scholarly journals No supernovae detected in two long-duration gamma-ray bursts

Author(s):  
D Watson ◽  
J.P.U Fynbo ◽  
C.C Thöne ◽  
J Sollerman

There is strong evidence that long-duration gamma-ray bursts (GRBs) are produced during the collapse of a massive star. In the standard version of the collapsar model, a broad-lined and luminous Type Ic core-collapse supernova (SN) accompanies the GRB. This association has been confirmed in observations of several nearby GRBs. Recent observations show that some long-duration GRBs are different. No SN emission accompanied the long-duration GRBs 060505 and 060614 down to limits fainter than any known Type Ic SN and hundreds of times fainter than the archetypal SN 1998bw that accompanied GRB 980425. Multi-band observations of the early afterglows, as well as spectroscopy of the host galaxies, exclude the possibility of significant dust obscuration. Furthermore, the bursts originated in star-forming galaxies, and in the case of GRB 060505, the burst was localized to a compact star-forming knot in a spiral arm of its host galaxy. We find that the properties of the host galaxies, the long duration of the bursts and, in the case of GRB 060505, the location of the burst within its host, all imply a massive stellar origin. The absence of an SN to such deep limits therefore suggests a new phenomenological type of massive stellar death.

2011 ◽  
Vol 7 (S279) ◽  
pp. 75-82
Author(s):  
Paolo A. Mazzali

AbstractThe properties of the Supernovae discovered in coincidence with long-duration Gamma-ray Bursts and X-Ray Flashes are reviewed, and compared to those of SNe for which GRBs are not observed. The SNe associated with GRBs are of Type Ic, they are brighter than the norm, and show very broad absorption lines in their spectra, indicative of high expansion velocities and hence of large explosion kinetic energies. This points to a massive star origin, and to the birth of a black hole at the time of core collapse. There is strong evidence for gross asymmetries in the SN ejecta. The observational evidence seems to suggest that GRB/SNe are more massive and energetic than XRF/SNe, and come from more massive stars. While for GRB/SNe the collapsar model is favoured, XRF/SNe may host magnetars.


2011 ◽  
Vol 7 (S279) ◽  
pp. 9-17
Author(s):  
Paul A. Crowther

AbstractThe locations of massive stars (≥ 8M⊙) within their host galaxies is reviewed. These range from distributed OB associations to dense star clusters within giant Hii regions. A comparison between massive stars and the environments of core-collapse supernovae and long duration Gamma Ray Bursts is made, both at low and high redshift. We also address the question of the upper stellar mass limit, since very massive stars (VMS, Minit ≫ 100M⊙) may produce exceptionally bright core-collapse supernovae or pair instability supernovae.


2015 ◽  
Vol 11 (A29B) ◽  
pp. 267-269
Author(s):  
Emily M. Levesque

AbstractThe host galaxies of nearby (z<0.3) core-collapse supernovae and long-duration gamma-ray bursts offer an excellent means of probing the environments and populations that produce these events' varied massive progenitors. These same young stellar progenitors make LGRBs and SNe valuable and potentially powerful tracers of star formation, metallicity, the IMF, and the end phases of stellar evolution. However, properly utilizing these progenitors as tools requires a thorough understanding of their formation and, consequently, the physical properties of their parent host environments. In this talk I will review some of the recent work on LGRB and SN hosts with resolved environments that allows us to probe the precise explosion sites and surrounding environments of these events in incredible detail.


2020 ◽  
Vol 641 ◽  
pp. A30
Author(s):  
J.-B. Vielfaure ◽  
S. D. Vergani ◽  
J. Japelj ◽  
J. P. U. Fynbo ◽  
M. Gronke ◽  
...  

Context. The identification of the sources that reionized the Universe and their specific contribution to this process are key missing pieces of our knowledge of the early Universe. Faint star-forming galaxies may be the main contributors to the ionizing photon budget during the epoch of reionization, but their escaping photons cannot be detected directly due to inter-galactic medium opacity. Hence, it is essential to characterize the properties of faint galaxies with significant Lyman continuum (LyC) photon leakage up to z ∼ 4 to define indirect indicators allowing analogs to be found at the highest redshift. Aims. Long gamma-ray bursts (LGRBs) typically explode in star-forming regions of faint, star-forming galaxies. Through LGRB afterglow spectroscopy it is possible to detect directly LyC photons. Our aim is to use LGRBs as tools to study LyC leakage from faint, star-forming galaxies at high redshift. Methods. Here we present the observations of LyC emission in the afterglow spectra of GRB 191004B at z = 3.5055, together with those of the other two previously known LyC-leaking LGRB host galaxies (GRB 050908 at z = 3.3467, and GRB 060607A at z = 3.0749), to determine their LyC escape fraction and compare their properties. Results. From the afterglow spectrum of GRB 191004B we determine a neutral hydrogen column density at the LGRB redshift of log(NH I/cm−2) = 17.2 ± 0.15, and negligible extinction (AV = 0.03 ± 0.02 mag). The only metal absorption lines detected are C IV and Si IV. In contrast to GRB 050908 and GRB 060607A, the host galaxy of GRB 191004B displays significant Lyman-alpha (Lyα) emission. From its Lyα emission and the non-detection of Balmer emission lines we constrain its star-formation rate (SFR) to 1 ≤ SFR ≤ 4.7 M⊙ yr−1. We fit the Lyα emission with a shell model and find parameters values consistent with the observed ones. The absolute (relative) LyC escape fractions we find for GRB 191004B, GRB 050908 and GRB 060607A are of 0.35−0.11+0.10 (0.43−0.13+0.12), 0.08−0.04+0.05 (0.08−0.04+0.05) and 0.20−0.05+0.05 (0.45−0.15+0.15), respectively. We compare the LyC escape fraction of LGRBs to the values of other LyC emitters found from the literature, showing that LGRB afterglows can be powerful tools to study LyC escape for faint high-redshift star-forming galaxies. Indeed we could push LyC leakage studies to much higher absolute magnitudes. The host galaxies of the three LGRBs presented here have all M1600 >  −19.5 mag, with the GRB 060607A host at M1600 >  −16 mag. LGRB hosts may therefore be particularly suitable for exploring the ionizing escape fraction in galaxies that are too faint or distant for conventional techniques. Furthermore, the time involved is minimal compared to galaxy studies.


2005 ◽  
Vol 192 ◽  
pp. 433-439
Author(s):  
Kevin Hurley

SummaryA “typical” GRB occurs in a star-forming region of a galaxy at a redshift z~1. In currently popular models, it is caused by the collapse of a massive star which has exhausted its nuclear fuel supply. The star collapses to a black hole threaded by a strong magnetic field, and possibly fed by an accretion torus. Through a variety of processes, electrons are accelerated and gamma-rays, X-rays, optical light, and radio emission ensue, with durations from seconds to years. In this talk, I will review the general observational properties of bursts, their afterglows and host galaxies, and some of the open questions about them.


Author(s):  
Andrew King

I consider various possibilities for making gamma-ray bursts, particularly from close binaries. In addition to the much-studied neutron star+neutron star and black hole+neutron star cases usually considered good candidates for short-duration bursts, there are also other possibilities. In particular, neutron star+massive white dwarf has several desirable features. These systems are likely to produce long-duration gamma-ray bursts (GRBs), in some cases definitely without an accompanying supernova, as observed recently. This class of burst would have a strong correlation with star formation and occur close to the host galaxy. However, rare members of the class need not be near star-forming regions and could have any type of host galaxy. Thus, a long-duration burst far from any star-forming region would also be a signature of this class. Estimates based on the existence of a known progenitor suggest that this type of GRB may be quite common, in agreement with the fact that the absence of a supernova can only be established in nearby bursts.


2019 ◽  
Vol 490 (4) ◽  
pp. 5366-5374
Author(s):  
A Melandri ◽  
D B Malesani ◽  
L Izzo ◽  
J Japelj ◽  
S D Vergani ◽  
...  

ABSTRACT The number of supernovae known to be connected with long-duration gamma-ray bursts (GRBs) is increasing and the link between these events is no longer exclusively found at low redshift (z ≲ 0.3) but is well established also at larger distances. We present a new case of such a liaison at z = 0.33 between GRB 171010A and SN 2017htp. It is the second closest GRB with an associated supernova of only three events detected by Fermi-LAT. The supernova is one of the few higher redshift cases where spectroscopic observations were possible and shows spectral similarities with the well-studied SN 1998bw, having produced a similar Ni mass ($M_{\rm Ni}=0.33\pm 0.02 ~\rm {M_{\odot }}$) with slightly lower ejected mass ($M_{\rm ej}=4.1\pm 0.7~\rm {M_{\odot }}$) and kinetic energy ($E_{\rm K} = 8.1\pm 2.5 \times 10^{51} ~\rm {erg}$). The host-galaxy is bigger in size than typical GRB host galaxies, but the analysis of the region hosting the GRB revealed spectral properties typically observed in GRB hosts and showed that the progenitor of this event was located in a very bright H ii region of its face-on host galaxy, at a projected distance of ∼ 10 kpc from its galactic centre. The star-formation rate (SFRGRB ∼ 0.2 M⊙ yr−1) and metallicity (12  + log(O/H) ∼8.15 ± 0.10) of the GRB star-forming region are consistent with those of the host galaxies of previously studied GRB–SN systems.


2008 ◽  
Vol 4 (S254) ◽  
pp. 41-48
Author(s):  
Johan P. U. Fynbo ◽  
J. Xavier Prochaska ◽  
Jesper Sommer-Larsen ◽  
Miroslava Dessauges-Zavadsky ◽  
Palle Møller

AbstractWe test the hypothesis that the host galaxies of long-duration gamma-ray bursts (GRBs) as well as quasar-selected damped Lyman-α (DLA) systems are drawn from the population of UV-selected star-forming, highzgalaxies (generally referred to as Lyman-break galaxies). Specifically, we compare the metallicity distributions of the GRB and DLA populations against simple disk models where these galaxies are drawn randomly from the distribution of star-forming galaxies according to their star-formation rate and HI cross-section respectively. We find that it is possible to match both observational distributions assuming very simple and constrained relations between luminosity, metallicity, metallicity gradients and HI sizes. The simple model can be tested by observing the luminosity distribution of GRB host galaxies and by measuring the luminosity and impact parameters of DLA selected galaxies as a function of metallicity. Our results support the expectation that GRB and DLA samples, in contrast with magnitude limited surveys, provide an almost complete census of star-forming galaxies atz≈ 3.


2012 ◽  
Vol 8 (S292) ◽  
pp. 190-190
Author(s):  
J. M. Chen ◽  
L. W. Jia ◽  
E. W. Liang

AbstractGRBs are the most luminous events in the Universe. They are detectable from local to high-z universe and may serve as probes for high-z galaxies (e.g., Savaglio et al. 2009; Kewley & Dopita 2002). We compile the observations for 61 GRB host galaxies from literature. Their redshifts range from 0.0085 to 6.295. We present the statistical properties of the GRB host galaxies, including the stellar mass (M*), star-forming rate (SFR), metallicity (Z), extinction (AV), and neutral hydrogen column density (NH). We explore possible correlations among the properties of gamma-ray burst host galaxies and their cosmic evolution with observations of 61 GRB host galaxies. Our results are shown in Figure 1. A clear Z-M* relation is found in our sample, which is Z ~ M0.4. The host galaxies of local GRBs with detection of accompanied supernovae also share the same relation with high-z GRB host galaxies. A trend that a more massive host galaxy tends to have a higher star-formation rate is found. The best linear fit gives a tentative relation, i.e, SFR ~ M0.75. No any correlation is found between AV and NH. A GRB host galaxy at a higher redshift also tends to have a higher SFR. Even in the same redshift, the SFR may vary over three orders of magnitude. The metallicity of the GRB host galaxies is statistically higher than that of the QSO DLAs. The full version of our results please refer to Chen et al. (2012).


2020 ◽  
Vol 495 (4) ◽  
pp. 4782-4799 ◽  
Author(s):  
Brendan O’Connor ◽  
Paz Beniamini ◽  
Chryssa Kouveliotou

ABSTRACT Observational follow up of well localized short gamma-ray bursts (SGRBs) has left $20\!-\!30{{\ \rm per\ cent}}$ of the population without a coincident host galaxy association to deep optical and NIR limits (≳26 mag). These SGRBs have been classified as observationally hostless due to their lack of strong host associations. It has been argued that these hostless SGRBs could be an indication of the large distances traversed by the binary neutron star system (due to natal kicks) between its formation and its merger (leading to an SGRB). The distances of GRBs from their host galaxies can be indirectly probed by the surrounding circumburst densities. We show that a lower limit on those densities can be obtained from early afterglow light curves. We find that ${\lesssim}16{{\ \rm per\ cent}}$ of short GRBs in our sample took place at densities ≲10−4 cm−3. These densities represent the expected range of values at distances greater than the host galaxy’s virial radii. We find that out of the five SGRBs in our sample that have been found to be observationally hostless, none are consistent with having occurred beyond the virial radius of their birth galaxies. This implies one of two scenarios. Either these observationally hostless SGRBs occurred outside of the half-light radius of their host galaxy, but well within the galactic halo, or in host galaxies at moderate to high redshifts (z ≳ 2) that were missed by follow-up observations.


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