J/ApJ/743/154 Multi-band photometry of GRB 110205A + 110213A (Cucchiara+, 2011)
Constraining gamma-ray burst emission physics with extensive early-time,
multiband follow-up.
Cucchiara A., Cenko S.B., Bloom J.S., Melandri A., Morgan A., Kobayashi S.,
Smith R.J., Perley D.A., Li W., Hora J.L., da Silva R.L., Prochaska J.X.,
Milne P.A., Butler N.R., Cobb B., Worseck G., Mundell C.G., Steele I.A.,
Filippenko A.V., Fumagalli M., Klein C.R., Stephens A., Bluck A., Mason R.
<Astrophys. J., 743, 154 (2011)>
=2011ApJ...743..154C 2011ApJ...743..154C
ADC_Keywords: Gamma rays ; Photometry, VRI ; Photometry, infrared ;
Photometry, ugriz ; Photometry, uvby
Keywords: gamma-ray burst: individual (GRB 110205A, GRB 110213A) -
techniques: photometric - techniques: polarimetric -
techniques: spectroscopic
Abstract:
We present rich, early-time, multiband data sets for two Swift events,
GRB 110205A and GRB 110213A. The former shows optical emission since
the early stages of the prompt phase, followed by the steep rising in
flux up to ∼1000s after the burst (t-α with
α=-6.13±0.75). We discuss this feature in the context of the
reverse-shock scenario and interpret the following single power-law
decay as being forward-shock dominated. Polarization measurements,
obtained with the RINGO2 instrument mounted on the Liverpool
Telescope, also provide hints on the nature of the emitting ejecta.
The latter event, instead, displays a very peculiar optical to
near-infrared light curve, with two achromatic peaks. In this case,
while the first peak is probably due to the onset of the afterglow, we
interpret the second peak to be produced by newly injected material,
signifying a late-time activity of the central engine.
Description:
GRB 110205A was discovered by the Swift satellite on 2011 February 5.
164s after the BAT detection, the UVOT instrument on board Swift began
observing GRB 110205A, identifying the source in the white-band filter
at RA=10:58:31.12 and DE=+67:31:31.2 (J2000) with a 0.63" accuracy in
both directions (Figure 2; Beardmore et al. 2011GCN.11639....1B 2011GCN.11639....1B). Soon
after the Swift trigger, several robotic facilities pointed at the GRB
location providing a series of photometric observations from optical
to near-infrared (NIR) and radio bands. Our group first identified an
infrared counterpart using the Peters Automated Infrared Imaging
Telescope (PAIRITEL; JHK). We also observed the field of GRB 110205A
with the automated Palomar 60 inch telescope (P60) in g',r',i', z'.
Multiband observations of the optical afterglow of GRB 110205A were
also acquired with the robotic 2m Liverpool Telescope (LT; g'r'i').
After ∼4.5 days, when the afterglow faded beyond the detectability
of these facilities, we activated our Target of Opportunity (ToO)
program at the Gemini-North telescope (PI: B. Cobb), in order to
monitor the late-time behavior of the OT and/or estimate the possible
host galaxy contribution. We performed a series of 10x3 minutes
exposure in r' and i' bands using the Gemini Multi-Object Spectrograph
(GMOS) camera. In order to establish a possible host galaxy
contribution, we repeated our r'-band observation on 2011 March 11.
GRB 110213A was discovered by Swift on 2011 February 13. The XRT
enhanced position of the afterglow is RA=02:51:51.37, DE=+49:16:21.2
(J2000), with an uncertainty of 1.5" in both directions. UVOT started
observing ∼100s after the BAT trigger. The afterglow was detected in
the white, u, b, v, and uvw1 filters. The Katzman Automatic Imaging
Telescope (KAIT) responded to the trigger within ∼70s after the
trigger, observing the afterglow in the unfiltered band followed by V
and I.
Objects:
-----------------------------------------------------------------
RA (2000) DE Designation(s) (Tables)
-----------------------------------------------------------------
10 58 31.12 +67 31 31.2 GRB 110205A = GRB 110205A = table1
02 51 51.37 +49 16 21.2 GRB 110213A = GRB 110213A = table4
-----------------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 41 382 Photometric observations for GRB 110205A
table4.dat 41 282 Photometric observations for GRB 110213A
--------------------------------------------------------------------------------
See also:
J/ApJS/195/2 : The second Swift BAT GRB catalog (BAT2) (Sakamoto+, 2011)
J/AJ/141/36 : GRB 080607 multi-band light curves (Perley+, 2011)
J/MNRAS/406/2473 : Photometry of GRB 071025 (Perley+, 2010)
J/MNRAS/397/1177 : Swift-XRT observations of GRBs (Evans+, 2009)
J/ApJ/690/163 : The first Swift UV-Opt GRB afterglow catalog (Roming+, 2009)
J/ApJ/672/449 : GRB 061126 light curves (Perley+, 2008)
Byte-by-byte Description of file: table[14].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Tel Telescope (Gemini-N, KAIT, Liverpool, P60,
PAIRITEL, Swift-UVOT or Gemini)
12- 20 F9.1 s t-t0 Time since the Swift trigger
22- 26 A5 --- Filt Filter used (JHK, VI, g'r'i'z', ubv, white or
clear) (1)
28 A1 --- l_mag Limit flag on mag
30- 35 F6.3 mag mag Observed magnitude in Filt
37- 41 F5.3 mag e_mag ? The 1σ error in mag
--------------------------------------------------------------------------------
Note (1): UVOT magnitudes [u, b, v, white] are in the natural UVOT
photometric system (Vega). See Breeveld et al. (2011AIPC.1358..373B 2011AIPC.1358..373B)
for the most updated zeropoint and conversion factors. Liverpool,
Palomar, Gemini, and KAIT magnitudes are in the AB system. PAIRITEL
magnitudes are in Vega system.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 15-May-2013