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Update on ACIS Operations and Calibration. Controlling the ACIS FP Temperature. FP is contained in the “Camera Body”. DH heater is on the “Camera Body”. ACIS FP Temperature after the DH was turned off. 2007.3-2008.3: year before the DH heater was turned off,
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Controlling the ACIS FP Temperature FP is contained in the “Camera Body” DH heater is on the “Camera Body”
ACIS FP Temperature after the DH was turned off 2007.3-2008.3: year before the DH heater was turned off, 334/904 (37%) observations had a T above -119.2 C Grant (MIT) DePasquale (SAO) -118.2 C, BI limit -119.2 C, FI limit 2008.3-2009.3: Year after the DH heater was turned off, 16/743 (2%) observations had a T above -119.2 C
ACIS FP Temperature after the DH was turned off 2007.3-2008.3: year before the DH heater was turned off, 106/232 (46%) observations had a T above -119.2 C Grant (MIT) DePasquale (SAO) -118.2 C, BI limit -119.2 C, FI limit 2008.3-2009.3: Year after the DH heater was turned off, 26/176 (15%) observations had a T above -119.2 C
Chandra’s Changing Orbit and Implications for the FP Temperature • Chandra’s orbit is changing such that in 2012 the inclination will be at its highest value in the mission and the perigee will be at it lowest • the solid angle of the Earth in the ACIS radiator FOV will also reach missions highs in 2012 • other mission constraints such as momentum management and thermal issues frequently conflict with keeping the ACIS FP cold during perigee passages Davis (Chandra FOT)
The FP Temperature during Recent Perigee Passages Adams-Wolk (SAO) Example of a good perigee passage science science cal cal perigee
The FP Temperature during Recent Perigee Passages Adams-Wolk (SAO) Example of a bad perigee passage science science cal cal perigee
ACIS Radiator Shade The complex shape of the shade has been approximated by a simpler shape, we are working on a more realistic model
Update on ACIS-specific Calibration Issues Calibration of less-frequently used ACIS modes Temperature-dependent CTI correction for FI and BI CCDs E0102 fits with new HRMA effective area and proposed revision to the ACIS contamination model Herman will describe the change to the HRMA effective area and the contamination model in the next talk
Census of ACIS Modes and CTI Correction Clocking Modes: “Timed Exposure” (TE) and “Continuous Clocking (CC) Telemetry Formats: “Faint” (F) reports 9 PHs in 3X3 event island “Very Faint” (VF) reports 25 PHs in 5X5 event island “Graded” (G) reports a summed PH all modes report frame #, position, grade, & summed PH
Comparison of Graded Mode and Faint Mode CTI Correction Vikhlinin & Posson-Brown (SAO) , Chipy=1:32 , Chipy=993:1024 , Graded mode , Faint mode Graded mode CTI correction provides most of the benefit of the Faint mode correction For FI CCDs only !
CC Faint Mode CTI Correction Edgar (SAO) • makes use of the trap density maps used for TE mode, the effects of CTI are different (less) in CC mode so the trap density maps are simply scaled • for gratings data, the position of the event in chipy is estimated from its location in the dispersed spectrum and that chipy value is used in the correction • for a CC mode imaging observation, the chipy of the target position is assumed • “good” X-ray events are lost to “bad” grades in CC mode, after applying the correction most of these good events are recovered into good graded HETG Spectrum of Capella
HETG Order-sorting Plot with CC Faint Mode CTI Correction Edgar (SAO) Order = detx X PH of event
Temperature-Dependent CTI Correction Grant (MIT) • many observations were affected by a warm FP temperature before April 2008 • FI and BI CCDs have different T dependence of CTI, FI CTI gets worse with increasing T, BI CTI gets slightly better • simply scaling the CTI correction with temperature recovers the mean PH well but the FWHM is significantly larger
Temperature-Dependent CTI Correction Grant (MIT)
IACHEC Thermal SNR Working Group One of the “Standard candle” working groups.: XMM-Newton RGS Andy Pollock (ESAC) Chandra HETG Dan Dewey (MIT) XMM-Newton MOS Steve Sembay (Leicester) XMM-Newton pn Frank Haberl, Victoria Grinberg (MPE) Chandra ACIS Joe DePasquale, Paul Plucinsky (SAO) Suzaku XIS Eric Miller (MIT) Swift XRT Andrew Beardmore, Olivier Godet (Leicester) Models Randall Smith (SAO/GSFC) Plucinsky et al., 2008 SPIE, Vol. 7011, arXiv:0807.2176
1E 0102.2-7219 • Young (~1,000-2,000 yr) SNR in the SMC (D~61 kpc), classified as “O-rich” SNR • Relatively simple morphology, but significant spectral variations Chandra Images of E0102: DePasquale (SAO) Three Color Image S3 Summed Data ~248 ks Red: 0.2-0.75 keV, Green: 0.8-1.1 keV, Blue: 1.1-2.0 keV 45 arcseconds
XMM-Newton RGS Spectrum of E0102: Haberl Grinberg (MPE) OVIII OVII NeIX Spectrum dominated by O & Ne, little or no Fe emission NeX OVIII CVI
Comparison of OVII, OVIII, NeIX, & NeX Normalizations: DePasquale(SAO)) OVII black OVIII red NeIX green NeX blue • 28 of 32 normalizations agree to within +/- 10% • appears to be a 4% difference between RGS1 & RGS2 which is mostly independent of energy • uncertainties are the statistical uncertainties and underestimate the true uncertainty • MOS QE was adjusted in 2007 with the intent of improving agreement with the RGS • ACIS, XIS, & XRT show similar trend with energy • max differences are 23% at O VII, 24% at O VIII, 13% at Ne IX, and 19% at Ne X • RGS, HETG, ACIS, MOS, XIS0 agree to within +/- 5% at Ne IX and Ne X
Comparison of OVII, OVIII, NeIX, & NeX Normalizations: Depasquale(SAO) OVII black OVIII red NeIX green NeX blue
Comparison of OVII, OVIII, NeIX, & NeX Normalizations: Depasquale(SAO) OVII black OVIII red NeIX green NeX blue Relative to ACIS, “the way it outta be”