|AGILE detection of a gamma-ray source possibly associated with Blazar TXS 0716+714|
ATel #1221; A. Giuliani, S. Vercellone, A. Chen, S. Mereghetti, A. Pellizzoni, F. Perotti, F. Fornari, M. Fiorini, P. Caraveo, A. Zambra (INAF/IASF Milano), A. Bulgarelli, F. Gianotti, M. Trifoglio, G. Di Cocco, C. Labanti, F. Fuschino, M. Marisaldi, M. Galli, (INAF/IASF Bologna), M. Tavani, G. Pucella, F. D'Ammando, V. Vittorini, E. Costa, M. Feroci, I. Donnarumma, L. Pacciani, E. Del Monte, F. Lazzarotto, P. Soffitta, Y. Evangelista, I. Lapshov, M. Rapisarda, A. Argan, A. Trois , G. De Paris (INAF/IASF Roma), G. Barbiellini, F. Longo (INFN Trieste), P. Picozza, A. Morselli (INFN Roma-2), M. Prest, E. Vallazza (Universita` dell'Insubria), P. Lipari, D. Zanello (INFN Roma-1), F. Mauri (INFN Pavia) and P. Giommi, C. Pittori, L. A. Antonelli, D. Gasparrini, S. Cutini, F. Verrecchia (ASDC) and L. Salotti (ASI)
Subjects: Gamma Ray, AGN, Quasars
The AGILE satellite, currently in its science performance verification phase, during the Observing Block that started on 2007-09-04 12:00 UT, detected significant gamma-ray emission from a source possibly associated with blazar TXS 0716+714.
A preliminary maximum likelihood analysis of the AGILE-GRID (Gamma-Ray Imaging Detector) data obtained between 2007-09-10 13:50 UT and 2007-09-20 10:13 UT for photon energies above 100 MeV results in a detection significance of about 8 sigma. The positional error box, that does not yet take into account possible systematic effects, is centered at Galactic coordinates l = 143.8 deg, b = 27.6 deg. The 95% confidence level contour has a radius of about 0.4 degrees. The blazar TXS 0716+714, that has been associated with the gamma-ray source 3EG J0721+7120, lies at a distance of 0.44 degrees from the best fit position of the gamma-ray source. We therefore tentatively associate the AGILE source with this blazar.
Considering that the in-flight calibration of the GRID is still ongoing, and despite the preliminary GRID positioning capability at off-axis angles (20 to 40 deg for this observation), we strongly encourage multi-frequency observations of the field of the gamma-ray source detected by AGILE. The AGILE pointing of the Galactic plane region that includes this gamma-ray source will continue until 2007-09-23 12:00 UT.
|AGILE detection of a gamma-ray source off the Galactic Plane|
ATel #1199; A. Bulgarelli (INAF/IASF Bologna), S. Vercellone, A. Giuliani, A. Chen, S. Mereghetti, A. Pellizzoni, F. Perotti, F. Fornari, M. Fiorini, P. Caraveo, A. Zambra (INAF/IASF Milano), M. Tavani, G. Pucella, F. D'Ammando, V. Vittorini, E. Costa, M. Feroci, I. Donnarumma, L. Pacciani, E. Del Monte, F. Lazzarotto, P. Soffitta, Y. Evangelista, I. Lapshov, M. Rapisarda, A. Argan, A. Trois (INAF/IASF Roma), G. Barbiellini, F. Longo (INFN Trieste), G. Di Cocco, C. Labanti, F. Fuschino, M. Marisaldi, M. Galli, F. Gianotti, M. Trifoglio (INAF/IASF Bologna), P. Picozza, A. Morselli (INFN Roma-2), M. Prest, E. Vallazza (Universita` dell'Insubria), P. Lipari (INFN Roma-1) and P. Giommi, C. Pittori, L. A. Antonelli, D. Gasparrini, S. Cutini, F. Verrecchia (ASDC) and L. Salotti (ASI)
on 31 Aug 2007; 16:53 UT
Subjects: Gamma Ray, AGN, Quasars, Transients
The AGILE satellite, currently in its science performance verification phase, during an observation centered near the Galactic plane (l=334.44, b=10.06) that started on 2007-08-27 12:00 UT, detected significant gamma-ray emission from a source at approximately 33 degrees off the AGILE pointing direction. A preliminary maximum likelihood analysis of the AGILE-GRID (Gamma-Ray Imaging Detector) data obtained between 2007-08-27 14:48 UT and 2007-08-30 10:50 UT for photon energies above 100 MeV results in a detection significance of about 4 sigma. The positional error box derived from our preliminary maximum likelihood analysis (that does not, as yet, take into account possible systematic effects) results in a 95% contour level centered at the position l = 351.1, b = 39.7 with a radius of about 0.5 degrees. We note that this position is marginally consistent with the radio position of the blazar TXS 1510-089 that has been associated with the gamma-ray source 3EG J1512-0849. Considering that the in-flight calibration of the GRID is still ongoing, and despite the preliminary GRID positioning capability at substantial off-axis angles, we strongly encourage multi-frequency observations of the field of the gamma-ray source detected by AGILE. The AGILE pointing of the Galactic plane region that includes this gamma-ray source will continue until 2007-09-01 12:00 UT.
|GRB 070824 - Combined SuperAGILE/IPN Localization|
TITLE: GCN CIRCULAR
SUBJECT: GRB 070824 - Combined SuperAGILE/IPN Localization
DATE: 07/08/30 17:46:04 GMT
FROM: Marco Feroci at IASF/INAF <email@example.com>
Combined SuperAGILE/IPN Localization of the long and bright GRB 070824
I. Donnarumma, E. Del Monte, F. Lazzarotto, M. Feroci, A. Giuliani, M. Marisaldi, on behalf of the AGILE Team,
B. Preger, on behalf of the AGILE Science Data Center, S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P. Oleynik, M. Ulanov and T. Cline on behalf of the Konus-Wind and Konus-A teams, K. Hurley on behalf of the IPN Teams, J. Cummings, D. Palmer and H. Krimm, on behalf of the Swift/BAT team,D. M. Smith, R. P. Lin, J. McTiernan, R. Schwartz, C. Wigger, W. Hajdas, and A. Zehnder, on behalf of the RHESSI GRB team,
GRB 070824 triggered the SuperAGILE ground software trigger on 24 August 2007, at 20:50:09 UT. The GRB was seen as a 3 s long event, preceded by a weaker 2 s precursor 5 s earlier. The SuperAGILE T90 for this event was 9.5 s. The event was observed by SuperAGILE at 48.1 deg off-axis, which is in a region of the instrument field of view with only one-dimensional imaging. In spite of this, the event was observed on all SuperAGILE detectors; due to its hardness, it passed through the collimator shields. In addition, its arrival direction was partially obscured by the Earth's atmosphere for AGILE. For these reasons, the event was imaged by SuperAGILE with only 4.6 sigma significance. The SuperAGILE-only error box is thus a long, narrow strip, limited by the instrument field of view and Earth occultation in one direction and by the imaging uncertainty in the other. For the latter we assumed a 20 arcmin error radius, including statistics and systematics, due to the low statistics of the detection and the far off-axis position. The resulting
error box is:
The SuperAGILE light curve may be found at the AGILE Science Data Center and AGILE-Team web pages.
This event was independently detected by other IPN experiments, namely Konus-Wind, Swift/BAT, RHESSI, AGILE/Minicalorimeter, and the AGILE/Anticoincidence, as well as by Konus-A (Cosmos-2421). Their detection combined to provide further constraints to the burst localization, as shown in the figure at www.ssl.berkeley.edu/ipn3/070824.
The final localization of GRB 070824 is thus limited by the corners of a triangular area:
1: 172.055 -26.864
2: 171.188 -27.715
3: 172.281 -27.240
"Credit: V. Pal'shin, Ioffe Physico-Technical Institute"
"Credit: AGILE Team"
|August 7, 2007 - AGILE detection of the blazar 3c454.3 in a high state|
The AGILE satellite, currently in the science performance verification phase, has observed the 3C 454.3 field starting on 2007-07-24 14:30 UT, and ending on 2007-07-30 11:40 UT following the significant flaring activity of this blazar recently detected in the optical and X-ray energy bands.
Considering that the AGILE in-flight calibration is still ongoing, a gamma-ray source positionally consistent with 3C 454.3 was detected by the AGILE GRID (Gamma-Ray Imaging Detector), see ATel #1160 and ATel #1167.
The images below show the AGILE detection of the source in the gamma-ray energy band E > 100 MeV. The left picture is a detector image with superimposed a grid of Galactic coordinates in ARC projection. The right picture shows the same gamma-ray image distorted to match the Hammer-Aitoff projection in Galactic coordinates
|AGILE-ACS position for the SGR 1806-20|
TITLE: GCN CIRCULAR
F.Perotti, A.Giuliani, S.Mereghetti, M.Fiorini, S.Vercellone, A.Chen, A.Pellizzoni (IASF-Milano), C.Labanti, M.Trifoglio, G.Di Cocco (IASF-Bologna), M.Tavani, M.Feroci, A.Argan, A.Trois (IASF-Roma), G.Picozza (INFN-Roma), F.Longo, G. Barbiellini (INFN-Trieste), on behalf of the AGILE Teamand P. Giommi, L.A. Antonelli, C. Pittori (ASDC), and L. Salotti (ASI) report:
The SGR-like burst detected on July 27 at about 06:41 UT with Konus/Wind, INTEGRAL-SPI-ACS, RHESSI and Suzaku-WAM (Golenetskii et al. GCN 6684), and likely associated to SGR 1806-20, has been seen also by the Anticoincidence system of AGILE.
This segmented anticoincidence detector surrounds the gamma-ray tracker on five sides (top and 4 lateral). The relative intensity of the count rates measured from the different sides allows to estimate the arrival direction of the detected bursts.
Based on a simple geometrical model, the detection of this event in two of the lateral panels and its non-detection in the top panel, yields an instrumental azimuthal angle within 3 degrees from that of SGR 1806-20.
We thus support the association of this event with SGR 1806-20.
|AGILE gamma-ray detection of the Blazar 3C 454.3
Gamma Ray, AGN, Transients
The AGILE satellite, currently in the science performance verification phase, started to observe the 3C454.3 field on July 24, 2007, following the significant flaring activity of this blazar recently detected in the optical and X-ray energy bands.
A gamma-ray source positionally consistent with 3C 454.3 is detected with a maximum likelihood analysis giving a significance of 4.9 sigma in the AGILE GRID (Gamma-Ray Imaging Detector) data acquired between 2007-07-24 14:30 UT and 2007-07-27 05:27 UT.
Due to satellite constraints, 3C 454.3 is about 36 degrees off-axis. Considering that the in-flight calibration of the GRID is still ongoing, we can only provide at this moment a preliminary estimate of the gamma-ray flux of (3+/-1)*10E-6 ph/cm2/s for E>100 MeV.
AGILE will point at the 3C 454.3 field until July 30, 12:00 UT. Multifrequency observations of the source are encouraged.
|GRB 070724B: the First Gamma Ray Burst Localized by SuperAGILE|
TITLE: GCN CIRCULAR
GRB 070724b: First Gamma Ray Burst Localization by SuperAGILE onboard AGILE
M. Feroci, E. Costa, E. Del Monte, I. Donnarumma, Y. Evangelista,
I. Lapshov, F. Lazzarotto, L. Pacciani, M. Rapisarda, P. Soffitta,
A. Rubini, E. Morelli, M. Mastropietro, G. Di Persio, M. Frutti,
and S. Mereghetti, A. Pellizzoni, G. Di Cocco, C. Labanti, M. Trifoglio,
G. Barbiellini, P. Picozza, A. Argan and M. Tavani,
on behalf of the AGILE Team, P. Giommi, L.A. Antonelli,
The SuperAGILE experiment onboard the AGILE mission, launched on April 23rd on an equatorial orbit, is currently performingthe in-flight check-out and performance verification. The experiment is not yet in its optimal configuration and not all the functions are active.
In particular, the onboard triggering and imaging is not active yet and the absolute position reconstruction is being calibrated by using celestial X-ray sources. During this testing phase SuperAGILE detected and imaged GRB 070724b.
The event starting time is approximately at
23:25:09 UT on July 24 and it was observed at 21 degrees off-axis.
The burst position was reconstructed as (RA, Dec) (17.629 deg, 57.673 deg), which is:
RA(J2000) = 01h 10m 31.0s
The given uncertainty is almost entirely systematic and it is due to the very preliminary absolute position calibration, carried out only on 3 X-ray sources.
At this preliminary stage the absolute positioning was obtained by the ground calibrations, preliminarily checked with these sources.
The error box may be improved over the next hours/days.An analysis of the AGILE Gamma Ray Imager (GRID) data is in progress.
A quick look analysis does not show any bright gamma-ray transient in coincidence with the X-ray emission of GRB 070724b.
Light curve of the gamma ray burst in the 20-60 keV energy range (1s time bin)
Sky Image of the event in the two SuperAGILE coordinates