Bez nadpisu

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Revision of Blazars Nature Objects with
Binary Supermassive Black Hole Bašta,
M. Astronomical Institute, Academy of Sciences
of the Czech Republic Supervisor RNDr. R.
Hudec, CSc. (ASU AV, CR) Consultant doc. A.
Sillanpaa (Tuorla, Finland)
Hello everyone, welcome to my lecture
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Outline of this lecture

• What AGN and blazars are
• What basic properties of blazars are
• About our blazar sample for which we suggest
  supermassive binary black hole should be present
• How we probe the binary nature of blazars and
  explain the observed behavior

I will tell you . . .
At first, let us talk about Active galactic
nuclei (AGN). We will see that blazars are just
a class of AGN.
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Active Galactic Nuclei ( AGN) in pictures
Blazar Mkn 421
Quasar 3C 273
Seyfert galaxy NGC5194
Radio galaxy Centaurus A
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Active Galactic Nuclei ( AGN)
Active Galactic Nuclei (AGN) powerful
luminosity non-stellar spectrum high
variability BH engine differ in luminosity,
spectra, variability, morphology 1 - 10 of
galaxies supposed to be AGN
Observational classification of AGN

• Quasars Quasi stellar radio sources, powerful,
  radio loud vs. quiet
• Blazars Highly variable
• Radio galaxies Powerful in radio, radio lobes,
  elliptical
• Seyfert galaxies Spiral, luminous center, SG I
  vs. SG II
• LINERs, Nuclear HII Regions Specific energy
  production
• Strong IRAS starburst galaxies Star formation

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Engine of AGN AGN Unification I
Dusty torus
Black hole Accretion disk
Radio lobes
Coming closer to AGN
Cygnus A
Blazar 3C 273
Centaurus A
Decreasing the angle between observer and jet
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Engine of AGN AGN Unification II
Quasar
Radio galaxy
Blazar
Seyfert 2 galaxy
Radio loud (strong jets) vs. Radio
quiet (weak jets)
Torus
Black hole Accretion disk
Seyfert 1 galaxy
Jet !!!
Antonucci, 1993
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Blazars their powerful jet
Supermassive black hole with accretion disc
Jet Beam of energetic particles and magnetic
field moving close to the speed of light!!

• Effects of the small angle between observer and
  jet
• Featureless continuum
• Relativistic beaming
• High luminosity
• Superluminal motion
• Gamma rays
• Rapid variability

Line of sight
Blazar observer
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Standard model of blazar one supermassive
black hole
According to the Unification model (Antonucci,
1993) there is ONE supermassive black hole in the
center of a blazar.
Standard model One supermassive black hole
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However, there are quite a lot of suggestions
that not ONE black hole but TWO are present in
several blazars . . .
Jet
Secondary black hole
Primary black hole
Artists conception of a supermassive binary
black hole ( BBH) system

• Volonteri et al., 2003
• BBHs should be common
• There is observational evidence for BBHs

Accretion disk
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Our blazar sample for grant proposal (Part I)

• ON 231
• Possible periodicities
• 13.6 years in optical
• (Liu et al., 1995)
• 2. Mkn 421
• Possible periodicities
• 23 years in the optical band (Liu et al., 1997)
• 104 second variations in the X-ray band (Marashi
  et al., 1999)
• 3. 0109224
• Possible periodicities
• Long-term oscillations of the base-level flux on
  a timescale of about 11.6 years (Smith Nair,
  1995)
• 4. Mkn 501
• Possible periodicities
• 23 days in the X-ray and TeV band (Nishikawa et
  al., 1999)

We have gathered following suggestions for
periodicity in our blazar sample.
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Our blazar sample for grant proposal (Part II)

• 5. Mkn 766
• Possible periodicities
• 4200 seconds in the X-ray band (Boller et al.,
  2001)
• 6. 3C 345
• Possible periodicities
• 5 and 11 years in the optical band (Caproni
  Abraham, 2004)
• 7. AO 023516
• Possible periodicities
• 5.7 years in the radio light curve (Raiteri et
  al., 2001)
• 2.95 years in the optical light curve (Fan et
  al., 2002)
• 8. 3C 279
• Possible periodicities
• 7.1 years in the long-term near infrared light
  curve (Fan, 1999)
• 22-year period from movement of jet components
  (Abraham Carrara, 1998)

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Our blazar sample for grant proposal (Part III)
The periodicity in the blazars may be a
suggestion of binary black hole systems.

• 9. PKS 0420-014
• Possible periodicities
• 13-months between
• optical major outbursts
• (Wagner et al., 1995)
• 10. 0716714
• Possible periodicities
• 0.7-year quasi-periodic ejection of VLBA
  components (Jorstad et al., 2001)
• 12.5, 2.5 0.14-day periodicity of polarization
  in the optical band (Impey et al., 2000)
• 4-day periodicity in the optical band (Heidt
  Wagner, 1996)
• 11. 3C 66a
• Possible periodicities
• 2.5 years (Belokon Babadzhanyants, 2003), 275
  and 64 days in the optical band (Marchenko, 1999
  Lainela et al., 1999)

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Origin of Binary Black Holes ( BBHs)
The origin of the binary black hole system is in
the merging of galaxies.
If each galaxy contains a supermassive black hole
? a binary black hole system is formed (frequent
in clusters)
Hibbard van Gorkom, 1996
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Observational evidence for BBH systems

• NGC 6240

Hubble, optical
Chandra, X-ray
Komossa et al., 2003

• High-redshift quasars observed in pairs
• Q1343.42640, LBQS0103-2753, UM425,...
• Komossa, 2003

True pairs x Chance alignments x Lensing effect
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The periods in our grant proposal sample of 11
blazars are not confirmed at all as their light
curves are not well-sampled and do not involve
much historical data.
We apply the following steps in our work

• Gathering of optical data
• Photographic plate collections
• Sonneberg Observatory, Germany (280 000 plates)
• Harvard College Observatory, USA (600 000 plates)
• UKSTU plate collection ROE Edinburgh, UK (18 000
  plates)
• Observatory Leiden, NL (40 000 plates)
• Papers
• Observational campaigns archives
• Gathering support data from other energy bands
• Periodicity analysis of the optical light curve
• An overall analysis to adopt a BBH model
• Establishing statistical results based on our
  sample of 11 blazars

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Possible origin of periods in blazars
It is necessary to watch out for the whole
spectrum behavior and for the behavior of colors
and flares to be able to distinguish between
different origin of periods in blazars.
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Blazars support data from other bands
Blazar emit their energy from radio to TeV band.
Data in all wavelength enable to specify the
nature of blazars.
Spectral energy distribution of blazars
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Optical data gathering Periodicity analysis
Sextractor screenshot
Sextractor processing
Determination of magnitude of a specific object
in individual plates
Modified Argelander method
Sonneberg photographic plate
Thousands of photographic plates
ANALYSIS OF THE TIME SERIES

• Stellingwerfs method (folded light curves)
• Deeming method
• CLEAN algorithm
• Wavelets analysis

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Violent optical variability of BL Lac on a long
time time scale
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• There is wide range of possible interpretations
  of periods found in the light curves (in
  different bands).

We present a short introduction into the
interpretation of periods using the supermassive
binary black hole scenario and the following
designation
q angle between jet and observer M mass of
the primary BH m mass of the secondary
BH Torbital orbital period rm separation of
black holes G Lorenz factor of the jet b
vjet/c bapparent apparent b z redshift
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Periodicity interpretation origin in jet I
Periods originating in the jet can be drastically
shortened due to relativistic effects and small
viewing angles
Angle q between direction to observer and jet
Tobserved is any observed period originating in
jet
Direction to the observer
q
Direction of the jet outflow
Time Dt.(1-v/c.cosq)
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Periodicity interpretation origin in jet II
The Lorenz factor G can be estimated i.e. from
superluminal motion.
Apparent speeds higher than c are observed in the
jet
Time Dt.(1-v/c.cosq)
From optical or VLBI measurements
The max. apparent speed can be used as an
estimate of G.
Typical values of G 10-15
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Periodicity interpretation origin in jet III
The period observed in the jet may be induced
i.e. by the tidal effect of the secondary black
hole on the accretion disk of the primary.
Figure credit Romero, Fan Nuza, 2003
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Periodicity interpretation origin in jet IV

• The periods originating in the jet period may be
  also caused by
• knots rotating in the jet
• emission from jet carried by the secondary BH
• components moving in helically distorted jets

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Periodicity interpretation origin in the
accretion disk

• While the secondary is piercing a channel into
  the accretion disk of the primary the gas gets
  heated and radiates.
• Timing of the outbursts enables the determination
  of the orbital period.
• Color behavior may support or reject the origin
  of the periodicity in disk!!

The secondary BH crosses twice the disk
The origin of the period in disk may be the case
of blazar OJ 287 Predicting the next outburst
of OJ 287, Valtonen, M. Lehto, H. . . . Hudec,
R. Basta, M . . ., in preparation for ApJ
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Determination of the mass of the primary via high
energy data support
Estimates of the mass of the primary black hole
can be sometimes obtained using the high energy
data.
g-ray
e, e-
X-ray
Estimating d and measuring variability timescales
in gamma-ray band gives an estimate of the mass
of the primary black hole.
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Determination of the mass of the secondary from
periodicity studies
Stages of evolution of a BBH system Dynamical
friction stage ? Non-hard binary stage ?
Hard-binary stage ? ? Gravitational radiation
stage The loss of energy via gravitational
radiation results in the orbit decay
Time Dt.(1-v/c.cosq)
Knowing Torbital , M and errors in determination
of Torbital, can lead to an estimate of the
upper limit of m.
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Predicting the next outburst of OJ 287 Valtonen,
M. Lehto, H. . . Hudec, R. Basta, M . . In
preparation for ApJ
We participate in a paper in preparation where a
specific model was applied to the blazar OJ 287.
OJ 287 light curve
Scalegram for OJ 287
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Conclusion and future plans

• It is highly possible that the engine of blazars
  and AGN is not associated with one supermassive
  black hole but with two supermassive black holes.
• Periodicity studies supported by data from other
  energy bands and supported by spectral/color and
  flare behavior may help
• to establish a viable model.
• Our studies are based on gathering the data for a
  larger sample of blazars and carrying out the
  appropriate analysis, results discussion and
  establishing a new model of blazar.
• We have applied our approach fully already to OJ
  287. The processing of other blazars is in the
  stage of data gathering and period analysis.

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References and acknowledgements
Some fundamental papers Antonucci, R. Unified
models for active galactic nuclei and quasar,
1993, ARAA, 31, 473A Bromm, V. Loeb, A.
Formation of the first supermassive black holes,
2003, ApJ, 596, 34B Conway, J. E. Murphy, D.
W. Helical jets and the misalignment
distribution for core-dominated radio sources,
1993, ApJ, 411, 89C Conway, J. E. Wrobel, J. M.
A helical jet in the orthogonally misaligned BL
Lacertae object Markarian 501, 1995, ApJ, 439,
98 De Paolis et al., F. Binary black holes in
Mkns as sources of gravitational radiation for
space based interferometer, 2003, AA, 410,
741 Faber, S. M. et al. The centres of
early-type galaxies with HST. IV. Central
parameter relations, 1997, AJ, 114, 1771F Fan,
MNRAS, 1999, 308, 1032 Hardee. P. E. Cooper, M.
A. Clarke, D. A. On jet response to a driving
frequency and the jets in 3C 449, 1994, ApJ, 424,
126H Katz, J. I. A precessing disk in OJ 287,
1997, ApJ, 478, 527 Komossa, S. Observational
evidence for supermassive black hole binaries,
2003, AIPC, 686, 161K Komossa, S. et al.
Discovery of a binary active galactic nucleus in
the ultraluminous infrared galaxy NGC 6240 using
Chandra, 2003, ApJ, 582, 15 Lehto, H. Valtonen,
M. OJ 287 outburst structure and binary black
hole model, 1996, ApJ, 460, 207 Liu et al., AA,
1995, 295, 1 Magorrian, J. et al. The
demography of massive dark objects in galaxy
centres, 1998, AJ, 115, 2285M Raiteri, C. M.
Optical and radio variability of the BL Lacertae
object AO 023516 A possible 5-6 year
periodicity, 2001, AA, 377, 396R Rieger, F. M.
Mannheim, K. Implications of a possible 23 day
periodicity for binary black hole models in Mkn
501, 2000, AA, 359, 948R Romero, G. E. Fan,
Jun-Hui Nuza, S. E. The binary black hole
scenario for the BL Lacertae object AO 023516,
2003, ChJAA, 3, 513R Sillanpaa, et al. OJ 287
Binary pair of supermassive black holes, 1988,
ApJ, 325, 628 Smith Nair, 1995, PASP, 107, 863
Valtaoja, E. et al. Radio Monitoring of OJ 287
and Binary Black Hole Models for Periodic
Outbursts 2000, ApJ, 531, 744 Villata, M.
Raiteri, C. M. Helical jets in blazars. I. The
case of MKN 501, 1999, AA, 347, 30V Villata, M.
et al. A beaming model for the OJ 287 periodic
optical outbursts, 1998, MNRAS, 293,
L13 Volonteri, M. et al., The assembly and
merging history of supermassive black holes in
hierarchical models of galaxy formation, 2003,
ApJ, 582, 559 Yu, Q. Evolution of massive binary
black holes, 2002, MNRAS, 331, 935Y Xu, W. et
al. The bimodal distribution of misalignment
angle in powerful extragalactic radio sources,
1994, cers.conf, 7
Some web references and photo credits
http//www.gsfc.nasa.gov
http//chandra.harvard.edu
http//users.rowan.edu/polikar/WAVELETS/WTtutoria
l.html
http//www-glast.stanford.edu/
THANKS
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Last thought
I expect to pass through this world but once any
good thing therefore that I can do, or any
kindness that I can show to any fellow creatures,
let me do it now let me not defer or neglect it,
for I shall not pass this way again. Ettiene De
Grallet
My thanks and acknowledgments for the support
with my scientific research and this presentation
are passed to the following
René Hudec, Aimo Sillanpaa, Harry Lehto, Mauri
Valtonen, Adam Hill, Filip Munz, Martin Toast
Topinka, Ivana Joanne Stoklasová, Libor Mekká
koza Švéda, Petr Skalický, Martin Matesí Péro
Jelínek, Petr Sobotka