GRB 070219

T. Sakamoto (NASA/ORAU), S. D. Barthelmy (GSFC), D. N. Burrows (PSU),
F. E. Marshall (NASA/GSFC), C. Pagani (PSU),
K. L. Page (U Leicester), D. M. Palmer (LANL), P. Schady (MSSL-UCL),
M. Stamatikos (NASA/ORAU), R. L. C. Starling (U Leicester) and
E. Troja (INAF-IASFPA) report on behalf of the Swift Team:

At 01:10:16 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 070219 (trigger=261132).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 260.198, +69.364 which is 
   RA(J2000)  =  17h 20m 48s
   Dec(J2000) = +69d 21' 51"
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 15 sec.  The peak count rate
was ~2000 counts/sec (15-350 keV), at ~1 sec after the trigger. 

The XRT began taking data at 01:11:38 UT, 82 seconds after the BAT
trigger.  From ground-based analysis we find a weak source at
RA, Dec (J2000) = 260.190, +69.369 which is
  RA(J2000)  = 17h 20m 45.5s 
  Dec(J2000) = +69d 22' 10.7" 
with an error radius of 5 arcseconds. 
This is 21 arcseconds from the BAT position. 

UVOT took a finding chart exposure of 100 seconds with the White
(160-650 nm) filter starting 87 seconds after the BAT trigger. No
afterglow candidate has been found in the initial data products at
the BAT or XRT position with a white band 3-sigma upper limit of 19.6
mag. The 2.7'x2.7' sub-image covers 25% of the BAT error circle and
100% of the XRT error circle. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.035

Richard J. Cool (Arizona), Daniel J. Eisenstein (Arizona), David W. Hogg
(NYU), Michael R. Blanton (NYU), David J. Schlegel (LBNL), J. Brinkmann
(APO),
Donald Q. Lamb (Chicago), Donald P. Schneider (PSU), and Daniel E. Vanden
Berk
(PSU) report:

The Sloan Digital Sky Survey (SDSS) imaged the field of burst GRB070219
prior to the burst.  As these data should be useful as a pre-burst comparison
and for calibrating photometry, we are supplying the images and photometry
measurements for this GRB field to the community.

Data from the SDSS, including 5 FITS images, 3 JPGS, and
3 files of photometry and astrometry, are being placed at
http://mizar.as.arizona.edu/~grb/public/GRB070219

We supply FITS images in each of the 5 SDSS bands of a 8'x8' region centered
on the GRB position (ra=260.198 (17:20:47.5), dec=69.3640 (69:21:50.4);
Swift-BAT TRIGGER 261132), as well as 3 gri color-composite JPGs (with
different stretches). The units in the FITS images are nanomaggies per pixel.
A pixel is 0.396 arcsec on a side. A nanomaggie is a flux-density unit equal
to 10^-9 of a magnitude 0 source or, to the extent that SDSS is an AB system,
3.631e-6 Jy.  The FITS images have WCS astrometric information.

In the file GRB070219_sdss.calstar.dat, we report photometry and astrometry
of 256 bright stars (r<20.5) within 15' of the burst location.  The
magnitudes
presented in this file are asinh magnitudes as are standard in the SDSS
(Lupton
1999, AJ, 118, 1406). Beware that some of these stars are not well-detected
in the u-band; use the errors and object flags to monitor data quality.

In the files GRB070219_sdss.objects_flux.dat and
GRB070219_sdss.objects_magnitudes.dat, we report photometry of 276
objects detected within 6' of the GRB position.  We have removed saturated
objects and objects with model magnitudes fainter than 23.0 in the r-band.
The fluxes listed in GRB070219_sdss.objects_flux.dat are in nanomaggies
while the magnitudes listed in GRB070219_sdss.objects_magnitudes.dat are
asinh magnitudes.


All quantities reported are standard SDSS photometry, meaning that they are
very close to AB zeropoints and magnitudes are quoted in asinh magnitudes.
Photometric zeropoints are known to about 2% rms.  None of the photometry
is corrected for dust extinction.  The Schlegel, Finkbeiner, and Davis
(1998) predictions for this region are A_U=0.178 mag, A_g=0.131 mag, A_r =
0.095 mag, A_i=0.072 mag, and A_z=0.051 mag.

There are currently no objects within 6 arcminutes of the GRB position in
the SDSS spectroscopic database.


SDSS astrometry is generally better than 0.1 arcsecond per coordinate.
Users requiring high precision astrometry should take note that the SDSS
astrometric system can differ from other systems such as those used in other
notices; we have not checked the offsets in this region.

More detailed information pertaining to our SDSS GRB releases can be found
in our initial data release paper (Cool et al. 2006, PASP 118, 733).  See the
SDSS DR4 documentation for more details: http://www.sdss.org/dr5.

These data have been reduced using a slightly different pipeline than that
used for SDSS public data releases.  We cannot guarantee that the values here
will exactly match those in the data release in which these data are
included.
In particular, we expect the photometric calibrations to differ by of order
0.01 mag.

This note may be cited, but please also cite the SDSS data release paper,
Adelman-McCarthy et al. (2006, ApJS, 162, 38), when using the data or
referring to the technical documentation.

H. Swan (U Mich), J. Aretakis (U Mich) report on behalf of the ROTSE  
collaboration:
ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB  
070219 (Swift trigger 261132), producing images beginning 35 minutes  
after the GCN notice time. An automated response took the first image  
at 01:44:52.6 UT, 2076.5 s after the burst, under twilight  
conditions. We took 10 5-sec, 10 20-sec and 6 60-sec eposures. These  
unfiltered images are calibrated relative to USNO A2.0 (R).

Comparison to the DSS (second epoch) reveals no new sources within  
the 3-sigma error circle, for both single images and coadding into  
sets of 10. Individual images have limiting magnitudes ranging from  
15.8-17.0; we set the following specific limits.

start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd?
--------------------------------------------------------------------
01:44:52.6 01:45:52.6 60 16.4 2076.5 N
02:13:52.6 02:14:52.6 60 17.0 3816.5 N
01:51:50.6 02:03:17.4 686 17.8 2494.5 Y

A. Melandri (Liverpool JMU) on behalf of the Liverpool
GRB group reports


The 2-m Liverpool Telescope robotically followed up GRB 070219
(Sakamoto et al., GCN 6104
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 , trigger=261132) beginning 53 min
after the GRB trigger time (UT:01:10:16).

The automatic detection mode (3x10sec) did not identify any new
bright object inside the XRT error circle (Sakamoto et al.,
GCN 6104
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 ).

Comparison with the USNO B1 for a coadded set of images (for a total 
exposure time of 300 sec) did not reveal any new object down to a
limiting magnitude R~20.2 (between 53-66 minutes after the burst).

Further observations are ongoing.

P. D'Avanzo (INAF-OAB), A. Magazzu` (INAF-TNG), Albar G. de Gurtubai 
(INAF-TNG), L. A. Antonelli (INAF-OAR) report on behalf of the MISTICI 
and CIBO collaborations:

We observed the field of GRB 070219 (Sakamoto et al., GCN 6104
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 ) with the 
Italian TNG telescope sited in La Palma, Canary Islands. Observations 
were carried out about 2.02
hours after the burst. No object is present inside the XRT error box 
(Sakamoto et al., GCN 6104
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 ) down to a limiting magnitude of R ~ 25 
(3sigma level, calibrated against the USNOB1 catalog).

We acknowledge the support of the TNG staff.

This message can be cited

GRB 070219, Swift-BAT refined analysis

D. Palmer (LANL), L. Barbier (GSFC), S. D. Barthelmy (GSFC),
J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC),
H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), A. Parsons (GSFC), 
T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS), 
M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC)
on behalf of the Swift-BAT team:
 
Using the data set from T-239.9 to T+499.2 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 070219
(trigger #261132)  (Sakamoto, et al., GCN Circ. 6104
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 ).  The BAT 
ground-calculated position is RA, Dec = 260.219, 69.345 deg which is 
   RA(J2000) = 17h 20m 52.6s 
   Dec(J2000) = 69d 20' 41.4" 
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment).  
The partial coding was 92%.

The mask-weighted lightcurve shows a weak FRED-like bump from T-4 to T+20 sec.  
T90 (15-350 keV) is 17 +- 1 sec (estimated error including systematics).
 
The time-averaged spectrum from T-1.5 to T+17.7 is best fit by 
a simple power-law model.  
The power law index of the time-averaged spectrum is 1.8 +- 0.2.  
The fluence in the 15-150 keV band is 3.2 +- 0.4 x 10^-07 erg/cm2.  
The 1-sec peak photon flux measured from T+1.31 sec in the 15-150 keV
band is 0.7 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90%
confidence level.

A. de Ugarte Postigo, A. J. Castro-Tirado, J. Gorosabel, 
M. Jelínek (IAA-CSIC, Granada), P.Rodríguez-Gil and 
S. López (IAC) on behalf of a larger collaboration,

report:

"We have imaged the field of GRB 070219 (Sakamoto el al. GCN 
6104
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 ) with the IAC80 telescope in I-band, starting on Feb 
19.28042 UT (5h34m after the burst). No object is detected 
in the XRT error box down to the POSS2 IR limit."

This message can be quoted.

A. Breeveld (MSSL/UCL) and T. Sakamoto (NASA/ORAU) report on behalf of
the Swift UVOT team:

The Swift/UVOT observed the field of GRB 070219 starting 68s after the
BAT trigger (Sakamoto et al. 2007, GCN Circ. 6104
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 ). We do not find any
source, in any of the UVOT observations, inside the XRT error circle.

The 3-sigma upper limits for detecting a source inside the XRT error
circle in the co-added frames are:

Filter    T_start    T_stop    Exp(s)    Mag(3-sigma UL)
--------------------------------------------------------
V         68         18502     2032      20.3
B         670        6909      432       20.4
U         646        13201     980       20.4
UVW1      622        12659     1160      21.0
UVM2      598        18983     1627      21.5
UVW2      698        17588     1356      21.5
White     87         7114      618       20.7

The values quoted above are not corrected for the expected Galactic
extinction corresponding to a reddening of E(B-V) = 0.035 towards the
direction of the burst (Schlegel et al. 1998)

R.L.C. Starling (U Leicester), T. Sakamoto (NASA/GSFC), K.L. Page, M.R. 
Goad and P.A. Evans (U Leicester) report on behalf of the Swift-XRT team:

We have analysed the first four orbits (up to 18.8 ks after the BAT 
trigger) of Swift XRT data for the faint X-ray afterglow of GRB 070219 
(Sakamoto et al., GCN 6104
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 ). Using ~6 ks of Photon Counting (PC) mode data 
we find the following astrometrically corrected XRT refined position (by 
matching the UVOT images with the USNO-B1 catalogue):

RA (J2000)  =  17h 20m 45.99s 
Dec(J2000)  = +69d 22' 10.6"

with an error radius of 3.6 arcseconds (90% confidence). This is 95.2, 
21.8 and 3.0 arcseconds away from the BAT refined, BAT initial and XRT 
initial positions respectively.

The lightcurve appears to follow the canonical three-phase decay. It 
decays with alpha_1~2.2, breaking at T_bk_1~330 s to alpha_2~0.3 and 
breaking again at T_bk_2~9200 s to a slope of alpha_3~1.5.

The PC mode spectrum, summed over all the data collected thus far, is not 
tightly constrained, but can be fitted with a single power law of photon 
index Gamma = 2 and a total absorbing column at z = 0 of nH = 1.3E21 cm-2, 
in excess of the Galactic value of 4.1E20 cm-2. The 0.3-10 keV observed 
(unabsorbed) flux is 9E-13 (1.2E-12) erg/cm2/s. There are too few counts 
for a time-resolved spectral analysis, hence any spectral evolution 
present cannot be measured.

If the decay continues with a slope of alpha = 1.5, the predicted count 
rate at 24 hours post-trigger is 5E-4 cts/s. This corresponds to an 
observed (unabsorbed) flux of 2E-14 (3E-14) erg/cm2/s.

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

V. Lipunov, V.Kornilov, N.Shatskiy, E.Gorbovskoy, A.Belinski, D.Kuvshinov, 
N.Tyurina, P.Gritsyk
Sternberg Astronomical Institute, Moscow Union 'Optic'

A. Tlatov, I.Golubov
Kislovodsk Solar Station of the Pulkovo observatory

"MASTER Very Wide Field Camera located at Kislovodsk Solar Station
(http://observ.pereplet.ru, D=70 mm, 420 square degrees, 20'' per pix) has 
moved to the Swift-BAT trigger 261132 and it has taken a series of 5s 
exposures  starting 76s after the GRB time and 15 s after notice arrivel 
time at   01-11-30.473 UT under good weather  condition.

The limiting magnitude is about 11.5m  for single  exposures.
These unfiltered images are calibrated relative to USNO A2.0 (R).
There is no OT was found inside Swift error box (T. Sakamoto et al., GCN 
Circ 6104
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 ).

T-Tgrb  Mean Time     Limit   Coadd?           Note

76s        78.5s       11.0     no       slightly moving

81s        106s        12.7     12

81s        331 s       13.5     84



The message can be cited.

mailto: lipunov@sai.msu.ru

S. B. Cenko (Caltech), P. A. Price (IfA/Hawaii), E. Berger (Carnegie), and
D. B. Fox (Penn State) report on behalf of a larger collaboration:

We have imaged the field of GRB070219 (Sakamoto et al., GCN 6104
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 )) with
the Gemini Multi-Object Spectrograph mounted on the Gemini North
Telescope.  Images consisted of 4 x 180 s exposures in z' and 2 x 180 s
exposures in i' at a mean epoch of approximately 14:50 19 February UT (~
13.7 hr after the burst).  Inside the revised XRT error circle (Starling
et al., GCN 6112
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 ), we see no sources to limiting magnitudues of i' >
23.0, z' > 22.0.  Photometric calibration was performed relative to the
SDSS fields provided by Cool et al. (GCN 6105
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 )