The X-ray Universe 2005 26-30 September 2005, El Escorial, Madrid, Spain The XMM-Newton Slew Survey...
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The X-ray Universe 2005 The X-ray Universe 2005 26-30 September 2005, El Escorial, Madrid, Spain 26-30 September 2005, El Escorial, Madrid, Spain The XMM-Newton Slew Survey The XMM-Newton Slew Survey XMM-Newton Slew 1 XMM-Newton Slew 1 (XMMSL1) (XMMSL1) Fig 1. Slew observation performed with the EPIC- pn camera. Current status Current status Images and exposure maps have been created and Images and exposure maps have been created and source searched for 220 slews giving: source searched for 220 slews giving: • 4177 sources in the total band 4177 sources in the total band • 2750 sources in the soft band 2750 sources in the soft band • 844 sources in the hard band 844 sources in the hard band Positional accuracy: 8 arcsec Positional accuracy: 8 arcsec Source density: ~0.65 sources per square degree Source density: ~0.65 sources per square degree Sky coverage: ~6300 square degrees (~15% of the Sky coverage: ~6300 square degrees (~15% of the sky) sky) Objective: issue of the first slew source catalogue Objective: issue of the first slew source catalogue (XMMSL1) by the end of 2005 and provide an upper (XMMSL1) by the end of 2005 and provide an upper limit server in 2006 limit server in 2006 Attitude Attitude reconstruction reconstruction The attitude The attitude reconstruction is crucial reconstruction is crucial in determination of in determination of source coordinates and is source coordinates and is differently performed in differently performed in slew observations with slew observations with respect to the pointed respect to the pointed ones where the AHF is ones where the AHF is used. used. The optimal attitude file The optimal attitude file for reconstructing the for reconstructing the astrometry during slew astrometry during slew observations is the Raw observations is the Raw Attitude File (RAF) Attitude File (RAF) subtracted by 0.75 subtracted by 0.75 seconds from every entry, seconds from every entry, timing error that is due timing error that is due to a delay of the star to a delay of the star tracker CCDs. tracker CCDs. Fig. 3. Comparison of data processing with the different attitude files used for astrometry reconstruction for the slew source XMMSL1 05:28:45.0-65:26:52. Right images: detected slew source in the total band. Left images: position of the slew source overplotting the corresponding optical counterpart. Top panel: source detected with the AHF as attitude file, the shift between the optical and the slew position is evidenced.. Bottom panel: corrected slew source position using the modified RAF for the attitude reconstruction. We can clearly see the difference between both processing and the improvement with the new attitude reconstruction. Spurious detections Spurious detections Systematic effects in the Systematic effects in the instrument and detection software instrument and detection software lead to a number of spurious lead to a number of spurious detections that are being flagged detections that are being flagged in different categories: in different categories: • False detection False detection • Within extended source Within extended source • Within halo of bright source Within halo of bright source • Position suspect Position suspect • Source near edge Source near edge • Detector flash Detector flash Observations and data Observations and data analysis analysis Processing challenges Processing challenges The XMM-Newton satellite is the most sensitive X-ray observatory flown to date due to the great collecting area of its mirrors coupled with the high quantum efficiency of the EPIC detectors. It performs slewing manoeuvers between observation targets with the EPIC cameras open and the other instruments closed, operating with the observing mode set to the one of the previous pointed observation and the medium filter in place. Slew observations from the EPIC- pn camera in FF, eFF and LW provide data, resulting in 15 seconds on-source time, which can be used to give a uniform survey of the X-ray sky. Only data from EPIC-pn slew observations are used for the Only data from EPIC-pn slew observations are used for the processing due to the faster readout in their observing processing due to the faster readout in their observing modes and its high effective area with respect to the modes and its high effective area with respect to the EPIC-MOS cameras. EPIC-MOS cameras. The low background of the observations ( The low background of the observations ( average average ~0.1c/arcmin ~0.1c/arcmin 2 ) and the tight PSF give good sensitivity to ) and the tight PSF give good sensitivity to detect extended sources. detect extended sources. Some high background observations that were performed at Some high background observations that were performed at times of enhanced solar activity were rejected for the times of enhanced solar activity were rejected for the processing. processing. Slew observations have to be subdivided into 1 square Slew observations have to be subdivided into 1 square degree images, then sky positions are recalculated. degree images, then sky positions are recalculated. Source search using a near standard pipeline Source search using a near standard pipeline eboxdetect/emldetect tuned for ~zero background. eboxdetect/emldetect tuned for ~zero background. Three different energy bands are source searched Three different energy bands are source searched independently: independently: total band (0.2–0.5 keV) soft band (0.2–2 total band (0.2–0.5 keV) soft band (0.2–2 keV) hard band (2–12 keV) keV) hard band (2–12 keV) Fig 5. Aitoff projection of the distribution of all XMMSL1 sources obtained during Fig 5. Aitoff projection of the distribution of all XMMSL1 sources obtained during slew observations. slew observations. Catalogue correlation and positional accuracy Catalogue correlation and positional accuracy Source correlation of 2178 no-extended sources with det_ml>10.0 Source correlation of 2178 no-extended sources with det_ml>10.0 RASS correlation (Fig 7 left) RASS correlation (Fig 7 left) ~56% of the slew sources have RASS counterpart within 60 arcsec ~56% of the slew sources have RASS counterpart within 60 arcsec 68% of the sources lies within 15 arcsec 68% of the sources lies within 15 arcsec SIMBAD correlation (Fig 7 right) SIMBAD correlation (Fig 7 right) 68% of the sources lies within 8 arcsec 68% of the sources lies within 8 arcsec Detected sources Detected sources A great variety of sources have been detected during A great variety of sources have been detected during slews, including AGN, QSO, galaxies, cluster of slews, including AGN, QSO, galaxies, cluster of galaxies , LMXB and SNR among others. galaxies , LMXB and SNR among others. We can study object variability from sources detected We can study object variability from sources detected in more than one slew or count rate ratios between in more than one slew or count rate ratios between the XMM slew sources and RASS sources. the XMM slew sources and RASS sources. ESAC ESAC The XMM-Newton Slew Survey The XMM-Newton Slew Survey Abstract Abstract Fig 2. Plots of the radial profile (solid line) of the detected source (this source is showed at the corner of the picture as an optical image and X-ray contours overplotted) and the PSF (dashed line). Left: the radial profile fits very well the PSF so the source can be classified as point-like. Right: for a extended source the radial profile does not fit the PSF. Fig 4. Subimage of the slew observation in revolution 0689. The real slew source is white circled and corresponding to 1A 1743-322. Spurious detections within the halo of this bright source are shown in light blue. Fig 7. Histogram of the distribution of the angular separation in arcsec derived from correlations of the slew Fig 7. Histogram of the distribution of the angular separation in arcsec derived from correlations of the slew source positions. source positions. Left: correlation with the RASS catalogue, 68% of the matches lie within 15 arcsec. Right: correlation with the Left: correlation with the RASS catalogue, 68% of the matches lie within 15 arcsec. Right: correlation with the SIMBAD database, 68% of the matches lie within 8 arcsec. SIMBAD database, 68% of the matches lie within 8 arcsec. Flux detection limits: sensitivity Flux detection limits: sensitivity of the survey of the survey Soft X-ray band detection limit: 6(4.5) 10 Soft X-ray band detection limit: 6(4.5) 10 -13 -13 ergs s ergs s -1 -1 cm cm -2 -2 close to ROSAT BS catalogue close to ROSAT BS catalogue Hard X-ray band detection limit deepest ever: Hard X-ray band detection limit deepest ever: 4(3) 10 4(3) 10 -12 -12 ergs s ergs s -1 -1 cm cm -2 -2 >10× deeper than EXOSAT, HEAO-1 >10× deeper than EXOSAT, HEAO-1 ~2.5× deeper than RXTE (only has 1° ~2.5× deeper than RXTE (only has 1° positional accuracy) positional accuracy) Fig.6. Counterpart galaxies of two slew sources derived from the SDSS Fig.6. Counterpart galaxies of two slew sources derived from the SDSS correlation. correlation. Fig 8. Flux limits of the X-ray large area surveys. The fluxes for the XMM-slew Fig 8. Flux limits of the X-ray large area surveys. The fluxes for the XMM-slew survey have been calculated for a source with DET_ML=10 and passing through the survey have been calculated for a source with DET_ML=10 and passing through the centre of the field of view. These fluxes were derived from count rates based on centre of the field of view. These fluxes were derived from count rates based on energy conversion factors assuming an absorbed power-law model with N energy conversion factors assuming an absorbed power-law model with N H =3.0 =3.0 ·10 ·10 20 20 cm cm 2 and slope 1.7 and slope 1.7 M.P. Esquej M.P. Esquej a , R.D. Saxton , R.D. Saxton a , A.M. Read , A.M. Read c , B. Altieri , B. Altieri a , M.J. Freyberg , M.J. Freyberg b , D. Bermejo , D. Bermejo a , V. Lazaro , V. Lazaro a a European Space Agency (ESA), European Space Astronomy Centre (ESAC), Villafranca, Apartado 50727, 28080 European Space Agency (ESA), European Space Astronomy Centre (ESAC), Villafranca, Apartado 50727, 28080 Madrid, Spain Madrid, Spain b Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse 1, 85784 Garching, Germany Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse 1, 85784 Garching, Germany c Dept. of Physics and Astronomy, Leicester University, Leicester LE1 7RH, U.K. Dept. of Physics and Astronomy, Leicester University, Leicester LE1 7RH, U.K.
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Transcript of The X-ray Universe 2005 26-30 September 2005, El Escorial, Madrid, Spain The XMM-Newton Slew Survey...
The X-ray Universe 2005The X-ray Universe 200526-30 September 2005, El Escorial, Madrid, Spain26-30 September 2005, El Escorial, Madrid, Spain
The XMM-Newton Slew SurveyThe XMM-Newton Slew Survey
XMM-Newton Slew 1XMM-Newton Slew 1(XMMSL1)(XMMSL1)
Fig 1. Slew observation performed with the EPIC- pn camera.
Current statusCurrent statusImages and exposure maps have been created and source searched for 220 Images and exposure maps have been created and source searched for 220 slews giving:slews giving:• 4177 sources in the total band4177 sources in the total band• 2750 sources in the soft band2750 sources in the soft band• 844 sources in the hard band844 sources in the hard band
Positional accuracy: 8 arcsecPositional accuracy: 8 arcsecSource density: ~0.65 sources per square degreeSource density: ~0.65 sources per square degreeSky coverage: ~6300 square degrees (~15% of the sky)Sky coverage: ~6300 square degrees (~15% of the sky)
Objective: issue of the first slew source catalogue (XMMSL1) by the end of Objective: issue of the first slew source catalogue (XMMSL1) by the end of 2005 and provide an upper limit server in 20062005 and provide an upper limit server in 2006
Attitude reconstructionAttitude reconstructionThe attitude reconstruction is crucial The attitude reconstruction is crucial in determination of source in determination of source coordinates and is differently coordinates and is differently performed in slew observations with performed in slew observations with respect to the pointed ones where the respect to the pointed ones where the AHF is used.AHF is used.
The optimal attitude file for The optimal attitude file for reconstructing the astrometry during reconstructing the astrometry during slew observations is the Raw Attitude slew observations is the Raw Attitude File (RAF) subtracted by 0.75 File (RAF) subtracted by 0.75 seconds from every entry, timing seconds from every entry, timing error that is due to a delay of the star error that is due to a delay of the star tracker CCDs.tracker CCDs.
Fig. 3. Comparison of data processing with the different attitude files used for astrometry reconstruction for the slew source XMMSL1 05:28:45.0-65:26:52. Right images: detected
slew source in the total band. Left images: position of the slew source overplotting the corresponding optical counterpart. Top panel: source detected with the AHF as attitude
file, the shift between the optical and the slew position is evidenced.. Bottom panel: corrected slew source position using the modified RAF for the attitude reconstruction. We can clearly see the difference between both processing and the improvement with the new
attitude reconstruction.
Spurious detectionsSpurious detectionsSystematic effects in the instrument and detection Systematic effects in the instrument and detection software lead to a number of spurious detections software lead to a number of spurious detections that are being flagged in different categories:that are being flagged in different categories:
• False detectionFalse detection
• Within extended sourceWithin extended source
• Within halo of bright sourceWithin halo of bright source
• Position suspectPosition suspect
• Source near edgeSource near edge
• Detector flashDetector flash
Observations and data analysisObservations and data analysis
Processing challengesProcessing challenges
The XMM-Newton satellite is the most sensitive X-ray observatory flown to date due to the great collecting area of its mirrors coupled with the high quantum efficiency of the EPIC detectors. It performs slewing manoeuvers between observation targets with the EPIC cameras open and the other instruments closed, operating with the observing mode set to the one of the previous pointed observation and the medium filter in place.
Slew observations from the EPIC-pn camera in FF, eFF and LW provide data, resulting in 15 seconds on-source time, which can be used to give a uniform survey of the X-ray sky.
Only data from EPIC-pn slew observations are used for the processing due to the faster Only data from EPIC-pn slew observations are used for the processing due to the faster readout in their observing modes and its high effective area with respect to the EPIC-readout in their observing modes and its high effective area with respect to the EPIC-MOS cameras.MOS cameras.
The low background of the observations (The low background of the observations (average ~0.1c/arcminaverage ~0.1c/arcmin22) and the tight PSF ) and the tight PSF give good sensitivity to detect extended sources. give good sensitivity to detect extended sources.
Some high background observations that were performed at times of enhanced solar Some high background observations that were performed at times of enhanced solar activity were rejected for the processing.activity were rejected for the processing.
Slew observations have to be subdivided into 1 square degree images, then sky Slew observations have to be subdivided into 1 square degree images, then sky positions are recalculated.positions are recalculated.
Source search using a near standard pipeline eboxdetect/emldetect tuned for ~zero Source search using a near standard pipeline eboxdetect/emldetect tuned for ~zero background. background.
Three different energy bands are source searched independently:Three different energy bands are source searched independently:
total band (0.2–0.5 keV) soft band (0.2–2 keV) hard band (2–12 total band (0.2–0.5 keV) soft band (0.2–2 keV) hard band (2–12 keV)keV)
Fig 5. Aitoff projection of the distribution of all XMMSL1 sources obtained during slew observations.Fig 5. Aitoff projection of the distribution of all XMMSL1 sources obtained during slew observations.
Catalogue correlation and positional accuracyCatalogue correlation and positional accuracySource correlation of 2178 no-extended sources with det_ml>10.0 Source correlation of 2178 no-extended sources with det_ml>10.0 RASS correlation (Fig 7 left)RASS correlation (Fig 7 left)~56% of the slew sources have RASS counterpart within 60 arcsec~56% of the slew sources have RASS counterpart within 60 arcsec68% of the sources lies within 15 arcsec68% of the sources lies within 15 arcsecSIMBAD correlation (Fig 7 right)SIMBAD correlation (Fig 7 right)68% of the sources lies within 8 arcsec68% of the sources lies within 8 arcsec
Detected sourcesDetected sourcesA great variety of sources have been detected during slews, including AGN, A great variety of sources have been detected during slews, including AGN, QSO, galaxies, cluster of galaxies , LMXB and SNR among others.QSO, galaxies, cluster of galaxies , LMXB and SNR among others.We can study object variability from sources detected in more than one slew or We can study object variability from sources detected in more than one slew or count rate ratios between the XMM slew sources and RASS sources.count rate ratios between the XMM slew sources and RASS sources.
ESACESACThe XMM-Newton Slew SurveyThe XMM-Newton Slew Survey
AbstractAbstract
Fig 2. Plots of the radial profile (solid line) of the detected source (this source is showed at the corner of the picture as an optical image and X-ray contours overplotted) and the PSF (dashed line). Left: the radial profile fits very well the PSF so the source can be classified as point-like. Right: for a extended source the radial profile does
not fit the PSF.
Fig 4. Subimage of the slew observation in revolution 0689. The real slew source is white circled and corresponding to 1A 1743-322.
Spurious detections within the halo of this bright source are shown in light blue.
Fig 7. Histogram of the distribution of the angular separation in arcsec derived from correlations of the slew source positions. Fig 7. Histogram of the distribution of the angular separation in arcsec derived from correlations of the slew source positions. Left: correlation with the RASS catalogue, 68% of the matches lie within 15 arcsec. Right: correlation with the SIMBAD database, 68% of the matches lie within 8 Left: correlation with the RASS catalogue, 68% of the matches lie within 15 arcsec. Right: correlation with the SIMBAD database, 68% of the matches lie within 8
arcsec.arcsec.
Flux detection limits: sensitivity of the surveyFlux detection limits: sensitivity of the survey Soft X-ray band detection limit: 6(4.5) 10Soft X-ray band detection limit: 6(4.5) 10-13-13 ergs s ergs s-1-1 cm cm-2-2
close to ROSAT BS catalogueclose to ROSAT BS catalogue
Hard X-ray band detection limit deepest ever: 4(3) 10Hard X-ray band detection limit deepest ever: 4(3) 10 -12-12 ergs s ergs s-1-1 cm cm-2-2 >10× deeper than EXOSAT, HEAO-1 >10× deeper than EXOSAT, HEAO-1 ~2.5× deeper than RXTE (only has 1° positional accuracy)~2.5× deeper than RXTE (only has 1° positional accuracy)
Fig.6. Counterpart galaxies of two slew sources derived from the SDSS correlation. Fig.6. Counterpart galaxies of two slew sources derived from the SDSS correlation.
Fig 8. Flux limits of the X-ray large area surveys. The fluxes for the XMM-slew survey have been calculated for a Fig 8. Flux limits of the X-ray large area surveys. The fluxes for the XMM-slew survey have been calculated for a source with DET_ML=10 and passing through the centre of the field of view. These fluxes were derived from count source with DET_ML=10 and passing through the centre of the field of view. These fluxes were derived from count
rates based on energy conversion factors assuming an absorbed power-law model with Nrates based on energy conversion factors assuming an absorbed power-law model with NHH=3.0=3.0·10·102020 cm cm22 and slope 1.7 and slope 1.7
M.P. EsquejM.P. Esquejaa, R.D. Saxton, R.D. Saxtonaa, A.M. Read, A.M. Readcc, B. Altieri, B. Altieriaa, M.J. Freyberg, M.J. Freybergbb, D. Bermejo, D. Bermejoaa, V. Lazaro, V. Lazaroaa
aaEuropean Space Agency (ESA), European Space Astronomy Centre (ESAC), Villafranca, Apartado 50727, 28080 Madrid, Spain European Space Agency (ESA), European Space Astronomy Centre (ESAC), Villafranca, Apartado 50727, 28080 Madrid, Spain bbMax-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse 1, 85784 Garching, GermanyMax-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse 1, 85784 Garching, Germany ccDept. of Physics and Astronomy, Leicester University, Leicester LE1 7RH, U.K. Dept. of Physics and Astronomy, Leicester University, Leicester LE1 7RH, U.K.
