Transcript R.Mushotzky_Future_HE_Mission2006 - X

X-ray Astronomy in the Next Decade
90% of the matter in the universe can only be seen via x-ray observations
main science themes and
• Cosmology
nature of dark matter
cosmic geometry
large scale structure
the role of x-ray observations
•Amount of and distribution of dark
matter in “spherical systems”
•How do AGN influence their galaxy
and how does this change with cosmic
time
•direct observation of star formation
• Galaxy formation and evolution- rates, chemical abundances and galactic
winds over a wide range of redshifts
• Extreme environments of
astrophysics
massive black holes
end stages of stellar evolution
•How does accretion work, physics of
black holes and neutron stars
Thanks to : C. Done, Y. Ueda, T. Boller, J. Tueller
Meeting Summary - AGN
• It is not possible to properly review
the wide variety of observations,
theory and instrumental technique
Chandra Obs of Hydra-A
• I will focus on what are ( I believe) are
the important science problems and
“Forget the technology”
I will not give specific numbers (e.g.
energy resolution, spatial resolution,
sensitivity) this has been well covered
in the talks on specific missions
I personally believe that we have the
technology to make major steps
forward
As Suzaku has shown even ‘small’
improvements can have major science
implications
Direct evidence for AGN influence
on cluster scales
Properties of active galaxies
• Energy due to accretion onto a Massive Black Hole
(but other processes may be at work)
exact mechanism which produces radiation is not known
• strong dynamical evidence for MBH from optical velocity data and x-ray
timing data
mass estimates are accurate to ~ 2-4.
• Strong connections between the host galaxy and MBH masses
• The Eddington ratio ranges from <10-7 to >1
• Relativistic effects very important in radio loud AGN -what is the role of
jets in the energy budget of the sources ?
4 Main areas of AGN research
• What is nature of the source of energy
– Accretion
– Spin
– ?
• Physics of matter close to a black hole (e.g. strong gravity)
• Affect of AGN on formation and structure of the universe
• physics of the radiation- what produces the photons (thermal, non-thermal,
relativistic phenomena)
Major issue : how to we communicate to our colleagues the importance of high energy
astrophysics.
I think that our theme should be
How the universe came to be the way it is
“Without x-rays life itself would be impossible”
What are the fundamental questions?
•
1) How do AGN "work"- e.g. how is energy produced/extracted and transformed
into radiation. What is the role of relativistic effects
• 2) How is the MBH connected to host galaxy
– how do they form and affect the galaxy
– how do they affect the formation and structure of the universe
• 3) What is the origin of the wide range of apparent types?
- what causes the difference (Unified Models)
• 4) How do they evolve with cosmic time? (Mass, luminosity, number)
• 5) What can we learn about strong gravity ?
• 6) What is the nature/geometry of the central regions ? (winds, disks, torus, jets)
• 7) What is the source of the material responsible for accretion and how does it
accrete
Big questions: strong gravity
• Accreting BH: huge X-ray
luminosity close to event
horizon
• Bright emission from
region of strong spacetime
curvature
• Spectral distortions
depend on velocity,
geometry and GR
• Observational constraints
on strong gravity if we
know velocity/geometry!
• Need to understand
accretion!
The sensitivity of missions circa 1980
• For AGN
Chandra,XMM
are well matched
to Hubble and
Spitzer for
imaging but not
for spectroscopy
• For next
generation (JWST,
ALMA, TMT) xray astronomy
needs much better
sensitivity
Active Galaxies in the post XMM/Chandra Era
Why are active galaxies interesting in the x-ray?
• AGN - most numerous class of extragalactic x-ray source (above F(x)>10-14
ergs/cm2/sec) - can be seen out to z~6 by XMM and Chandra
• "x-ray" (0.1-100 keV) band has ~0.05-0.3 (1.0?) of the total energy
• x-rays originate very close to the supermassive black hole (MBH) - x-ray band most
"rapidly" variable of all wavelength bands x-ray band
• x-ray band has the only spectral signature that originates close to MBH
– the "Fe K" line
• X-ray band is the most efficient way of finding AGN
– Many/most x-ray selected AGN cannot be detected by optical techniques
• Significant x-ray radiation from jets (in plane of sky and in "Blazars" )
• All types of AGN are luminous x-ray sources
(Bl Lac, Quasar, Seyfert I/II, LINER, NLAGN. BLRG......)
– Intrinsic luminosity covers an extremely wide range <1040 ergs/sec (Ho et al
2001)- 1047 ergs/sec (Fabian et al 1997)
The last 6 years - XMM and Chandra
• Vast improvement in
• grasp
• high spectral resolution
• multiwavelength capability
• angular resolution
• sensitivity
XMM/Chandra are ideally suited for
• extending previous studies to fainter, higher redshift, higher
– and lower luminosity systems
• detailed studies of many bright low redshift objects.
• critical progress in the temporal/spectral domain
Combined with other facilities
• building up a complete picture of the multiwavelength spectrum of active
galaxies as a function of redshift, type and luminosity probing the evolution of
quasars over the lifetime of the Universe.
• examine structure of the central engine in Seyfert galaxies via observations of their
multiwavelength spectral properties and time dependent spectral signatures
Some of the new unexpected results
(a biased list)
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narrow absorption lines are strongest features in grating obs of Seyfert I galaxies– total opacity dominated by edges-low E emission lines are weak
• Almost certainly due to winds carrying significant energy/momentum
Extended line emission from OVII and Fe K (NGC4151, Circinus)
– Extended soft x-ray regions (NGC4945,Circinus etc) Chandra images.
Fe K lines are very complex- lots of velocity structure
Narrow +broad Fe K lines are common- but not ubiquitous
ionized Fe K lines detected -Chandra grating obs.
Seyfert II galaxies are photoionization dominated--grating observations
Majority of AGN in the universe do not have strong optical lines or bright optical nuclei– XMM and Chandra deep fields
Serious difference between optical and x-ray classification schemes
(SAX, XMM and Chandra serendipitous sources)
X-ray selected AGN evolve very differently than optically selected objects
peaking at z~1
Direct x-ray detection of cold material via resonance absorption
lack of strong absorption features in Bl Lacs- grating
first features in power density spectra (XTE and XMM) -lack of simple correlation
between UV and X-ray
"real" soft excess have been detected XMM-EPIC
What have been the new exciting observations?
(Suzaku additions )
•
•
Reality of reflection and broad lines - broad band spectra allow ‘unique’ deconvolution
of continuum
No simple relation between reflection and Fe K lines
Confirmation of Complex time variability across wide energy range
• Confirmation of complex shape of Fe K lines
Simultaneous Suzaku and XMM
Observation- notice the excellent
Iron line Profile of
MCG -5-23-16
Ratio to =1.8 PL
agreement on Fe K line shape
EPIC-PN
Suzaku XIS
Red-wing
Fe K Core (peak energy
at 6.397 keV - within
10eV for PN and XIS)
Fe K (at 7.06 keV)
Fe K edge (at 7.1 keV)
AGN viewed edge-on
through the optically
thick torus
Black Hole Finder?
Chandra results show that
many AGN lie in the
nuclei of optically normal
galaxies
Photons/cm s2 keV
The Seyfert II Galaxy NGC 4945
ASCA
Ginga
AXAF/XMM energy band
Black hole finder
energy band
Energy (keV)
The present paradigm for AGN
consists of a black hole,
accretion disk, and a physically
thick region of obscuration (“the
torus”)
Most lines of sight to the AGN are
“blocked” by the torii which has
an effective column density
>1023atms/cm2,
The torii are optically thick in the
near-IR,optical, UV and soft x-ray
band
A detection in the hard x-ray band
of a source with Lx>1040.5. ergs/s
is a direct indictor of a AGN
What is required to make
progress ??
Relation of soft to hard x-ray flux
The requirements to answer the major
questions are NOT THE SAME- thus
requiring either several missions or a
wide range of capabilities
• The evolution of AGN and the
x-ray background
– Chandra and XMM have probed the
z=0.5-3.0 universe in the restframe 120 keV band- however models of the
x-ray background indicate that they
may have missed up to 50% of the
sources
– Need the 15-50 kev band at z<1 Models of XRB background highly
• Many AGN have high absorbing
columns
• I.e. they can be “hidden” from line of
sight in optical, UV, soft X-ray
• Hard X-ray band (> 15 keV) is one
window where opacity is low
needed to make a census of AGN
sensitive to spectral
assumptions(Ueda) -2 models that
accurately predict 2-10 kev Log NLog S have factor of 2 difference in
20-100 kev band
Luminosity Function in 20-200 Compared to 2-10 kev
• See systematic trend of more sources
at lower luminosity in 20-200 keV
survey -e.g. 2-10 keV survey miss a
large fraction of sources at L<1043
ergs/sec at z=0
20-200 keV
2-10 keV
Hard x-ray survey
reaching to z~1 is crucial
for AGN evolution and
luminosity function .
Nature of Hard X-ray selected sources
• Followed up Swift BAT
selected sources with
XMM, Suzaku and
XRT
• Wide range of x-ray
spectra
• Many of the Ids have
– no optical evidence
for activity in
literature even
though they are very
low z bright galaxies
Obvious why soft and hard x-ray
band are uncorrelated
What is Needed
ACCURATE MEASURE OF OBSCURATION:
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Required in order to accurately determine the AGN contribution to the energetics of the
host galaxy emission
Properly calculate the obscured:unobscured AGN ratio vs X-ray luminosity-true census of
AGN in universe
PROPERTIES OF THE CENTRAL ENGINE:
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Study high accretion rate processes (many luminous sources are likely to be growing their
black holes at close to the Eddington limit)
Compare the accretion and obscuration properties of obscured and unobscured AGN
Constrain relativistic vs ‘thermal’ processes
AGN FEEDBACK IN THE FORMATION OF MASSIVE GALAXIES:
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Measure the properties of outflowing gas and estimate their effect on the formation of
massive galaxies and the enrichment of the intra-galactic medium
Observe the direct effects of relativistic particles
“TRACING THE BLACK-HOLE GROWTH OF MASSIVE GALAXIES”
Origin of X-ray Background
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Pre-Chandra results indicate that the background was made up of the superposition of a huge
number of very faint sourcesby 1980 it was clear that the number of objects required to make up the XRB exceeded
(in surface density) that of known AGN by >10
However the x-ray spectra of the objects detected (clusters of galaxies, active galaxies,
blazars etc) showed that none had the spectrum of the x-ray background out to 200 keV (!)-
– this is the so-called "spectral paradox"
E-2
200 keV
BAT UL
Spectrum of bright sources from
Swift
------------
A possible answer
• The main assumption - most of the
flux is produced by supermassive
black holes in the center of galaxies
containing large amounts of dust and
gas and thus having x-ray spectra
dominated, at low energies, by
photoelectric absorption.
• Suitable algebraic superposition- just
the right number of objects, evolving
the right way with redshift, with the
right distribution of column densities
can produce the volume emissivity,
log N-log S and the x-ray spectrum.
• Such models are remarkably
flexible. (Ueda)
Spectrum of individual objects sums
to XRB spectrum
Swift BAT and Integral sources
AGN Evolution
Strong selection effects- low luminosity
sources more absorbed than high
luminosity sources
•
Differential evolution of low vs high z
sources
UN-Absorbed fraction
1
1
1
0.1
•
Radio loud
Blazar
Compton thick
Z=1
L(x) 20-100 kev
•Probable evolution of N(H)/L
distribution with redshift- numbers are
very uncertain
•z~1 is where ‘most’ of XRB originates
• to get to Log L(x)=43 at z=1
Z=0.6
requires a sensitivity of ~2x10-15
ergs/cm2/sec in 20-200 keV band
•NEED HARD X-RAY Imaging
Z=0.25
Log L(x) 2-10 kev
42
43
44
45
46
NeXT Has the capability to resolve ~50% of XRB in 20-40 keV band
•
With ~100 srcs/deg^2 - 2-4 sources per NeXT field of view at 3x10-14
ergs/cm2/sec
– Need ~100 fields to perform survey with exposure of 100ks per field
to ‘solve’ XRB
Ueda+ 03
Fraction of Compton thick AGNs
NeXT limit
~40-50% XRB
10-30 keV Survey
BAT
2-8 keV Survey
NeXT
How the Observable Universe Came to Be
•
Dark matter evolution in the universe now
understood
– it is not at all understood how
‘baryonic structures’ (galaxies,
groups, clusters) form.
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For models to fit the data additional
physics (beyond gravity and
hydrodynamics) is required (heating,
cooling, mass and metal injection, gas
motions etc)
Up until now this has been parameterized
in ‘semi-analytic’ models - just so stories
•
The critical problem in all of astrophysics
is to put physics into these stories
•
Ideas and material stolen from
M.Begelman, TJ Cox, D. Croton, T.
DiMatteo, I. George, C. Martin, J.
Ostriker, V. Springel, C. Steidel, S.
White…
Semi-analytic modeling
Formation of Large Scale
structure
1/2 stars formed
The standard theory of the formation of
structure by the evolution of dark matter
halos has been remarkably successful
But it has several “missing
pieces”/problems
•How does gas become galaxies, clusters
and groups?
•What is the origin of the “feedback”
process that controls efficiency of
conversion of gas in to stars and governs
the star formation rate in the universe?
•Do galaxies actually form via cooling
and what is the interaction with star
formation ?
•How is the chemical evolution of
galaxies connected with their formation ?
z
Growth of galaxy mass vs redshift
50% of mass created at z<1 (Drory et
al 2004, astro-ph 412167)
Strong relation of Galaxy to Black hole and SF to BH Growth
Black holes create and
are influenced by their
environment
Star forming history vs
accretion history Marconi+ 0
How the universe came to be
the way it is
What has changed in the last 4 years
• We now know (Barger et al 2004, Heavens
et al 2004, Conselice et al 2004, lots more)
that
– at z>1.5 the universe is very
different from today
– Most stars in the universe formed
from 0.3<z<1.5
– The epoch of black holes is z~1
– Cluster evolution is doing
something quite interesting at z~1
•
We need to study the z~1 universe (AGN,
clusters and galaxy/star formation) in great
detail
•
Only x-ray astronomy can measure how,
where and when most of the energy that
controlled how universe formed was
produced
Barger et al 2005
Stellar mass density
When did the stars form?
•
Integration of the SFR rate
would give the 1/2 mass
redshift at z~1.5
• This agrees with the new
x-ray data for AGN
reinforcing the coevolution of black holes
and galaxies
Stellar mass density/year
• Recent work (e.g Bell et
al 2004, Heavens et al
2004, Rudnick et al
2003) shows that ~1/2 of
all stars form at z<1
The AGN History of Universe- X-ray Selected AGN
• Even including
upper limits there
is less energy
emitting per unit
volume at z>1
Barger et al 2005
X-ray selected
AGN have a
similar
evolution to
total star
formation rate
at z<2
type I AGN,
all objects
Open box- assigning all objects without a redshift to
to redshift bin
Comparison of Energy Densities and Evolution
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Optical samples miss most of the
energy radiated by BHs at z< 2
Most of the AGN luminosity is due to
M~10 7+/-1 M objects
The x-ray data show that lower mass
black holes evolve later and grow more
than more massive objects.
5x
When BHs get their mass
z
Marconi et al 2004
Energy densities from AGN from
Optical (---) x-ray (-------) surveys
Each line is the growth of a
Massive BH vs z
Formation of structure in the Universe
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Detailed numerical
calculations of the
formation of structure via
the collapse of
gravitational perturbations
in a LCDM universe
(Springel et al 2003,
White et al 2004) cannot
‘produce’ the present day
universe without invoking
‘feedback’ (the injection
of energy, heat
momentum)
Similar results are
obtained in analytic work
(Ostriker and colleagues)
The nature of the
feedback is not clear, but
must be related to star
formation and AGN - the
only possible sources with
sufficient energy
Calculation of K band
galaxy luminosity
function in N body
simulation
Gravity+
hydrodynamics no
AGN+ starburst+
reionization - get low
luminosity range
‘right’
Gravity+ hydrodynamics
only- get it all wronglow luminosity, slope,
high luminosity slope and
number and mass in
galaxies
Blue lines are datablack models
Gravity+ hydrodynamics
+AGN+ starburst+
reionization - get it all
‘right’
Thanks to V. Springel
and S. White
Springel 2004
AGN Heating and Groups
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the x-ray luminosity and
entropy profiles (Lapi et
al, Dave et al, Borgani et
al) cannot be produced by
pure gravitational effects
- the effects of star
formation and cooling are
not sufficient to produce
the observed entropy
profiles
AGN heating (both
internal and pre-heating)
of same order to solve the
galaxy formation problem
‘works’ to solve entropy
problem - may not solve
cooling flow problem
------------ just hydro
------------ star formation
------------ AGN +SFR
L(X)
L(X)
The first black holes
• This maybe the
mechanism by which
AGN ‘heat’ the
universe
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Log N(H)
Winds In AGN
In >1/2 of all high S/N Chandra/XMM
observations of AGN one detects
ouflowing winds
Kaastra et al 2003
In deep fields ~15% of luminous galaxies
are x-ray sources (high duty cycle)
Log ionization
V~500-2000km/sec
Mass and energy flux in wind is rather
uncertain (Chelouche 2005) but may reach
Lwind~0.1Lradiation
Need to obtain time resolved, high
Maybe more mass/momentum at higher
ionization states
resolution spectra for a large number of
objects to get accurate estimates of mass and
energy flux in wind and dependence on
AGN parameters
What is needed?
• High resolution spectra of
objects to understand the
winds, the evolution and total
energy - only x-ray spectra can
determine whether AGN can
influence structure formation
in the universe
• High resolution at E= 6 kev in
the rest frame to detect the
momentum majority of the
wind.
• High resolution spectra for
extended sources to see the
velocity structure in clusters
and groups and determine the
relative importance of winds or
jets
Mass outflow from high resolution spectra
Courtesy Ian George
What are the spectral signatures- Very High Velocity Outflows
Very High Velocity Outflows
•
In several objects outflow
velocities of ~0.1c are
detected (Hasinger et al
2003, Pounds et al 2002,
Reeves et al 2003) implying
very high energy and mass
loss rates.
•
These high velocities are
only seen in the Fe K lines
•
Its possible that such
features are common but
hard to see in CCD spectra
Q uic
kTim e™and a
TI F ( Pac
kBit s) deco
m pr ess
or
ar eneede
d t osee this pictur e.
PG1211- blue shifted resonance Fe absorpt
feature V~0.08c (Reeves et al 2003)
Need high spectral resolution at E~6 keV
How Do the AGN Influence their environment?
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Radio jets/double sources
Mechanical winds
Radiation
Each one of these has
visible and testable effects
radiation effects have to occur
(Sazonov et al 2004) and can
photo-ionize and Compton heat
the gas in the host galaxy to
kT~2x107k- almost exactly what
is needed for the ‘entropy’
problem.
• However the gas is only heated at
R< 0.5-10 kpc and thus can
strongly effect spheroid evolution
but not groups or clusters.
M=108
•
M=109
Direct Evidence From Chandra Images of Influence of Black
holes on their Environment- the effect of relativistic particles
X-ray temperature Map of
Perseus cluster- AGN at the
center
131 kpc
• Chandra x-ray image of Cygnus-A
Cluster of Galaxies with AGN in
center (Wilson et al 2002)- notice
the structure related to the radio
source
Fabian et al. 2003
Observable consequences of AGN heating in a gaseous
environment
A3667 (z = 0.055)
• Turbulence/velocity shear from
line shapes
• transport properties/dissipation
• Precise abundances
• Radiative energy of nucleus
• magnetic field from IC
scattering ( hard emission)
• Thermal state of the gas
• Optical depth of gas (resonance
scattering) allows details of
velocity
Astro_E2 simulations of
cluster velocity field
1000 km/s
A2256 (z = 0.058)
1000 km/s
How Can We Tell is the Fe Line is really broad
•
In NGC3783 (Reeves et al ) the XMM long look data
do not have a “need” for a broad Fe K line but
apparently require a complex highly ionized absorber.
•
Such absorption components must contain features due
to Fe K shell transitions
seen as a “sea” of Fe resonance absorption lines from a
variety of ionization states
Such features are diagnostic and remove the ambiguity from cold
or ionized absorbers or reflection features
XRS
Physics of the Central Region
• Only x-ray astronomy has the diagnostics to determine what is
occurring near the Black hole
• Need
– broad band pass,
– high signal to noise
– High spectral resolution
Probing the Central Regions
of Black Holes
Possible geometries near
the black hole
• The x-ray spectral features due to
reprocessing (Fe-K line complex,
Compton reflector) are probes of the
matter distribution near the black hole
(Reynolds and Novak 2003)
Theoretical spectra from an ionized
accretion disk Ballantyne et al
High spectral resolution at high S/N is
crucial
Components of the X-ray AGN Spectrum
• The high energy cutoff
and power law slope
contains information
on the nature of the
continuum and its
origin
(Comptonization??
• The origin of the ‘soft
excess’ is not clear- it
is due to reprocessing,
absorption by a
relativistic wind, or is
it a continuum
component
• The ‘Compton hump”
and Fe K line come
from reprocessing of
the x-rays by ‘cold’
material -somewhere
Shape of Fe K line
The detailed line shape carries
Information about spin of the BH ,
geometry and distribution of material
near the black hole (Reynolds and Novak
2003)
Line shape as a function of geometry
Line shape as a function of inclination from a
rapidly spinning black hole
Line shape as a function of black hole spin
Time variability of Fe K line
• It is not expected
that the line shape
will be stationarythe disk has many
instabilities and the
detailed variation of
the line shape with
time carries much
information
• The prime
requirement is high
signal to noise with sufficient
energy resolution
XMM/Suzaku data
have just barely
enough S/N to
detect such events
Reynolds and Armitage 2004
Time behavior of Fe K
line in NGC3516
Iwasawa, Miniutti &
Fabian 2004
Strong gravity and black hole physics
Broad iron lines as probes of strong gravity
- power of line variability
- orbiting structure on disk and probes of time-like paths in metric
- relativistic reverberation and probes of null paths in metric
* Demographics of black hole mass and spin
- implications for SMBH formation
- strong gravity and spin across the whole mass range
Physics of Accretion
• Comparison of models of disk which
fit present data are rather different
• Need high spectral resolution to
distinguish amongst the large range of
reasonable possibilities
Reflection spectrum interpretation
Thermal disc interpretation
Photons cm-2 s-1 keV-1
Fabian 2004
Energy [keV]
1H0707-495
Energy [keV]
Boller 2002,3
Tanaka 2004
Gallo 2004
High Spectral Resolution Breaks Model degeneracies
Reflection model fitted with
thermal emission from the disc
Thermal model fitted with ionized
reflection from the disc
Summary
• Black holes are critical
components of the universe
• What is needed to enhance our
understanding is
– Broad band pass
– High sensitivity
– High spectral resolution
“NeXT” and
beyond
1 Ms simulation: z=1.06 lensed SCUBA gal

Evidence of emission from an
outflowing wind (some SCUBA
galaxies show evidence of largescale outflows): feedback in the
formation of massive galaxies

X-ray spectra of the brightest
obscured quasars can achieve this
quality in ~100 ks exposures
Phase space for discovery is immense
• Set of
sources
chosen
from
serendip
itous
Chandra
sources
1
Redshift
2 3 4
5 6
Black Hole Finder
Primary Mission Science Goal:
•Obscured AGN and accretion history of universe
•
•
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We do not understand the number of,
luminosity density and evolution of AGN
These issues are crucial for
understanding the origin of galaxies and
the luminosity density of the universe
A hard x-ray survey is necessary for
finding and studying AGN in the z<1
universe.
Mission parameters:
•Sufficient sensitivity in the 10-40keV band to find a large number
(~104)of AGN in the local volume of space
•Accurate enough positions to obtain IR,radio, soft x-ray, optical followups
AGN viewed edge-on
through the optically
thick torus
Black Hole Finder
Chandra results show
that many AGN lie in
the nuclei of optically
normal galaxies
Photons/cm s2 keV
The Seyfert II Galaxy NGC 4945
ASCA
Ginga
AXAF/XMM energy band
Black hole finder
energy band
Energy (keV)
The present paradigm for AGN
consists of a black hole,
accretion disk, and a physically
thick region of obscuration (“the
torus”)
Most lines of sight to the AGN are
“blocked” by the torii which has
an effective column density
>1023atms/cm2,
The torii are optically thick in the
near-IR,optical, UV and soft x-ray
band
A detection in the hard x-ray band
of a source with Lx>1040.5. ergs/s
is a direct indictor of a AGN
Black Hole Finder
•X-ray data show that most AGN
have high column density of dust and
gas in the line of sight and are
optically “invisible”.
•Chandra data show that there are >7x
more hard x-ray selected than
optically selected AGN (at same optical
threshold)
•The most numerous AGN (Lx<1044
ergs/sec) evolve inversely from the
well studied quasars and are more
numerous in the local than high z
universe
What produces the luminosity in the universe?
Luminosity Density in the Universe
Hasinger (2001)
• The x-ray background is
due to black holes
• The Far IR background
is due to star formation
in “starburst” galaxies
• Not clear at present
what fraction of the
optical-mid IR flux is
produced by mixture of
AGN and star
formation-
• recent estimates have
AGN producing 1030% of total energy
radiated in universe.
Comparison with other Surveys
Black hole finder needs sufficient sensitivity to extend ROSAT (soft x-ray) and
complement GLAST (-ray) all sky imaging surveys:
Only complete hard x-ray sky survey to date
12 high latitude sources
xx
Black hole finder
-100x more sensitive
~104 sources
Probing the Innermost Disk - the Suzaku Long Look
of MCG-6-30-15 Fabian et al (Jan 06)
Suzaku lightcurve
Strong iron K line and disk
reflection from around a Kerr
(spinning) black hole
No variations in Fe line/reflection
- gravitational light bending
around a Kerr BH? (Miniutti &
Fabian 2004)
Constant Reflection hump
Where is the Energy Emitted ?
• Spectral energy
distribution of the
absorbed sources show
that a large fraction of the
AGN energy is emitted in
the E>2 keV band
Energy density
Spectral Energy Distribution of NGC6240
Prototype of Hard X-ray sources
Chandra image
of NGC6240
Frequency Hz
X-ray Astronomy in the Next Decade
the main science themes and the role of x-ray astronomy
• Cosmology
nature of dark matter
cosmic geometry
large scale structure
• Galaxy formation and evolution-
• Extreme environments of astrophysics
massive black holes
end stages of stellar evolution
Cosmic evolution of clusters and
groups provides strong constraints on
cosmological parameters
direct observation of star formation
rates and galactic winds over a wide
range of redshifts
measuring properties of black holes
and neutron stars (e.g. mass/spin,
gaseous environment)-search for the
direction connection between SMBH
and galaxy formation
X-ray Astronomy in the Next Decade
COSMOLOGY and the role of x-ray astronomy
•
Cosmology
nature of dark matter
cosmic geometry
large scale structure
a proper large scale x-ray survey can
• determine cosmological parameters to
extraordinary precision +/-0.01 errors in L
Wm,s8,
• measure the power spectrum of mass as a
function of z
• directly observe the large scale structure
• Constrain w to +/-15%
Such as survey requires
•a large contiguous solid angle
•sensitivity ~50x better than Rosat
•sufficient angular resolution
•to select clusters and groups
and
•allow optical identifications
•broad bandpass
•theoretical and observational
calibration of x-ray properties to
mass
X-ray Astronomy in the Next Decade
Galaxy formation and evolution-and the role of x-ray astronomy
Directly observe star
formation rates and
ejection of metal
enriched material in
galactic winds
N0 UV extinction corrected
UV extinction corrected
Chandra image of galactic
wind in NGC1569 (Martin
et al 2002)
X-ray and
UVSFR
rates for Lybreak
galaxies
Nandra et al
2002
Comparison of x-ray and radio SFR
Alexander et al 2002
X-ray Astronomy in the Next Decade
Galaxy formation and evolution-and the role of x-ray astronomy
Directly observe star
formation rates and
ejection of metal
enriched material in
galactic winds
The sensitivity of Con-X
allows spectroscopy of star
forming objects with 10
M/yr to z=.03 and
1000M/yr at z~1
This corresponds to
objects of ~1mJy in the radio
Con-X via x-ray
spectroscopy
of starforming regions in
nearby galaxies, integrated
spectra of distant galaxies
will determine
the wind speed, metallicity
NGC4038 NE quadrant
and total metal creation rate.
Chandra soft band image of
Arp220- showing ~15kpc xray “wind”
From Taos Meeting 1989 (!)
• Origin of the Energy and the
Continuum
• At present we have no "reliable"
theory for either the origin of the
energy in the high energy continuum
or of the creation of the spectrum.
•
•While results from GRO, Granat, Ginga, SAX
and XTE will probably suggest a "best" theory
for low redshift, low luminosity objects these
missions are not sensitive enough to test the
evolution with cosmic time of the underlying
physical conditions.
•There are strong reasons to believe that the
physical mechanism(s) should vary with cosmic
time (e.g the spin and mass of the
Most of the proposed theories for
central object, the relative
photon creation are "best" tested by
looking at time variable spectral shape accretion rate and angular
momentum of material etc) and
and/or spectral features at E>>20 kev. luminosity (compactness ratio of
It is not clear if we have any "testable" "disk" to non-thermal
theory for the origin of the energy.
luminosity).
However if it is due to "relativistic"
•Missions with sensitivity >10x that of XTE are
phenomena (such as tapping the spin required to start such a study.
of the black hole, shock acceleration
of particles or magnetic reconnection)
this bound also applies.