The soft N132D to study the gain of the EPIC-pn camera María de Juan Ovelar Trainee XMM-Newton SOC Tutor: Matteo Guainazzi ESAC Summer Alumni Meeting 2009

The soft N132D to study the gain of the EPIC camera Index Introduction Sources for calibration RGS based models Results Conclusions and nexts steps Summer Alumni Meeting 2009 The soft N132D to study the gain of the EPIC camera

The soft N132D to study the gain of the EPIC camera Introduction Summer Alumni Meeting 2009 The soft N132D to study the gain of the EPIC camera

The soft N132D to study the gain of the EPIC camera 1. Introduction Calibration 1. On ground 2. On flight Calibration on satellite instruments? How??? 1. Using standard sources 2. Using models of non-standard sources based on more accurate instruments model quality and accuracy is of high importance when it comes to calibration Summer Alumni Meeting 2009 The soft N132D to study the gain of the EPIC camera

1. Introduction XMM-Newton X-ray instruments overview X-ray imaging, moderate resolution spectroscopy, and X-ray photometry EPIC (European Photon Imaging Camera) EPIC MOS Range: 0.15 – 12 keV PSF: 5”/14” Spectral res. : ~ 70 keV EPIC pn Range: 0.15 – 15 keV PSF: 6”/15” Spectral res. : ~ 80 keV High-resolution X-ray spectroscopy and spectro-photometry RGS (Reflecting Grating Spectrometer) Range: 0.35 – 2.5 keV Spectral res. : 0.04 Å (1st order) 0.025 Å (2nd order) Summer Alumni Meeting 2009 The soft N132D to study the gain of the EPIC camera

Previous calibration campaigns for the EPIC instrument 1. Introduction Previous calibration campaigns for the EPIC instrument Models based on EPIC Images taken from XMM-SOC-CAL-TN-0082 (M. Guainazzi, April 2009) Summer Alumni Meeting 2009 The soft N132D to study the gain of the EPIC camera

The soft N132D to study the gain of the EPIC camera 1. Introduction Project Goal Build an RGS based model of the spectra of a bright and rich line source and apply it to the EPIC both MOS and pn data Project guideline Define a source bright and line rich object Take X-ray spectra (resolution> EPIC) RGS data Create an RGS based model as accurate as possible Compare model with EPIC MOS and pn cameras Summer Alumni Meeting 2009 The soft N132D to study the gain of the EPIC camera

The soft N132D to study the gain of the EPIC camera 2. Sources for calibration Summer Alumni Meeting 2009 The soft N132D to study the gain of the EPIC camera

2. Sources for calibration Supernova Remnants Extended sources Provide a lot of information (high emitting objects in the X-ray range) Geometry based operation of RGS Matter in SNR is moving quite fast!! This affects the width of the lines in the spectrum and data reduction has to be carried out carefully. Scheme of the RGS instrument Summer Alumni Meeting 2009 The soft N132D to study the gain of the EPIC camera

2. Sources for calibration N132D Description: Magellanic Cloud supernova remnant Center of X-ray emission: RA=05 25 03.3 Dec= -69 38 27.4 X-ray size (arcmin): 2.1x1.6 Distance: 50kpc (distance to LMC, Westerlund (1990)) Image from Chandra SNR Catalog Summer Alumni Meeting 2009 The soft N132D to study the gain of the EPIC camera

2. Sources for calibration Cassiopea A Description: Gallactic supernova remnant (shell like), brightest radio source beyond our solar system Center of X-ray emission: RA=23 23 27.7 Dec= 58 48 54.1 X-ray size (arcmin): 5.9x5.5 Distance: 3.4 kpc (Reed et al., 1995 ) Image from Chandra SNR Catalog Summer Alumni Meeting 2009 The soft N132D to study the gain of the EPIC camera

The soft N132D to study the gain of the EPIC camera 3. RGS based models Summer Alumni Meeting 2009 The soft N132D to study the gain of the EPIC camera

Modelling process: SAS & XSPEC 3. RGS based models Modelling process: SAS & XSPEC Extraction of RGS data has been carried out using SAS meta-task rgsproc directly. This led to a few complications later: rgsproc doesn´t substract the background automatically, so at first both models carried it within Analysis over the background and spectrum lightcurves of N132D, showed that less than ~8% of the counts actually come from the background Since Cas A is wider than the RGS aperture (5¨) the background needed to be created from a template Summer Alumni Meeting 2009 The soft N132D to study the gain of the EPIC camera

Modelling process: SAS & XSPEC 3. RGS based models Modelling process: SAS & XSPEC 2) EPIC data reduced using emproc and then the spectral products were subtracted (background and spectrum from the selected regions in the same CCD, response matrices and ancillary files) 3) XSPEC model build using both Photoelectric Absorption (Wisconsin cross sections) and Bremsstrahlung for the continuum, and as many Gaussian profiles as needed to keep a confidence level of 99% (2.6σ for 3 parameters) using Cash statistics Summer Alumni Meeting 2009 The soft N132D to study the gain of the EPIC camera

Modelling process: SAS & XSPEC 3. RGS based models Modelling process: SAS & XSPEC 4) Due to the shockwaves inside SNR, the effect of velocity in the emission lines width has to be taken into account. h(x) : v= 4500 m/s g(x) : v= 2500 m/s f(x) : v= 1500 m/s r(x) : v= 500 m /s Summer Alumni Meeting 2009 The soft N132D to study the gain of the EPIC camera

The soft N132D to study the gain of the EPIC camera 3. RGS based models N132D RGS 1&2 Cst = 6975.17 for 5311 PHA bins Range: [0.32 – 2.0] keV Model components: photon absorption * bremsstrahlung (0.85 keV) + 42 gaussian profiles Summer Alumni Meeting 2009 The soft N132D to study the gain of the EPIC camera

The soft N132D to study the gain of the EPIC camera 3. RGS based models Cas A RGS 1&2 Cst = 3803.5 for 2640 PHA bins Range: [0.6 – 2.0] keV Model components: photon absorption * bremsstrahlung (1.51 keV) + 43 gaussian profiles Summer Alumni Meeting 2009 The soft N132D to study the gain of the EPIC camera

The soft N132D to study the gain of the EPIC camera 4. Results Summer Alumni Meeting 2009 The soft N132D to study the gain of the EPIC camera

The soft N132D to study the gain of the EPIC camera 4. Results N132D Excellent agreement!!! Summer Alumni Meeting 2009 The soft N132D to study the gain of the EPIC camera

RGS is missing some X-ray emission!!! 4. Results Cas A Cas A is not centered in the EPIC ccd RGS is missing some X-ray emission!!! Dispersion direction Cross-dispersion direction The model doesn’t fit the EPIC data Why?? Summer Alumni Meeting 2009 The soft N132D to study the gain of the EPIC camera

The soft N132D to study the gain of the EPIC camera 5. Conclusions and next steps Summer Alumni Meeting 2009 The soft N132D to study the gain of the EPIC camera

Ger, Jamie, Leila, Eleonora, Bea!!, Ana, Maël and Cherry Thanks to… Matteo Guainazzi Andy Pollock Ger, Jamie, Leila, Eleonora, Bea!!, Ana, Maël and Cherry … and THANK YOU ALL!!!! Summer Alumni Meeting 2009 The soft N132D to study the gain of the EPIC camera

5. Conclusions and next steps RGS accuracy and spectral resolution allows us to significantly improve the models and therefore the whole calibration process of the EPIC instruments N132D RGS-based model reproduces quite well the EPIC source spectrum directly using rgsproc extended sources around 2.1 arcmin wide can be treated as point-like sources (if they are centered in the RGS ccd!!) in terms of data reduction Next steps Correct RGS model for Cas A taking into account the position of the source respect to the RGS instrument Update cross calibration studies for EPIC with RGS based models for both sources Summer Alumni Meeting 2009 The soft N132D to study the gain of the EPIC camera