PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002 PSF in-flight calibration for PN camera Simona Ghizzardi Silvano Molendi

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002 ENERGY RANGES: 0.3 keV[ ] eV 0.6 keV[ ] eV 1.0 keV[ ] eV 1.8 keV[ ] eV 3.7 keV[ ] eV 6.5 keV[ ] eV 10.0 keV[ ] eV DATA SAMPLE: SOURCES (TARGET) included OFF-AXIS ANGLES: from on-axis position up to  10 arcmin - most of them are observed within  2 arcmin.

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002 We adopt the same procedure and the same algorithm used for the two MOS cameras. The pixel size of the PSF images is taken 1.1”. According to the MOS results, the profile of the PSF is well represented by a King model: PSF = KING + BKG Analysis procedure and PSF model

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002 King profile core slope Two shape parameters: core radius (r c ) and slope (  ) IT CAN BE INTEGRATED ANALYTICALLY IN rdr!!!

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002 We merged the observations having the same source target the same pointing position different filters and/or operating mode ---> ---> different pile-up levels The centroid is determined accounting for the mask of the detector For each curve a good fitting range must be defined (points suffering for pile-up must be excluded). Building the radial profile

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002 Algorithm for the averaged radial profile Energy selection and pattern (0-12) selection BASIC METHOD We bin the image (with larger bins at larger radii) RADIAL PROFILE: dN/dA (the area is not 2  r dr because of the mask) each (squared) pixel is assigned to the (round) bin to which its CENTER belongs for these pixels it works fairly these pixels belong to two different bins in comparable fractions the effect is less important at larger radii ADDITIONAL RECIPE ADDED TO THE BASIC PROCEDURE We enclose each pixel in a circle. If the circle is fully enclosed in the bin then the pixel is too. If the circle is partly enclosed in another bin, the pixel may belong to two bins: we divide such pixels in NSUBPIXELS

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002 The physical pixel size is 4.1”, not much smaller than the core radius of the PSF. The calibration of the core is quite tricky The frame time is smaller than the MOS one. The pile-up effect is less important The effective area is larger than the MOS one. Good statistics

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002 In order to enhance the statistics, we fit simultaneously the different curves with different pile-up levels PSF = King + BKG  e r c are the same for each curve BKG and the normalization are different for each curve for each energy and off-axis angle we derive  and r c. Fitting the radial profiles

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, D FIT: 0.3 keV

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, D FIT: 0.6 keV

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, D FIT: 1.0 keV

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, D FIT: 1.8 keV

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, D FIT: 3.7 keV

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, D FIT: 6.5 keV

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, D FIT: 10. keV

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, D FIT: 1.0 keV

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, D FIT: 1.8 keV

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, D FIT: THE 2-D FIT IS DRIVEN BY THE ON-AXIS POINTS. 3.7 keV

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002 BINNING Data are not well represented by the 2-D data because they present a very large scatter. The 2-D fit ( but also each 1-D fit for any fixed energy) is completely driven by the on-axis data. We bin on the off-axis angle variable with bin 12” wide.

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, D FIT: 0.3 keV

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, D FIT: 0.6 keV

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, D FIT: 1.0 keV

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, D FIT: 1.8 keV

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, D FIT: 3.7 keV

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, D FIT: 6.5 keV

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, D FIT: 10. keV

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, D FIT: 1.0 keV

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, D FIT: 1.8 keV

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, D FIT: 3.7 keV

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002 Profiles using the best fit values

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002 Profiles using the best fit values

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002 WHY SUCH A SCATTER ? Out of time events can affect the slope of the profile Pile up is less evident in the PN data. Are we neglecting a pile up effect? Centroiding is very difficult because of the large size of the pixels. This makes the determination of the core uncertain especially for the Small Window op. mode. …TO BE INVESTIGATED

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002 FULL FRAME SMALL WINDOW

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002 WHY SUCH A SCATTER ? Out of time events can affect the slope of the profile Pile up is less evident in the PN data. Are we neglecting a pile up effect? Centroiding is very difficult because of the large size of the pixels. This makes the determination of the core uncertain especially for the Small Window op. mode. …TO BE INVESTIGATED

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002 WHY SUCH A SCATTER ? Out of time events can affect the slope of the profile Pile up is less evident in the PN data. Are we neglecting a pile up effect? Centroiding is very difficult because of the large size of the pixels. This makes the determination of the core uncertain especially for the Small Window op. mode. …TO BE INVESTIGATED

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002 King Core Radius for PN

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002 King Slope for PN

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002 BEST FIT VALUES

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002 ENCIRCLED ENERGY FRACTION

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002 Range of Application

PSF in-flight calibration - PN IFC/CNRRingberg, April 2-4, 2002 CONCLUSIONS By using a large set of data we modeled the PSF profile with a King function and provided the best fit values of the core and of the slope as functions of the energy and of the off-axis angle. To be done … We must include in the sample some other off-axis sources to enlarge the region of the range of application. Check on : evaluation of the background in the Small Window measures out of time events pile-up centroiding procedures in order to reduce the scatter of the points