- ID:
- ivo://CDS.VizieR/J/MNRAS/421/1874
- Title:
- GRB 100901A and GRB 100906A light curves
- Short Name:
- J/MNRAS/421/1874
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of the prompt, early and afterglow optical observations of five {gamma}-ray bursts (GRBs): GRB 100901A, GRB 100902A, GRB 100905A, GRB 100906A and GRB 101020A. These observations were made with the Mobile Astronomical System of TElescope-Robots in Russia (MASTER-II Net), the 1.5-m telescope of the Sierra Nevada Observatory and the 2.56-m Nordic Optical Telescope.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/169/62
- Title:
- GRB database of spectral lags
- Short Name:
- J/ApJS/169/62
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a database of spectral lags and internal luminosity function (ILF) measurements for gamma-ray bursts (GRBs) in the BATSE catalog. Measurements were made using 64ms count rate data and are defined for various combinations of the four broadband BATSE energy channels.
- ID:
- ivo://CDS.VizieR/J/ApJ/778/128
- Title:
- GRB-host galaxies photometry
- Short Name:
- J/ApJ/778/128
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present observations and analysis of the host galaxies of 23 heavily dust-obscured gamma-ray bursts (GRBs) observed by the Swift satellite during the years 2005-2009, representing all GRBs with an unambiguous host-frame extinction of A_V_>1mag from this period. Deep observations with Keck, Gemini, Very Large Telescope, Hubble Space Telescope, and Spitzer successfully detect the host galaxies and establish spectroscopic or photometric redshifts for all 23 events, enabling us to provide measurements of the intrinsic host star formation rates, stellar masses, and mean extinctions. Compared to the hosts of unobscured GRBs at similar redshifts, we find that the hosts of dust-obscured GRBs are (on average) more massive by about an order of magnitude and also more rapidly star forming and dust obscured. While this demonstrates that GRBs populate all types of star-forming galaxies, including the most massive, luminous systems at z{approx}2, at redshifts below 1.5 the overall GRB population continues to show a highly significant aversion to massive galaxies and a preference for low-mass systems relative to what would be expected given a purely star-formation-rate-selected galaxy sample. This supports the notion that the GRB rate is strongly dependent on metallicity, and may suggest that the most massive galaxies in the universe underwent a transition in their chemical properties ~9Gyr ago. We also conclude that, based on the absence of unobscured GRBs in massive galaxies and the absence of obscured GRBs in low-mass galaxies, the dust distributions of the lowest-mass and the highest-mass galaxies are relatively homogeneous, while intermediate-mass galaxies (~10^9^M_{sun}_) have diverse internal properties.
- ID:
- ivo://CDS.VizieR/J/A+A/607/A107
- Title:
- GRB 080810 Keck/HIRES spectrum
- Short Name:
- J/A+A/607/A107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We reveal multiple components of an interacting galaxy system at z~3.35 through a detailed analysis of the exquisite high-resolution Keck/HIRES spectrum of the afterglow of a gamma-ray burst (GRB). Through Voigt-profile fitting of absorption lines from the Lyman-series, we constrain the neutral hydrogen column density to N_HI_<=10^18.35^cm^-2^ for the densest of four distinct systems at the host redshift of GRB 080810, among the lowest NHI ever observed in a GRB host, despite the line of sight passing within a projected 5kpc of the galaxy centres. By detailed analysis of the corresponding metal absorption lines, we derive chemical, ionic and kinematic properties of the individual absorbing systems, and thus build a picture of the host as a whole. Striking differences between the systems imply that the line of sight passes through several phases of gas: the star-forming regions of the GRB host; enriched material in the form of a galactic outflow; the hot and ionised halo of a second, interacting galaxy falling towards the host at a line-of-sight velocity of 700km/s; and a cool, metal-poor cloud which may represent one of the best candidates yet for the inflow of metal-poor gas from the intergalactic medium.
- ID:
- ivo://CDS.VizieR/J/ApJ/828/36
- Title:
- GRB light-curve decay indices with Swift
- Short Name:
- J/ApJ/828/36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this work, we study the distribution of temporal power-law decay indices, {alpha}, in the gamma-ray burst (GRB) afterglow phase, fitted for 176 GRBs (139 long GRBs, 12 short GRBs with extended emission, and 25 X-ray flashes) with known redshifts. These indices are compared with the temporal decay index, {alpha}_W_, derived with the light-curve fitting using the Willingale+ (2007ApJ...662.1093W) model. This model fitting yields similar distributions of {alpha}_W_ to the fitted {alpha}, but for individual bursts a difference can be significant. Analysis of ({alpha}, L_a_) distribution, where L_a_ is the characteristic luminosity at the end of the plateau, reveals only a weak correlation of these quantities. However, we discovered a significant regular trend when studying GRB {alpha} values along the Dainotti+ (2013ApJ...774..157D) correlation between L_a_ and the end time of the plateau emission in the rest frame, T_a_^*^, hereafter LT correlation. We note a systematic variation of the {alpha} parameter distribution with luminosity for any selected T_a_^*^. We analyze this systematics with respect to the fitted LT correlation line, expecting that the presented trend may allow us to constrain the GRB physical models. We also attempted to use the derived correlation of {alpha}(T_a_) versus L_a_(T_a_) to diminish the luminosity scatter related to the variations of {alpha} along the LT distribution, a step forward in the effort of standardizing GRBs. A proposed toy model accounting for this systematics applied to the analyzed GRB distribution results in a slight increase of the LT correlation coefficient.
5716. GRB list (1990-2014)
- ID:
- ivo://CDS.VizieR/IX/51
- Title:
- GRB list (1990-2014)
- Short Name:
- IX/51
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The next generation interferometric radio telescope, the Square Kilometre Array (SKA), which will be the most sensitive and largest radio telescope ever constructed, could greatly contribute to the detection, survey and characterization of Gamma Ray Bursts (GRBs). By the SKA, it will be possible to perform the follow up of GRBs even for several months. This approach would be extremely useful to extend the Spectrum Energetic Distribution (SED) from the gamma to the to radio band and would increase the number of radio detectable GRBs. In principle, the SKA could help to understand the physics of GRBs by setting constraints on theoretical models. This goal could be achieved by taking into account multiple observations at different wavelengths in order to obtain a deeper insight of the sources. Here, we present an estimation of GRB radio detections, showing that the GRBs can really be observed by the SKA. The approach that we present consists in determining blind detection rates derived by a very large sample consisting of merging several GRB catalogues observed by current missions as Swift, Fermi, Agile and INTEGRAL and by previous missions as BeppoSAX, CGRO, GRANAT, HETE-2, Ulysses and Wind. The final catalogue counts 7516 distinct sources. We compute the fraction of GRBs that could be observed by the SKA at high and low frequencies, above its observable sky. Considering the planned SKA sensitivity and through an extrapolation based on previous works and observations, we deduce the minimum fluence in the range 15-150keV. This is the energy interval where a GRB should emit to be detectable in the radio band by the SKA. Results seem consistent with observational capabilities.
- ID:
- ivo://CDS.VizieR/J/ApJ/807/76
- Title:
- 373 GRBs between 0.008<z<6.7
- Short Name:
- J/ApJ/807/76
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we examine the spatial distribution of gamma-ray bursts (GRBs) using a sample of 373 objects. We subdivide the GRB data into two redshift intervals over the redshift range 0<z<6.7. We measure the two-point correlation function, {xi}(r), of the GRBs. In determining the separation distance of the GRB pairs, we consider two representative cosmological models: a cold dark matter universe plus a cosmological constant {Lambda}, with ({Omega}_m_,{Omega}_{Lambda}_)=(0.28,0.72), and an Einstein-de Sitter universe, with ({Omega}_m_,{Omega}_{Lambda}_)=(1,0). We find a z-decreasing correlation of the GRB distribution, which is in agreement with the predictions of the current structure formation theory. We fit a power-law model {xi}(r)=(r/r0)^-{gamma}^ to the measured {xi}(r) and obtain an amplitude and slope of r_0_=1235.2+/-342.6h^-1^Mpc and {gamma}=0.80+/-0.19, respectively (1{sigma} confidence level), over the scales r=200-10^4^h^-1^Mpc. Our results provide a supplement to the measurement of matter correlation on large scales, while the matter distribution below 200h^-1^Mpc is usually described by the correlation function of galaxies.
5718. GRBs data
- ID:
- ivo://CDS.VizieR/J/MNRAS/477/2173
- Title:
- GRBs data
- Short Name:
- J/MNRAS/477/2173
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The detections of some long gamma-ray bursts (LGRBs) relevant to mergers of neutron star (NS)-NS or black hole (BH)-NS, as well as some short gamma-ray bursts (SGRBs) probably produced by collapsars, muddle the boundary of two categories of gamma-ray bursts (GRBs). In both cases, a plausible candidate of central engine is a BH surrounded by a hyperaccretion disc with strong outflows, launching relativistic jets driven by Blandford-Znajek mechanism. In the framework of compact binary mergers, we test the applicability of the BH hyperaccretion inflow-outflow model on powering observed GRBs. We find that, for a low outflow ratio, ~50 per cent, post-merger hyperaccretion processes could power not only all SGRBs but also most of LGRBs. Some LGRBs might originate from merger events in the BH hyperaccretion scenario, at least on the energy requirement. Moreover, kilonovae might be produced by neutron-rich outflows, and their luminosities and time-scales significantly depend on the outflow strengths. GRBs and their associated kilonovae are competitive with each other on the disc mass and total energy budgets. The stronger the outflow, the more similar the characteristics of kilonovae to supernovae (SNe). This kind of 'nova' might be called 'quasi-SN'.
- ID:
- ivo://CDS.VizieR/J/A+A/589/A97
- Title:
- GRBs Ep and Fourier PDS slope correlation
- Short Name:
- J/A+A/589/A97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The origin of the gamma-ray burst (GRB) prompt emission still defies explanation, in spite of recent progress made, for example, on the occasional presence of a thermal component in the spectrum along with the ubiquitous non-thermal component that is modelled with a Band function. The combination of finite duration and aperiodic modulations make GRBs hard to characterise temporally. Although correlations between GRB luminosity and spectral hardness on one side and time variability on the other side have long been known, the loose and often arbitrary definition of the latter makes the interpretation uncertain. We characterise the temporal variability in an objective way and search for a connection with rest-frame spectral properties for a number of well-observed GRBs. We studied the individual power density spectra (PDS) of 123 long GRBs with measured redshift, rest-frame peak energy E_p,i_ of the time-averaged {nu}F{nu} spectrum, and well-constrained PDS slope {alpha} detected with Swift, Fermi and past spacecraft. The PDS were modelled with a power law either with or without a break adopting a Bayesian Markov chain Monte Carlo technique.
- ID:
- ivo://CDS.VizieR/J/ApJ/754/121
- Title:
- GRBs from Fermi/GBM and LAT
- Short Name:
- J/ApJ/754/121
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We examine 288 gamma-ray bursts (GRBs) detected by the Fermi Gamma-ray Space Telescope's Gamma-ray Burst Monitor (GBM) that fell within the field of view of Fermi's Large Area Telescope (LAT) during the first 2.5 years of observations, which showed no evidence for emission above 100MeV. We report the photon flux upper limits in the 0.1-10GeV range during the prompt emission phase as well as for fixed 30s and 100s integrations starting from the trigger time for each burst. We compare these limits with the fluxes that would be expected from extrapolations of spectral fits presented in the first GBM spectral catalog and infer that roughly half of the GBM-detected bursts either require spectral breaks between the GBM and LAT energy bands or have intrinsically steeper spectra above the peak of the {nu}F_{nu}_ spectra (E_pk_). In order to distinguish between these two scenarios, we perform joint GBM and LAT spectral fits to the 30 brightest GBM-detected bursts and find that a majority of these bursts are indeed softer above E_pk_ than would be inferred from fitting the GBM data alone. Approximately 20% of this spectroscopic subsample show statistically significant evidence for a cutoff in their high-energy spectra, which if assumed to be due to {gamma}{gamma} attenuation, places limits on the maximum Lorentz factor associated with the relativistic outflow producing this emission. All of these latter bursts have maximum Lorentz factor estimates that are well below the minimum Lorentz factors calculated for LAT-detected GRBs, revealing a wide distribution in the bulk Lorentz factor of GRB outflows and indicating that LAT-detected bursts may represent the high end of this distribution.