J/A+A/691/A158 Measurements of GRB afterglows with GROND (Greiner+ 2024)
The GROND GRB sample: I. Overview and statistics.
Greiner J., Kruehler T., Bolmer J., Klose S., Afonso P.M.J., Elliott J.,
Filgas R., Graham J.F., Kann D.A., Knust F., Kuepcue-Yoldas A., Nardini M.,
Nicuesa Guelbenzu A.M., Olivares Estay F., Rossi A., Schady P., Schweyer T.,
Sudilovsky V., Varela K., Wiseman P.
<Astron. Astrophys. 691, A158 (2024)>
=2024A&A...691A.158G 2024A&A...691A.158G (SIMBAD/NED BibCode)
ADC_Keywords: GRB ; Photometry, SDSS ; Photometry, infrared
Keywords: gamma-rays bursts: general - gamma rays: stars
Abstract:
A dedicated gamma-ray burst (GRB) afterglow observing program was
performed between 2007 and 2016 with GROND, a seven-channel optical
and near-infrared imager at the 2.2m telescope of the Max-Planck
Society at ESO/La Silla, In this first of a series of papers, we
describe the GRB observing plan, providing first readings of all so
far unpublished GRB afterglow measurements and some observing
statistics. In total, we observed 514 GRBs with GROND, including 434
Swift-detected GRBs, representing 81% of the observable Swift sample.
For GROND-observations within 30 min of the GRB trigger, the
optical/NIR afterglow detection rate is 81% for long- and 57% for
short-duration GRBs. We report the discovery of ten new GRB afterglows
plus one candidate, along with redshift estimates (partly improved)
for four GRBs and new host detections for seven GRBs. We identify the
(already known) afterglow of GRB 140209A as the sixth GRB exhibiting a
2175Å dust feature. As a side result, we identified two blazars,
with one at a redshift of z=3.8 (in the GRB 131209A field).
Description:
table2.dat: Photometric measurements of either unpublished
GROND-observed GRBs or those with updates relative to published GCNs.
All magnitudes are in the AB system, and are not corrected for the
galactic foreground extinction. The 2nd column contains notes for
special circumstances, and the 3rd column marks GRBs for which
hitherto unknown optical afterglows are reported. For each GRB, the
mid-time of the data used (To denotes the trigger time of the
gamma-ray instrument), the exposure times for the optical and NIR
channels, and the measured brightness in the 7 GROND filters is given.
The long/short classification is given in Table 5.
table5.dat: All 517 (514 plus the 3 with large error boxes; see sect.
3) GROND-observed GRBs. The "L/S" in the 2nd column denotes the
long/short duration classification, and "y/n" in the 5th column
refers to the afterglow detection with GROND.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea2.dat 133 123 Photometric measurements of either unpublished
GROND-observed GRB afterglows or those with
updates relative to published GCNs
tableb1.dat 64 517 *All GROND-observed GRB afterglows
refs.dat 80 70 References
tablea2.tex 169 130 LaTeX version of table2
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Note on tableb1.dat: GRBs 100225A, 110426A and 130310A have a very large error
box, and thus not listed in table2.dat.
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Name GRB Name (YYMMDDA)
9- 11 A3 --- Notes Comments for particular GRBs (1)
13 A1 --- Dis [D] Flag to identify newly identified GRB
afterglows
15- 30 A16 "date" Mid-Time Mid-time of the exposure
32- 37 F6.2 h Mid-Timeh Mid-time of the exposure in hours after the
gamma-ray burst trigger time
39- 43 F5.1 min ETimegriz Exposure time for the griz channels
44 A1 --- --- [/]
45- 49 F5.1 min ETimeJHK Exposure time for the JHK channels
51 A1 --- l_gpmag Limit flag on g' magnitude
52- 56 F5.2 mag gpmag ?=- Brightness of the afterglow in channel
g' (AB)
58- 61 F4.2 mag e_gpmag ? Brightness of the afterglow in channel
g' (AB) error
63 A1 --- l_rpmag Limit flag on r' magnitude
64- 68 F5.2 mag rpmag ?=- Brightness of the afterglow in channel
r' (AB)
70- 73 F4.2 mag e_rpmag ? Brightness of the afterglow in channel
r' (AB) error
75 A1 --- l_ipmag Limit flag on i' magnitude
76- 80 F5.2 mag ipmag ?=- Brightness of the afterglow in channel
i' (AB)
82- 85 F4.2 mag e_ipmag ? Brightness of the afterglow in channel
i' (AB) error
87 A1 --- l_zpmag Limit flag on z' magnitude
88- 92 F5.2 mag zpmag ?=- Brightness of the afterglow in channel
z' (AB)
94- 97 F4.2 mag e_zpmag ? Brightness of the afterglow in channel
z' (AB) error
99 A1 --- l_Jmag Limit flag on J magnitude
100-104 F5.2 mag Jmag ?=- Brightness of the afterglow in channel
J (AB)
106-109 F4.2 mag e_Jmag ? Brightness of the afterglow in channel
J (AB) error
111 A1 --- l_Hmag Limit flag on H magnitude
112-116 F5.2 mag Hmag ?=- Brightness of the afterglow in channel
H (AB)
118-121 F4.2 mag e_Hmag ? Brightness of the afterglow in channel
H (AB) error
123 A1 --- l_Kmag Limit flag on K magnitude
124-128 F5.2 mag Kmag ?=- Brightness of the afterglow in channel
K (AB)
130-133 F4.2 mag e_Kmag ? Brightness of the afterglow in channel
K (AB) error
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Note (1): Note as follows:
1 = See the section Notes on individual sources
2 = g'r'i'z' images only cover 70% of the error circle
3 = Electronic noise in z'-band: no detection
4 = Afterglow position is not covered in g'r'i'z'
5 = This is for the newly identified afterglow, and not the one retracted by
Sudilovsky & Greiner (2013GCN.14358....1S 2013GCN.14358....1S)
6 = Temporally not operating i'z' detectors
7 = The PSF of a known r'=14.1/J=13.0 mag star fills the full 1.7 arcsec
XRT error circle, so the photometry is purely determined by the noise
of that known star
8 = The GROND pointing does cover the first reported Swift/XRT source, but
not the second (believed to be the afterglow)
9 = These limits are estimates against the bright galaxy
10 = The GROND pointings towards Swift/XRT sources #1 and #2 (Melandri et al.,
2015GCN.17348....1M 2015GCN.17348....1M) cover only 15% of the MAXI error circle
(Fukushima et al., 2015GCN.17345....1F 2015GCN.17345....1F)
11 = The PSF of a known star fills half of the 2.3 arcsec XRT error circle
12 = Two non-fading objects within the Swift/XRT error circle
13 = Three objects within the 7 arcsec Swift/XRT error circle, all seen on
archival SkyMapper images
14 = Only observed in twilight with JHK
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Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- GRB GRB name (YYMMDDA)
9 A1 --- L/S [L/S] Label for GRB duration classification
(L = long, S = short)
11- 29 A19 "date" GROND-Start Start-time of observation: MMDD-HH:MM:SS
31- 36 I6 s T-To Time-delay after Gamma-ray trigger
38 A1 --- Det [y/n] Flag for GROND detection (yes/no)
39 A1 --- Flag [?] Flag for questionable afterglow (?)
41- 45 I5 --- GCN1 ? GCN (GRB Coordinate Network) number
reference (1)
47- 51 I5 --- GCN2 ? GCN (GRB Coordinate Network) number
reference (1)
53- 56 I4 --- GCN3 ? GCN (GRB Coordinate Network) number
reference (1)
58- 64 A7 --- Ref Other references, in refs.dat file
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Note (1): GCN can be retrieved from https://gcn.nasa.gov/circulars/NNNNN
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference number
4- 22 A19 --- BibCode BibCode
24- 47 A24 --- Aut Author's name
49- 80 A32 --- Com Comments
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Acknowledgements:
Jochen Greiner, jcg(at)mpe.mpg.de
(End) Patricia Vannier [CDS] 04-Jul-2024