Highly luminous supernovae associated with gamma-ray bursts

Abstract

Context. GRB 111209A, one of the longest gamma-ray bursts (GRBs) ever observed, is linked to SN 2011kl, which is the most luminous GRB supernova (SN) detected so far. Several lines of evidence indicate that this GRB-SN is powered by a magnetar central engine. Aims. We place SN 2011kl into the context of large samples of SNe, addressing in more detail the question of whether this GRB-SN could be radioactively powered, and whether it represents an extreme version of a GRB-SN or an underluminous superluminous SN (SLSN). Methods. We modelled SN 2011kl using SN 1998bw as a template and derived a bolometric light curve including near-infrared data. We compared the properties of SN 2011kl to literature results on stripped-envelope and SLSNe. Results. A comparison in the k, s context, i.e. comparing SN 2011kl to SN 1998bw templates in terms of luminosity and light-curve stretch, clearly shows SN 2011kl is the most luminous GRB-SN to date and is spectrally very dissimilar to other events because it is significantly bluer/hotter. Although SN 2011kl does not reach the classical luminosity threshold of SLSNe and evolves faster than any of these objects, it resembles SLSNe more than the classical GRB-associated broad-lined Type Ic SNe in several aspects. Conclusions. GRB 111209A was a very energetic event, both at early (prompt emission) and at very late (SN) times. We show in a companion publication that with the exception of the extreme duration, the GRB and afterglow parameters are in agreement with the known distributions for these parameters. SN 2011kl, on the other hand, is exceptional both in luminosity and spectral characteristics, indicating that GRB 111209A was likely not powered by a standard-model collapsar central engine, further supporting our earlier conclusions. Instead, it reveals the possibility of a direct link between GRBs and SLSNe.

Broad-lined type Ic supernova iPTF16asu: A challenge to all popular models

“…iPTF16asu was discovered by the intermediate Palomar Transient Factory (iPTF; Law et al 2009;Cao et al 2016;Masci et al 2017) on 2016 May 11.26 UT. It represents one of the most luminous type Ic SNe, with an absolute magnitude of −20.4 mag in g band, similar to the luminous transients (Drout et al 2011(Drout et al , 2014Greiner et al 2015;Wang et al 2015b;Arcavi et al 2016;Kann et al 2019) discovered recently. Thanks to the wide field and high cadence of iPTF, the rapid rise of the light curve of iPTF16asu (4 days to peak luminosity since the discovery) was captured.…”

The Koala: A Fast Blue Optical Transient with Luminous Radio Emission from a Starburst Dwarf Galaxy at z = 0.27

“…Note that the peak mag of iPTF15ul includes a large host-galaxy extinction correction, whereas the other sources have zero host extinction correction. Also note that SN 2011kl was associated with an ultra-long duration GRB 111209A (Kann et al 2018), and the light-curve properties shown here reflect the afterglowsubtracted light curve (Kann et al 2019). On 2019 January 4 (+115 days), we obtained a spectrum of the host galaxy of ZTF18abvkwla using the Low Resolution Imaging Spectrometer (Oke et al 1995;McCarthy et al 1998) on the Keck I 10 m telescope, with the 400/3400 grism in the blue camera and the 400/8500 grating in the red camera.…”

Studying the environment of AT 2018cow with MUSE

“…This results in the typically larger explosion energies and luminosities and temperatures of GRB-SNe cf. standard CCSNe (Lyman et al 2016;Modjaz et al 2016;Kann et al 2019;Taddia et al 2019). The geometric alignment of these bi-polar jets and the Earth may be the single greatest factor in determining whether a GRB is detected associated with a collapsar SN.…”