Transcript Diapositiva 1

Blazars: the gamma-ray view of AGILE
Filippo D’Ammando
Università degli Studi di Roma “Tor Vergata”
INAF - Istituto di Astrofisica Spaziale e Fisica Cosmica Roma
on behalf of the AGILE WG-AGN
44th Recontres de Moriond, 1 - 8 February 2009
AGILE flaring blazars and paper list
44th Reconstres de Moriond
Filippo D’Ammando
4 February 2009
AGILE flaring blazars sky distribution
Most of the sources lie in the Northern Hemisphere
Several AGILE detection triggered by northern-based telescopes
44th Reconstres de Moriond
Filippo D’Ammando
4 February 2009
First AGILE multi-λ campaign: 3C 279
Giuliani, D’Ammando, Vercellone, et al., A&A in press
First extragalactic source detected by AGILE-GRID, monitored simultaneously in
optical by REM telescope and in X-rays by Swift
<Fg> = (210  38) 10-8 ph cm-2 s-1 E > 100 MeV
Gamma-ray flux similar to the EGRET high state
Soft spectrum during a flaring episode, could be an indication of a dominant
contribution of EDC emission compared to ECC emission model
9 - 13 July 2007
44th Reconstres de Moriond
Filippo D’Ammando
4 February 2009
PKS 1510 - 089
Pucella, Vittorini, D’Ammando, et al. 2008,
A&A, 491, L21
<Fg> = (195  30) 10-8 ph cm-2 s-1
E >100 MeV
Possible correlation between optical and gamma-ray
bands: contemporaneous decrease in fluxes
The IC contribution from the BLR can explain the
observed hard gamma-ray spectrum
23 August - 1 September 2007
44th Reconstres de Moriond
Filippo D’Ammando
4 February 2009
PKS 1510-089: a rapid gamma-ray flare in March 2008
17 - 21 March 2008
D’Ammando et al., in preparation
Serendipitous detection during an AGILE
pointing towards the Galactic Center
3 ToO by Swift/XRT: the spectrum becomes
harder when the source is brighter
GASP-WEBT observed intense optical activity
between January and April 2008
44th Reconstres de Moriond
Filippo D’Ammando
4 February 2009
S5 0716+714 in September - October 2007
Chen, D’Ammando, Villata, et al. 2008,
A&A, 489, L37
<Fg> = (97  15) 10-8 ph cm-2 s-1 E >100 MeV
with a peak level of (193  42) 10-8 ph cm-2 s-1
z = 0.31  0.08 (Nilsson et al., 2008)
Total power transported in the jet is extremely
high ( Ltot > 3 x 1045 erg s-1)
To fit the SED we use two SSC components
4 - 23 September 2007
44th Reconstres de Moriond
Filippo D’Ammando
4 February 2009
Swift and AGILE simultaneous observations in October - November 2007
23 October - 13 November 2007
Giommi, Colafrancesco, Cutini, et al., 2008, A&A, 487, L49
<Fg> = ( 47 ± 11 ) 10-8 ph cm-2 s-1
E >100 MeV
The g-ray flux about a factor of 2 lower than in September
Strong variability in soft X-ray, moderate at optical/UV and
approximately constant in hard X-ray
The SED is consistent with a two-component SSC model
44th Reconstres de Moriond
Filippo D’Ammando
4 February 2009
3C 273: simultaneous detection by GRID & SA
Pacciani, Donnarumma, Vittorini, et al.,
A&A, 494, 49
<Fg> = (22  6) 10-8 ph cm-2 s-1
E >100 MeV
Fg [peak] = (33 11) 10-8 ph cm-2s-1 E >100 MeV
Multi-l campaign: REM, Swift, RXTE, INTEGRAL
and AGILE
Indication of an anti-correlated variability
between X-rays and gamma-rays
SSC + EC: spectral variability consistent with an
acceleration episode of the electron population
16 December 2007 – 8 January 2008
44th Reconstres de Moriond
Filippo D’Ammando
4 February 2009
3C 454.3: July 2007
24 - 30 July 2007
Vercellone, Chen, Giuliani, et al, 2008, ApJL, 676, 13
AGILE repointing the source during a period of strongly enhanced optical
emission
<Fg> = (280 ± 40) 10-8 ph cm-2 s-1 E >100 MeV
Highest gamma-ray flux from this source (published … but see Fermi:
ATel #1628)
44th Reconstres de Moriond
Filippo D’Ammando
4 February 2009
MW Observations of 3C 454.3 in November 2007
Vercellone, Chen, Vittorini, et al. 2009, ApJ, 690, 1018
<Fg> = (170  13) 10-8 ph cm-2 s-1 E >100 MeV
Emission in the optical range appears to be correlated with that at gamma-ray energies
10 November - 1 December 2007
The gamma-ray emission is dominated by
inverse Compton scattering of the external
photons from the broad line region clouds
44th Reconstres de Moriond
Filippo D’Ammando
4 February 2009
3C 454.3: December 2007 campaign
Donnarumma et al., in preparation
Multi- campaign with the contribution of
Spitzer, REM, WEBT, MITSuME, Swift,
Suzaku and AGILE
<Fg> ~ 250 x 10-8 ph cm-2 s-1 E > 100 MeV
The SED seems to require external
Compton of seed photons from a hot
corona with T = 106 K
1 - 16 December 2007
44th Reconstres de Moriond
Filippo D’Ammando
4 February 2009
W Comae: a ToO triggered by VERITAS
This source belongs to an AGILE Guest Investigator: E. Pian
The results of a multi-wavelength campaign involving WEBT, Swift, AGILE
and VERITAS will be published (Acciari et al., in preparation)
44th Reconstres de Moriond
Filippo D’Ammando
4 February 2009
Mrk 421: WEBT + AGILE + VERITAS +
MAGIC = …
44th Reconstres de Moriond
Filippo D’Ammando
4 February 2009
Mrk 421 from optical to TeV energies
Donnarumma et al., 2009, ApJ 691, L13
<Fg> = (42 ± 13) 10-8 ph cm-2 s-1 E >100 MeV
Swift/XRT: Flux (2 - 10 keV) = 2.6 x 10-9 ph cm-2
s-1
Possible correlated variability between optical, Xrays and high-energy parts of the spectrum
SSC model: hardening/softening of electron
energy distribution caused by particle acceleration
process
Other papers in preparation:
• PKS 0537−441: October 2008 flare
• 3C 454.3:
monitoring
One
year
of
AGILE
• Detailed analysis of Virgo region
• Two articles on theoretical models for
emission mechanisms in BL Lacs and
FSRQs
44th Reconstres de Moriond
Filippo D’Ammando
4 February 2009
AGILE results on Blazars
• After 18 months, 7 flaring blazars detected by AGILE
• No blazar candidates flared above 100 MeV at a
significance greater than 5-s (..but see Fermi GST)
• 6 other Blazars or Blazar candidates detected in the
AGILE First Catalogue
• Multi-wavelength campaigns promptly activated
• 8 multi-l papers already out, several others very soon
44th Reconstres de Moriond
Filippo D’Ammando
4 February 2009