AGN à la Blandford, cont.
[ What Worked, What Didn’t, and What Next? ]
P.Coppi, Yale
?
What’s a Blandford, à la Google:
Kid’s definition
Dr. Roger Blandford
Astrophysicist
His research interests include: black holes, those famous
supermassive space objects that gobble up matter and
light; "gravitational lensing," which refers to the way
light travels in curved paths around stars and galaxies;
high-energy waves from space known as gamma ray
bursts; the dim class of stars known as white dwarfs; and
the structure and evolution of the universe.
[pbs.org]
AGN à la Blandford, ca. 1986, IAUS
EGRET
GeV Blazars…
Mkn 421
TeV Blazars…
Fossati et al. 2002
Mkn 421
Gaidos et al. 1996
Pian et al. 1998
One of the biggest
surprises!
PKS 2155, ~5 min variability
Another superluminal jet source
…oops …
it’s in our galaxy!
A “boring” object in the sky: the nearby elliptical galaxy M87
Optical
“FEAST vs. FAMINE”
A starved black hole…..
Radio
X-ray variability seen
in HST-1 knot too!!
M87 jet is not wimpy!!!
D. Harris,2003
ADIOS: The X-ray/Radio correlation …
GX339 - Corbel et al. 2004
AGN !? - Maccarone et al. 2003
Another major development: arcsecond X-ray Imaging
CDF-N/GOODS
2Msec(!) Chandra
CDF-S
When you can see with X-rays, again black holes much more common!
Guess what: our black hole
is not special!
Every big galaxy has one !
The “M-s Relation”
(Ferrarese & Merritt, see also Gebhardt et al.)
Finally some answers?
Rare long-lived AGN vs. many short-lived AGN?
Seems to be tilting decisively towards
M  s relation,
(  many relic SMBH)
X-ray/2MASS counts
(  many active AGN missed optically)
No more Soltan/M  s problem?
Also, M  s relation  BH and galaxy know about each other!?
Galaxy & BH formation same process?
(Once correct for obscuration, redshift evolution similar?)
FEEDBACK??? Even “low energy” astronomers can’t ignore black holes…
Mergers/gas are clearly important in at least AGN phase.
Blandford was right…. While LCDM appears correct,
Both galaxy and AGN formation do seem to be anti-hiearchical (kind of) …
At z=2, massive elliptical progenitors COMPACT and this one
may have σ ~500 km/sec!!
The “Feasting Objects” (FSRQ): interesting probes?
Eagerly await Fermi results on n(z),
but in meantime have SWIFT/BAT
survey: see Ajello et al. 2009 ….
Old (pre-CGRO) view
of gamma-ray Universe.
My model for the
pre-CGRO sources…
The transition
from a non-thermal
to a thermal pair
plasma…
Coppi 1998
After CGRO…
Johnson et al., 1994 ….
There goes the thesis….
EGRET Blazars and gamma-spheres:
Even though pairs may not be dominant,
that pair plasma code was good for something ….
Compilation by A. Zdziarski
Spectra of this quality generally do not exist for AGN!
Chandra
??
Possible AGN spectral “states” not well-sampled!
What if you don’t have broad band data
– X-ray binary example…
What’s E_cut =>
no idea what reflection
spectrum to expect !
No broad band data = big uncertainties!
kTe = 85 keV,R = 1.0, t = 1.3
(green)
PEXRIV
Ecut =900 kev, R=0.5, x=100
kTe = 68 keV,R = 0.4, t = 1.8
Your line fit is only as good as your
continuum fit/model!
RXTE PCA
OSSE
Ecut =100 kev, R=1, x=0
BAT
Fitting only <20 keV or >50 keV leaves big uncertainty in predictions
for other half of spectrum. Even with great statistics, an X-ray mission
that only measured spectrum 20-150 keV allows a factor two uncertainty
in reflection fraction!
Spectra of this quality generally do not exist for AGN!
Chandra
??
Possible AGN spectral “states” not well-sampled!
In fact, we are just starting to see tip of
iceberg in terms of possible AGN spectra!
Red dots - measured
values
Black dots – lower limits
?
Typical (single)
value assumed
for XRB models…
Contrary to what is assumed
in XRB model fits, there is a
large scatter in high energy
spectra of AGN (both in
power law index and
high-energy cutoff).
~30% of objects have
E_C > 400 keV, which is
NOT obviously compatible
with XRB shape …
[N.B. The objects shown are
a large fraction of the existing
sample of AGN with
good HX spectra! ]
Risaliti et al. 2002, BeppoSAX survey of Compton-thin Seyfert 2’s (NH~ 1022 – 1024 ) …
Our view of the black hole universe is still highly biased….
The Super-Antennae, IRAS 19254 (Braito et al., 2009, Suzaku)
Even if the unabsorbed spectrum did not vary (unlikely), we know the
environment varies. Details like the exact geometry of the absorber matter,
especially in the Compton thick (NH > 1024) case, and may depend on host
type, redshift, etc. This complication is largely ignored in current XRB models
– we need broadband measurements of many objects to disentangle intrinsic
vs. extrinsic (absorber-induced) variations!
Sample theoretical calculation (Monte Carlo, exact) -Lines of sight
Geometry of obscuring material –
a sphere. with an empty conical hole, and
possible paths of photons.
Spectrum on axis (black), perpendicular to axis (green), and on edge
of obscuring material (red), and spectrum of source (dashed), for an
opening of 30% of surface area, NH=1.0E25 and EC=300 KeV.
Different obscuration geometries imply different polarization signatures.
X-ray/gamma-ray polarimetry difficult but very useful! Disentangles geometry
and emission
components.
Degree of polarization perpendicular to axis (green) and on edge of obscuring material
(red) – same parameters as above.
On cosmic train wrecks, feasting, and the formation of black holes…
How do we make quasars at z>6!?
Don’t ignore that gas!
Escala et al. 2004
Multi-scale simulation by Mayer et al. 2009
LISA: gravitational waves!
Sensitivity best for LOWER
mass (MBH<106 Mo) mergers!
Escala 2008
Origin of
M-sigma relation?
Fueling-limited
scenario!
ENZO AMR simulation
including star formation
and accretion onto
“large” central black hole
particle --
who needs
a seed black hole?
Radio
Where
are the
black
holes??
1 arc sec
?
Keck Adaptive Optics
2.2 micron
X-Ray
NGC 6240
Max et al. 2007, Science
[Sorry  ]