J/ApJS/280/39 Gamma-ray burst polarization measurements (Li+, 2025)
Relativistic effects and gamma-ray burst polarization in power-law evolution.
Li L., Xue S.-S., Cai R.-G.
<Astrophys. J. Suppl. Ser., 280, 39 (2025)>
=2025ApJS..280...39L 2025ApJS..280...39L
ADC_Keywords: GRB; Polarization; Optical; Radio sources; X-ray sources;
Redshifts
Keywords: Gamma-ray bursts ; Astronomy data analysis ; Time domain astronomy
Abstract:
Despite decades of polarization observations and high significance of
polarized γ-ray, X-ray, optical, and radio emissions in
gamma-ray bursts (GRBs) accumulating in dozens of cases, people have
yet to find a consistent scenario for understanding the globally
observed timing properties of GRB polarization to date. Here, we
report that the observed properties of GRB polarization exhibit a
four-segment timing evolution at a cosmological distance: (i) an
initial hump early on (within the first few seconds); (ii) a later-on
power-law decay (from ∼101 to ∼104s), which takes the form of
Πobs∝t-0.50±0.02; (iii) afterward a late-time
rebrightening hump (from ∼104 to ∼105s); and (iv) finally a
flattening power-law decay (from ∼105 to ∼107s), with the form of
Πobs∝t-0.21±0.08. We show that these results can be
explained by relativistic and geometric effects of a highly
relativistic and magnetized jet generated by a central engine, and
"magnetic patches" distributed as a globally random but locally
coherent form. The long-term timing evolution of observed GRB
polarization follows a scaling law Πobs∝1/Sobs,
dominantly determined by how "magnetic patches" are randomly
distributed in the observed emission region Sobs on the jet plane of
1/Γ cone. It predicts the polarization hump and tail form in
accordance with the luminosity jet-break phenomenon. Our analysis
suggests that there is a single dominant mechanism (relativistic and
geometric effects) that may account for the global observational
properties of GRB polarization, and other emission mechanisms and
effects may play a role in spatially local and temporally short
effects on GRB polarization.
Description:
We conducted an extensive search of the literature for published and
archival polarimetric observations and attempted to include all the
bursts that had polarization measurements to date. With this dedicated
search, the complete GRB polarization sample, which consists of
76 bursts (45 bursts with known redshifts; see Figure 1) and covers a
broad wavelength range (from radio to gamma-ray emission) of
polarization measurements, is provided (see Table 1).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 207 258 A full catalog of GRB polarimetric observations
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See also:
J/other/NewA/29.65 : MASTER polarization observations (Pruzhinskaya+, 2014)
J/ApJ/843/143 : Polarimetry & photometry of GRB with RINGO2 (Steele+, 2017)
J/ApJ/886/20 : Bayesian time-resolved spectra of Fermi GBM pulses (Yu+, 2019)
J/ApJS/254/35 : Fermi GBM GRBs with multiple pulses (Li+, 2021)
J/A+A/690/A216 : GRB210610B polarization images (Agui Fernandez+, 2024)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- GRB Gamma-Ray Burst identifier
9- 12 A4 --- l_PolDeg [≤> ] Limit flag on PolDeg
14- 18 F5.2 % PolDeg [0/98]? Degree of polarization; πobs% (1)
20- 24 F5.2 % E_PolDeg [0.3/57]? Upper uncertainty in PolDeg (1)
26- 30 F5.2 % e_PolDeg [0.04/46]? Lower uncertainty in PolDeg (1)
32- 32 A1 --- n_PolDeg [∼lc%] Note on PolDeg (2)
34- 34 A1 --- l_PolAng Limit flag on PolAng
36- 41 F6.2 deg PolAng [-78.1/189]? Polarization angle (1)
43- 46 F4.1 deg E_PolAng [4.5/25]? Upper uncertainty in PolAng (1)
48- 53 F6.2 deg e_PolAng [2.3/67.5]? Lower uncertainty in PolAng (1)
55- 55 A1 --- n_PolAng [∼v] Note on PolAng (2)
57- 75 A19 --- Freq Energy or wavelength band (3)
77- 92 A16 --- Band Wave band ("Optical", "Radio", "hard X-rays",
"γray" or "soft γ-ray")
94-114 A21 --- Time Time since maximum
116-130 A15 --- Sig Significance
132-132 A1 --- f_Inst [def] Flag on Inst (4)
134-177 A44 --- Inst Instrument
179-197 A19 --- Bibcode Reference's ADS bibcode
199-199 A1 --- l_z Limit flag on z
200-205 F6.4 --- z [0.0085/4.5]? Redshift; spectroscopic
unless noted
207-207 A1 --- f_z [a?] Flag on z (a=photometric) (4)
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Note (1): If no upper uncertainty value is given, the lower uncertainty is
the symmetric uncertainty around the polarization value.
Note (2): Note as follows:
l = Linear polarization measurement;
c = Circular polarization measurement;
% = percentage degree of polarization;
∼ = approximate
v = variable
Note (3): Units given in the value otherwise keV
Note (4): Flag as follows:
d = The Gamma-Ray Burst Polarimeter (GAP) on board the small
solar-power-sail demonstrator IKAROS.
e = The purpose-built RINGO2 polarimeter20 on the Liverpool Telescope.
f = Compton Spectrometer and Imager.
a = a photometric derived redshift. A photometric redshift is an estimate
for the recession velocity of an astronomical object such as a
galaxy or quasar, made without measuring its spectrum.
? = an uncertain redshift.
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History:
From electronic version of the journal
License: CC-BY-4.0
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 04-Jun-2026