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31. Radio to UV observations of GRB 181201A
ID:
ivo://CDS.VizieR/J/ApJ/884/121
Title:
Radio to UV observations of GRB 181201A
Short Name:
J/ApJ/884/121
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present comprehensive multiwavelength radio to X-ray observations of GRB 181201A spanning from ~150s to ~163days after the burst, comprising the first joint ALMA-VLA-GMRT observations of a gamma-ray burst (GRB) afterglow. The radio and millimeter-band data reveal a distinct signature at ~3.9days, which we interpret as reverse-shock (RS) emission. Our observations present the first time that a single radio- frequency spectral energy distribution can be decomposed directly into RS and forward shock (FS) components. We perform detailed modeling of the full multiwavelength data set, using Markov Chain Monte Carlo sampling to construct the joint posterior density function of the underlying physical parameters describing the RS and FS synchrotron emission. We uncover and account for all discovered degeneracies in the model parameters. The joint RS-FS modeling reveals a weakly magnetized ({sigma}~3x10^-3^), mildly relativistic RS, from which we derive an initial bulk Lorentz factor of {Gamma}_0_~103 for the GRB jet. Our results support the hypothesis that low-density environments are conducive to the observability of RS emission. We compare our observations to other events with strong RS detections and find a likely observational bias selecting for longer lasting, nonrelativistic RSs. We present and begin to address new challenges in modeling posed by the present generation of comprehensive, multifrequency data sets.
32. Search for GW signals associated with GRBs
ID:
ivo://CDS.VizieR/J/ApJ/886/75
Title:
Search for GW signals associated with GRBs
Short Name:
J/ApJ/886/75
Date:
02 Feb 2022 13:41:32
Publisher:
CDS
Description:
We present the results of targeted searches for gravitational-wave transients associated with gamma-ray bursts during the second observing run of Advanced LIGO and Advanced Virgo, which took place from 2016 November to 2017 August. We have analyzed 98 gamma-ray bursts using an unmodeled search method that searches for generic transient gravitational waves and 42 with a modeled search method that targets compact-binary mergers as progenitors of short gamma-ray bursts. Both methods clearly detect the previously reported binary merger signal GW170817, with p-values of <9.38x10^-6^ (modeled) and 3.1x10^-4^ (unmodeled). We do not find any significant evidence for gravitational-wave signals associated with the other gamma-ray bursts analyzed, and therefore we report lower bounds on the distance to each of these, assuming various source types and signal morphologies. Using our final modeled search results, short gamma-ray burst observations, and assuming binary neutron star progenitors, we place bounds on the rate of short gamma-ray bursts as a function of redshift for z<=1. We estimate 0.07-1.80 joint detections with Fermi-GBM per year for the 2019-20 LIGO-Virgo observing run and 0.15-3.90 per year when current gravitational-wave detectors are operating at their design sensitivities.
33. Short gamma-ray bursts (sGRBs) data
ID:
ivo://CDS.VizieR/J/ApJ/852/1
Title:
Short gamma-ray bursts (sGRBs) data
Short Name:
J/ApJ/852/1
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this paper, we study the luminosity function and formation rate of short gamma-ray bursts (sGRBs). First, we derive the Ep-Lp correlation using 16 sGRBs with redshift measurements and determine the pseudo redshifts of 284 Fermi sGRBs. Then, we use the Lynden-Bell c^-^ method to study the luminosity function and formation rate of sGRBs without any assumptions. A strong evolution of luminosity L(z){propto}(1+z)^4.47^ is found. After removing this evolution, the luminosity function is {Psi}(L){propto}L_0_^-0.29+/-0.01^ for dim sGRBs and {psi}(L){propto}L_0_^-1.07+/-0.01^ for bright sGRBs, with the break point 8.26x10^50^erg/s. We also find that the formation rate decreases rapidly at z<1.0, which is different from previous works. The local formation rate of sGRBs is 7.53 events Gpc^-3^/yr. Considering the beaming effect, the local formation rate of sGRBs including off-axis sGRBs is 203.31_-135.54_^+1152.09^ events Gpc^-3^/yr. We also estimate that the event rate of sGRBs detected by the advanced LIGO and Virgo is 0.85_-0.56_^+4.82^ events yr^-1^ for an NS-NS binary.
34. Swift BAT gamma-ray burst durations
ID:
ivo://CDS.VizieR/J/ApJ/896/L20
Title:
Swift BAT gamma-ray burst durations
Short Name:
J/ApJ/896/L20
Date:
21 Mar 2022 07:00:25
Publisher:
CDS
Description:
The duration of a gamma-ray burst (GRB) is a key indicator of its physical origin, with long bursts perhaps associated with the collapse of massive stars and short bursts with mergers of neutron stars. However, there is substantial overlap in the properties of both short and long GRBs and neither duration nor any other parameter so far considered completely separates the two groups. Here we unambiguously classify every GRB using a machine-learning dimensionality reduction algorithm, t-distributed stochastic neighborhood embedding, providing a catalog separating all Swift GRBs into two groups. Although the classification takes place only using prompt emission light curves, every burst with an associated supernova is found in the longer group and bursts with kilonovae in the short, suggesting along with the duration distributions that these two groups are truly long and short GRBs. Two bursts with a clear absence of a supernova belong to the longer class, indicating that these might have been direct-collapse black holes, a proposed phenomenon that may occur in the deaths of more massive stars.
35. Swift long gamma-ray bursts
ID:
ivo://CDS.VizieR/J/ApJS/248/21
Title:
Swift long gamma-ray bursts
Short Name:
J/ApJS/248/21
Date:
21 Oct 2021
Publisher:
CDS
Description:
The exact relationship between the long gamma-ray burst (LGRB) rate and the cosmic star formation rate (CSFR) is essential for using LGRBs as cosmological probes. In this work, we collect a large sample composed of 371 Swift LGRBs with known redshifts and prompt emission properties. We first compare the rest-frame prompt properties of these bursts in different redshift bins, finding negligible redshift evolution of the luminosity of LGRBs with L_iso_>~10^51^erg/s between z~1 and z~4. Then, by utilizing the CSFR obtained from the large-scale cosmological hydrodynamical simulation, the Illustris simulation, we calculate the cumulative redshift distribution of LGRBs under different metallicity thresholds. After comparing with our sample, we find that the predictions with a moderate threshold between 0.3Z_{sun}_<=Z_th_<=1.0Z_{sun}_ are consistent with the sample between redshift 0<z<3, while at higher redshifts, between 3<z<5, all metallicity thresholds fit the data well. When changing to an empirical model based on observations, the predictions show similar results as well. After comparing with the metallicity distribution of the observed LGRB host galaxies between 0<z<1, we confirm that the production of LGRBs in galaxies with super-solar metallicity is suppressed. Nevertheless, considering that a significant fraction of stars are born in sub-solar metallicity environments at z>~3, we suggest that, as a first approximation, LGRBs can be used as direct tracers of the CSFR in this redshift range.
36. Swift X-ray flash & rich gamma-ray bursts in BAT3
ID:
ivo://CDS.VizieR/J/ApJ/866/97
Title:
Swift X-ray flash & rich gamma-ray bursts in BAT3
Short Name:
J/ApJ/866/97
Date:
21 Oct 2021
Publisher:
CDS
Description:
We build a comprehensive sample to statistically describe the properties of X-ray flashes (XRFs) and X-ray riches (XRRs) from the third Swift Burst Alert Telescope (BAT3) catalog of Gamma-ray bursts (GRBs). We obtain 81 XRFs, 540 XRRs, and 394 classical GRBs (C-GRBs). We statistically explore the different properties of the {gamma}-ray prompt emission, the X-ray emission, the X-ray light-curve type, the association with supernovae (SNe), and the host galaxy properties for these sources. We confirm that most XRFs/XRRs are long GRBs with low values of peak energy E_peak_^obs^ and they are low-luminosity GRBs. XRFs, XRRs, and C-GRBs follow the same E_X,iso_-E_{gamma},iso_-E_peak,z_ correlations. Compared to the classical GRBs, XRFs are favorable to have the association with SN explosions. We do not find any significant differences of redshift distribution and host galaxy properties among XRFs, XRRs, and C-GRBs. We also discuss some observational biases and selection effects that may affect our statistical results. The GRB detectors with wide energy range and low energy threshold are expected for the XRF/XRR research in the future.
37. The CGM-GRB study. I. GRB hosts at z~2-6
ID:
ivo://CDS.VizieR/J/ApJ/884/66
Title:
The CGM-GRB study. I. GRB hosts at z~2-6
Short Name:
J/ApJ/884/66
Date:
21 Oct 2021
Publisher:
CDS
Description:
Recent studies have revealed a dynamic interplay between the galaxy ecosystem and circumgalactic medium (CGM). We investigate the CGM at high redshifts (z>~2) by using bright afterglows of gamma-ray bursts (GRBs) as background sources. We compiled a sample of medium-resolution ({Delta}v<50km/s) and high signal-to-noise ratio (typical S/N~10) spectra from 27 GRB afterglows covering z~2-6, with six of them at z>~4. We analyzed the high- and low-ionization absorption features within +/-400km/s to extract the CGM and interstellar medium (ISM) kinematics. In the stacked spectra, high-ionization absorption profiles (e.g., CIV, SiIV) present significant absorption excess in their blue wings (v{<}-100km/s) relative to the red wings (v>100km/s). The stronger blue wings in high-ionization species are indicative of the presence of ubiquitous warm outflows in the GRB hosts at high redshifts. We used simple toy models to kinematically distinguish the CGM and ISM absorption and estimate the CGM mass and outflow velocity. We find tentative evidence of the evolution of the CGM metal mass by ~0.5dex between two redshift bins, each spanning 1 Gyr, z1: 2-2.7 and z2: 2.7-5. By comparing with past studies, we find that over the course of evolution of present-day galaxies with M_*_>10^10^M_{sun}_, the ratio of CIV mass in the CGM to the stellar mass remains fairly uniform, with log(M_CIV_/M_*_)~-4.5 within +/-0.5dex from z~4 to z~0, suggesting CGM-galaxy coevolution.
38. The Fermi-GBM three-year X-ray burst catalog
ID:
ivo://CDS.VizieR/J/ApJ/826/228
Title:
The Fermi-GBM three-year X-ray burst catalog
Short Name:
J/ApJ/826/228
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Fermi Gamma-ray Burst Monitor (GBM) is an all-sky gamma-ray monitor well known in the gamma-ray burst (GRB) community. Although GBM excels in detecting the hard, bright extragalactic GRBs, its sensitivity above 8 keV and its all-sky view make it an excellent instrument for the detection of rare, short-lived Galactic transients. In 2010 March, we initiated a systematic search for transients using GBM data. We conclude this phase of the search by presenting a three-year catalog of 1084 X-ray bursts. Using spectral analysis, location, and spatial distributions we classified the 1084 events into 752 thermonuclear X-ray bursts, 267 transient events from accretion flares and X-ray pulses, and 65 untriggered gamma-ray bursts. All thermonuclear bursts have peak blackbody temperatures broadly consistent with photospheric radius expansion (PRE) bursts. We find an average rate of 1.4 PRE bursts per day, integrated over all Galactic bursters within about 10 kpc. These include 33 and 10 bursts from the ultra-compact X-ray binaries 4U 0614+09 and 2S 0918-549, respectively. We discuss these recurrence times and estimate the total mass ejected by PRE bursts in our Galaxy.
39. The fourth Fermi-GBM GRB catalog: 10 years
ID:
ivo://CDS.VizieR/J/ApJ/893/46
Title:
The fourth Fermi-GBM GRB catalog: 10 years
Short Name:
J/ApJ/893/46
Date:
07 Dec 2021 08:50:03
Publisher:
CDS
Description:
We present the fourth in a series of catalogs of gamma-ray bursts (GRBs) observed with Fermi's Gamma-ray Burst Monitor (Fermi-GBM). It extends the six year catalog by four more years, now covering the 10yr time period from trigger enabling on 2008 July 12 to 2018 July 11. During this time period GBM triggered almost twice a day on transient events, 2356 of which we identified as cosmic GRBs. Additional trigger events were due to solar flare events, magnetar burst activities, and terrestrial gamma-ray flashes. The intention of the GBM GRB catalog series is to provide updated information to the community on the most important observables of the GBM-detected GRBs. For each GRB the location and main characteristics of the prompt emission, the duration, peak flux, and fluence are derived. The latter two quantities are calculated for the 50-300keV energy band, where the maximum energy release of GRBs in the instrument reference system is observed and also for a broader energy band from 10-1000keV, exploiting the full energy range of GBM's low-energy detectors. Furthermore, information is given on the settings of the triggering criteria and exceptional operational conditions during years 7 to 10 in the mission. This fourth catalog is an official product of the Fermi-GBM science team, and the data files containing the complete results are available from the High-Energy Astrophysics Science Archive Research Center.
40. The third Swift/BAT GRB catalog (past ~11yrs) (BAT3)
ID:
ivo://CDS.VizieR/J/ApJ/829/7
Title:
The third Swift/BAT GRB catalog (past ~11yrs) (BAT3)
Short Name:
J/ApJ/829/7
Date:
21 Oct 2021
Publisher:
CDS
Description:
To date, the Burst Alert Telescope (BAT) onboard Swift has detected ~1000 gamma-ray bursts (GRBs), of which ~360 GRBs have redshift measurements, ranging from z=0.03 to z=9.38. We present the analyses of the BAT-detected GRBs for the past ~11 years up through GRB151027B. We report summaries of both the temporal and spectral analyses of the GRB characteristics using event data (i.e., data for each photon within approximately 250s before and 950s after the BAT trigger time), and discuss the instrumental sensitivity and selection effects of GRB detections. We also explore the GRB properties with redshift when possible. The result summaries and data products are available at http://swift.gsfc.nasa.gov/results/batgrbcat/index.html. In addition, we perform searches for GRB emissions before or after the event data using the BAT survey data. We estimate the false detection rate to be only one false detection in this sample. There are 15 ultra-long GRBs (~2% of the BAT GRBs) in this search with confirmed emission beyond ~1000s of event data, and only two GRBs (GRB 100316D and GRB 101024A) with detections in the survey data prior to the starting of event data.

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