J/A+A/617/A122 GRB 111209A GROND and UVOT light curves (Kann+, 2018)
The optical/NIR afterglow of GRB 111209A: Complex yet not unprecedented.
Kann D.A., Schady P., Olivares E.F., Klose S., Rossi A., Perley D.A.,
Zhang B., Kruehler T., Greiner J., Nicuesa Guelbenzu A., Elliott J.,
Knust, F., Cano Z., Filgas R., Pian E., Mazzali P., Fynbo J.P.U.,
Leloudas G., Afonso P.M.J., Delveaux C., Graham J.F., Rau A.,
Schmidl S., Schulze S., Tanga M., Updike A. C., Varela K.
<Astron. Astrophys. 617, A122 (2018)>
=2018A&A...617A.122K 2018A&A...617A.122K (SIMBAD/NED BibCode)
ADC_Keywords: Gamma rays ; Photometry, infrared ; Photometry, SDSS;
Photometry, ultraviolet
Keywords: gamma-rays: bursts - gamma rays: bursts: individual: GRB 111209A -
gamma rays: bursts: individual: GRB 130925A
Abstract:
Afterglows of Gamma-Ray Bursts (GRBs) are simple in the most basic
model, but can show many complex features. The ultra-long duration GRB
111209A, one of the longest GRBs ever detected, also has the
best-monitored afterglow in this rare class of GRBs. We want to
address the question whether GRB 111209A was a special event beyond
its extreme duration alone, and whether it is a classical GRB or
another kind of high-energy transient. The afterglow may yield
significant clues. We present afterglow photometry obtained in seven
bands with the GROND imager as well as in further seven bands with the
UVOT telescope on-board the Neil Gehrels Swift Observatory. The light
curve is analysed by multi-band modelling and joint fitting with
power-laws and broken power-laws, and we use the contemporaneous GROND
data to study the evolution of the spectral energy distribution. We
compare the optical afterglow to a large ensemble we have analysed in
earlier works, and especially to that of another ultra-long event, GRB
130925A. We furthermore undertake a photometric study of the host
galaxy. We find a strong, chromatic rebrightening event at ∼0.8-days
after the GRB, during which the spectral slope becomes redder. After
this, the light curve decays achromatically, with evidence for a break
at about 9 days after the trigger. The afterglow luminosity is found
to not be exceptional. We find that a double-jet model is able to
explain the chromatic rebrightening. The afterglow features have been
detected in other events and are not unique. The duration aside, the
GRB prompt emission and afterglow parameters of GRB 111209A are in
agreement with the known distributions for these parameters. While the
central engine of this event may differ from that of classical GRBs,
there are multiple lines of evidence pointing to GRB 111209A resulting
from the core-collapse of a massive star with a stripped envelope.
Description:
GROND g', r', i', z', J, H, Ks and UVOT uvw2, uvm2, uvw1, u, b, v,
white bands photometry of GRB 111209A. The file grond.dat contains 7
columns with: mid-time of the observation [ks after the GRB trigger],
mid-time of the observation [d after the GRB trigger], AB magnitude
not corrected for extinction [mag], magnitude error [mag], exposure
time of the observation [s], seeing [arcsec], filter The file uvot.dat
contains 7 columns with: mid-time of the observation [ks after the GRB
trigger], mid-time of the observation [d after the GRB trigger], AB
magnitude not corrected for extinction [mag], positive magnitude error
[mag], negative magnitude error [mag], exposure time of the
observation [s], seeing [arcsec], filter All data are in AB magnitudes
and not corrected for Galactic foreground extinction.
Midtimes are derived logarithmically,
t=10([log(t(1)-t(0))+log(t(2)-t(0))]/2), hereby t(1.2) are the
absolute start and stop times, and t(0) is the Swift trigger time. To
obtain Vega magnitudes, it is uvw2AB-uvw2Vega=1.73mag,
uvm2AB-uvm2Vega=1.69mag, uvw1AB-uvw1Vega=1.51mag,
uAB-uVega=1.02mag, bAB-bVega=-0.13mag, vAB-vVega=-0.01mag,
whiteAB-whiteVega=0.80mag for UVOT data (as given at
https://swift.gsfc.nasa.gov/analysis/uvot_digest/zeropts.html), and
g'AB-g'Vega=-0.062mag, r'AB-r'Vega=0.178mag,
i'AB-i'Vega=0.410mag, z'AB-z'Vega=0.543mag, JAB-JVega=0.929mag,
HAB-HVega=1.394mag, KsAB-KsVega=1.859mag for GROND data.
Corrections for Galactic extinction are, using E(B-V)=0.017 (Schlegel
et al., 1998ApJ...500..525S 1998ApJ...500..525S) and the Galactic extinction curve of
Cardelli et al. (1989ApJ...345..245C 1989ApJ...345..245C): Auvw2=0.134mag,
Auvm2=0.150mag, Auvw1=0.119mag, Au=0.085mag, Ab=0.066mag,
Av=0.053mag, Awhite=0.084mag, Ag'=0.066mag, Ar'=0.046mag,
Ai'=0.034mag, Az'=0.025mag, AJ=0.015mag, AH=0.010mag,
AKs=0.006mag.
Objects:
----------------------------------------------------
RA (2000) DE Designation(s)
----------------------------------------------------
00 57 22.64 -46 48 03.6 GRB 111209A = SN 2011kl
----------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
grond.dat 47 329 GRB 111209A afterglow GROND photometry
uvot.dat 50 231 GRB 111209A afterglow UVOT photometry
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Byte-by-byte Description of file: grond.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 F8.2 ks Timeks Time after trigger in ks
10- 19 F10.6 d Timed Time after trigger in days
21 A1 --- l_mag [>] Limit flag on mag
23- 28 F6.3 mag mag Magnitude in Band in (AB), not corrected for
extinction
30- 34 F5.3 mag e_mag ? Error in mag
36- 39 I4 s TimeExp Total exposure time
41- 44 F4.2 arcs Seeing Seeing in arcsec
46- 47 A2 --- Band [JHKs g'r'i'z'] Observed band
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Byte-by-byte Description of file: uvot.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.4 ks Timeks Time after trigger in ks
11- 19 F9.6 d Timed Time after trigger in days
21 A1 --- l_mag [>] Limit flag on mag
23- 27 F5.2 mag mag Magnitude in Band in (AB), not corrected for
extinction
29- 32 F4.2 mag E_mag ? Positive error in mag
34- 37 F4.2 mag e_mag ? Negative error in mag
39- 44 F6.1 s TimeExp Total exposure time
46- 50 A5 --- Band [UBV uvw1 uvw2 uwm2 white] Observed band
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Acknowledgements:
David Alexander Kann, kann(at)iaa.es
(End) Patricia Vannier [CDS] 17-May-2018