J/MNRAS/478/2 IR-bright gamma-ray burst host galaxies (Chrimes+, 2018)
Investigating a population of infrared-bright gamma-ray burst host galaxies.
Chrimes A.A., Stanway E.R., Levan A.J., Davies L.J.M., Angus C.R.,
Greis S.M.L.
<Mon. Not. R. Astron. Soc., 478, 2-27 (2018)>
=2018MNRAS.478....2C 2018MNRAS.478....2C (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, IR ; GRB
Keywords: gamma-ray burst: general - infrared: galaxies - galaxies: statistics -
galaxies: star formation - dust, extinction
Abstract:
We identify and explore the properties of an infrared-bright gamma-ray
burst (GRB) host population. Candidate hosts are selected by
coincidence with sources in WISE, with matching to random coordinates
and a false alarm probability analysis showing that the contamination
fraction is ∼0.5. This methodology has already identified the
host galaxy of GRB 080517. We combine survey photometry from
Pan-STARRS, SDSS, APASS, 2MASS, GALEX, and WISE with our own WHT/ACAM
and VLT/X-shooter observations to classify the candidates and identify
interlopers. Galaxy SED fitting is performed using MAGPHYS, in
addition to stellar template fitting, yielding 13 possible IR-bright
hosts. A further seven candidates are identified from the previously
published work. We report a candidate host for GRB 061002, previously
unidentified as such. The remainder of the galaxies have already been
noted as potential hosts. Comparing the IR-bright population
properties including redshift z, stellar mass M*, star
formation rate SFR, and V-band attenuation AV to GRB host catalogues
in the literature, we find that the infrared-bright population is
biased towards low z, high M*, and high AV. This naturally
arises from their initial selection - local and dusty galaxies are
more likely to have the required IR flux to be detected in WISE. We
conclude that while IR-bright GRB hosts are not a physically distinct
class, they are useful for constraining existing GRB host populations,
particularly for long GRBs.
Description:
In order to investigate the true hosts and determine which matches are
spurious, we have observed subsets of the sample with WHT/ACAM,
VLT/X-shooter, and ATCA. 7 targets were observed with ACAM/WHT, 5 with
VLT/X-shooter and 14 with ATCA
A population of infrared-bright GRB host galaxies has been identified
by cross-matching X-ray afterglow positions to the ALLWISE catalogue.
Selective cuts in apparent magnitude and catalogue quality flags, in
addition to an FAP analysis, yield 55 IR-sources that are convincingly
associated with a GRB X-ray position.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 88 55 The 55 GRB X-ray positions for which a catalogued
WISE source is identified within 1.5R90 of the
X-ray error circle centroid, and is not rejected
based on FAP, CCF, or blend cuts
table2.dat 83 15 The 15 GRB X-ray positions which match to at
least one WISE source within 1.5R90, but which
have these matches rejected due to FAP, CCF,
or WISE blending cuts
table3.dat 36 26 WHT/ACAM observations, taken on 2015 January 19/20
tablea1.dat 173 31 Full table of archival photometry for 30 GRB
locations with reliable WISE detected
counterparts, where optical data were available
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Byte-by-byte Description of file: table1.dat table2.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- GRB GRB designation (YYMMDDA)
9- 10 A2 --- l_T90 [~≤ >] Limit flag on T90
11- 18 F8.3 s T90 Time over which 90 per cent of the
gamma-ray radiation arrives
20- 21 A2 --- Short/Long [LS? ] Short or long burst (1)
23- 30 F8.4 deg RAdeg X-ray Right ascension (J2000)
33- 40 F8.4 deg DEdeg X-ray Declination (J2000)
42- 45 F4.1 arcsec R90 Radius enclosing 90% gamma-ray flux
48- 55 F8.4 deg RAWdeg WISE Right ascension (J2000)
58- 65 F8.4 deg DEWdeg WISE Declination (J2000)
67- 70 F4.2 arcsec Sep Separation between X-ray and WISE positions
72- 79 F8.6 --- FAP False alarm probability for association with
the WISE source
81- 88 A8 --- Type Our classification of the candidates (2)
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Note (1): SGRB 050724 is a disguised short burst, despite the long T90.
Note (2): classification code as follows:
s = star
Ps = photometric star
G = galaxy
PG = photometric galaxy
NC = no coverage
ND = optical non-detection
LG = identified as an IR-bright host galaxy by comparison to the
published literature
CA = rejected due to possible or confirmed chance alignment
CC = flagged as confused in WISE
WB = flagged as a blend in W1 band
FR = Rejected due to FAP>0.05
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- GRB GRB name (YYMMDDA)
9 A1 --- Filter [griz] Filter
11- 14 I4 s Int Integration time
16 A1 --- l_mag 2σ limit for mag
17- 21 F5.2 mag mag Magnitude in filter (AB)
23- 26 F4.2 mag e_mag ? rms uncertainty on mag
28- 31 F4.1 --- Depth 2 σ depth
33- 36 F4.2 arcsec Seeing Seeing
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- GRB GRB designation (YYMMDDA)
8 A1 --- n_GRB [*] *: GRB 150120A has two sets of photometry,
one for each component (see Section 6.1)
10 A1 --- l_FUV 2σ upper limit flag on FUV
11- 15 F5.2 mag FUV FUV magnitude (1)
17- 20 F4.2 mag e_FUV ?=- rms uncertainty on FUV
21 A1 --- l_NUV 2σ upper limit flag on NUV
22- 26 F5.2 mag NUV NUV magnitude (1)
28- 31 F4.2 mag e_NUV ?=- rms uncertainty on NUV
32 A1 --- l_umag 2σ upper limit flag on umag
33- 37 F5.2 mag umag ?=- u magnitude (1)
39- 42 F4.2 mag e_umag ?=- rms uncertainty on umag
43 A1 --- l_gmag 2σ upper limit flag on
44- 49 F6.3 mag gmag g magnitude (1)
50- 53 F4.2 mag e_gmag ?=- rms uncertainty on e_gmag
55- 59 F5.2 mag rmag r magnitude (1)
61- 64 F4.2 mag e_rmag rms uncertainty on rmag
66- 70 F5.2 mag imag i magnitude (1)
72- 75 F4.2 mag e_imag rms uncertainty on imag
76 A1 --- l_zmag 2σ upper limit flag on zmag
77- 81 F5.2 mag zmag ?=- z magnitude (1)
83- 86 F4.2 mag e_zmag ?=- rms uncertainty on zmag
87 A1 --- l_ymag 2σ upper limit flag on ymag
88- 92 F5.2 mag ymag ?=- y magnitude (1)
94- 97 F4.2 mag e_ymag ?=- rms uncertainty on ymag
98 A1 --- l_Jmag 2σ upper limit flag on Jmag
99-103 F5.2 mag Jmag J magnitude (1)
105-108 F4.2 mag e_Jmag ?=- rms uncertainty on Jmag
109 A1 --- l_Hmag 2σ upper limit flag on Hmag
110-114 F5.2 mag Hmag H magnitude (1)
116-119 F4.2 mag e_Hmag ?=- rms uncertainty on Hmag
120 A1 --- l_Kmag 2σ upper limit flag on Kmag
121-125 F5.2 mag Kmag K magnitude (1)
127-130 F4.2 mag e_Kmag ?=- rms uncertainty on Kmag
132-136 F5.2 mag W1mag W1 magnitude (1)
138-141 F4.2 mag e_W1mag rms uncertainty on W1
142 A1 --- l_W2mag 2σ upper limit flag on W2mag
143-147 F5.2 mag W2mag W2 magnitude (1)
149-152 F4.2 mag e_W2mag ?=- rms uncertainty on W2mag
153 A1 --- l_W3mag 2σ upper limit flag on W3mag
154-158 F5.2 mag W3mag W3 magnitude (1)
160-163 F4.2 mag e_W3mag ?=- rms uncertainty on W3mag
164 A1 --- l_W4mag 2σ upper limit flag on W4mag
165-168 F4.2 mag W4mag W4 magnitude (1)
170-173 F4.2 mag e_W4mag ?=- rms uncertainty on W4mag
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Note (1): No Galactic dust correction has been applied.
If no value is entered, then photometry in that band was unavailable.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 25-Jun-2021