GRB 170214A
GCN Circular 20675
Subject
GRB 170214A: Fermi GBM detection
Date
2017-02-14T22:26:42Z (8 years ago)
From
Bagrat Mailyan at UAH <bm0054@uah.edu>
B. Mailyan and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:
"At 15:34:26.92 UT on 14 February 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 170214A (trigger 508779271 / 170214649).
The on-ground calculated location, using the GBM trigger
data, is RA = 255.61, DEC = -5.78 (J2000 degrees), equivalent to
J2000 17h 02m, -05d 46',
with an uncertainty of 1 degree (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 trigger resulted in an Autonomous Repoint Request (ARR)
by the GBM Flight Software owing to the high peak flux
of the GRB. This ARR was accepted and the spacecraft slewed to the GBM in-flight
location. The initial angle from the Fermi LAT boresight to
the GBM ground location is 29 degrees.
The GBM light curve shows multiple overlaping peaks
with a duration (T90) of about 123 s (50-300 keV).
The time-averaged spectrum from T0+12.8 s to T0+136.7 s is
best fit by a Band function with Epeak = 408.50 +/- 9.09 keV,
alpha = -0.84 +/- 0.01, and beta = -2.34 +/- 0.05.
The event fluence (10-1000 keV) in this time interval is
(1.8 +/- 0.002)E-4 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+61.7 s in the 10-1000 keV band
is 17.8 +/- 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 20676
Subject
GRB 170214A: Fermi-LAT detection
Date
2017-02-15T00:13:48Z (8 years ago)
From
Judith Racusin at GSFC <judith.racusin@nasa.gov>
J. L. Racusin (NASA/GSFC), G. Vianello (Stanford), and J. Perkins (NASA/GSFC),
report on behalf of the Fermi-LAT team:
At 15:34:26.92 on February 14, 2017, Fermi-LAT detected high-energy
emission from GRB 170214A, which was also detected by Fermi-GBM
(trigger 508779271 / 170214649, Mailyan et al., GCN 20675).
The best LAT on-ground location is found to be
RA, Dec: 256.33, -1.88 (degrees, J2000)
with an error radius of 0.08 deg (90% containment, statistical error only).
This was 33 deg from the LAT boresight at the time of the trigger, and
triggered an autonomous repoint of the spacecraft.
The data from the Fermi-LAT show a significant increase in the event rate
that is spatially and temporally correlated with the GBM emission with high
significance. More than 160 photons above 100 MeV and more than 13
photons above 1 GeV are observed within 1000 seconds. The highest-
energy photon is a 7.8 GeV event which is observed ~105 seconds after
the GBM trigger.
A Swift ToO has been approved for this burst.
The Fermi-LAT point of contact for this burst is
Judith Racusin (judith.racusin@nasa.gov).
The Fermi-LAT is a pair conversion telescope designed to cover the energy
band from 20 MeV to greater than 300 GeV. It is the product of an international
collaboration between NASA and DOE in the U.S. and many scientific institutions
across France, Italy, Japan and Sweden.
GCN Circular 20677
Subject
GRB 170214A: Swift ToO observations
Date
2017-02-15T02:17:33Z (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 Fermi/LAT GRB 170214A.
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00020740
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 Fermi/LAT 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 20678
Subject
Konus-Wind observation of GRB 170214A
Date
2017-02-15T14:44:18Z (8 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov,
D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline,
on behalf of the Konus-Wind team, report:
The long GRB 170214A (Fermi-GBM detection: Mailyan & Meegan, GCN 20675;
Fermi-LAT detection: Racusin et al., GCN 20676)
triggered Konus-Wind at T0=56076.276 s UT (15:34:36.276)
The light curve shows count rate increase around ~T0-50 s
followed by a bright, multi-peaked structure
which starts at ~T0-14 s and has a total duration of ~150 s.
The emission is seen up to ~10 MeV.
As observed by Konus-Wind, the burst had a fluence of
(2.41 �� 0.17)x10^-4 erg/cm2 and a 64-ms peak energy flux,
measured from T0+52.480, of (8.77 �� 0.13)x10^-6 erg/cm2
(both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum (measured from T0 to T0+147.968 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.70 (-0.06,+0.07),
the high energy photon index beta = -2.61 (-0.27,+0.16),
the peak energy Ep = 330 (-19,+21) keV,
chi2 = 96/97 dof.
The spectrum near the peak count rate (measured from T0+47.360
to T0+56.248 s) is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.75 (-0.12,+0.15),
the high energy photon index beta = -2.56 (-1.15,+0.33),
the peak energy Ep = 412 (-68,+73) keV,
chi2 = 110/97 dof.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB170214_T56076/
All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.
[GCN OPS NOTE(15feb17): Per author's request, the value for the
peak energy flux was changed from "10^-5" to "10^-6".]
GCN Circular 20679
Subject
GRB 170214A: Swift-XRT observations
Date
2017-02-15T14:47:44Z (8 years ago)
From
Andy Beardmore at U Leicester <ab271@leicester.ac.uk>
A.P. Beardmore (U. Leicester), A. D'Ai (INAF-IASFPA), A. Melandri
(INAF-OAB), P. D'Avanzo (INAF-OAB), A. Cholden-Brown (PSU), S. J.
LaPorte (PSU), J.A. Kennea (PSU), S.L. Gibson (U. Leicester) and P.A.
Evans (U. Leicester) report on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the
Fermi/LAT-detected burst GRB 170214A (Racusin et al. GCN Circ. 20676),
collecting 4.9 ks of Photon Counting (PC) mode data between T0+38.6 ks
and T0+65.3 ks.
Two uncatalogued X-ray sources have been detected, however none of them
is above the RASS limit or shows definitive signs of fading. Therefore,
at the present time we cannot identify which, if any, is the afterglow.
Details of these sources are given below:
Source 1:
RA (J2000.0): 256.34147 = 17:05:21.95
Dec (J2000.0): -1.88746 = -01:53:14.9
Error: 2.4 arcsec (radius, 90% conf. [Enhanced position])
Count-rate: 0.0131 +/- 0.0021 ct s^-1
Distance: 49 arcsec from Fermi/LAT position.
Flux: (4.88 +/- 0.78)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)
Source 3:
RA (J2000.0): 256.3873 = 17:05:32.95
Dec (J2000.0): -2.0113 = -02:00:40.8
Error: 8.8 arcsec (radius, 90% conf.)
Count-rate: (1.94 [+0.96, -0.74])e-3 ct s^-1
Distance: 515 arcsec from Fermi/LAT position.
A catalogued source was also detected.
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/00020740.
This circular is an official product of the Swift-XRT team.
GCN Circular 20681
Subject
GRB170214A: RATIR Optical and NIR Observations
Date
2017-02-15T21:59:15Z (8 years ago)
From
Eleonora Troja at GSFC <eleonora.troja@nasa.gov>
Eleonora Troja (GSFC), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer
(UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB),
Antonino Cucchiara (UVI), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz
(UCSC), Jes��s Gonz��lez (UNAM), Carlos Rom��n-Z����iga (UNAM), Harvey
Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and
Vicki Toy (UMD) report:
We observed the field of GRB 170214A (Mailyan, et al., GCN 20675;
Racusin, et al., GCN 20676) with the Reionization and Transients
Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson
Telescope at the Observatorio Astron��mico Nacional on Sierra San Pedro
M��rtir from 2017/02 15.44 to 2017/02 15.50 UTC (10.58 to 11.99 hours
after the GBM trigger). We performed a series of tiled observations
partially covering the LAT error circle, obtaining a total of 0.40
hours exposure in the r and i bands and 0.32 hours exposure in the Z
and Y bands.
At the position of the first Swift/XRT source (source 1; Beardmore,
et al., GCN 20679), in comparison with the SDSS DR9 and 2MASS catalogs,
we obtain the following detections:
r 21.06 +/- 0.11
i 20.89 +/- 0.13
Z 20.54 +/- 0.18
Y 20.34 +/- 0.32
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.
We did not detect any significant fading during our observations, so
at present we cannot confirm the nature of this source. Further
observations are planned.
The second, fainter XRT source (source 3; Beardmore, et al., GCN 20679)
falls outside our set of frames.
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.
GCN Circular 20682
Subject
GRB 170214A: Swift/UVOT Upper Limits
Date
2017-02-16T07:17:01Z (8 years ago)
From
Alice Breeveld at MSSL-UCL <a.breeveld@ucl.ac.uk>
A. A. Breeveld (UCL-MSSL) and A.P. Beardmore (U. Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 170214A
38603 s after the LAT trigger (Mailyan and Meegan, GCN Circ. 20675).
No optical afterglow consistent with the XRT���s source 1 position
(Beardmore et al., GCN Circ. 20679, Troja et al., GCN Circ. 20681)
is detected in the initial UVOT exposures. The source 3 position is just
off the edge of the field of view.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for source 1 in the
initial exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
w1 38603 65287 4856 >21.0
The magnitude in the table is not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.36 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 20683
Subject
GRB 170214A: NOT optical afterglow confirmation
Date
2017-02-16T07:38:43Z (8 years ago)
From
Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst <malesani@dark-cosmology.dk>
Daniele Malesani (DARK/NBI), Jens-Kristian Krogager (IAP and DARK/NBI),
and Adarsh Ranjan (IAP), report on behalf of a larger collaboration:
We observed the candidate optical counterpart of GRB 170214A (Mailyan &
Meegan , GCN 20675; Racusin et al., GCN 20676; Beardmore et al., GCN
20679; Troja et al., GCN 20681) with the Nordic Optical Telescope (NOT),
equipped with the AlFOSC camera. Three observations by 300 s each were
taken in the SDSS r band, under a seeing of 0.7", starting on 2017 Feb
16.263 UT (38.90 hr after the Fermi/GBM trigger). We note that our
pointing only covers XRT source #1 from Beardmore et al. (GCN 20679).
Within the XRT error circle (Beardmore et al., GCN 20679), we detect a
single object at coordinates (0.5" error):
RA(J2000) = 17:05:21.90
Dec(J2000) = -01:53:15.7
We assume that this is the same object reported by Troja et al. (GCN
20681). Calibrating against nearby SDSS stars, we measure r = 22.45 +-
0.07 AB. The fading by more than 1 mag compared to the RATIR measurement
(Troja et al., GCN 20681), as well as the spatial association with an
X-ray source (Beardmore et al., GCN 20679), confirm this object to be
the optical afterglow of GRB 170214A.
GCN Circular 20684
Subject
GRB 170214A: GROND detection in all bands
Date
2017-02-16T14:07:29Z (8 years ago)
From
Patricia Schady at MPE/Swift <pschady@mpe.mpg.de>
Patricia Schady and Thomas Kruehler (MPE Garching) report:
We observed the field of the Fermi GRB 170214A (trigger 508779271/170214649, Mailyan et al., GCN #20675) 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 08:53 UT on 2017-02-15, 17.3 hrs after the GRB trigger, and they were performed at an average seeing of 1.5" and at an average airmass of 1.6. We detect an uncatalogued source within the XRT error circle of Source 1 (Beardmore et al., GCN #20679), at the same position reported by Malesani et al., (GCN #20683).
Based on combined images with 16 min of total integration time in g�r�i�z� and 19 min in JHK at a mid-time of 09:05 UT on 2017-02-15, this source has the following preliminary magnitudes (all in the AB system):
g' = 22.6 +/- 0.3 mag
r� = 21.3 +/- 0.1 mag
i� = 20.8 +/- 0.1 mag
z' = 20.3 +/- 0.1 mag
J = 19.6 +/- 0.1 mag
H = 19.3 +/- 0.1 mag
K = 18.8 +/- 0.3 mag
We re-observed the target on 2017-02-16 at a mid-time of 08:45 UT, and the r�-band magnitude has decayed by a further 0.1 mag compared to the NOT measurement (Malesani et al., GCN #20683).
The given magnitudes are derived based on calibrating the images against SDSS in the optical and 2MASS field stars in the NIR bands. They are not corrected for the Galactic foreground extinction corresponding to a reddening of E_(B-V)= 0.30 in the direction of the burst (Schlafly & Finkbeiner 2011).
We acknowledge the excellent help provided by the observer on the 2.2 m telescope at La Silla, Simona Ciceri, in obtaining these data.
GCN Circular 20685
Subject
GRB170214A: RATIR Optical and NIR Afterglow Confirmation
Date
2017-02-16T15:00:45Z (8 years ago)
From
Eleonora Troja at GSFC <eleonora.troja@nasa.gov>
Eleonora Troja (GSFC), Nat Butler (ASU), Alan M. Watson (UNAM),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer
(UNAM), Ori Fox (STScI), J. Xavier Prochaska (UCSC), Josh Bloom (UCB),
Antonino Cucchiara (UVI), Owen Littlejohns (ASU), Enrico Ramirez-Ruiz
(UCSC), Jes��s Gonz��lez (UNAM), Carlos Rom��n-Z��niga (UNAM), Harvey
Moseley (GSFC), John Capone (UMD), V. Zach Golkhou (ASU), and
Vicki Toy (UMD) report:
We observed the field of GRB 170214A (Mailyan, et al., GCN 20675;
Racusin, et al., GCN 20676) with the Reionization and Transients
Infrared Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson
Telescope at the Observatorio Astron��mico Nacional on Sierra San
Pedro M��rtir from 2017/02 16.46 to 2017/02 16.54 UTC (43.4
to 45.4 hours after the GBM trigger), obtaining a total of 1.42
hours exposure in the r and i bands and 0.60 hours exposure in the
Z and Y bands.
Source 1 (Beardmore, et al., GCN 20679; Troja, et al., GCN 20681) is
still detected in our observations at a position consistent with the
NOT source (Malesani, et al., GCN 20683). In comparison with the
SDSS DR9 and 2MASS catalogs, we obtain the following detections:
r 22.78 +/- 0.08
i 22.40 +/- 0.15
Z 21.54 +/- 0.17
Y 21.22 +/- 0.17
These magnitudes are in the AB system and are not corrected for Galactic
extinction in the direction of the GRB.
Compared to our first night of observations (Troja, et al., GCN 20681)
the source significantly faded in all filters, confirming that it is the
optical (Malesani, et al., GCN 20683) and NIR afterglow of GRB170214A.
We thank the staff of the Observatorio Astron��mico Nacional in San Pedro
M��rtir.
GCN Circular 20686
Subject
GRB 170214A: VLT/X-shooter spectroscopy and tentative redshift
Date
2017-02-16T16:41:59Z (8 years ago)
From
Thomas Kruehler at MPE Garching <kruehler@mpe.mpg.de>
T. Kruehler, P. Schady, J. Greiner (all MPE Garching) and
N. R. Tanvir (U. Leicester) report:
We observed the optical counterpart (Troja et al. GCN 20681,
Malesani et al. GCN 20683, Schady et al. GCN 20684) of GRB 170214A
(Mailyan and Meegan, GCN 20675, Racusin et al. GCN 20676)
with the ESO Very Large Telescope UT 2 (Kueyen) equipped
with the X-shooter spectrograph, covering the wavelength range
3200-20000 AA. Observations started at 08:18 UT on 2017-02-16,
roughly 40.7 hours after the burst and consisted of 6 exposures
of 600 s each.
Our spectrum has a low signal-to-noise ratio with no signal being
detected bluewards of around 5800 AA due to a combination of
high background from the bright moon and faint afterglow.
In the red part, the spectrum exhibits four marginal absorption
features, which are consistent with coming from various FeII
transitions at a common redshift of z=2.53.
We acknowledge excellent support from the ESO observing staff
in Paranal, in particular Marcela Espinoza, Cedric Ledoux,
and Stephane Brillant.
GCN Circular 20687
Subject
GRB 170214A: Mondy optical upper limit
Date
2017-02-16T17:10:55Z (8 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Mazaeva (IKI), A. Pozanenko (IKI), E. Klunko (ISTP), A. Volnova (IKI),
report on behalf of larger GRB follow-up collaboration:
We observed the field of GRB 170214A (Mailyan et al., GCN 20675; Racusin
et al., GCN 20676) with AZT-33IK telescope of Sayan observatory (Mondy)
starting on Feb., 15 (UT) 20:58:01. We obtained several images in R-filter.
The optical counterpart of GRB 170214A (Troja et al., GCN 20681; Malesani
et al., GCN 20683; Schady et al., GCN 20684) is not detected in our stacked
image.
Preliminary photometry of the field is following
Date UT start t-T0 Filter Exp. OT UL
(mid, days) (s)
2017-02-15 20:58:01 1.24558 R 120*30 n/d 21.4
Photometry is based on nearby SDSS-DR9 stars
SDSS-DR9_id R(Lupton)
J170525.39-015302.5 17.50
J170522.63-015255.8 17.31
J170519.90-015220.7 18.47
J170517.04-015226.0 15.51
J170515.90-015250.9 17.81
J170518.92-015435.6 17.44
J170512.43-015325.4 16.54
J170511.57-015336.2 18.05
GCN Circular 20691
Subject
GRB 170214A: Swift-XRT afterglow detection
Date
2017-02-18T02:47:32Z (8 years ago)
From
Andy Beardmore at U Leicester <ab271@leicester.ac.uk>
A.P. Beardmore (U. Leicester), A. D'Ai (INAF-IASFPA), A. Melandri
(INAF-OAB), P. D'Avanzo (INAF-OAB), A. Cholden-Brown (PSU), S. J.
LaPorte (PSU), J.A. Kennea (PSU), S.L. Gibson (U. Leicester) and P.A.
Evans (U. Leicester) report on behalf of the Swift-XRT team:
Swift-XRT has conducted further observations of the field of the
Fermi/LAT-detected burst GRB 170214A. The observations now extend from
T0+38.6 ks to T0+274.4 ks.
Of the sources previously reported, "Source 1" is above the RASS limit
and fading with 3-sigma significance, and is therefore likely the GRB
afterglow. Using 4445 s of PC mode data and 4 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 = 256.34147, -1.88746
which is equivalent to:
RA (J2000): 17h 05m 21.95s
Dec(J2000): -01d 53' 14.9"
with an uncertainty of 2.4 arcsec (radius, 90% confidence). This
position is 49 arcsec from the Fermi/LAT position. The source is
fading with alpha >0.7.
The results of the XRT-team automatic analysis of the likely afterglow
are at http://www.swift.ac.uk/ToO_GRBs/00020740/index_1.php.
The results of the full analysis of the XRT observations are available
at http://www.swift.ac.uk/ToO_GRBs/00020740.
This circular is an official product of the Swift-XRT team.