GRB 170209A
GCN Circular 20652
Subject
GRB 170209A: Fermi GBM Detection
Date
2017-02-09T22:26:43Z (8 years ago)
From
Oliver J Roberts at USRA/NASA <oliver.roberts@nasa.gov>
O.J. Roberts (USRA/NASA) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:
"At 01:08:38.08 UT on the 9th of February 2017,
the Fermi Gamma-Ray Burst Monitor triggered and
located GRB 170209A (trigger 508295323 / 170209048),
for which MASTER reported an OT in follow-up
observations of the reported GBM location region
(Podesta et al. 2017, GCN 20650). The on-ground
calculated location using the GBM trigger data is,
RA = 113.40, DEC = -49.64 (J2000 degrees), equivalent
to J2000 7h 33m, -49d 38',
with an uncertainty of 3.22 degrees (radius, 1-sigma
containment, statistical only; there is additionally
a systematic error which we have characterized as a
core-plus-tail model, with 90% of GRBs having a 3.7 deg.
error and a small tail suffering a larger than 10 deg.
systematic error [Connaughton et al. 2015, ApJS, 216, 32]).
The angle from the Fermi LAT boresight at the GBM trigger
time is 120 degrees.
The GBM light curve consists of a long GRB with two bright
episodes of emission over a duration (T90) of about 40 s
(50-300 keV). The time-averaged spectrum from T0+0 s to
T0+40.0 s is best fit by a power law function with an
exponential high-energy cutoff. The power law index is
-0.95 +/- 0.07 and the cutoff energy, parameterized as
Epeak is 132 +/- 9 keV.
The event fluence (10-1000 keV) in this time interval is
(9.34 +/- 0.37)E-06 erg/cm^2. The 1-sec peak photon flux
measured starting from T0+1.9 s in the 10-1000 keV band
is 12.6 +/- 0.4 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 20656
Subject
IPN Triangulation of GRB 170209A
Date
2017-02-09T23:58:53Z (8 years ago)
From
Anna Kozlova at Ioffe Institute <ann_kozlova@mail.ioffe.ru>
K. Hurley, on behalf of the IPN,
I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin,
on behalf of the HEND-Odyssey GRB team,
A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin,
and T. Cline on behalf of the Konus-Wind team,
V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa,
and A. Goldstein, on behalf of the Fermi GBM team,
A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
and
W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr,
on behalf of the GRS-Odyssey GRB team, report:
The long-duration GRB 170209A
(Fermi GBM Detection: Roberts & Meegan, GCN Circ. 20652)
has been detected by Fermi (GBM), Konus-Wind, INTEGRAL (SPI-ACS),
and Mars-Odyssey (HEND), so far, at about 4118 s UT (01:08:38).
We have triangulated it to a preliminary, 3 sigma error box whose
coordinates are:
---------------------------------------------
RA(2000), deg Dec(2000), deg
---------------------------------------------
Center:
110.686 (07h 22m 45s) -51.959 (-51d 57' 34")
Corners:
111.873 (07h 27m 29s) -55.694 (-55d 41' 38")
111.366 (07h 25m 28s) -55.308 (-55d 18' 29")
109.742 (07h 18m 58s) -48.166 (-48d 09' 58")
110.149 (07h 20m 36s) -48.575 (-48d 34' 30")
---------------------------------------------
The error box area is 1.66 sq. deg, and its maximum
dimension is 7.64 deg (the minimum one is 13.1 arcmin).
The Sun distance was 105 deg.
This box may be improved.
The distance between the narrowest annulus (GBM-HEND annulus with
3 sigma half width of 0.109 deg) center line and the optical transient
J072307.30-521446.6 (Podesta et al., GCN Circ. 20650) is 1 arcmin,
supporting the association of the transient and the GRB.
A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB170209_T04120/IPN/
The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.
GCN Circular 20658
Subject
GRB 170209A: Swift ToO observations
Date
2017-02-10T14:42:18Z (8 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a ToO observation of the IPN GRB 170209A.
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00020739
Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the IPN event. Any X-ray source
considered to be a probable afterglow candidate will be reported via a
GCN Circular after manual consideration.
Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).
This circular is an official product of the Swift-XRT team.
GCN Circular 20659
Subject
Konus-Wind observation of GRB 170209A
Date
2017-02-10T15:04:10Z (8 years ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>
D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:
The long-duration GRB 170209A
(Fermi-GBM detection: Roberts and Meegan, GCN Circ. 20652;
IPN triangulation: Hurley et al., GCN Circ. 20656)
triggered Konus-Wind at T0=4120.061 s UT (01:08:40.061).
The burst light curve shows two multipeaked episodes
started at ~T0-2 s with a total duration of ~40 s.
The emission is seen up to ~1 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB170209_T04120/
As observed by Konus-Wind, the burst
had a fluence of 8.35(-0.69,+0.76)x10^-6 erg/cm2,
and a 64-ms peak flux, measured from T0+1.904 s,
of 2.75(-0.80,+0.84)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum of the burst
(measured from T0 to T0+41.216 s)
is best fit in the 20 keV - 2 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -0.59(-0.30,+0.35)
and Ep = 126(-13,+18) keV (chi2 = 68/60 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.6
(chi2 = 68/59 dof).
The spectrum near the maximum count rate
(measured from T0+0.256 to T0+8.448 s)
is best fit in the 20 keV - 2 MeV range
by a power law with exponential cutoff model:
with alpha = -0.92(-0.31,+0.35)
and Ep = 164(-28,+47) keV (chi2 = 60/60 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.2
(chi2 = 60/59 dof).
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.
GCN Circular 20662
Subject
GRB 170209A: Swift-XRT observations
Date
2017-02-11T02:09:50Z (8 years ago)
From
Aaron Cholden-Brown at PSU/Swift <aaronb@swift.psu.edu>
B. Mingo (U. Leicester), A.P. Beardmore (U. Leicester), V. D'Elia
(ASDC), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), D.N. Burrows
(PSU), A. Cholden-Brown (PSU), S. J. LaPorte (PSU) and P.A. Evans (U.
Leicester) report on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the IPN-detected
burst GRB 170209A (Roberts et al. GCN Circ. 20652), collecting 5.0 ks
of Photon Counting (PC) mode data between T0+134.5 ks and T0+153.7 ks.
No X-ray sources have been detected consistent with being within 16
arcsec of the MASTER-OAFA position. The 3-sigma upper limit in the
field ranges from ~0.002 to ~0.005 ct s^-1, corresponding to a 0.3-10
keV observed flux of 8.6e-14 to 2.0e-13 erg cm^-2 s^-1 (assuming a
typical GRB spectrum).
The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
http://www.swift.ac.uk/ToO_GRBs/00020739.
This circular is an official product of the Swift-XRT team.
GCN Circular 20670
Subject
GRB 170209A: AstroSat CZTI detection
Date
2017-02-13T20:10:05Z (8 years ago)
From
Vidushi Sharma at IUCAA <vidushi@iucaa.in>
V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IITB), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
Analysis of AstroSat CZTI data showed a clear detection of GRB 170209A (Fermi GBM detection: O.J. Roberts et al., GCN Circ. 20652) in the 40-200 keV energy range. The light curve showed multiple peaks emission. The first emission peak occurred at 01:08:40.08 UT, 2 s after the Fermi trigger and a second group of emission peaked at ~34 s after the trigger. An interval of ~9 s between these two showed no detectable emission. The measured peak count rate was 245.1 counts/s above the background in combined data of four quadrants, with a total 1453.0 counts. The local mean background count rate was 343.9 counts/s. Using cumulative rates, we measured a T90 of 40.4 s.
It was clearly detected in the CsI anticoincidence detector (Veto) also as bright detection in the 100-500 keV energy range.
CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.
GCN Circular 20680
Subject
GRB 170209A: GROND confirmation of MASTER afterglow
Date
2017-02-15T16:29:28Z (8 years ago)
From
Jochen Greiner at MPI <jcg@mpe.mpg.de>
P. Schady, J. Greiner (both MPE Garching), and S. Steinmassl (TU Munich),
report:
We observed the field of the optical transient reported by MASTER
(Podesta et al. 2017, GCN #20650) of GRB 170209A (Fermi/GBM trigger 508295323;
Roberts & Meegan 2017, GCN #20652) simultaneously in g'r'i'z'JHK with GROND
(Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at
ESO La Silla Observatory (Chile).
Observations started at 03:16 UT on 2017-02-10, 26 hrs after the GRB trigger,
resulting in 36 min of total exposures in g'r'i'z' and 30 min in JHK.
They were performed at an average seeing of 2.3" and at an airmass of 1.1.
A second epoch observation was started at 03:03 UT on 2017-02-15, around 6 days
after the GRB trigger, resulting in 72 min of total exposures in g'r'i'z' and
60 min in JHK. Seeing conditions were better, around 1.3".
We detect two sources close to the MASTER position: the fainter one, to the
North-West, has faded by more than 1.2 mag, while the second source (to the
South-West) stayed constant within the errors.
The position of the fading object is
RA (2000.0) = 07:23:07.19
Decl.(2000.0) = -52:14:45.5
with an error of +-0.3", and about 1.5 arcsec from the MASTER position.
We find the following magnitudes of the fading object:
epoch 1 epoch 2
g' > 23.5 mag > 24.6 mag
r' = 23.4 +- 0.1 mag > 24.6 mag
i' = 23.3 +- 0.3 mag > 24.2 mag
z' = 23.1 +- 0.3 mag > 24.2 mag
J > 21.3 mag > 21.7 mag
H > 21.0 mag > 21.3 mag
K > 19.3 mag > 19.7 mag
The close match with the MASTER object, the fading and the powerlaw-like
r'i'z colors confirm the nature of this object as the afterglow of
GRB 170209A, as suggested also by Hurley et al. 2017, GCN #20656 based
purely on the positional coincidence.
Given magnitudes are calibrated against GROND zeropoints and 2MASS field stars
and are not corrected for the Galactic foreground extinction corresponding to
a reddening of E(B-V)= 0.12 mag in the direction of the burst (Schlafly &
Finkbeiner 2011).
We thank the support astronomer, S. Ciceri, for the support of the observations.