Xavier Barcons

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AGN and Surveys with the new X-ray observatories

• Xavier Barcons
• Instituto de Física de Cantabria (CSIC-UC)

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Index

• Introduction The AGN paradigm and X-ray
  observations
• New windows with the new X-ray observatories
• The inner disk Fe line diagnostics
• The circum-nuclear environment warm absorbers,
  jets and outflows
• Challenges to the AGN unified model
• X-ray Surveys, Obscured accretion, and the X-ray
  background
• A few questions for the future

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Acknowledgements

• The IFCA X-ray Astronomy group Francisco
  Carrera, Maite Ceballos, Silvia Mateos, Amalia
  Corral, Jacobo Ebrero
• The XMM-Newton Survey Science Centre, especially
  Mike Watson, Mat Page, Tommaso Maccacaro, Roberto
  Della Ceca, Paola Severgnini, Axel Schwope, etc.
• The Lockman Hole team, especially Günther
  Hasinger, Alina Streblyanska, Ingo Lehmann,
  Thomas Boller and the
• Andy Fabian

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The X-ray view of an AGN
C. Done, Durham U
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The X-ray spectrum of an AGN

• Radiation from the accretion disk, reprocessed by
  a relativistic electron corona
• Reflection (fluorescence lines and Compton recoil
  bump)
• Absorbers
• Soft excess (direct disk radiation)

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The new X-ray observatories
XMM-Newton (ESA) December 1999
Chandra (NASA) July 1999
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How does an X-ray telescope work?
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Chandra

• Spatially resolved (0.5) low resolution
  spectroscopy (E/?E20-50)
• Intermediate resolution dispersive spectroscopy
  (0.02-0.04 Ang, E/?E200-500)

• High-resolution camera (HRC) Micro-Channel Plate
• Advanced CCD Imaging Spectrometer (ACIS)
• Low Energy Transmission Grating Spectrometer
  (LETGS) 0.08-2 keV, E/?E30-2000 (HRC-S)
• High Energy Transmission Grating Spectrometer
  (HETGS) 0.4-10 keV, E/?E?1000 (ACIS-S)

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XMM-Newton

• Spatially resolved (15) low-resolution
  spectroscopy (E/?E20-50)
• Intermediate resolution dispersive spectrometry
  (0.03-0.06 Ang, E/?E200-500)

• EPIC (3) CCD spectroscopic imaging cameras
  0.1-12 keV
• (2) Reflection Grating Spectrometers (RGS)
  0.05-3 keV
• (1) Optical monitor (OM) Optical/UV imaging and
  grism spectroscopy.

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Comparison between Chandra and XMM-Newton

• XMM-Newton
• Effective area 0.4 m2
• Angular resolution 15 HEW
• Limiting sensitivity 10-15 erg cm-2 s-1

• Chandra
• Effective area 0.08 m2
• Angular resolution 0.5 HEW
• Limiting sensitivity lt10-16 erg cm-2 s-1

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New windows Hard X-ray energies
Sensitivity to hard X-ray energies (up to 12
keV with XMM-Newton)
Absorbed sources can be seen!
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New windows high-resolution imaging over wide FOV
XMM-Newton images a FOV of 30 with moderate
resolution (15)
Chandra images down to Sub-arcsec
resolution (0.5-1)
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New windows moderate resolution dispersive
spectroscopy
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The inner disk Fe line diagnostics
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Radiation from the accretion disk
Reflection
Incident radiation
Emission
Transmission
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Reflection from cold matter
George Fabian 91
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XMM-Newton spectrum of the Circinus Galaxy
Molendi, Bianchi Matt 03
Fe Ka,ß and Ni Ka
Fluorescence lines
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Reflection from photoionized matter
(Ross Fabian 93, 04)
Increasing ionisation parameter
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Relativistic line broadening
Schwarzschild
Kerr
Fabian et al 91
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Discovery of broad Fe lines
MCG-6-30-15
ASCA Tanaka et al 1995
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More broad lines in AGN
MCG-5-23-16 (Dewangan 2003)
NGC 3516 (Turner 02)
PG 1211143 (Pounds 2003)
IRAS 18325 (Iwasawa 2004)
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XMM-Newton observations of the Fe line in
MCG-6-30-15
pn
MOS 1,2
Vaughan 04
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Simultaneous XMM-Newton and BeppoSAX observations
of MCG-6-30-15
Compton reflection hump
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Spectral changes seen in MCG-6-30-15
The Fe line stays virtually constant, in spite
of strong changes in the continuum NO
REVERBERATION?
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Understanding spectral variability in MCG-6-30-15
Spectrum of the variable component
Spectrum of the constant component
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Light bending model in a Kerr BH
Miniutti et al 03,04
Kevin Rauch JHU
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Fe line PLC correlation
III
II
I
Regime III large source height and
anti-correlation
Regime II intermediate source height and
constant Fe line
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The variety of Fe line profiles
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More relativistic emission lines?
Lee et al (2001)
XMM
Chandra
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Ionised absorbers, outflows and jets
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Warm absorbers the low resolution view
H1419480 z0.07229
X-ray ionized absorbers Associated UV
absorbers
Barcons, Carrera Ceballos 2003b
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The high-resolution view of warm absorbers
Sako et al 2001
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NGC 3783 (Krongold et al 2003)
Chandra/HETGS
100 features detected Two-phase absorbing
medium, pressure equilibrium Outflowing velocity
750 km/s Turbulence 300 km/s
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Jets detected in X-rays
Pks 0637-752 First point-like target for
Chandra
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Jets commonly seen in X-rays
Cen-A
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M87
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3C273
MERLIN
HST
Chandra
SEDs indicate that synchrotron might be dominant
in most knots, but additional processes might Be
required in other cases.
Marshall et al (2001)
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Binary BHs in the centres of AGN
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Challenges to the AGN unified model
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The unified AGN scheme confronts X-ray
observations
Since type 2 AGN are seen through absorbing
material, they should display higher photoelectri
c absorption in X-rays

• but there are apparent
• discrepancies
• Type 1 AGN with absorbed X-ray
• spectra
• Type 1.8/1.9/2 AGN with low or
• no photoelectric absorption

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Type 1 AGN (moderately) absorbed in X-rays
XMMU J061515.2710204
S 0.5-4.5 keV 7.2 x 10-14 erg cm-2 s-1
XMM
NH2.8?1021 cm-2
z0.872
L 2-103.2?1044 erg s-1
WHT/ISIS
Broad-Line AGN
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A type1.9 AGN with no absorption
XMM-Newton Disk reprocessing Absorptionlt1020
cm-2
H1320551, z0.0653 Seyfert 1.8/1.9 H?/H?gt27 Expec
ted absorption gt1022 cm-2
Barcons, Carrera Ceballos 2003
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Photoelectric absorption

• The AXIS survey
• Slim(0.5-4.5 keV)10-14 erg cm-2 s-1
• 10 of type 1 AGN are absorbed
• (with NHlt1022 cm-2)
• 40 of type 2 AGN are absorbed

• The Lockman Hole survey
• Slim(0.5-4.5 keV)10-14 erg cm-2 s-1
• 15 (lt30 at 3?) of type 1 AGN
• are absorbed (with NHlt1022 cm-2)
• 80 (gt50 at 3?) of type 2 AGN
• are absorbed. But 5/28 are unabsorbed

Mateos et al (2004b)
See talk by Maite Ceballos
Mateos et al (2004a)
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Options/explanations

• The 10-15 of absorbed type 1 AGN could be BALs,
  or hosted by edge-on galaxies this should be
  testable
• Unabsorbed type 2 AGN
• These are Compton-thick Seyfert 2 galaxies, where
  only unabsorbed scattered X-rays are seen but Fe
  line is weak or absent and should be very strong
• Optical spectroscopy properties and X-ray
  absorption agree with each other, but the
  absorbing material varies should be testable
  with simultaneous X-ray and optical spectroscopy
• The optical spectroscopic properties are
  intrinsic to the Broad Line Region, and not
  associated to absorbing material.

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X-ray/optical mismatches variability?
Simultaneous XMM-Newton and 3.5m/CAHA
spectroscopy of Mkn 993 z0.0155 (Changing type
Seyfert)
Poster by A. Corral
Optical spectral type intrinsic to BLR, not due
to absorption
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X-ray Surveys, obscured accretion and the X-ray
background.
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The XMM-Newton Survey Science Centre
serendipitous sky Surveys

• Thanks to its large field of view and
  sensitivity, every XMM-Newton pointing discovers
  30-150 serendipitous X-ray sources.
• The 1XMM source catalogue contains 30000 sources.
  The 2XMM catalogue will contain 150000 X-ray
  sources
• The Survey Science Centre sky survey consists of
• Core programme
• Bright Source Sample
• Medium Flux Survey
• Faint Surveys (i.e., LH)
• Galactic Plane Surveys
• Optical imaging programme of many XMM-Newton
  fields
• Statistical identification of many catalogued
  sources

OY Car
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The X-ray background and the AGN unified model

• The spectral energy distribution of the XRB peaks
  at 30 keV, far beyond existing X-ray telescopes.
• Unified model The XRB is produced by a
  superposition of unabsorbed and absorbed AGN.
• Predictions
• The majority of accretion onto super-massive
  black holes is absorbed
• A large number of type 2 QSOs is expected.

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Optically dull, X-ray luminous galaxies
Severgnini et al (2003)
XMM
?1.7 NH2 1023 cm-2
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Type 2 (Radio) QSOs

• Selected by its X-ray
• emission
• Only narrow emission lines
• at z1.246
• X-ray luminosity gt 1045 erg/s
• Double-lobed radio-source
• X-ray emission unrelated
• to radio lobes
• Normal AGN mildly
• absorbed in X-rays

RX J1011.25545
WHT/ISIS
XMM
VLA
XMM
NH4 1022 cm-2
Barcons et al 1998 Barcons et al 2003
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Type-2 Radio-Quiet QSOs
z2.978 (Ly?, CIV, CIII) X-ray flux (2-10 keV)
8 10-15 erg cm-2 s-1 Intrinsic X-ray luminosity
4 1044 erg s-1
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The various classes of AGN
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Optical colours of X-ray sources
Early-type galaxies
QSOs
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The Chandra deep fields

• The bulk of X-ray emissivity (50) in the
  Universe (AGNs) occurs at zlt1
• Sources are increasingly reddened in the optical,
  including EROs.

Tozzi et al 2001, Barger et al 2003, Alexander et
al 2003
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The redshift distribution in deep X-ray surveys
Mostly AGN-1
Mostly AGN-2
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Obscured accretion

• Most of the growth of the black holes by
  accretion occurs in obscured sources.
• Assuming that the growth of BHs is dominated by
  accretion and not by mergers, the local BH
  density can set constraints on the amount of
  obscured accretion

Salvati et al (2004)
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Some questions for the future

• Perform reverberation mapping on relevant
  timescales.
• Test properties of supermassive black holes out
  to very high zs (mass, angular momentum,
  accretion rate)
• Reach the thermal limit in X-ray
  high-resolution spectroscopy to do proper
  Astrophysics on circumnuclear matter
• Trace the cosmic evolution of obscured and
  unobscured accretion
• What was first Supermassive Black Holes or Stars
  in the history of galaxies?