Bez nadpisu

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Blazars INTEGRAL BH Binaries René Hudec,
Filip Munz, Milan Bašta, Filip Hroch, Vojtech
Šimon Astronomical Institute Ondrejov, Czech
Republic ISDC, Versoix, Switzerland Elena
Pian, INAF Trieste, Italy and Luigi Foschini,
IASF-CNR Bologna Italy Loredana Bassani,
IASF-CNR Bologna Italy Aimo Sillanpaa, Esko
Valtaoja, Leo Takalo and Students Tuorla
Observatory, Pikkiio, Finland within the AGN CP
topics led by Thierry Courvoisier and Loredana
Bassani
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• Blazars - the most extreme class of active
  galaxies, powerful and variable
• observed in all wavelength bands - from radio
  through VHE gamma frequencies
• maximum spectral output and largest variability
  often at gamma ray energies
• 66 blazars identified as sources of gt100 MeV
  emission by EGRET oboard CGRO (Hartman et al.
  1999)
• 6 blazars identified as VHE gamma sources (gt350
  GeV) by Cerenkov telescopes
• suitable targets for INTEGRAL especially during
  active states (flares)

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Blazars INTEGRAL

• Core Program CP (Galactic Plane Scans, Galactic
  Centre Deep Exposure,...)
• AO-1,2 Program (allocated pointed observations)
• Objects inside FOV of AO-1,2 observations

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The INTEGRAL instruments INTEGRAL - ESA
led mission in collaboration with Russia, United
States, Czech Rep. and Poland
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• Blazars in the INTEGRAL Galactic Plane Scans
  (GPS)
• GPS zone usually neglected by extragalactic
  astronomers due to heavy obscuration
• in optical, 20 of the sky obscured by our
  Galaxy
• INTEGRAL allows detectability of up to few mCrabs
  in the most exposed regions

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Blazars INTEGRAL
Seven optically bright (Vlt17 mag) blazars
within galactic scans of INTEGRAL 1ES 0647250
A secret object PKS 0823-223 no gamma from
EGRET, grav. lensing candidate 1ES 2344514 TeV
gamma ray source, very close 8C 0149710 BL Lac
candidate? 4C 47.08 A secret object 87GB
021095130 poorly understood blazar, TeV
candidate BL Lac The prototype ?
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Object z optical gamma X-rays radio
1ES 0647250 z0.20 V15.3 TeV candidate ROSAT Einstein source 0.08 Jy at 5 GHz
PKS 0823-223 z0.91 V16.2 not detected by EGRET ? 0.78 Jy at 5 GHz
1ES 2344514 z 0.044 V 15.5 TeV gamma ray source large variability, spectral changes 0.23 Jy at 5 GHz
8C 0149710 z0.022 V15.5 ? ROSAT 0.64 Jy at 5 GHz
4C 47.08 z0.475 V17.0 ? ROSAT ?
87GB 021095130 z0.049 V16.5 TeV candidate? ROSAT 0.29 Jy at 5GHz
BL Lac z0.069 B12.5 - 16 polarization variable/outbursts both comp. detected 2.94 Jy at 5 GHz, polar.

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BL Lac
Violent optical variability of BL Lac on a long
time time scale good candidate to be detected at
flaring
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BL Lac is well studied .... but Most of the
INTEGRAL GPS blazars are poorly investigated and
poorly understood The study with Sonneberg
Observatory Archival Plates reveals that most of
these objects are optically variable, hence a
gamma ray variability can be expected
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IBIS total exposure times for blazars, INTEGRAL
Core Program (CP) data, rev 1-250
IBIS total exposure times for blazars, all data,
rev 1-250
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Most observed blazars, CP (rev 1-250) public
(AO-1)
id name ra decl scws
sec 287 3EG J1800-3955 180242 -394001 961 1780
516288 3EG J1832-2110 183300 -213600 832 1497
43259 QSO B0637-7513 063546 -751616 489 11012
54357 NRAO 530 173302 -130449 480 79100452 Q
SO B0528134 053056 133155 454 1245729315 QS
O B1622-297 162606 -295127 366 563387314 QSO
B1622-253 162546 -252738 362 630769140 J1242
3440 124141 344031 311 835312318 QSO
B1908-202 191109 -200655 307 481383134 QSO
B12253145 122824 312837 296 806857131 QSO
B1218304 122121 301037 258 723653317 QSO
B1741-0348 174358 -035004 258 450219302 QSO
B1229-0207 123200 -022404 255 737799362 J1917
44.8-1921 191744 -192131 248 393979128 QSO
B1215303 121752 300700 246 697787147 QSO
B1308328 131028 322043 244 534738
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Most observed blazars in AO (rev 1-250)
id name ra decl SW
sec 125 B1206416 120922 411941 114 404490126
QSO B120739 121026 392909 113 402477283 3C
445 222349 -020612 96 347728288
3EG J1832-2110 183300 -213600 75 1491561
35 3C 273 122906
020308 73 209863130 QSO B1217023 122011 020
342 73 209327145 B1255244 125731 241240 65
139014302 QSO B1229-0207 123200 -022404 56 16
1087287 3EG J1800-3955 180242 -394001 55 1011
3926 B0224014 022713 013523 51 178909147 QS
O B1308328 131028 322043 50 11019152 QSO
B0528134 053056 133155 45 135653303 QSO
B1243-072 124604 -073046 41 120673144 3C
279 125611 -054721 38 114465335 RX
J0227.202 022716 020200 38 133162314 QSO
B1622-253 162546 -252738 36 64280
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15-40 keV
ISGRI 40-100 keV
rev5296 260ksec
4C 47.08
100-200 keV
200-400 keV
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• NRAO530 (1730- 130)
• a well known OVV in the INTEGRAL GPS
• m (B) 18.5 mag (Whelch and Spinrad 1973)
• z 0.902 (Junkkarinen 1984)
• The source is detectable from radio to g -ray
• ROSAT 1.84 10 -6 Jy at 1.3 keV
• (Brinkmann et al. 1994)
• EGRET 4.6 10 -11 Jy at 2.55 GeV
• (Fichtel et al. 1994 Thompson et al. 1995).

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• NRAO530 (1730- 130)
• the object is known to exhibit prominent and
  sharp optical flares with very large amplitude
• good candidate for detection by IBIS gamma-ray
  imager on INTEGRAL during these flares (not
  predictable)
• so far no evidence of detection by IBIS JEM-X

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Historical optical light curve of NRAO530 The
source exhibits rare but large amplitude optical
flares (Dm 4 mag) Optical R band good tracer
for the HE activity of blazars (CGRO experience,
Collmar (2004)) - gamma flares can be expected
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• NRAO530 (1730- 130)
• example of blazar with violent optical activity
  (4 mag within 1 month)
• in flare, the object is expected to be much
  brighter also in gamma
• the role of optical monitoring and ToO program -
  the flare can be recognized by optical monitoring
  with small (D 50 cm) telescopes

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• Conclusion - blazars in INTEGRAL GPS
• no positive detection by HE instruments onboard
  INTEGRAL yet (except marginal detection of 1ES
  0647250 and the newly confirmed PKS1830-211 )
• the targets quiet level is still below the
  sensitivity threshold of the instruments
• positive detection may be possible in the future
  as
• - there will be more cumulative time available
• - the probability to see a blazar during a flare
  (and hence much brighter) will also increase
  with time

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• The AO-2 ToO blazar observation No. 220049 by
  Pian et al. (Pian et al., 2005)
• optical and/or X-ray monitoring (RXTE ASM
  others) of flaring activity of a large list of
  blazars
• or, alternatively, soft gamma-ray monitoring by
  INTEGRAL itself (serendipitous detection of a
  flaring blazar in the IBIS FOV)
• ToO INTEGRAL observation activated meeting the
  "trigger criteria" (major flaring event)
• coordinated with XMM Newton ToO program

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• Blazar S5 0716714
• a BL Lac object
• monitored at radio and optical wavelengths by
  Whole Earth Blazar Telescope (gt40 telescopes,
  Villata et al. 2004)
• ToO triggered by optical activity - 2 outbursts
  up to the extreme level of R 12.1 mag
  (historical maximum, light increase by 1 mag in 2
  weeks and 2 magnitudes in 4 months)
• ToO performed 2004 April 2-7

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• INTEGRAL observation S5 0716714 detected only
  by IBIS ISGRI at 4.5 sigma, 30-60 keV band, for a
  count rate of 0.11 counts/s (exposure 280 ksec).
  No signal above 60 keV. Better detected at the
  beginning (decline) ... the useful exposure
  reduced to 84 ksec
• No detection in IBIS/PICsIT, SPI and JEM-X (less
  than 292, 6 and 6 mCrab)
• observed at somewhat higher (2x) gamma-ray state
  when in Oct 2000 (BeppoSAX ToO, Tagliaferri et
  al., 2003) (R12.5 versus 12.1)
• low signal/noise ratio - no intra-orbit
  variability study possible, - no spectrum
  extraction possible

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INTEGRAL ToO Observation
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• Other extragalactic sources observed in the IBIS
  FOV (19 x 19 deg at hallf response) - 3
  additional AGNs with higher significance than the
  main blazar target
• these 3 AGNs were observed up to 100 keV
• no intra-orbit variability study possible
• spectrum extraction possible
• S5 0836710 (high z blazar of the FSRQ sub-class)
  single power law spectrum
• Mkn 6 (bright Seyfert) single power law spectrum
• Mkn 3 (bright Seyfert) broken power-law with
  cutoff at gt50 keV

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The target and the three additional AGNs in the
IBIS FOV (30-60 keV)
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S5 0836710
Markarian 6
single power law spectrum G1.5
single power law spectrum G1.3
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Hints for a break or cutoff in Markarian 3
Broken power law
IBIS/ISGRI spectrum
Power law with high energy cutoff
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• Conclusion - the AO blazar observation
• with relatively short exposures the INTEGRAL is
  efficient tool to study bright AGNs at high
  Galactic latitudes
• importance of HE instruments with large FOV and
  good angular resolution

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INTEGRAL and high redshift Universe detection of
two high z blazars (S5 0836710 at z2.17 and PKS
1830-21 at z2.51) - the most distant objects
seen by INTEGRAL so far - INTEGRAL can also play
a role in investigation of high z Universe
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Blazars - Objects with Binary Supermassive Black
Hole?
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There are indications that not ONE black hole but
TWO may be present in some blazars . . .
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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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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Our blazar sample - objects with suspected
periodicity (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)

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Our blazar sample (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 (Part III) - except OJ287
(finished)

• 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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The periods in our sample of 11 blazars are
mostly not confirmed as their light curves are
not well-sampled and do not involve much
historical data. Our project

• 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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Optical data gathering Periodicity analysis
Sextractor screenshot
Sextractor (or other) 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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The
OJ287 - long term light curve ( gt 100 years)
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Possible origin of periods in blazars
It is necessary to observe the whole spectrum
behavior the behavior of colors and flares to be
able to distinguish between different origin of
periods in blazars.
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Conclusion - BBH Project

• Optical periodicity studies supported by data
  from other energy bands and supported by
  spectral/color and flare behavior may help to
  confirm and to study the BBH in blazars
• These studies require very long data bases gt 50
  years, but better even more!
• It is evident that only (digitised) astronomical
  plate archives can provide these data bases
• This was already confirmed for blazar OJ287 where
  thousands of data points were collected covering
  gt 100 years, confirming the period

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The End
The End