- ID:
- ivo://nasa.heasarc/ipngrb
- Title:
- Gamma-Ray Bursts from the Interplanetary Network
- Short Name:
- GRB/IPN
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Interplanetary Network (IPN) is a group of spacecraft equipped with gamma-ray burst detectors used to localize gamma-ray bursts (GRB) and soft gamma repeaters (SGRs, or magnetars). The astronomical locations of GRBs are determined by the comparison of the arrival times of the event at the locations of the detectors used on different space missions. The precision is proportional to the distance of spacecraft separations, so that the localizational accuracy of a network with baselines of thousands of light-seconds can be equal or superior to that of any other technique. The primary disadvantage of the IPN method, however, is the 1-day to 1.5-day delay in the acquisition of data from all the spacecraft in the network. Interplanetary GRB networks have been in existence since 1977, contributing to the studies of various astrophysical gamma-ray transients, most notably GRBs and SGRs (soft gamma repeaters). The IPN3 began operations in 1990, with the launch of the Ulysses spacecraft. It was joined by the Compton Gamma Ray Observatory in 1991. Pioneer Venus Orbiter, Mars Observer, and the Italian X-ray astronomy satellite BeppoSAX were part of the network while they were operating. Twenty-six experiments or missions have joined the network so far. Today, the main spacecrafts contributing their data are Konus-WIND, Mars Odyssey, INTEGRAL, RHESSI, Swift, Agile, BepiColombo, and Fermi. XMM-Newton and MAXI are kept to record the cosmic ray and SGR but not used for triangulation because of the different energy range. The IPNGRB database table is derived from a list provided by Kevin Hurley <khurley@ssl.berkeley.edu>, based on the IPN3. The initial list also includes particles and solar events as well as unconfirmed SGRs and GRBs. The IPNGRB database includes only the observations of confirmed cosmic gamma-ray bursts and SGR since the launch of the Ulysses spacecraft. It is updated every time a new list is provided to the HEASARC. This HEASARC catalog is derived from the master list of IPN3 events provided by Kevin Hurley. He also provided a FORTRAN program that generates the list of selected events. The output of this program is run at GSFC and ingested into the HEASARC database system. Information on the IPN3 system is available at <a href="http://ipn3.ssl.berkeley.edu/">http://ipn3.ssl.berkeley.edu/</a>. <p> Information on the IPN can be found at <a href="http://heasarc.gsfc.nasa.gov/docs/heasarc/missions/ipn.html">http://heasarc.gsfc.nasa.gov/docs/heasarc/missions/ipn.html</a>. <p> In December 2021 Kevin Hurley passed away. He was one of the initiator of the IPN and its evolution. The last table provided is dated August 2021. This is a service provided by NASA HEASARC .
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/787/90
- Title:
- Gamma-ray bursts minimum timescales
- Short Name:
- J/ApJ/787/90
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We develop a robust technique to determine the minimum variability timescale for gamma-ray burst (GRB) light curves, utilizing Haar wavelets. Our approach averages over the data for a given GRB, providing an aggregate measure of signal variation while also retaining sensitivity to narrow pulses within complicated time series. In contrast to previous studies using wavelets, which simply define the minimum timescale in reference to the measurement noise floor, our approach identifies the signature of temporally smooth features in the wavelet scaleogram and then additionally identifies a break in the scaleogram on longer timescales as a signature of a true, temporally unsmooth light curve feature or features. We apply our technique to the large sample of Swift GRB gamma-ray light curves and for the first time - due to the presence of a large number of GRBs with measured redshift - determine the distribution of minimum variability timescales in the source frame. We find a median minimum timescale for long-duration GRBs in the source frame of {Delta}t_min_=0.5 s, with the shortest timescale found being on the order of 10 ms. This short timescale suggests a compact central engine (3x10^3^ km). We discuss further implications for the GRB fireball model and present a tantalizing correlation between the minimum timescale and redshift, which may in part be due to cosmological time dilation.
- ID:
- ivo://CDS.VizieR/J/MNRAS/407/2075
- Title:
- Gamma-ray bursts spectral peak estimator
- Short Name:
- J/MNRAS/407/2075
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Simple hardness ratios are found to be a good estimator for the spectral peak energy in gamma-ray bursts (GRBs). Specifically, a high correlation strength is found between the nuFnu peak in the spectrum of Burst and Transient Source Experiment (BATSE) GRBs, Ep,obs and the hardness of GRBs, inline image, as defined by the fluences in channels 3 and 4, divided by the combined fluences in channels 1 and 2 of the BATSE Large Area Detectors (LADs). The correlation is independent of the type of the burst, whether long-duration GRB (LGRB) or short-duration (SGRB) and remains almost linear over the wide range of the BATSE energy window (20-2000KeV). Based on Bayes theorem and Markov Chain Monte Carlo techniques, we also present multivariate analyses of the observational data while accounting for data truncation and sample incompleteness. Prediction intervals for the proposed inline image relation are derived. Results and further simulations are used to compute Ep,obs estimates for nearly the entire BATSE catalogue: 2130 GRBs.
7054. Gamma-ray bursts types
- ID:
- ivo://CDS.VizieR/J/ApJ/508/314
- Title:
- Gamma-ray bursts types
- Short Name:
- J/ApJ/508/314
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A multivariate analysis of gamma-ray burst (GRB) bulk properties is presented to discriminate between distinct classes of GRBs. Several variables representing burst duration, fluence, and spectral hardness are considered. Two multivariate clustering procedures are used on a sample of 797 bursts from the Third BATSE Catalog, a nonparametric average linkage hierarchical agglomerative clustering procedure validated with Wilks' {LAMBDA}* (1932, Biometrika, 24, 471) and other multivariate analysis of variance tests and a parametric maximum likelihood model-based clustering procedure assuming multinormal populations calculated with the Expectation-Maximization algorithm and validated with the Bayesian Information Criterion. The two methods yield very similar results. The BATSE GRB population consists of three classes with the following duration/fluence/spectrum bulk properties: class I with long/bright/soft bursts, class II with short/faint/hard bursts, and class III with intermediate/intermediate/soft bursts. One outlier due to spurious data is also present. Classes I and II correspond to those reported by Kouveliotou et al., but class III is clearly defined here for the first time.
- ID:
- ivo://CDS.VizieR/J/PAZh/35/10
- Title:
- Gamma-ray bursts with known redshifts
- Short Name:
- J/PAZh/35/10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observational parameters of the optical and gamma-ray emissions from 58 gamma-ray bursts (GRBs) with discovered afterglows and known redshifts are analyzed. The distributions of these parameters and pair correlations between them are studied. Approximately half of the objects exhibit a relatively slow decrease in the optical flux at initial afterglow phases (with a power-law index in the decay law {alpha}<1). Correlations have been found between the luminosities, energies, and durations of the optical and gamma-ray emissions, which can be explained by the presence of universal features in the light curves. A correlation of the peak luminosity for afterglows with the redshift and an anticorrelation of their durations with the redshift have been found for the first time. Against the background of a weak z dependence of the total afterglow energy, this effect can be explained by cosmological evolution of the GRB environment, which determines the rate of optical energy release.
- ID:
- ivo://CDS.VizieR/J/other/RAA/13.259
- Title:
- {gamma}-ray Doppler factor for Fermi blazars
- Short Name:
- J/other/RAA/13.2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observations suggest that gamma-ray loud blazars are strongly beamed. The Fermi mission has detected many of blazars, which provide us with a good opportunity to investigate the emission mechanism and the beaming effect in the gamma-ray region. We compiled the X-ray observations for 138 Fermi blazars (54 flat spectrum radio quasars, 36 low-peaked BL Lacertae objects, and 48 high-peaked BL Lacertae objects) and calculated their Doppler factors, {delta}_{gamma}. It is interesting that the calculated Doppler factors, {delta}_{gamma}, are strongly correlated with the gamma-ray luminosity.
- ID:
- ivo://CDS.VizieR/J/ApJ/894/88
- Title:
- {gamma}-ray emission of star-forming galaxies
- Short Name:
- J/ApJ/894/88
- Date:
- 19 Jan 2022 13:04:51
- Publisher:
- CDS
- Description:
- A majority of the {gamma}-ray emission from star-forming galaxies is generated by the interaction of high-energy cosmic rays with the interstellar gas and radiation fields. Star-forming galaxies are expected to contribute to both the extragalactic {gamma}-ray background and the IceCube astrophysical neutrino flux. Using roughly 10yr of {gamma}-ray data taken by the Fermi Large Area Telescope, in this study we constrain the {gamma}-ray properties of star-forming galaxies. We report the detection of 11 bona fide {gamma}-ray-emitting galaxies and 2 candidates. Moreover, we show that the cumulative {gamma}-ray emission of below-threshold galaxies is also significantly detected at ~5{sigma} confidence. The {gamma}-ray luminosity of resolved and unresolved galaxies is found to correlate with the total (8-1000{mu}m) infrared luminosity as previously determined. Above 1GeV, the spectral energy distribution of resolved and unresolved galaxies is found to be compatible with a power law with a photon index of ~2.2-2.3. Finally, we find that star-forming galaxies account for roughly 5% and 3% of the extragalactic {gamma}-ray background and the IceCube neutrino flux, respectively.
- ID:
- ivo://CDS.VizieR/J/ApJ/722/520
- Title:
- Gamma-ray light curves of Fermi blazars
- Short Name:
- J/ApJ/722/520
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents light curves as well as the first systematic characterization of variability of the 106 objects in the high-confidence Fermi Large Area Telescope Bright AGN Sample (LBAS). Weekly light curves of this sample, obtained during the first 11 months of the Fermi survey (2008 August 4-2009 July 4), are tested for variability and their properties are quantified through autocorrelation function and structure function analysis. For the brightest sources, 3 or 4 day binned light curves are extracted in order to determine power density spectra (PDSs) and to fit the temporal structure of major flares. More than 50% of the sources are found to be variable with high significance, where high states do not exceed 1/4 of the total observation range. Variation amplitudes are larger for flat spectrum radio quasars and low/intermediate synchrotron frequency peaked BL Lac objects. Autocorrelation timescales derived from weekly light curves vary from four to a dozen of weeks.
7059. {gamma}-ray loud blazars
- ID:
- ivo://CDS.VizieR/J/ApJ/726/16
- Title:
- {gamma}-ray loud blazars
- Short Name:
- J/ApJ/726/16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The radio properties of blazars detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope have been observed as part of the VLBA Imaging and Polarimetry Survey. This large, flux-limited sample of active galactic nuclei (AGNs) provides insights into the mechanism that produces strong {gamma}-ray emission. At lower flux levels, radio flux density does not directly correlate with {gamma}-ray flux. We find that the LAT-detected BL Lac objects tend to be similar to the non-LAT BL Lac objects, but that the LAT-detected FSRQs are often significantly different from the non-LAT FSRQs. The differences between the {gamma}-ray loud and quiet FSRQs can be explained by Doppler boosting; these objects appear to require larger Doppler factors than those of the BL Lac objects. It is possible that the {gamma}-ray loud FSRQs are fundamentally different from the {gamma}-ray quiet FSRQs. Strong polarization at the base of the jet appears to be a signature for {gamma}-ray loud AGNs.
- ID:
- ivo://CDS.VizieR/J/A+AS/127/445
- Title:
- Gamma-ray loud blazars optical monitoring. II.
- Short Name:
- J/A+AS/127/445
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New data from the optical monitoring of gamma-ray loud blazars at the Torino Astronomical Observatory are presented.