The Chandra Multi-wavelength Project (ChaMP)

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The Chandra Multi-wavelength Project (ChaMP)

• PIs Paul Green Belinda Wilkes
• X-ray Dong-Woo Kim
• Imaging Rob Cameron, Wayne Barkhouse
• Spectroscopy John Silverman
• and the ChaMP Collaboration

Serendipitous X-ray Survey using Chandra Archival
Data
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Principal Motivations

• Sample X-ray selected AGN across L,z plane
• Study populations contributing to the CXRB
• Find high-z clusters to constrain Cosmology
• Study cosmic variance and clustering
• Sample DLya absorbers to XSQSOs
• Detect mass limits of stellar coronal emission

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Quasar and AGN Evolution What do we know?

Optical surveys Unobscured population (view the
BLR and/or NLR) Technically feasible for wide
and deep sky coverage to sample to z6
2dF (Boyle et al. 2000)
SDSS (Fan et al. 2001)
0ltzlt2 depletion of fuel? (Cavaliere Vittorini
2000) zgt3 SMBH growth and highly efficient
accretion? (Wyithe Loeb 2002 etc.)
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Quasar and AGN EvolutionPast X-ray surveys
Cosmic X-Ray Background (CXRB)
Significant obscured population (Gilli et al.
2001, Comastri et al. 1995) Einstein Medium
Sensitivity Survey (Maccacaro et al. 1991
EMSS) 420 AGNs, zlt2 and fxgt10-13 erg s-1 cm-2
resolved 40 CXRB at 2 keV ROSAT (Miyaji et
al. 2000) Compilation of various depth surveys
690 AGNs with 8 at zgt3 resolved 90 0.5-2.0
keV CXRB Luminosity evolution similar to optical
surveys
ROSAT Luminosity function
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Space Density of Luminous Quasars

• Optical and radio LFs peak at z2
• X-ray space density MAY flatten at zgt3
• Need more high-z, X-ray selected AGN

(Miyaji et al 2000)
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Chandra Advances
1 positions, small PSF low background
10-100 fainter flux limits unambiguous source
IDs Source extent and morphology
XMM is Complementary
4 Effective Area larger Field-of-View Harder
energy band 0.5-20 keV
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Do High and Low L AGN Evolve Differently?
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Quasar and AGN EvolutionCurrent Chandra and XMM
deep surveys

Comastri et al. 1995
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CXRB Spectral Synthesis
Comastri et al. 1995
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Hard CXRB Dominated by Bright Sources
Cowie et al. (2002)
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Outline of the ChaMP

• 135 selected ACIS fields from Cycles 12
• X-ray source detection photometry
• Source IDs via optical imaging g r i
• Classification in X-ray/optical multicolor plane
• Optical spectroscopy of bright subsample
• Radio NVSSFIRST VLA
• 2MASS near-IR Imaging (TBD)

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ChaMP Field Distribution

• 137 Cycle 12 ACIS Fields 14 sq. deg
• Exposure times 2-190 ksec
• 6000 X-ray sources

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X-ray Analysis
Dong-Woo Kim, H. Ghosh, V. Kashyap, T. Aldcroft,
A. Vikhlinin

• Chandra Level 2 Data Products
• Correct gain, bad or flaring pixels, high bkg
• Generate exposure map
• Wavdetect 7 kernel sizes, 3 bands B 0.3-8 keV
  S 0.3-2.5 keV H 2.5-8 keV
• Determine source properties flux, hardness,
  extent, spectrum, variability
• 62 fields processed to date 4000 sources
• Kim et al. 2003

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Predicted Number Counts
Grimes, Green, Kim

• 4000 AGN (800 absbd) 2000 galaxies, 200-300 M
  stars, 40 clusters
• Chandra Deep Surveys 12 Msec (ACIS-I)
• ROSAT compilation (Miyaji et al. 2000)

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ChaMP logN-logS
Kim et al. 2003
Bridges flux gaps between ROSAT, ASCA Chandra
Deep Fields
Soft Band
Hard Band
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ChaMP logN-logS Results
Kim et al. 2003

• Soft band differential logN-logS requires a
  broken powerlaw
• ßbright2.30.2, ßfaint1.70.1, Sbreak610-15
• Hard band ß1.30.1 single PL acceptable
• Both consistent with XMM (Baldi et al. 2001),
  CDF-N (Brandt et al. 2001)

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Cosmic Variance?

• 62 fields
• countsgt20 ?lt400
• typical errors shown
• No significant Cosmic Variance!
• 3C295 cluster field exposures marked
• 100ksec exposure belies earlier claim of
  overdensity

Kim et al. 2003
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ChaMP logN-logS Clusters
29 cluster target fields
33 non-cluster fields
Kim et al. 2003
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X-ray Simulations
SAOSAC raytrace simulations Grid of off-axis
angles 10 1000 count sources Std XPIPE
detection Photometry Compare input/output -
detection rates - positions - fluxes
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Wavdetect Positional Uncertainties

• Typically lt1
• Strong increase with ? due to PSF
• Greatly improved after detection by a 2d wavdet
  pass using small kernel
• Centroid uncertainty decreases for strong
  sources.

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Optical Identification
P. Green, W. Barkhouse. R. Cameron, J. Silverman,
A. Mossman

• With reduced, stacked NOAO MOSAIC images
• Detect sources with SExtractor
• Astrometric solution GSC II, lt0.3 rms
• Cross-correlate X-ray and optical
• Fine tune X-ray astrometry
• Prioritize counterparts by X-O distance
• Visual check of all optical IDs

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X-ray/Optical Matching
Cameron, Silverman, Green

• NOAO 4m/MOSAIC
• Sloan g r i
• Automated OAA dependent matching
• Visual inspection

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Optical Counterparts
Green et al. 2003 6 fieldsgt30ksec 483
sources gt 3e-16 328 optical IDs (68)
125 spectra (25)
194 sources gt 3e-15 156 optical IDs (78)
78 spectra (40) spectra for 64 of rlt22 IDs
55 sources gt 1e-14 52 optical IDs (95) 34
spectra (62) spectra for 72 of rlt22 IDs
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Optical Spectroscopic ProgramJ. Silverman, P.
Green, P. Smith (Steward), S. Ellison (PUC), C.
Foltz (NSF), C. Smith, M. Smith (CTIO), E.
Colmenero-Romero (SAAO)

• Spectroscopic identification rlt23

Telescope/Instrument of
nights Magellan/6.5m
9 -LDSS-2 multi-slit spectrograph (FOV
5) MMT/6.5m
9 -long slit
KPNO/WIYN, CTIO/4m 19 -HYDRA
multi-fiber (FOV 1 deg) KPNO/4m
3 -MARS(Multi-aperture red
spectrograph)
FLWO/1.5m FAST, SAAO -longslit (Queue observing)
Additional spectra from J. Huchra, G. Torres, W.
Brown, K. Adelberger, K. Krisciunas(CTIO), B.
Kirshner
30/40 clear nights (400 spectra)
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Quasars at z gt 3
Chandra Image 30 ksec exposure
ACIS-I
8.5
ACIS-S
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Covering the Lx-z Plane

• ChaMP complements the CDFs by finding numerous
• high-z, high-L QSOs
• low-z, moderate-L AGN

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Covering the Lo-z Plane
ChaMP garners high-L galaxies and QSOs. But no
galaxies beyond z0.8 !
Galaxy z limit set by rlt22
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Optical vs. X-ray Fluxes

• BLAGN and stars well-separated
• Different sample than optical surveys
• Some ALGs have QSO-like fx/fopt
• Many bright X-ray sources unmatched to r 25

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Hidden AGN

• Hard sources appear at fX lt10-14
• May compose CXRB
• Many have no broad lines Optical Type2 AGN?
• Yes! LX gt1043
• X-ray, optical absorption not 11

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X-ray absorption properties
Soft 0.3-2.5 keV Hard 2.5-8.0 keV

• As expected, BLAGN are predominately unobscured
• Hard X-ray Sources are
• obscured AGN
• (Lx gt1042 erg/s)
• NELG and ALG have a
• wide range of X-ray
• spectral properties
• No type II QSOs detected
• -selection effect
• -5 detected in the CDF-S
• -1 CDF-N

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Absorbed Objects
X-ray faint objects tend to be redder
X-ray hard objects tend to be redder
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ChaMP X-ray Spectral Fits
CHaMPs XFit pipeline uses Slang scripting
running Sherpa fitting in CIAO
Ctsgt Params
50 2
100 3
300 4
500 5
1000 6
Fits span 28 models (35 for known z)
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Serendipitous Clusters
z0.3? cluster with extended X-ray emission
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Serendipitous Clusters
z0.72 QSO with extended X-ray emission offset
from QSO by rcore
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Spin-Off Projects

• Clusters from optical and X-ray images
• Lenses, pairs, jets
• Variability pipeline (Bayesian block analysis)
• Damped Lya survey
• AGN-AGN and AGN-galaxy clustering

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X-ray Properties of Optically Selected Clusters

• Select clusters from both optical and X-ray
  images.
• Use VTP on photometric catalog for optical
  cluster detection (Ramella et al. 2001).
• Use color slices to raise sensitivity to red
  sequence.

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Damped Lya Survey

• ODLA increases with optical magnitude (Ellison
  et al. 2001)
• Radio-selected quasar results show higher n(z)
  at 1s
• Are optical QSO DLA surveys are dust-biased?
• ChaMP zgt2 QSOs with rgt20 will provide a
  stringent test

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Clustering QSO Lifetimes

• Current Limits
• Proximity Effect ? TQSO gt105 yr
• Overall Population ? TQSOlt109 yr

QSO Lifetime Space Density Halo Mass Clustering
short common typical weak
long rare massive strong
(Martini Weinberg 2001 Haiman Lam 2001)
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ChaMP the Community

• ChaMP fields 20 of archived Cycle 12 targets
• Public database X-ray sources, optical IDs,
  matched optical images, photometry and colors
• Will enhance Chandra science return!
• Graduate student thesis projects available.

Thanks to NASA for CXC Archival Research funding,
to NOAO for telescope time awarded, and thanks to
the whole ChaMP Collaboration!
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ChaMP Results to Date

• Cosmic Variance consistent with Poisson
• No significant source overabundance associated
  with clusters
• aox or fx/fr dependence on L or z consistent with
  expectations from LF simulations limits
• Half the objects with Lxgt1043 are hard
  presumably obscured AGN
• Wide area suitable for samples of rare objects.