ESAC Status of XMMNewton crosscalibration with SAS6 1

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) European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 1

ESAC Talk outline • • Response stability at low energies : • SNR (extended) • AGN view (trend analysis) Low-energy problem: effect of the new pn redistribution in SAS-6. 1 Spectral fitting examples on various type of sources Chandra/Newton cross-calibration Other cross-calibration problems: • Conclusions • ü MOS low-energy overestimated redistribution ü EPIC high-energy discrepancy ü Fudging RGS low-energy (<0. 5 ke. V) effective area proposal European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 2

EPIC-pn flux stability: N 132 D M. P. Esquej EPIC-pn is stable European Space Astronomy Centre ESAC XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 3

ESAC EPIC-pn Flux stability: RXJ 1856 • Confirmed by the Isolated Neutron star: EPIC-pn is extremely stable F. Haberl European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 4

ESAC MOS flux stability: N 132 D Rev 771 Rev 828 Rev 771: • flux decrease in 0. 5 -1 ke. V • Redistributed below 0. 4 ke. V Rev 828 : • Less clear, especially MOS 2, while at the same distance relative to low-E on -axis patch. Some changes at low energies (0. 5 -1 ke. V) at ~5% level. • spatial dependent • time dependent European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 5

MOS flux stability: N 132 D (2) ESAC · Why MOS’s see more flux deficit in 0. 5 -1 ke. V band in rev. 771 than rev. 828 ? While it is relatively at the same distance from the onaxis patch. European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 6

EPIC flux stability: N 132 D ESAC N 132 D 0. 4 -0. 8 ke. V band: • EPIC-pn: ü pn flux is stable ü pn-LW lower fluxes than pn-SW due to pile-up • MOSs : ü MOS 1 lower than MOS 2 by 5% ü Both MOSs have decreased by 6% since launch ü MOS 2 lower than pn by 10% at launch up to 15% by rev. ~800 ü MOS 1 lower than pn by 15% at launch up to 20% by rev. ~800 ü But MOS/pn normalisation TBD because of possible small pile-up for MOSs. M. P. Esquej European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 7

MOS flux stability: 1 ES 0102 ESAC 1 ES 0102 0. 4 -0. 8 ke. V band: • MOS cameras seems stable in flux since launch but. . ü for off-axis positions • also consistent with a 5% decrease. • 10% lower flux observed onaxis where a spatially dependent degraded redistribution has developed (‘patch’) A. M. R. Read European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 8

MOS on-axis low-E patch (1) ESAC When the SNR is centered close to on-axis position one observes : • a deficit in 0. 35 -0. 7 ke. V • an excess below 0. 3 ke. V A. M. R. Read European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 9

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 European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 10

EPIC Low-energy flux stability : The SNR story ESAC · EPIC-pn stable below 2 ke. V and particularly in the 0. 4 -0. 8 ke. V band · MOSs were possibly ~10% below EPIC-pn at launch in 0. 4 -0. 8 ke. V with MOS 1 5% lower than MOS 2 · MOSs seem to have lost 5%+ since launch, in the 0. 4 -1 ke. V band · possibly redistributed to lower energies (< 0. 4 ke. V) where a low-energy patch is observed on-axis. European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 11

Flux stability: The AGN view cooling (I) ESAC Sample of AGNs mostly in SW/Medium analysed in 15 -40 arcsec annulus used, hence excluding the “MOS patch. ” Low-energy problem : • Either MOSs & RGSs loose flux relative to pn at (II) 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 ? S. Sembay European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 12

ESAC RGS flux stability: 1 ES 0102 • RGS flux in 0. 4 -0. 8 ke. V band consistent with a 5 -8% decrease but : • very little flux below 0. 55 ke. V • 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) M. Smith red: 0. 33 -0. 7 ke. V, green: 0. 7 -0. 972 ke. V, blue: 0. 972 -1. 74 ke. V • At other energies > 0. 7 ke. V, it seems stable contamination ? European Space Astronomy Centre A. Pollock XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 13

ESAC Interim cross-cal. results · Somewhat contradictory results : – EPIC-pn seems stable – MOS response is changing – loosing flux in 0. 4 -1 ke. V- redistributed below 0. 4 ke. V – 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 ? European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 14

SAS-6. 1 : effect of new pn RMF (1) SAS 6. 0 ESAC SAS 6. 1 H 1426+428, rev 278, single MOS/OM power-law model European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 15

ESAC H 1426: new pn rmf residuals Strange residuals shape below 0. 6 ke. V but could be due to a CTI/gain problem at low energies hence residuals around the O-edge. European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 16

SAS-6. 1 : effect of new pn RMF (2) M. Kirsch SAS-6. 0 PKS 2155 -504, rev 545 ESAC SAS-6. 1 • Same 0. 5 ke. V non-physical dip of pn residuals • combined fit is possibly the “truth” ? European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 17

ESAC SAS-6. 1 : effect of new pn RMF (3) • Another case of “ 0. 5 ke. V dip” on a continuum spectrum • black : MOS 1 • Red: pn SAS-6. 0 • Green: pn SAS-6. 1 R. Saxton European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 18

ESAC H 1426 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 European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 19

ESAC Early mission : no excess ? • MS 0737. 9+7441 (BL Lac) • rev. 63 (Cal/PV) • Best fit MOSs model: wabs *power • very nice agreement overall R. Saxton European Space Astronomy Centre • No excess of pn wrt to MOS at low energies (pn/MOS=0. 95 ! ) XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 20

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

ESAC Extremely soft sources GD 153, White Dwarf, k. T=25 e. V, 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 0. 2 -0. 3 ke. V. European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 22

ESAC Bright (extended) galaxy cluster • Good combined fit overall • 0. 5 -1 ke. V : ~ 10% pn excess (or MOS deficit) • above 3 ke. V : >10% MOS excess • pn residuals at Fe-K (CTI or gain) European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 23

ESAC Hot Compact high-z cluster • Rather good combined fit (but lower statistics) • 0. 5 -1 ke. V : about 15% pn excess (or MOS deficit) MOS 1: k. T=15 ke. V MOS 2: k. T=12 ke. V pn : k. T=10 ke. V European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 24

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

Newton/Chandra cross-cal. : PKS 2155 ESAC Rev 362 Rev 545 • LETG agrees very well with MOSs Model: wabs*bknpower • pn low-energy excess higher in rev. 545 Best fit: MOSs European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 26

ESAC Newton/Chandra cross-cal. : 3 C 273 (1) Rev. 277 European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 27

ESAC Newton/Chandra cross-cal. : 3 C 273 (2) Rev. 655 EPIC-pn excess also higher with time MOS/LETG agreement excellent. European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 28

ESAC Newton/Chandra cross-cal. · MOSs agree very well with Chandra (LETG, HETG & HRC) · RGSs too low in 0. 3 -0. 5 ke. V · EPIC-pn too high at E < 1 ke. V wrt too all other instruments. European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 29

ESAC Zeta Puppis wide cross-correlation · Assuming zeta Puppis is a stable source… · All measurement agree except pn SAS-6. 0 European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 30

ESAC RGS low-E effective area • Effective area correction of up to 20% below 0. 5 ke. V 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 European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 31

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

ESAC EPIC high-E discrepancy • MOSs return higher fluxes than pn above 3 ke. V • F 5 -10 ke. V (MOS) higher than F 5 -10 ke. V(pn) by 10 -15% • MOS 1 > MOS 2 > pn • MOS (MOS 1) finds always • Harder spectra (AGNs) • Hotter temperature (galaxy clusters) European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 33

ESAC Low-energy status · A MOS/RGS deficit wrt EPIC-pn is developing with time at low energies (<1 ke. V) 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 ? European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 34

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: – Hz 43 : comparison with early rev. 89 obs. (June 2005) – H 1426+428 simultaneously with FUSE (June 2005 ) · Fudge RGS effective area below 0. 55 ke. V · Need for a change of boresight for MOSs ? European Space Astronomy Centre XMM-Newton Bruno Altieri EPIC Calibration meeting, Feb. 1 -3, 2005 Page 35