@article{discovery10190966,
           pages = {1--19},
            note = {{\copyright} 2024 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.},
       publisher = {Oxford University Press (OUP)},
            year = {2024},
         journal = {Monthly Notices of the Royal Astronomical Society},
           title = {Multiband analyses of the bright GRB 230812B and the associated SN2023pel},
           month = {May},
          number = {1},
          volume = {530},
        keywords = {methods: statistical, techniques: photometric, techniques: spectroscopic, gamma-ray burst: individual: GRB 230812B, gamma-ray bursts, transients: supernovae},
        abstract = {GRB 230812B is a bright and relatively nearby (z = 0.36) long gamma-ray burst (GRB) that has generated significant interest in the community and has thus been observed over the entire electromagnetic spectrum. We report over 80 observations in X-ray, ultraviolet, optical, infrared, and submillimetre bands from the GRANDMA (Global Rapid Advanced Network for Multimessenger Addicts) network of observatories and from observational partners. Adding complementary data from the literature, we then derive essential physical parameters associated with the ejecta and external properties (i.e. the geometry and environment) of the GRB and compare with other analyses of this event. We spectroscopically confirm the presence of an associated supernova, SN2023pel, and we derive a photospheric expansion velocity of v {$\sim$} 17 {$\times$} 103 km s-1. We analyse the photometric data first using empirical fits of the flux and then with full Bayesian inference. We again strongly establish the presence of a supernova in the data, with a maximum (pseudo-)bolometric luminosity of 5.75 {$\times$} 1042 erg s-1, at 15.76+-10.2181 d (in the observer frame) after the trigger, with a half-max time width of 22.0 d. We compare these values with those of SN1998bw, SN2006aj, and SN2013dx. Our best-fitting model favours a very low density environment (log10(nISM/cm-3) = -2.38+-11.6045) and small values for the jet's core angle {\ensuremath{\theta}}core = 1.54+-01.8102 deg and viewing angle {\ensuremath{\theta}}obs = 0.76+-01.7629 deg. GRB 230812B is thus one of the best observed afterglows with a distinctive supernova bump.},
          author = {Hussenot-Desenonges, T and Wouters, T and Guessoum, N and Abdi, I and Abulwfa, A and Adami, C and Ag{\"u}{\'i} Fern{\'a}ndez, JF and Ahumada, T and Aivazyan, V and Akl, D and Anand, S and Andrade, CM and Antier, S and Ata, SA and D'Avanzo, P and Azzam, YA and Baransky, A and Basa, S and Blazek, M and Bendjoya, P and Beradze, S and Boumis, P and Bremer, M and Brivio, R and Buat, V and Bulla, M and Burkhonov, O and Burns, E and Cenko, SB and Coughlin, MW and Corradi, W and Daigne, F and Dietrich, T and Dornic, D and Ducoin, JG and Duverne, PA and Elhosseiny, EG and Elnagahy, FI and El-Sadek, MA and Ferro, M and Le Floc'H, E and Freeberg, M and Fynbo, JPU and G{\"o}tz, D and Gurbanov, E and Hamed, GM and Hasanov, E and Healy, BF and Heintz, KE and Hello, P and Inasaridze, R and Iskandar, A and Ismailov, N and Izzo, L and Jhawar, S and Jegou du Laz, T and Kamel, TM and Karpov, S and Klotz, A and Koulouridis, E and Kuin, NP and Kochiashvili, N and Leonini, S and Lu, KX and Malesani, DB and Ma{\vs}ek, M and Mao, J and Melandri, A and Mihov, BM and Natsvlishvili, R and Navarete, F and Nedora, V and Nicolas, J and Odeh, M and Palmerio, J and Pang, PTH and De Pasquale, M and Peng, HW and Pormente, S and Peloton, J and Pradier, T and Pyshna, O and Rajabov, Y and Rakotondrainibe, NA and Rivet, JP and Rousselot, L and Saccardi, A and Sasaki, N and Schneider, B and Serrau, M and Shokry, A and Slavcheva-Mihova, L and Simon, A and Sokoliuk, O and Srinivasaragavan, G and Strausbaugh, R and Takey, A and Tanvir, NR and Th{\"o}ne, CC and Tillayev, Y},
            issn = {0035-8711},
             url = {http://dx.doi.org/10.1093/mnras/stae503}
}