XMM-Newton slew sources A quick analysis

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XMM-Newton slew sourcesA quick analysis

• Refiz Duro
• ESAC, Madrid
• 2009

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Aims

• Find new variable sources
• Quick, automatic analysis of slew data with
  results provided to the user

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Agenda

• XMM-Newton slew data description
• Comparison to ROSAT data
• Results
• Conclusion

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Slew data

• Slews images taken while the telescope is
  changing its position from one pointed
  observation to the next
• Slew speed of 90 deg/hour
• EPIC-pn data
• Shallow survey of the sky. Image properties
• 0.2 2.0 keV (soft energy band)
• Median exposure time 6.2 seconds (min 1s,
  max12s)
• Images roughly 1 degree by 0.5 degree

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Source searching

• SAS (Science Analysis Software) tasks
• eslewchain (create images, exposure maps)
• emask (area for source searching)
• eboxdetect (source searching)
• esplinemap (constructs background map)
• emldetect (info on the sources)
• Tables with the sources and their properties
• More details in Saxton et al. 2008

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Comparison to ROSAT

• Aim find variable sources
• ROSAT X-ray all sky survey (RASS) (done in
  1991/92) soft X-ray 0.2-2.4 keV
• Bright, faint point source catalogues
• Expected factor of difference between XMM-Newton
  and ROSAT fluxes for a non-variable source is 6.4
  (Spectral model of an absorbed power-law with
  slope 2.4 and NH31020cm(-2))
• Larger/smaller factors suggest a variable source

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Results

• Table 1 XMM-Newton sources compared to ROSAT
  source counterparts.
• Table 2 Upper limits table. Sources which were
  expected to be found in the slew images based on
  the coordinates from RASS, but which were not
  detected in the analysis.

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Conclusion

• Quickly analyzed X-ray slew data
• Results presented on the web
• New variable sources