the xmm large scale structure (xmm-lss) survey andy read university of leicester university of...
Post on 21-Dec-2015
215 views
TRANSCRIPT
The XMM Large Scale Structure The XMM Large Scale Structure (XMM-LSS) Survey(XMM-LSS) Survey
Andy ReadAndy Read
UniversityUniversity ofof LeicesterLeicester (for the XMM-LSS Consortium)(for the XMM-LSS Consortium)
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
A EuropeA Europe/Chile/Chile Consortium Consortium
Birmingham Birmingham BristolBristol CopenhagenCopenhagen DublinDublin ESO/ SantiagoESO/ Santiago LeidenLeiden LiègeLiège
Marseille (LAM)Marseille (LAM) Milano (AOB)Milano (AOB) Milano (IFCTR)Milano (IFCTR) Munich (MPA)Munich (MPA) Paris (IAP)Paris (IAP) Santiago (Uni. Cato.)Santiago (Uni. Cato.)
PI : Saclay, France
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
XMM sensitivityXMM sensitivity
12.5Å 1.25Å
EffectiveArea
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
The XMM-LSS SurveyThe XMM-LSS Survey
- Goal: determine the cluster correlation function in two redshift bins 0 < z < 0.5, 0.5 < z < 1, each bin containing 450 clusters
- Fixes the XMM-LSS survey characteristics: 8x8 sq.deg. area covered by 10 ksec XMM pointings
- Sensitivity: 5e-15 ergs/s/cm² in [0.5-2 keV] band
- XMM’s unrivalled sensitivity, large FOV (d~25’) and good PSF opens a new area for the study of the cluster Large Scale Structure (LSS)
- Able to Map the evolution of the LSS of the universe out to z~1, with both the galaxy cluster and the QSO
populations for the first time
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
Expected number of clustersExpected number of clusters in an 8x8 sq. deg. area in an 8x8 sq. deg. area
~ 900 clusters 0 < z < 1 for CDM~ 300 clusters z > 1
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
Expected numbers of objectsExpected numbers of objects
200200 QSO QSO/AGN /AGN (( 40% 40% z < 1) z < 1)
15 clusters z<115 clusters z<1 5 clusters 1< z <2 ?5 clusters 1< z <2 ? Galaxies + stars Galaxies + stars
At the survey sensitivity: ~ 5e-15 erg/s/cm² (0.5-2 keV)
~ 250 X-ray sources per square degree:
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
The XMM-LSS … The XMM-LSS … so farso far
- Aim: 64 sq.deg. 10 ksec exposures
-Already observed: 46 XMM pointings ~5 sq.deg. (May 03)
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
Multi-wavelength follow-upMulti-wavelength follow-up CFHT/CFH12K (VVDS Deep): 2 sq.deg. GT(WL)CFHT/CFH12K (VVDS Deep): 2 sq.deg. GT(WL) CFHT/CFH12K (VVDS Wide): 3 sq.deg. GO(WL)CFHT/CFH12K (VVDS Wide): 3 sq.deg. GO(WL) CFHT/Megacam: 72 sq.deg. (WL)CFHT/Megacam: 72 sq.deg. (WL) CTIO 4m/MOSAIC: ~16 sq.deg.CTIO 4m/MOSAIC: ~16 sq.deg. UKIRT/WFCAM: 8.75 sq.deg.UKIRT/WFCAM: 8.75 sq.deg. VLA A array: 110 sq.deg. @ 74 MHzVLA A array: 110 sq.deg. @ 74 MHz VLA A array: 5.6 sq.deg. @325 MHzVLA A array: 5.6 sq.deg. @325 MHz OCRA: all XMM clusters @ 30 GHzOCRA: all XMM clusters @ 30 GHz AMIBA: 70 sq.deg. @ 95 GHzAMIBA: 70 sq.deg. @ 95 GHz SIRTF/IRAC: 8.7 sq.deg. (SWIRE Legacy)SIRTF/IRAC: 8.7 sq.deg. (SWIRE Legacy) SIRTF/MIPS: 8.9 sq.deg. (SWIRE Legacy)SIRTF/MIPS: 8.9 sq.deg. (SWIRE Legacy) GALEX: ~ 20 sq.deg. GALEX: ~ 20 sq.deg.
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
XMM Subaru Deep Survey
VIRMOS VVDS wide
XMDS & VIRMOS VVDS deep
SIRTF Legacy : SWIRE
NOAO Deep Survey
Galex
XMM-LSS
Survey Survey LocationLocation
HI map NH~1.4-3.5 e20
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
First XMM pointings (GT) – 20 ksec First XMM pointings (GT) – 20 ksec
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
The First Data: 15 GO PointingsThe First Data: 15 GO Pointings 15 Pointings (MOS1, MOS2 & pn, all with ~10 ksec)15 Pointings (MOS1, MOS2 & pn, all with ~10 ksec) Standard XMM-SAS (emchain and epchain) processingStandard XMM-SAS (emchain and epchain) processing Flare-cleaned to common level of low backgroundFlare-cleaned to common level of low background Bad pixel analysis and removalBad pixel analysis and removal RGB mosaic constructed (0.3-1, 1-2.5, 2.5-10 keV)RGB mosaic constructed (0.3-1, 1-2.5, 2.5-10 keV) Rigorous background subtraction, to account for Rigorous background subtraction, to account for
extended sources, involving background event filesextended sources, involving background event files
(Read & Ponman 2003) and closed datasets (Marty(Read & Ponman 2003) and closed datasets (Marty
et al. 2002)et al. 2002)
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
Imaging: Background subtraction
Source data Closed data Background data
Source (vignetted) +
Background: - Photons (vignetted) Particles (non-vignetted)
Background: -
Particles (non-vignetted)
Background: - Photons (vignetted) Particles (non-vignetted)
Only BG particles appear in out-of-field-of-view (out-of-FOV) areas [i.e. corners]
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
Imaging: Double-background subtractionSource Closed data (Particles) Background data (photons+particles)
- Evaluate all out-of-FOV events – calculate scalings
Create image Create scaled P image Create scaled BG image
-Subtract to give Source image (no particles)
-Subtract to give scaled BG image (no particles)
- Create exposure map in small energy band – use to create full field `soft excess’ image
Create large-R annular image Create large-R annular P image Create large-R annular BG image
Scale to source Scale to source
-Subtract to give Source annulus (no particles)
-Subtract to give BG annulus (no particles)
-Subtract to calculate ‘soft excess’ at large-R for particular energy
* Start `soft excess’ loop over several small energy bands
* End Loop over energies to accumulate total energy, full field `soft excess’ image
-Add `soft excess’ to Scaled BG image to create double background
-Add double background to scaled particles image to create total background
(source-free)
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
The First Data: Flare-cleaned exposure The First Data: Flare-cleaned exposure
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
Part of the XMM-LSS mosaic : 15 pointings (~1.6 sq.deg.) Part of the XMM-LSS mosaic : 15 pointings (~1.6 sq.deg.)
Red[0.3-1]keV Green[1-2.5]keV Blue[2.5-10]keV
Andy ReadAndy Read
Circles: ROSATAll-Sky Survey
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
‘‘Big C’ – XMMUJ022540-031111Big C’ – XMMUJ022540-031111Hardness map of centre
-Hotter at interface (kT~7.6keV)
All-EPIC, BG-sub, exp-corr. contours on CFHT I band imagez~0.29, kT~6.2 keV, Lx~3e44 erg/s
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
Detection Algorithm OverviewDetection Algorithm Overview- Standard SAS processing - emchain & epchain + flare removal- Wavelet filtering of images (M1-M2-PN) - in counts (preserving Poisson stats) - computing threshold by histogram auto-convolution- Exposure correction on a per instrument basis- Addition of exposure-corrected images- 1st detection step: Sextractor (XMM-PPS uses eboxdetect)
- on co-added images - with low detection threshold, to avoid missing faint sources - with parameters adjusted for X-ray filtered images- Max. Likelihood fit step: EMLdetect (with extension fit & CAL psf) - source input list from Sextractor - X/Y & extent tied for 3 instruments, normalization free - ML min = 8.5 - Final X-ray catalogue: - Mix of Sextractor/EMLdetect results
Sergio Dos Santos, Saclay
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
Detection Algorithm ValidationDetection Algorithm Validation
On instrument by instrument basis: - Instrumental effects included:
PSF (analytic), vignetting (energy dependent), CCD gaps, bad pixels
- Background (Read & Ponman 2003): Cosmic (vignetted) & Particles (non-vignetted)
- Source modelling (in at least two bands): - Point sources (random positioning in FOV): Flux distribution: LogN-LogS (Moretti et al. 2003) - Extended sources: King model surface brightness - β = 2/3 - Rcore = Rvirial/10 (Rvirial from temperature) Flux from local Lx-T (Arnaud & Evrard 1999)
XMM Simulations
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
Simulated XMM ImagesSimulated XMM Images
Single pointing (10ks) Photon image [0.4-4 keV]
Wavelet-filtered + Poisson photonstatistics model (Starck & Pierre 1998) [pre-Sextractor detection]
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
Detection Algorithm ValidationDetection Algorithm ValidationResultsResults
-Results encouraging:
- Most, if not all clusters (T>4keV) up to z~1 can be detected using 10 ksec XMM pointings - Richest clusters should be detected at z<2 (if they exist!) - Very small rate of spurious detections (<1 per pointing), due to 2-stage process
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
• ~60 Candidate extended sources over ~ 3.5 sq.deg. i.e. as expected ~15+ extended sources per sq.deg.
• 10 ksec XMM + 2h VLT allow T (±1 keV) measurement and velocity dispersion at z~0.8
• Intermediate mass systems are being uncovered by XMM
• First results described in four papers• Pierre et al, 2003, astro-ph/0305191• Valtchanov et al, 2003, astro-ph/0305192• Willis et al, 2003, in prep• Andreon et al, in prep
XMM-LSS: Selected ResultsXMM-LSS: Selected Results
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
Identification procedureIdentification procedureXMM EPIC image + contours CFHT 3-colour VRI image + EPIC contours
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
PhotometricPhotometricredshift redshift
CFHT I-band image
EPIC contours
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
Predicted z (photometric) Predicted z (photometric) from VBRI images: from VBRI images:
Measured z: Measured z: 0.61 !0.61 !
Sources ~1’ from centre
All sources
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
CFH12k I-bandCFH12k I-band
EPIC contours
Nearby group
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
Cluster without X-ray counterpart
(z~0.3-0.4)
Image: zImage: z´́-band CTIO-band CTIO
EPIC contours
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
A relaxed medium cluster at z~0.84A relaxed medium cluster at z~0.84
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
A collapsing cluster at z~0.77 A collapsing cluster at z~0.77
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
Some AGNs in the same fieldSome AGNs in the same field
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
A structure at z~1
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
Z > 1 CandidateZ > 1 Candidate
CFH12k VRI imagesVIRMOS DS
~ 560 cts [0.5-5] keV
XMM-EPIC X-ray contours from wavelet filtering
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
NIR identification of z~1 XMM-LSS clustersNIR identification of z~1 XMM-LSS clusters
XMM (PN) image (+X-ray detection ellipse)
SOFI (NTT) K-band image (galaxies hardly seen on deep I (CFHT) and z’ (CTIO) images)
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
NIR confirmed clustersNIR confirmed clustersExtended X-ray sources showing spatially coincident, statistically significant galaxyoverdensity
EPIC contours on K-band images ~1’x1’
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
006 012
EPIC contours on CFHT images – cluster candidates at z~0.4
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
2-D fitting of X-ray emission2-D fitting of X-ray emission• Simultaneous fitting of MOS1, MOS2 and pn images
- Images and exposure maps required• PSF images required (created via XMM-SAS-calview)• Masks can be used to ignore e.g. nearby point sources• Source (src) and background (BG) boxes are chosen
2-D fitting: β-model (using CIAO-sherpa)
• 3 separate models (with tied parameters) for M1, M2, pn• Constant BG level(s) fit to BG emission• src+BG model fit to source emission (src = β-model)• Core radius Ro, slope β, ellipticity ε, pos.angle θ tied between 3 instruments, normalization free
f(x,y) = f(r) = A_________(1+[r/r0])
3β-½ [r=f(x,y,ε,θ)]
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
2-D model contours overlayed on XMM-EPIC X-ray emission
Ro=24.0" β=0.63 Ro=24.2" β=0.40 Ro=59.8" β=0.72 Ro=8.7" β=0.44
Ro=12.9" β=0.73 Ro=37.4" β=0.51 Ro=11.8" β=0.67 Ro=4.7" β=0.40
Ro=6.5" β=0.40 Ro=2.5" β=0.42 Ro=12.1" β=0.55 Ro=5.3" β=0.41
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
2-D model contours overlayed on residuals (data – model)
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
First accepted papers:
astro-ph/0305191
astro-ph/0305192
http://vela.astro.ulg.ac.be/themes/spatial/xmm/LSS/index_e.html
XMM-LSSXMM-LSS
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
Data releaseData release• 2003: clusters published (coordinates, z) 2003: clusters published (coordinates, z)
astro-ph/0305191 astro-ph/0305192
• 2004:2004: publication of the X-ray catalogue from publication of the X-ray catalogue from the XMM A01 datathe XMM A01 data
• Database increased/updated annually: Database increased/updated annually: X-ray, optical, VLA, then SIRTFX-ray, optical, VLA, then SIRTF
University of LeicesterUniversity of Leicester2525thth November 2003 November 2003
Andy ReadAndy ReadUniversity of LeicesterUniversity of Leicester
QSOs