GRB 160113A
GCN Circular 18859
Subject
GRB 160113A: iPTF P48 Observations and Optical Transient Candidates
Date
2016-01-13T20:43:09Z (9 years ago)
From
Leo Singer at GSFC/iPTF <leo.p.singer@nasa.gov>
L. P. Singer (NASA/GSFC), V. Bhalerao (IUCAA), S. B. Cenko (NASA/GSFC),
and M. M. Kasliwal (Carnegie) report on behalf of a larger collaboration:
Fermi GBM detected GRB 160113A (trigger 474370354 / bn160113398) at
2016-01-13 09:32:30.52. At 10:31:39, about 1 hour after the burst, we
began searching for optical counterparts using the Palomar 48-inch Oschin
telescope (P48).
We imaged 18 fields covering an area of 133 deg^2 in the 1-sigma
statistical+systematic region of the final Fermi GBM localization. We
estimate a 78% prior probability that these fields contain the true
location of the source. Sifting through candidate variable sources using
image subtraction and standard iPTF vetting procedures, we detected the
following optical transient candidates:
name RA Dec mag t Notes
----------------------------------------------------------------------------
Hostless
----------------------------------------------------------------------------
iPTF15flo 192.718034 +12.070614 20.29 1.99
iPTF15fls 187.113722 +7.078087 20.59 2.42 near elliptical galaxy at z=0.175
----------------------------------------------------------------------------
Hosts with spectroscopic redshifts
----------------------------------------------------------------------------
iPTF15flq 179.356225 +11.915619 20.02 2.10 z=0.165
iPTF15flm 191.925125 +13.140841 19.99 1.82 z=0.155
iPTF15fly 180.870452 +13.440016 19.41 2.10 z=0.090
iPTF15fln 192.218146 +15.660583 20.23 1.88 z=0.081, possibly fading
iPTF15flp 181.050555 +11.765386 19.28 1.52 z=0.296, BL Lac (Veron+ 2010)
----------------------------------------------------------------------------
Hosts with photometric redshifts
----------------------------------------------------------------------------
iPTF15flk 184.180492 +13.204215 20.66 1.58 z=0.382
iPTF15flr 181.775607 +9.400882 19.03 2.19 z=0.087
----------------------------------------------------------------------------
Possibly stellar
----------------------------------------------------------------------------
iPTF15flx 181.613083 +13.008351 20.33 1.52
Times are in hours since the GBM trigger. Magnitudes are in the Mould R
filter and in the AB system, calibrated with respect to point sources in
SDSS as described in Ofek et al. (2012, http://dx.doi.org/10.1086/664065).
We have scheduled all of the above sources for multi-band photometry on
the robotic Palomar 60" telescope (P60) tonight. We have requested Swift
target-of-opportunity observations of iPTF15flo.
Further observations of the above candidates, particularly iPTF15flo and
iPTF15fls, are encouraged to determine their nature and if one of them is
the optical afterglow of the GRB.
The diagram http://asd.gsfc.nasa.gov/Leo.Singer/Fermi474370354.pdf
shows the locations of our candidates and the P48 fields in relation to
the Fermi GBM 1- and 2-sigma statistical+systematic contours.
GCN Circular 18860
Subject
GRB 160113A: Swift ToO observations
Date
2016-01-13T22:31:17Z (9 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/GBM GRB 160113A.
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00020594
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/GBM 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 18861
Subject
GRB 160113A: Fermi GBM detection
Date
2016-01-14T00:57:55Z (9 years ago)
From
Eric Burns at U of Alabama <eb0016@uah.edu>
O.J. Roberts (UCD) and E. Burns(UAH)
report on behalf of the Fermi GBM Team:
"At 09:32:30.52 UT on 13 January 2016, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 160113A (trigger 474370354 / 160113398).
The on-ground calculated location, using the GBM trigger
data, is RA = 187.3, DEC = 11.5, with an uncertainty
of 1.2 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] ).
All of the optically variable sources detected by iPTF (Singer, GCN 18859)
are contained in the uncertainty region surrounding the final location.
The angle from the Fermi LAT boresight at the GBM trigger time is 98
degrees.
The GBM light curve consists of a smaller peak between
T-5 and T+10 followed by a bright peak from T+20 to about T+60
with a duration (T90) of about 25 s (50-300 keV).
The time-averaged spectrum from T0+25.60 s to T0+51.20 s is
best fit by a Band function with Epeak = 98 +/- 1 keV,
alpha = -0.40 +/- 0.03, and beta = -3.16 +/- 0.11
The event fluence (10-1000 keV) in this time interval is
(3.12 +/- 0.04)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+31.51 s in the 10-1000 keV band
is 27.7 +/- 0.5 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 18862
Subject
GRB 160113A: Swift-XRT observations
Date
2016-01-14T10:15:05Z (9 years ago)
From
Sarah Gibson at U.of Leicester <slg44@leicester.ac.uk>
A.P. Beardmore (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA),
A. Maselli (INAF-IASFPA), L.M. McCauley (PSU), J.A. Kennea (PSU), B.
Sbarufatti (INAF-OAB/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/GBM-detected burst GRB 160113A (Roberts et al. GCN Circ. 18861),
collecting 2.7 ks of Photon Counting (PC) mode data between T0+46.7 ks
and T0+53.0 ks. The pointing was aimed at the optical transient
candidate iPTF15flo (Singer et al. GCN Circ. 18859).
No X-ray sources have been detected inside or close to the iPTF15flo
error region. The 3-sigma upper limit at the iPTF15flo position is
0.005 ct s^-1, corresponding to a 0.3-10 keV observed flux of 2.1e-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/00020594.
This circular is an official product of the Swift-XRT team.
GCN Circular 18871
Subject
IPN Triangulation of GRB 160113A
Date
2016-01-15T18:43:15Z (9 years ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@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,
S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin, A. Kozlova,
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,
S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer,
on behalf of the Swift-BAT 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 160113A has been detected by Fermi (GBM: Roberts
and Burns, GCN Circ. 18861), Konus-Wind, INTEGRAL (SPI-ACS), Swift
(BAT), and Mars-Odyssey (HEND), so far, at about 34350 s UT (09:32:30).
The burst was outside the coded field of view of the BAT.
We have triangulated it to a preliminary, 3 sigma error box whose
coordinates are:
---------------------------------------------
RA(2000), deg Dec(2000), deg
---------------------------------------------
Corners:
197.219 (13h 08m 52s) +18.468 (+18d 28' 03")
197.479 (13h 09m 55s) +19.448 (+19d 26' 51")
177.907 (11h 51m 38s) -19.867 (-19d 52' 02")
178.597 (11h 54m 23s) -19.094 (-19d 05' 38")
---------------------------------------------
The error box area is 17.0 sq. deg, and its maximum
dimension is 42.8 deg (the minimum one is 45 arcmin).
The Sun distance was about 100 deg.
This box may be improved.
The intersection of the box with the 3 sigma contours of the GBM ground
position was outside of the BAT coded FoV.
There is only one OT candidate, iPTF15fln (Singer et al., GCN Circ.
18859), consistent with the box; the candidate was marked as possibly
fading. The distance between the narrowest annulus (Konus-HEND annulus
with 3 sigma half width of 0.375 deg) center line and the iPTF15fln is
5.2 arcmin, supporting the association of the transient and the GRB.
A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB160113_T34379/IPN/
The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.
GCN Circular 18876
Subject
Konus-Wind observation of GRB 160113A
Date
2016-01-17T14:23:27Z (9 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
S. Golenetskii, R.Aptekar, D. Frederiks, 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-duration GRB 160113A
(Fermi-GBM detection: Roberts & Burns, GCN 18861;
IPN triangulation: Hurley et al., GCN 18871)
triggered Konus-Wind at T0=34379.515 s UT (09:32:59.515).
The light curve shows a smooth pulse in the interval
from ~T0-5 s to ~T0+20 s, preceded by a much weaker pulse
around ~T0-28 s.
The emission is seen up to ~7 MeV.
As observed by Konus-Wind, the burst had a fluence
of 2.4(-0.1,+0.1)x10^-5 erg/cm2, and a 64-ms peak flux,
measured from T0+5.184 s, of 4.0(-0.3,+0.4)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum (measured from T0 to T0+21.248 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 = -0.51 (-0.15,+0.17),
the high energy photon index beta = -3.55 (-0.83,+0.37),
the peak energy Ep = 97 (-4,+4) keV,
chi2 = 71.7/97 dof.
The spectrum near the peak count rate (measured from T0+0.256
to T0+8.192 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 = -0.24 (-0.19,+0.24),
the high energy photon index beta = -3.36 (-0.71,+0.39),
the peak energy Ep = 130 (-9,+8) keV,
chi2 = 71.5/97 dof.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB160113_T34379/
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.