GRB 140301A

K. L. Page (U Leicester), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU),
N. Gehrels (NASA/GSFC) and M. H. Siegel (PSU) report on behalf of the
Swift Team:

At 15:24:49 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 140301A (trigger=589590).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 69.548, -34.283 which is 
   RA(J2000)  =  04h 38m 11s
   Dec(J2000) = -34d 16' 58"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows a single peak
with a duration of about 10 sec.  The peak count rate
was ~1300 counts/sec (15-350 keV), at ~1 sec after the trigger. 

The XRT began observing the field at 15:26:15.5 UT, 86.1 seconds after
the BAT trigger. Using promptly downlinked data we find a bright, fading,
uncatalogued X-ray source with an enhanced position: RA, Dec 69.5584,
-34.2565 which is equivalent to:
   RA(J2000)  = 04h 38m 14.02s
   Dec(J2000) = -34d 15' 23.6"
with an uncertainty of 3.4 arcseconds (radius, 90% containment). This
location is 100 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
http://www.swift.ac.uk/sper.  

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 2.23
x 10^20 cm^-2 (Kalberla et al. 2005). 

The initial flux in the 2.5 s image was 3.38e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 95 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.03. 

Burst Advocate for this burst is K. L. Page (kpa AT star.le.ac.uk). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)

A. Trotter, J. Haislip, A. LaCluyze, D. Reichart, A. Verveer, T. Spuck, 
A. Foster, N. Frank, K. Ivarsen, J. Moore, M. Nysewander, R. Beauchemin, 
T. Berger, M. Carroll, H. T. Cromartie, R. Egger, M. Hinckle, A. 
Ireland, M. Maples, L. Scott, and J. A. Crain report:

Skynet observed the Swift-BAT localization of GRB 140301A (Page et al., 
GCN 15896
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 , Swift trigger 589590) with the 14-inch R-COP telescope at 
Perth Observatory, Australia.  Observations began at 93s and continued 
until 33m post-trigger, with rotating exposures in the BVRI bands 
increasing from 10s to 80s. We detect no optical source in stacked 
images in any band at the position of the source detected by the Swift 
XRT. Preliminary upper limits are:
Band      tmid      mag
V         17m       >18.5
R         22m       >19.0
I         18m       >18.0

Photometry is calibrated to seven APASS-DR7 stars in the field, and has 
not been corrected for the Galactic foreground extinction corresponding 
to E(B-V)=0.03 (Schlegel et al. 1998).

No further Skynet observations are scheduled.

M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 691 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 140301A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 69.55743, -34.25679 which is equivalent
to:

RA (J2000): 04h 38m 13.78s
Dec (J2000): -34d 15' 24.4"

with an uncertainty of 1.9 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.

T. Kruehler (ESO), D. Malesani, D. Xu, J. P. U. Fynbo (DARK/NBI),
T. J. Rivera-Thorsen (Stockholm), J. Puschnig (Stockholm),
P. Jakobsson (Univ. Iceland), report on behalf of a larger
collaboration:

We observed the field of GRB 140301A (Page et al., GCN 15896
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 ) with the
Nordic Optical Telescope equipped with the MOSCA imager. Observations
were taken at high airmass, in twilight, using the R and z filters.

Consistent with the position of the XRT afterglow (Goad et al.,
GCN 15898
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 ), our images show the presence of a faint object in the
R band, with coordinates:

RA = 04:38:13.78
Dec = -34:15:23.5

and uncertainties of approximately 0.5" in each coordinate.

At a midtime of 4.97 hr after the trigger, we measure a brightness
of R = 23.1 +/- 0.3 mag. This magnitude is calibrated against stars
from the USNO-B1 catalog.

No statement about fading can be made at this point.

T. Kruehler (ESO), N. R. Tanvir (Univ. Leicester) D. Malesani,
D. Xu, J. P. U. Fynbo (DARK/NBI) report on behalf of a larger
collaboration:

We observed the optical source (Kruehler et al., GCN 15899
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 )
inside the XRT error circle (Goad et al., GCN 15898
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 ) of
GRB 140301A (Page et al., GCN 15896
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 ) with the VLT equipped
with the X-shooter spectrograph.

Our spectrum covers the wavelength range between 3000 and
20000 AA and consists of 12 nodded spectra with an
integration time of 600 s each. A preliminary analysis of
the spectrum reveals a faint continuum in which we
tentatively identify absorption lines of the MgII doublet
at z = 1.416.

At the same redshift and with a spatial offset of up to ~1"
we detect strong emission lines of [OII], Hbeta, [OIII],
Halpha and [NII], characteristic for emission from the
GRB host.

We acknowledge excellent support from the observing staff
in Paranal, in particular Julien Girard and Valentin Ivanov.

J. Elliott (MPE Garching), S. Schmidl (TLS Tautenburg), J. Greiner (also
MPE Garching) report on behalf of the GROND team:

We observed the field of GRB 140301A (Swift trigger 589590; Page et al.,
GCN #15896
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 ) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008,
PASP 120, 405) mounted at the 2.2 m MPG/ESO telescope at La Silla
Observatory (Chile).

Observations started at 00:07 UT on 2nd March 2014, 9.72 hrs after the GRB
trigger. They were performed at an average seeing of
2.2" and at an average airmass of 1.3.

We find a single point source within the 1.9" refined Swift-XRT error
circle reported by Goad et al. (GCN #15898
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 ) and confirm the source found
by Kruehler et al. (GCN #15899
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 , #15900
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 ).

Based on an exposure of 2.5 hours we estimate preliminary magnitudes (AB
system) of

g' = 24.2 +/- 0.2,
r' = 23.8 +/- 0.2,
i' = 23.2 +/- 0.2,
z' = 22.4 +/- 0.2,
J  > 21.8,
H  > 21.3, and
K  > 20.6.

Given magnitudes are calibrated against GROND zeropoints as well as 2MASS
field stars and are not corrected for the expected Galactic foreground
extinction corresponding to a reddening of E(B-V) = 0.03 mag in the
direction of the burst (Schlegel et al. 1998).

K. L. Page (U Leicester) reports on behalf of the Swift-XRT team:

We have analysed 5.9 ks of XRT data for GRB 140301A (Page  et al. GCN
Circ. 15896
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 ),  from 92 s to 51.3 ks after the  BAT trigger. The data
comprise 382 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Goad et al. (GCN Circ. 15898
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 ).

The late-time light curve (from T0+6.4 ks) can be modelled with  a
power-law decay with a decay index of alpha=0.95 (+0.32, -0.29).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index	of 2.01 (+/-0.09). The
best-fitting absorption column is  3.3 (+/-1.0) x 10^21 cm^-2, at a
redshift of 1.416, in addition to the Galactic value of 2.2 x 10^20
cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index
of 2.42 (+0.32, -0.29) and a best-fitting absorption column of 7.2
(+4.1, -3.3) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10
keV flux conversion factor deduced from this spectrum  is 3.0 x 10^-11
(4.8 x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Galactic foreground: 2.2 x 10^20 cm^-2
Intrinsic column:    7.2 (+4.1, -3.3) x 10^21 cm^-2 at z=1.416
Photon index:	     2.42 (+0.32, -0.29)

If the light curve continues to decay with a power-law decay index of
0.95, the count rate at T+24 hours will be 5.8 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.7 x
10^-13 (2.8 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00589590.

This circular is an official product of the Swift-XRT team.

T. N. Ukwatta (MSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
A. Y. Lien (NASA/UMBC), C. B. Markwardt (GSFC), K. L. Page (U Leicester),
D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), J. Tueller (GSFC),
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+886 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 140301A (trigger #589590)
(Page, et al., GCN Circ. 15896
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 ).  The BAT ground-calculated position is
RA, Dec = 69.521, -34.249 deg, which is 
   RA(J2000)  =  04h 38m 05.0s 
   Dec(J2000) = -34d 14' 56.8" 
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 66%.
 
The mask-weighted light curve shows a roughly symmetric peak starting
at ~T-15 sec, peaking at ~T+1 sec, and ending at ~T+20 sec.
T90 (15-350 keV) is 31.0 +- 5.7 sec (estimated error including systematics).
 
The time-averaged spectrum from T-13.18 to T+22.82 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.96 +- 0.28.  The fluence in the 15-150 keV band is 4.4 +- 0.8 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.82 sec in the 15-150 keV band
is 0.7 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/589590/BA/

B. Porterfield (PSU) and R. Starling (U Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 140301A
95 s after the BAT trigger (Page et al., GCN Circ. 15896
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 ).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 15898
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 )
is detected in the initial UVOT exposures. 
No counterpart consistent with the optical counterpart observed by 
NOT (Kruehler et al. GCN Circ. 15899
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 ) is detected.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           108          258          292         >21.8
u_FC               320          744          265         >20.7
white              108          920          231         >21.1
v                  650          843           38         >18.7
v                 6583        22273          392         >20.2
b                  749          769           19         >19.2
b                27968        28212          240         >21.0
u                  320          744          265         >20.7
w1                 700          719           19         >17.9
w1               11294        45552         1408         >21.1
w2                 799          818           19         >17.8
w2                6378        58531         1122         >21.4

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).

A. Klotz, D. Turpin (IRAP-CNRS-OMP), D. Macpherson (UWA/ICRAR), D. 
Coward (UWA),
M. Boer, B. Gendre, K. Siellez, H. Dereli, O. Bardho (UNS-CNRS-OCA),
A. Williams (PO-UWA), R. Martin (PO-UWA)
report:

We imaged the field of GRB 140301A detected by SWIFT
(trigger 589590) with the Zadko robotic telescope (D=100cm)
located at the observatory - Gingin, Australia.

The observations started 70.7s after the GRB trigger
(40.5s after the notice). The elevation of the field was at
26 degrees above horizon and weather conditions
were good. Images were retrieved 30 days after their
acquisitions due to a storage software problem.

The first image is trailed with a duration of 60.0s
(see the description in Klotz et al., 2006, A&A 451, L39).
We do not detect any OT with a limiting magnitude of:
t0+70.7s to t0+130.7s : Rlim = 18.4

The second image is 30.0s exposure in tracking mode:
t0+159s to t0+189s : Rlim = 19.7

We co-added series of unfiltered exposures.
The OT discovered by Kruehler et al. (GCNC 15899)
is marginally detected 841 s (+/-255 s) after
the trigger. More precisely the photometry is:

=start= =end=
  159 s   275 s  CRlim = 21.8
  289 s   465 s  CRlim = 21.8
  586 s  1096 s  CR = 21.7 +/- 0.4
1217 s  1727 s  CRlim = 21.9

This suggests this faint afterglow had culminated in
brightness R=21.7 at t0+841s. Then it had declined
to R=23.1 at t0+4.97h (Kruehler et al. GCN 15899
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 )
and to r'=23.8 at t0+11h (Elliott et al. GCNC 15904).
This is compatible with a temporal decay of ~0.5.

A photometry follow-up was performed with the Zadko
telescope :

=start= =end=
20.4 h  20.8 h  CRlim = 22.2

All magnitudes were estimated with the nearby NOMAD1
stars and are not corrected for galactic dust extinction.