- GCN Circular #12666
F. Lazzarotto, E. Del Monte, I. Donnarumma, Y. Evangelista, M. Feroci,
L. Pacciani, P. Soffitta, E. Costa, I. Lapshov, M. Rapisarda
(INAF/IASF Rome), G. Barbiellini, F. Longo, E. Moretti (INFN Trieste),
A. Bulgarelli, F. Gianotti, M. Trifoglio, G. Di Cocco, C. Labanti,
F. Fuschino, M. Marisaldi, M. Galli (INAF/IASF Bologna),
A. Giuliani, A. Chen, S. Mereghetti, F. Perotti, P. Caraveo (INAF/IASF
Milan), M. Tavani, G. Pucella, V. Vittorini, A. Argan, A. Trois,
G. Piano, S. Sabatini, M. Cardillo (INAF/IASF Rome), A. Pellizzoni, M. Pilia
(INAF/OA Cagliari), S. Vercellone, F. D'Ammando (INAF/IASF Palermo),
P. W. Cattaneo, A. Rappoldi (INFN Pavia), P. Picozza, A. Morselli,
E. Striani, (INFN Roma-2), M. Prest, E. Vallazza (Universita`
dell'Insubria), P. Lipari, D. Zanello (INFN Roma-1),
P. Giommi, C. Pittori, F. Lucarelli, P. Santolamazza, F. Verrecchia
(ASDC) and L. Salotti (ASI), on behalf of the AGILE Team, report:
"SuperAGILE detected a gamma ray burst on 11 December 2011, at 22:17:33 UT.
The event had a duration of about 15 s in the 20-60 keV energy range,
with a double peak (with internal structure). Assuming a
crab-like energy spectrum, the peak flux on 1-s timescale was 1.50E-06
erg/cm2/s.
The burst position was reconstructed as (RA, Dec)
(153.091, 11.182) deg, which is:
RA(J2000) = 10h 12m 21.84s
Dec(J2000) = 11d 10' 55.52"
with an uncertainty of 3' radius. The given uncertainty accounts
for both the statistical and systematic errors.
An analysis of the AGILE Gamma Ray Imager (GRID) data is in progress."
This message may be cited.
- GCN Circular #12668
D.A. Kann (TLS Tautenburg), J. Greiner (MPE Garching),
T. Kruehler (DARK/NBI) and S. Klose (TLS Tautenburg)
report on behalf of the GROND team:
We observed the field of the SuperAGILE burst GRB 111211A (Feroci
et al. 2011, GCN #12666) simultaneously in g'r'i'z'JHK with GROND
(Greiner et al. 2008, PASP, 120, 405) mounted at the 2.2 m ESO/MPG
telescope at La Silla Observatory (Chile). Observations
started on December 12, 2011, at 07:50 UT, 8.5 hrs after the GRB.
They were performed at an average seeing of 1".1 and at an airmass
of 1.4
Within the 3 arcmin error circle we find one source brighter
than the DSS limit, and not seen on the DSS2-red plate or SDSS-r,
at the following coordinate:
RA (2000.0) = 10:12:21.7
Decl. (2000.0) = 11:12:30
with a conservative error of 0.7 arcsec. This is 1.6 arcmin from the
center of the SuperAGILE error circle. We propose this source as the
afterglow of GRB 111211A.
We estimate a rough r-band magnitude (calibrated against the SDSS) of
r'(AB) = 19.0
No obvious fading is detected, though this is not constraining
given the short GROND coverage and the time after the GRB.
Further observations are encouraged to check for the expected fading.
- GCN/BACODINE POSITION NOTICE
TITLE: GCN/SuperAGILE NOTICE
NOTICE_DATE: Mon 12 Dec 11 14:11:21 UT
NOTICE_TYPE: SuperAGILE GRB Ground Position
TRIGGER_NUM: 100
GRB_RA: 153.091d {+10h 12m 22s} (J2000),
153.250d {+10h 13m 00s} (current),
152.425d {+10h 09m 42s} (1950)
GRB_DEC: +11.182d {+11d 10' 55"} (J2000),
+11.123d {+11d 07' 22"} (current),
+11.430d {+11d 25' 46"} (1950)
GRB_ERROR: 3.00 [arcmin radius, statistical plus systematic]
GRB_INTEN: 358.377 403.748 [X & Y cnts]
GRB_SIGNIF: 12.77 10.67 [sigma]
GRB_DATE: 15906 TJD; 345 DOY; 11/12/11
GRB_TIME: 80255.00 SOD {22:17:35.00} UT
SUN_POSTN: 259.33d {+17h 17m 19s} -23.07d {-23d 04' 28"}
SUN_DIST: 109.01 [deg] Sun_angle= 7.1 [hr] (West of Sun)
MOON_POSTN: 103.95d {+06h 55m 49s} +20.32d {+20d 19' 27"}
MOON_DIST: 48.16 [deg]
MOON_ILLUM: 96 [%]
GAL_COORDS: 228.19, 49.42 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 151.02, 0.08 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS: SuperAGILE GRB Coordinates.
COMMENTS: This is a GRB.
COMMENTS:
COMMENTS: NOTE: This AGILE event is temporally(19.0<100sec) coincident with the INTEGRAL_SPIACS event (trignum=6415).
COMMENTS: SuperAGILE ground GRB coordinates
- red DSS finding chart
ps-file
- GCN Circular #12673
B.-B. Zhang (PSU) report on behalf of the Swift Team:
Swift began a target of opportunity observation of GRB 111211A on
December 12, 2011 at 15:53 UT, approximately 0.74 days after the burst
was detected by SuperAGILE. Swift data for these observations utilize
Target ID 20192.
We have analysed 2.5 ks of XRT data for the SuperAGILE-detected burst:
GRB 111211A (Lazzarotto et al. et al. GCN Circ. 12666), from 63.5 ks to
66.0 ks after the SuperAGILE trigger. The data are entirely in Photon
Counting (PC) mode. An X-ray source is detected within the SuperAGILE
error circle. Using 2512 s of PC mode data and 3 UVOT images, we find
an enhanced XRT position (using the XRT-UVOT alignment and matching
UVOT field sources to the USNO-B1 catalogue): RA, Dec = 153.09040,
+11.20789 which is equivalent to:
RA (J2000): 10h 12m 21.70s
Dec(J2000): +11d 12' 28.4"
with an uncertainty of 1.8 arcsec (radius, 90% confidence). This
position is 93 arcsec from the SuperAGILE position and 1.6 arcsec from
the GROND afterglow candidate position (Kann et al. GCN Circ. 12668),
which confirms it is the X-ray afterglow of GRB 111211A. The light
curve is consistent with a constant source of mean count rate 1.3e-01
ct/sec. A power-law fit gives an index of -1.309 (+4.183, -0.020).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.02 (+0.18, -0.26). The
best-fitting absorption column is 1.3 (+0.7, -0.6) x 10^21 cm^-2, in
excess of the Galactic value of 3.4 x 10^20 cm^-2 (Kalberla et al.
2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum is 3.7 x 10^-11 (4.9 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 1.3 (+0.7, -0.6) x 10^21 cm^-2
Galactic foreground: 3.4 x 10^20 cm^-2
Excess significance: 2.5 sigma
Photon index: 2.02 (+0.18, -0.26)
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00020192.
This circular is an official product of the Swift-XRT team.
- GCN Circular #12675
T. Kruehler and D. Malesani (both DARK/NBI) report on behalf of a larger collaboration:
We observed the field of the AGILE GRB 111211A (Lazzarotto et al., GCN 12666) with the NOT telescope equipped with StanCam. A single R-band image with an integration time of 600 s was obtained on 2011-12-13 at 03:34 UT, which is roughly 29.3 hours after the trigger.
We clearly detect the optical afterglow candidate (Kann et al., GCN 12668) at
RA = 10:12:21.68
Dec = +11:12:29.3
with an uncertainty of approximately 0.3 arcsec in each coordinate.
Calibrating our R-band image against the r- and i-band magnitudes of the SDSS catalog via the transformation of Lupton et al. (2006), we measure a preliminary magnitude of R = 19.5 +/- 0.1 (Vega system). This implies a significant fading with respect to the earlier measurements of Kann et al. (GCN 12668), and hence confirms this source to be the afterglow of GRB 111211A.
We are grateful to the NOT staff and observer, Ilya Ilyin for obtaining these observations.
- GCN Circular #12676
S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P.
Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind
team report:
The long GRB 111211A localized by SuperAGILE (Lazzarotto et al., GCN
12666) was detected by Konus-Wind in the waiting mode.
The burst light curve shows two pulses with a total duration of ~25 s.
As observed by Konus-Wind, the burst had a fluence of (9.2 +/-
0.8)x10^-6 erg/cm2 (in the 20 - 1200 keV energy range).
Fitting the K-W 3-channel time-integrated spectrum (from T0-18.141 s to
T0+8.355 s) by a simple power-law model yields a power law index of
2.77(-0.16, +0.18) (chi2=2.0/1 dof).
All the quoted errors are at the 90% confidence level.
The K-W light curve of this burst is available at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB111211A/
- GCN Circular #12677
S.D. Vergani (OAB/INAF), S. Piranomonte (OAR/INAF), O.E.Hartoog (UvA,
Netherland), V. D'Elia (ASDC/INAF), G. Cupani (OAT/INAF), A. de Ugarte
Postigo (IAA-CSIC, DARK/NBI), T. Kruehler, J.P.U. Fynbo, Bo
Milvang-Jensen, D. Malesani (DARK/NBI), P. Vreeswijk (U. Iceland), N.
R. Tanvir (U. Leicester) and L. Kaper (UvA, Netherland) report on
behalf of the X-shooter GTO GRB afterglow collaboration:
The afterglow of the AGILE GRB 111211A (Lazzarotto et al., GCN 12666,
Kann et al. 12668 and Kruehler et al. GCN 12675) was
observed with the X-shooter spectrograph mounted on the ESO-VLT.
Observations started around 7 UT on 13 December
2011 (1.3 days after the GRB). A series of four spectra of 600 s each
were secured, covering the approximate wavelength range 3000-25000 AA.
Preliminary reduction of the ultraviolet, visual and near-infrared
parts of the spectra show a smooth continuum with some weak
absorption features that we can identify with resonance absorption
lines of FeII, MgII and CaII at a redshift of z=0.478, which very
likely correspond to the redshift of GRB 111211A.
Weak emission lines ([O III] doublet and Halpha) are also observed at
the same redshift.
We thank D.A. Kann for providing us the GROND finding chart and we
are grateful for the excellent support from the Paranal Observatory
staff, in particular Willem-Jan de Wit (Shift coordinator), Dimitri
Gadotti (Night Astronomer), Marcelo Lopez (Telescope and
Instrument Operator) and Gabriel Brammer (Day Astronomer).
- GCN Circular #12678
M. H. Siegel and B.-B. Zhang (PSU) report on behalf of the Swift-UVOT team:
We have analyzed 4.5 ks of UVOT data for the SuperAGILE-detected burst GRB
111211A (Lazzarotto et al., GCN Circ 12666), taken 63.5 to 76.6 ks after the
trigger. Data were taken entirely in the white filter. We confirm the
uncatalogued source reported by Kann et al. (GCN Circ. 12668), Zhang (GCN
Circ. 12673) and Kruehler et al. (GCN Circ. 12675). However, we can not
confirm any statistically significant fading at this time. The UVOT position is
RA, Dec = 153.09037, +11.20801 which is equivalent to:
RA (J2000): 10h 12m 21.69s
Dec(J2000): +11d 12' 28.9"
with an uncertainty of 0.5 arcsec (radius, 90% confidence). Preliminary
photometry using the UVOT photometric system (Breeveld et al. 2011, AIP
Conf. Proc. 1358, 373) shows:
Filter T_start(ks) T_stop(ks) Exp(s) Mag
white 63.5 76.6 4550 19.51+-0.03
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.05 in the direction of the burst
(Schlegel et al. 1998).
- GCN Circular #12704
A.Volnova (SAI MSU), M. Andreev, A. Sergeev (Terskol Branch of INASAN), V.
Petkov (Baksan Neutrino Observatory of INR), N. Karpov, O. Andrienko, K.
Martynyuk-Lototsky, N. Parakhin, N. Borachok, V. Kozlov, G. Butenko, V.
Godunova (IC AMER, NASU), A. Pozanenko (IKI) report:
We observed field of the SuperAGILE GRB 111211A (Lazzarotto et al. GCN
12666) with Zeiss-600 telescope of Mt.Terskol observatory in R filter
between Dec. 12 (UT) 23:09:07 -- Dec.13 00:55:27. We took several images
of 60 exposure under good weather conditions and mean seeing (FWHW) of about
1.8". We detect the source reported as candidate in afterglow (Kann et
al., GCN 12668; Kruehler et al., GCN 12675). A photometry is based on the
USNO-B1.0 1011-0183238 (10:12:26.16 +11:11:26.6) star assuming R = 14.41.
T0+ Filter, Exposure, OT, UpperLimit
(mid, d) (s)
1.07273 R 104x60 19.25 +/- 0.10 20.0
- GCN Circular #12802
A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), C.C. Thoene and J. Gorosabel (IAA-CSIC) report on behalf of a larger collaboration:
Using the 10.4m GTC telescope + OSIRIS, at the Roque de los Muchachos Observatory (La Palma, Spain), we obtained late imaging and spectroscopy of the SuperAGILE GRB 111211A (Lazzarotto et al. GCN 12666, Kann et al. GCN 12668), located at a redshift of 0.478 (Vergani et al. GCN 12677) at 2 epochs.
On 27 December 2011 (15.3 days after the burst) we obtained imaging in r-band of 6x180s with a seeing of ~0.9". This image clearly shows the afterglow of GRB 111211A at a magnitude of r ~ 22.6 (compared to SDSS stars) superposed to its resolved host galaxy but slightly offset towards the North East.
Spectroscopy of the afterglow was obtained on 1 January 2012 (20.3 days after the burst) under good seeing conditions (~1"). At that time, the afterglow was detected at r ~ 22.7 in the acquisition frame, implying an almost flat evolution since the previous epoch which indicates a possible supernova component contributing to the light curve. We obtained 3x1800s spectroscopy at a resolution of ~ 500 and wavelength coverage from ~ 5 000 to 10 000 Angstrom. The spectrum shows both emission from the GRB and the host galaxy. The host shows emission lines of [OII], H-beta, [OIII] and H-alpha at a redshift of 0.478, consistent with the redshift of the GRB (Vergani et al. GCN 12677). The spectrum at the position of the afterglow shows undulations typical of a SN spectrum similar to the spectrum of the type Ic SN 2006aj / GRB 060218 close to maximum.
We acknowledge excellent support from the GTC staff, in particular D. Reverte, A. Cabrera Lavers and R. Rutten.
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