AGN and Surveys with the new X-ray observatories

JENAM, 13 Sep 2004 AGN and Surveys with the new X-ray observatories

AGN and Surveys with the new X-ray observatories

Xavier Barcons

Instituto de Física de Cantabria (CSIC-UC)


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


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


The X-ray view of an AGNThe X-ray view of an AGN

C. Done, Durham U


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)


The new X-ray observatories

Chandra (NASA)July 1999

XMM-Newton (ESA)December 1999


How does an X-ray telescope work?


Chandra

• High-resolution camera (HRC): Micro-Channel Plate

• Advanced CCD Imaging Spectrometer (ACIS)

• Low Energy Transmission Grating Spectrometer (LETGS): 0.08-2 keV, E/E=30-2000 (+HRC-S)

• High Energy Transmission Grating Spectrometer (HETGS): 0.4-10 keV, E/E1000 (+ACIS-S)

• Spatially resolved (0.5“) low resolution spectroscopy (E/E~20-50)

• Intermediate resolution dispersive spectroscopy (0.02-0.04 Ang, E/E~200-500)


XMM-Newton• Spatially resolved (15“) low-

resolution spectroscopy (E/E~20-50)

• Intermediate resolution dispersive spectrometry (0.03-0.06 Ang, E/E~200-500)

• 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.


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: <10-16 erg cm-2 s-1


New windows: Hard X-ray energies

Sensitivity to hard X-rayenergies (up to 12 keV

with XMM-Newton) RosatXMM/Chandra

log NH=

Absorbed sources can be seen!


New windows: high-resolution imaging over wide FOV

XMM-Newton imagesa FOV of 30’ with

moderate resolution (15”)

Chandra images down to Sub-arcsec resolution

(0.5-1”)


New windows: moderate resolution dispersive spectroscopy


The inner disk: Fe line diagnostics


Radiation from the accretion disk

Incident radiation Reflection

Transmission

Emission


Reflection from cold matter

George & Fabian 91


XMM-Newton spectrum of the Circinus Galaxy

Fe Kα,β and Ni Kα

Molendi, Bianchi & Matt 03

Fluorescence lines


Reflection from photoionized matter(Ross & Fabian 93, 04)

Incr

easi

ng io

nisa

tion

para

met

er


Relativistic line broadening

Schwarzschild

Kerr

Fabian et al 91


Discovery of broad Fe lines

ASCATanaka et al 1995

MCG-6-30-15


More broad lines in AGNMCG-5-23-16 (Dewangan 2003) NGC 3516 (Turner 02)

PG 1211+143 (Pounds 2003) IRAS 18325 (Iwasawa 2004)


XMM-Newton observations of the Fe line in MCG-6-30-15

pn

MOS 1,2

Vaughan 04


Simultaneous XMM-Newton and BeppoSAX observations of MCG-6-30-15

Comptonreflectionhump


Spectral changes seen in MCG-6-30-15

The Fe line stays virtually constant, in spite of strongchanges in the continuum:

NO REVERBERATION?


Spectrum of the variable component

Understanding spectral variability in MCG-6-30-15

Spectrum of the constant component

Fe line


Light bending model in a Kerr BH

KevinRauchJHU

Miniutti et al 03,04

JENAM, 13 Sep 2004 AGN and Surveys with the new X-ray observatoriesRegime III: large source height and anti-correlationRegime II: intermediate source height and constant

Fe line

IIIIII

Fe line – PLC correlation


The variety of Fe line profiles

Reeves et al (2001)

Disk

Torus

XMM

Nandra (2001)

ASCA


More relativistic emission lines?

Branduardi-Raymont et al (2001)Lee et al (2001)

ChandraXMM


Ionised absorbers, outflows and jets


Warm absorbers: the low resolution viewH1419+480

z=0.07229

IUE

XMM-Newton

Barcons, Carrera & Ceballos 2003b

X-ray ionized absorbers ~“Associated” UV absorbers

Photoionisation edge


The high-resolution view of warm absorbers

Sako et al 2001

Fe MUnresolvedTransition Array (UTA)

Low ionisation component

High ionisation component


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


Jets detected in X-raysPks 0637-752:

First “point-like” targetfor Chandra


Jets commonly seen in X-rays

Cen-A


M87


3C273

Chandra

Marshall et al (2001)

MERLIN HSTChandra

SEDs indicate that synchrotron might be dominant in most knots,but additional processes mightBe required in other cases.


NGC 6240

Binary BHs in the centres of AGN

ChandraKomossa et al (2002)

NGC 6240

Starburst

AGN


Challenges to the AGN unified model


The unified AGN scheme confronts X-ray observations

Maiolino (2001)

Since type 2 AGN are seen through absorbing material, they should display higherphotoelectric absorption in X-rays

… but there are apparent discrepancies:•Type 1 AGN with absorbed X-rayspectra•Type 1.8/1.9/2 AGN with low orno photoelectric absorption


Type 1 AGN (moderately) absorbed in X-rays

S 0.5-4.5 keV= 7.2 x 10-14 erg cm-2 s-1

z=0.872 NH=2.81021 cm-2

Broad-Line AGN

L 2-10=3.21044 erg s-1

WHT/ISIS

XMM

XMMU J061515.2+710204


A type1.9 AGN with no absorption

Barcons, Carrera & Ceballos 2003

H1320+551, z=0.0653Seyfert 1.8/1.9H/H>27Expected absorption: >1022 cm-2

XMM-Newton:Disk + reprocessingAbsorption<1020 cm-2


Photoelectric absorptionThe AXIS surveySlim(0.5-4.5 keV)~10-14 erg cm-2 s-1

•10% of type 1 AGN are absorbed(with NH<1022 cm-2) •40% of type 2 AGN are absorbed

Mateos et al (2004a)

The Lockman Hole surveySlim(0.5-4.5 keV)~10-14 erg cm-2 s-1

•15% (<30% at 3) of type 1 AGN are absorbed (with NH<1022 cm-2) •80% (>50% at 3) of type 2 AGN are absorbed. But 5/28 are unabsorbed

Mateos et al (2004b)

See talk byMaite Ceballos


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.


X-ray/optical mismatches: variability?Simultaneous XMM-Newton and 3.5m/CAHA spectroscopy ofMkn 993; z=0.0155 (Changing type Seyfert)

3.5m/TWINXMM

Optical: Seyfert 1.8Balmer decrement=9(NH~ 5 1021 cm-2)

X-ray: weak absorption (NH~ 7 1020 cm-2)

Poster by A. Corral

Optical spectral typeintrinsic to BLR,

not due to absorption


X-ray Surveys, obscured accretion and the X-ray

background.


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


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.

Gilli et al 2000


Optically dull, X-ray luminous galaxies

z=0.044LX=1042 erg/s

TNG

Subaru

=1.7NH=2 1023 cm-2

XMM

Severgnini et al (2003)


Type 2 (Radio) QSOs•Selected by its X-ray emission•Only narrow emission lines at z=1.246•X-ray luminosity > 1045 erg/s•Double-lobed radio-source•X-ray emission unrelatedto radio lobes•“Normal” AGN mildly absorbed in X-rays

Barcons et al 1998Barcons et al 2003

XMM

VLA

RX J1011.2+5545

NH=4 1022 cm-2

XMM

WHT/ISIS


Type-2 Radio-Quiet QSOs

AAT/2dF(Mat Page)

XMM

NH~5 1022 cm-2

z=2.978 (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


The various classes of AGN

15

16

17

18

19

20

21

22

23

24

25

1 10 100

X-ray flux 0.5-4.5 keV (10-14 erg cm-2 s-1)

r/R

op

tica

l mag

nit

ud

e

FX/Fopt=1

FX/Fopt=10

FX/Fopt=0.1

AGN

Obscured AGN

Gal


Optical colours of X-ray sources

Optical colours

-1,0

-0,5

0,0

0,5

1,0

1,5

2,0

2,5

3,0

-1,0 0,0 1,0 2,0 3,0

g'-r'

r'-i

'

QSOs

Early-typegalaxies


The Chandra deep fields

• The bulk of X-ray emissivity (50%) in the Universe (AGNs) occurs at z<1

• Sources are increasingly reddened in the optical, including EROs.

Tozzi et al 2001, Barger et al 2003, Alexander et al 2003


The redshift distribution in deep X-ray surveys

Barger et al (2003)

MostlyAGN-2

MostlyAGN-1


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)


Some questions for the future

• Perform reverberation mapping on relevant timescales.• Test properties of supermassive black holes out to very

high z’s (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?

Documents

AGN and Surveys with the new X-ray observatories