No Arabic abstract
The properties of the broad-lined type Ic supernova (SN) 2013dx, associated with the long gamma-ray burst GRB130702A at a redshift z = 0.145, are derived via spectral modelling. SN2013dx was similar in luminosity to other GRB/SNe, with a derived value of the mass of 56Nickel ejected in the explosion of ~0.4 Msun. However, its spectral properties suggest a smaller explosion kinetic energy. Radiation transport models were used to derive a plausible mass and density distribution of the SN ejecta in a one-dimensional approximation. While the mass ejected in the explosion that is obtained from the modelling (Mej ~ 9 Msun) is similar to that of all other well-studied GRB/SNe, the kinetic energy is significantly smaller (KE ~ 10^{52}erg). This leads to a smaller KE/Mej ratio, ~ 10^{51} erg/Msun, which is reflected in the narrower appearance of the spectral lines. While the low KE does not represent a problem for the scenario in which magnetar energy aids powering the explosion and the nucleosynthesis, it is nevertheless highly unusual. SNe Ic with similar KE have never been seen in coincidence with a GRB, and no well-observed GRB/SN has shown similarly low KE and KE/Mej.
We present optical observations of SN 2013dx, related to the Fermi burst GRB 130702A occurred at a redshift z = 0.145. It is the second-best sampled GRB-SN after SN~1998bw: the observational light curves contain more than 280 data points in uBgrRiz filters until 88 day after the burst, and the data were collected from our observational collaboration (Maidanak Observatory, Abastumani Observatory, Crimean Astrophysical Observatory, Mondy Observatory, National Observatory of Turkey, Observatorio del Roque de los Muchachos) and from the literature. We model numerically the multicolour light curves using the one-dimensional radiation hydrodynamical code STELLA, previously widely implemented for the modelling of typical non-GRB SNe. The best-fitted model has the following parameters: pre-supernova star mass M = 25 M_Sun, mass of a compact remnant M_CR = 6 M_Sun, total energy of the outburst E_oburst = 3.5 x 10^(52) erg, pre-supernova star radius R = 100 R_Sun, M_56Ni = 0.2 M_Sun which is totally mixed through the ejecta; M_O = 16.6 M_Sun, M_Si = 1.2 M_Sun, and M_Fe = 1.2 M_Sun, and the radiative efficiency of the SN is 0.1 per cent.
We here report a spectroscopic monitor for the supernova SN,2017iuk associated with the long-duration low-luminosity gamma-ray burst GRB,171205A at a redshift of 0.037, which is up to now the third GRB-SN event away from us. Our spectroscopic observations and spectral analysis allow us to identify SN,2017iuk as a typical broad-line type Ic SN. A comparison study suggests that the type-IcBL SN,2017iuk resembles to SN,2006aj in following aspects: 1) similar spectra at the nearby epochs, 2) comparable evolution of the photospheric velocity obtained from the measurements based on both ion{Si}{2}$lambda$6355 line and spectral modeling, and 3) comparable explosion parameters. This analogy could imply a formation of a neutron star in the core-collapse of GRB,171205A/SN,2017iuk as previously suggested in GRB,060218/SN,2006aj. The properties of the host galaxy is discussed, which suggests that GRB,171205A/SN,2017iuk occurred in an early type (S0), high-mass, starforming galaxy with low specific SFR and solar metallicity.
Long-duration gamma-ray bursts (GRBs) have been found to be associated with broad-lined type-Ic supernovae (SNe), but only a handful of cases have been studied in detail. Prompted by the discovery of the exceptionally bright, nearby GRB130427A (redshift z=0.3399), we aim at characterising the properties of its associated SN2013cq. This is the first opportunity to test directly the progenitors of high-luminosity GRBs. We monitored the field of the Swift long duration GRB130427A using the 3.6-m TNG and the 8.2-m VLT during the time interval between 3.6 and 51.6 days after the burst. Photometric and spectroscopic observations revealed the presence of the type Ic SN2013cq. Spectroscopic analysis suggests that SN2013cq resembles two previous GRB-SNe, SN1998bw and SN2010bh associated with GRB980425 and XRF100316D, respectively. The bolometric light curve of SN2013cq, which is significantly affected by the host galaxy contribution, is systematically more luminous than that of SN2010bh ($sim$ 2 mag at peak), but is consistent with SN1998bw. The comparison with the light curve model of another GRB-connected SN2003dh, indicates that SN2013cq is consistent with the model when brightened by 20%. This suggests a synthesised radioactive $^{56}$Ni mass of $sim 0.4 M_odot$. GRB130427A/SN2013cq is the first case of low-z GRB-SN connection where the GRB energetics are extreme ($E_{rm gamma, iso} sim 10^{54}$ erg). We show that the maximum luminosities attained by SNe associated with GRBs span a very narrow range, but those associated with XRFs are significantly less luminous. On the other hand the isotropic energies of the accompanying GRBs span 6 orders of magnitude (10$^{48}$ erg $< E_{rm gamma, iso} <$ 10$^{54}$ erg), although this range is reduced when corrected for jet collimation. The GRB total radiated energy is in fact a small fraction of the SN energy budget.
The association of Type Ic SNe with long-duration GRBs is well established. We endeavor, through accurate ground-based observational campaigns, to characterize these SNe at increasingly high redshifts. We obtained a series of optical photometric and spectroscopic observations of the Type Ic SN2012bz associated with the Swift long-duration GRB120422A (z=0.283) using the 3.6-m TNG and the 8.2-m VLT telescopes. The peak times of the light curves of SN2012bz in various optical filters differ, with the B-band and i-band light curves reaching maximum at ~9 and ~23 rest-frame days, respectively. The bolometric light curve has been derived from individual bands photometric measurements, but no correction for the unknown contribution in the near-infrared (probably around 10-15%) has been applied. Therefore, the present light curve should be considered as a lower limit to the actual UV-optical-IR bolometric light curve. This pseudo-bolometric curve reaches its maximum (Mbol = -18.56 +/- 0.06) at 13 +/- 1 rest-frame days; it is similar in shape and luminosity to the bolometric light curves of the SNe associated with z<0.2 GRBs and more luminous than those of SNe associated with XRFs. A comparison with the model generated for the bolometric light curve of SN2003dh suggests that SN2012bz produced only about 15% less 56Ni than SN2003dh, about 0.35 Msol. Similarly the VLT spectra of SN2012bz, after correction for Galactic extinction and for the contribution of the host galaxy, suggest comparable explosion parameters with those observed in SN2003dh (EK~3.5 x 10^52 erg, Mej~7 Msol) and a similar progenitor mass (~25-40 Msol). GRB120422A is consistent with the Epeak-Eiso and the EX,iso-Egamma,iso-E_peak relations. GRB120422A/SN2012bz shows the GRB-SN connection at the highest redshift so far accurately monitored both photometrically and spectroscopically.
We present the spectroscopic discovery of a broad-lined Type Ic supernova (SN 2010bh) associated with the nearby long-duration gamma-ray burst (GRB) 100316D. At z = 0.0593, this is the third-nearest GRB-SN. Nightly optical spectra obtained with the Magellan telescopes during the first week after explosion reveal the gradual emergence of very broad spectral features superposed on a blue continuum. The supernova features are typical of broad-lined SNe Ic and are generally consistent with previous supernovae associated with low-redshift GRBs. However, the inferred velocities of SN 2010bh at 21 days after explosion are a factor of ~2 times larger than those of the prototypical SN 1998bw at similar epochs, with v ~ 26,000 km/s, indicating a larger explosion energy or a different ejecta structure. A near-infrared spectrum taken 13.8 days after explosion shows no strong evidence for He I at 1.083 microns, implying that the progenitor was largely stripped of its helium envelope. The host galaxy is of low luminosity (M_R ~ -18.5 mag) and low metallicity (Z < 0.4 Z_solar), similar to the hosts of other low-redshift GRB-SNe.