XMM-Newton Users Handbook

B. XMM-Newton Routine Calibration Programme

To monitor the performance of the XMM-Newton science instruments, regular observations on a number of targets are performed during the routine phase that started after the end of the Calibration & Performance Verification Phase (CALPV) (July 1, 2000, XMM-Newton revolution 103).

Such observations are defined in the Routine Calibration Plan (available at
http://xmm2.esac.esa.int/external/xmm_sw_cal/calib/documentation.shtml#General)
and are used to update the Current Calibration Files (CCFs, see § 6.2) whenever necessary.
Routine calibration targets are also included in the Observation Lokator
(at URL: http://xmm2.esac.esa.int/external/xmm_sched/obs_lokator/).

The following monitoring observations are foreseen:

• EPIC
  • CTI, Gain and bright Pixel Monitoring: with filter closed or cal-closed during parts of a revolution when scientific observations are not possible due to high background radiation. MOS full frame mode cal-closed data are also collected during slews between adjacent science targets. Longer observations are scheduled in parallel to RGS and OM calibration observations. In addition, diagnostics and noise mode exposures are taken on a regular basis
  • Effective Area, Gain & Offset Monitoring: preferred target is the SNR 1ES0102-72
  • Monitoring of Spectral Capabilities and Contamination: the Vela and $\zeta$ Orionis are observed
  • Detector Response and Redistribution Monitoring: the isolated neutron star RXJ1856.6-3754 is used to monitor these detector characteristics
  • Relative and absolute timing Monitoring: based on observations of the Crab pulsar
  • Stability of the boresight: to be monitored on request, for example after an eclipse season
• RGS
  • Confirmation of the Wavelength Scale: with target Capella
  • Long-wavelength calibration: with target PSR B0833-45
  • Monitoring of Effective Area: with target PKS2155-304.
  • Gain and CTI monitoring: with PKS 2155-304 at large cross-dispersion offsets and (on request) with Sco-X1 on- and off-axis pointings.
• OM
  • Monitoring of the Grisms absolute Flux Calibration: observing the spectrophotometric standard targets GD153 and HZ2
  • Monitoring of the Visual and UV Grisms Wavelength Calibration: HZ2 is also used for wavelength scale monitoring of the Visible Grism. In addition the F type star HD 13499 is observed
  • Monitoring of the Photometric Calibration: targets are BPM 16274 and the standard field SA95-42
  • Engineering Mode Observations: are performed whenever OM does not allow any filter observations but needs to be blocked because of bright optical sources.
• XMM-Newton Cross Calibration
  In 2003, a major cross-calibration campaign started to regularly monitor the internal agreement of the XMM-Newton detectors and the cross-calibration with other observatories, especially with the Chandra X-ray satellite.
  • Main cross calibration targets, that are observed as coordinated observations with other observatories whenever possible, are PKS 2155-304 and 3C 273. Since 2006, the former has been observed once a year simultaneously by Chandra, Suzaku, and XMM-Newton. The data are available through the XSA. The following paper: Ishida et al. 2011, PASJ, 63, 657 discusses the results of this cross-calibration campaign. As of the second semester of 2013, the blazar 1553+113 is expected to replace 3C 273.
• XMM-Newton Long-Wavelength Response
  The routine calibration task to monitor RGS and EPIC energy responses is addressed by observations of zeta Puppis.

The time needed to fulfil the monitoring requests defined in the routine calibration plan should stay below a 5% margin of the available time for science (cf. Policies and Procedures at http://xmm.esac.esa.int/external/xmm_user_support/documentation/AOpolicy/).