR is centered close to on-axis position one observes : a deficit in keV an excess below 0.3 keV

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 10 XMM-Newton ESAC MOS on-axis low-E patch (2)  MOS low-E patch elongated along the line joining the 2 bore-sights. A.M.R. Read

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 11 XMM-Newton ESAC EPIC Low-energy flux stability : The SNR story   EPIC-pn stable below 2 keV and particularly in the keV band   MOSs were possibly ~10% below EPIC-pn at launch in keV with MOS1 5% lower than MOS2   MOSs seem to have lost 5%+ since launch, in the keV band   possibly redistributed to lower energies (< 0.4 keV) where a low-energy patch is observed on-axis.

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 12 XMM-Newton ESAC Sample of AGNs mostly in SW/Medium analysed in arcsec annulus used, hence excluding the “MOS patch.” Low-energy problem : Either MOSs & RGSs loose flux relative to pn at the same rate : 8% in 800 revs (I) because of : MOS on-axis redistribution ? RGS ?? contamination of MOSs and RGSs, cooler CCDs than pn. or pn is gaining flux at the same rate (II) : filters degradation discarded from SNRs redistribution ? Flux stability: The AGN view S. Sembay (I) (II) cooling

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 13 XMM-Newton ESAC RGS flux stability: 1ES0102 red: keV, green: keV, blue: keV A.Pollock M. Smith contamination ? At other energies > 0.7 keV, it seems stable  contamination ? RGS flux in keV band consistent with a 5-8% decrease but : very little flux below 0.55 keV background subtraction not easy for extended source, ~20% of the flux not confirmed by Zeta Puppis Nitrogen line flux monitoring (preliminary result, full analysis underway, by A. Pollock)

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 14 XMM-Newton ESAC  Somewhat contradictory results : –EPIC-pn seems stable –MOS response is changing –loosing flux in keV- redistributed below 0.4 keV –In the on-axis area (‘patch’) only ? –RGS constant ? Study of RGS stability crucial  MOS: Contamination or redistibution only ?  Exact amount of variations ?  Why RGS and MOS relative calibration is unchanged ? –RGS and MOS CCDs are cooler –mirror contamintion ? Interim cross-cal. results

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 15 XMM-Newton ESAC SAS-6.1 : effect of new pn RMF (1) H , rev278, single MOS/OM power-law model SAS 6.0SAS 6.1

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 16 XMM-Newton ESAC H1426: new pn rmf residuals Strange residuals shape below 0.6 keV but could be due to a CTI/gain problem at low energies hence residuals around the O-edge.

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 17 XMM-Newton ESAC SAS-6.1 : effect of new pn RMF (2) SAS-6.0 PKS , rev 545 SAS-6.1 Same 0.5 keV non-physical dip of pn residuals combined fit is possibly the “truth” ? M.Kirsch

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 18 XMM-Newton ESAC SAS-6.1 : effect of new pn RMF (3) Another case of “0.5 keV dip” on a continuum spectrum Another case of “0.5 keV dip” on a continuum spectrum black : MOS1 black : MOS1 Red: pn SAS-6.0 Red: pn SAS-6.0 Green: pn SAS-6.1 Green: pn SAS-6.1 R. Saxton

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 19 XMM-Newton ESAC H1426 second revisit Although the increasing pn/MOS discrepancy could be attributed to MOS … MOS seem to have the right spectral slope at low energies even in late revs Assuming a single power-law from UV to soft X-ray

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 20 XMM-Newton ESAC R. Saxton Early mission : no excess ? MS MS (BL Lac) (BL Lac) rev.63 (Cal/PV) rev.63 (Cal/PV) Best fit MOSs Best fit MOSs model: wabs *power model: wabs *power very nice agreement overall very nice agreement overall No excess of pn wrt to MOS at low energies (pn/MOS=0.95 ! ) No excess of pn wrt to MOS at low energies (pn/MOS=0.95 ! )

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 21 XMM-Newton ESAC Very soft sources RXJ 1856 pn exhibits a strong excess attributed to pile- up from photons below detection threshold. MOS agree well with Chandra (nH, kT) EPIC-pn cannot be used on very soft sources

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 22 XMM-Newton ESAC Extremely soft sources GD153, White Dwarf, kT=25eV, maximum below detection threshold OM-MOSs can be fitted with a WD SED model EPIC-pn displays an excess by a factor 2 in the range keV.

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 23 XMM-Newton ESAC Bright (extended) galaxy cluster Good combined fit overall keV : ~ 10% pn excess (or MOS deficit) above 3keV : >10% MOS excess pn residuals at Fe-K (CTI or gain)

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 24 XMM-Newton ESAC Hot Compact high-z cluster Rather good combined fit (but lower statistics) keV : about 15% pn excess (or MOS deficit) MOS1: kT=15 keV MOS2: kT=12 keV pn : kT=10 keV

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 25 XMM-Newton ESAC MOS vs EPIC-pn  Why MOSs -the apparently varing instrument- is making good or better fits than EPIC-pn - the constant instrument - on various types of objects/spectras at any epoch ?

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 26 XMM-Newton ESAC Newton/Chandra cross-cal.: PKS2155 Rev 362Rev 545 LETG agrees very well with MOSs pn low-energy excess higher in rev.545 Model: wabs*bknpower Best fit: MOSs

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 27 XMM-Newton ESAC Newton/Chandra cross-cal.: 3C273 (1) Rev.277

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 28 XMM-Newton ESAC Rev.655 EPIC-pn excess also higher with time MOS/LETG agreement excellent. Newton/Chandra cross-cal.: 3C273 (2)

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 29 XMM-Newton ESAC Newton/Chandra cross-cal.  MOSs agree very well with Chandra (LETG, HETG & HRC)  RGSs too low in keV  EPIC-pn too high at E < 1 keV wrt too all other instruments.

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 30 XMM-Newton ESAC Zeta Puppis wide cross-correlation Assuming zeta Puppis is a stable source… All measurement agree except pn SAS-6.0

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 31 XMM-Newton ESAC RGS low-E effective area Effective area correction of up to 20% below 0.5 keV suggested by a statistical analysis of BL Lacs (Pollock) It is unavoidable to be fudged. The exact function will be based on upcoming Crab observation (special set-up) This will bring MOSs and RGSs in very good agreement on the whole RGS energy range

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 32 XMM-Newton ESAC MOS low-E redistribution Still too much redistribution at low energies ?

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 33 XMM-Newton ESAC EPIC high-E discrepancy MOSs return higher fluxes than pn above 3 keV F 5-10 keV ( MOS) higher than F 5-10 keV (pn) by 10-15% MOS1 > MOS2 > pn  MOS (MOS1) finds always Harder spectra (AGNs) Hotter temperature (galaxy clusters)

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 34 XMM-Newton ESAC Low-energy status  A MOS/RGS deficit wrt EPIC-pn is developing with time at low energies (<1keV) increasing by up to 10% apparently due to a loss of flux from MOS/RGS  Was there a deficit a launch ?  Did the trend accelerate after cooling ?  Is it due to the MOS on-axis degraded response (“patch”)?  If due to contamination why at same rate for MOSs & RGSs ?  Why Chandra agree better with MOSs at any epoch ?  On very soft sources pn shows a strong excesses   EPIC pn cannot be used for very soft sources  To what extent bright & soft (  >1.7) AGNs are affected ?

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 35 XMM-Newton ESAC XMM-Newton cross-cal. : To do  Document current status with SAS-6.1  Extend the statistical analysis on AGNs –Investigate possible flux/mode and spatial dependence and spatial of MOS/pn relative calibration. –EPIC-pn redistribution  NRCOs: –Hz43 : comparison with early rev.89 obs. (June 2005) –H simultaneously with FUSE (June 2005 )  Fudge RGS effective area below 0.55 keV  Need for a change of boresight for MOSs ?

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 36 XMM-Newton ESAC The End

Bruno Altieri EPIC Calibration meeting, Feb. 1-3, 2005 European Space Astronomy Centre Page 37 XMM-Newton ESAC H , rev852, pn fit