ORCID Profile
0000-0001-8005-4030
Current Organisation
Stockholm University
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Publisher: American Astronomical Society
Date: 06-07-2015
Publisher: EDP Sciences
Date: 12-2022
DOI: 10.1051/0004-6361/202244134
Abstract: We present the first results of a comprehensive supernova (SN) radiative-transfer (RT) code-comparison initiative (StaNdaRT), where the emission from the same set of standardised test models is simulated by currently used RT codes. We ran a total of ten codes on a set of four benchmark ejecta models of Type Ia SNe. We consider two sub-Chandrasekhar-mass ( M tot = 1.0 M ⊙ ) toy models with analytic density and composition profiles and two Chandrasekhar-mass delayed-detonation models that are outcomes of hydrodynamical simulations. We adopt spherical symmetry for all four models. The results of the different codes, including the light curves, spectra, and the evolution of several physical properties as a function of radius and time are provided in electronic form in a standard format via a public repository. We also include the detailed test model profiles and several Python scripts for accessing and presenting the input and output files. We also provide the code used to generate the toy models studied here. In this paper, we describe the test models, radiative-transfer codes, and output formats in detail, and provide access to the repository. We present ex le results of several key diagnostic features.
Publisher: Oxford University Press (OUP)
Date: 29-08-2017
Publisher: American Astronomical Society
Date: 28-08-2019
Publisher: American Astronomical Society
Date: 09-02-2015
Publisher: American Astronomical Society
Date: 19-08-2016
Publisher: American Astronomical Society
Date: 13-09-2018
Publisher: American Astronomical Society
Date: 09-01-2015
Publisher: Oxford University Press (OUP)
Date: 18-01-2018
Publisher: American Astronomical Society
Date: 31-10-2019
Publisher: Oxford University Press (OUP)
Date: 05-06-2013
DOI: 10.1093/MNRAS/STT813
Publisher: American Astronomical Society
Date: 09-11-2018
Publisher: Oxford University Press (OUP)
Date: 26-11-2015
Publisher: Springer Science and Business Media LLC
Date: 16-10-2017
DOI: 10.1038/NATURE24303
Abstract: Gravitational waves were discovered with the detection of binary black-hole mergers and they should also be detectable from lower-mass neutron-star mergers. These are predicted to eject material rich in heavy radioactive isotopes that can power an electromagnetic signal. This signal is luminous at optical and infrared wavelengths and is called a kilonova. The gravitational-wave source GW170817 arose from a binary neutron-star merger in the nearby Universe with a relatively well confined sky position and distance estimate. Here we report observations and physical modelling of a rapidly fading electromagnetic transient in the galaxy NGC 4993, which is spatially coincident with GW170817 and with a weak, short γ-ray burst. The transient has physical parameters that broadly match the theoretical predictions of blue kilonovae from neutron-star mergers. The emitted electromagnetic radiation can be explained with an ejected mass of 0.04 ± 0.01 solar masses, with an opacity of less than 0.5 square centimetres per gram, at a velocity of 0.2 ± 0.1 times light speed. The power source is constrained to have a power-law slope of -1.2 ± 0.3, consistent with radioactive powering from r-process nuclides. (The r-process is a series of neutron capture reactions that synthesise many of the elements heavier than iron.) We identify line features in the spectra that are consistent with light r-process elements (atomic masses of 90-140). As it fades, the transient rapidly becomes red, and a higher-opacity, lanthanide-rich ejecta component may contribute to the emission. This indicates that neutron-star mergers produce gravitational waves and radioactively powered kilonovae, and are a nucleosynthetic source of the r-process elements.
Publisher: Oxford University Press (OUP)
Date: 18-03-2020
Abstract: Comparison of theoretical line profiles to observations provides important tests for supernova explosion models. We study the shapes of radioactive decay lines predicted by current 3D core-collapse explosion simulations, and compare these to observations of SN 1987A and Cas A. Both the widths and shifts of decay lines vary by several thousand kilometres per second depending on viewing angle. The line profiles can be complex with multiple peaks. By combining observational constraints from 56Co decay lines, 44Ti decay lines, and Fe IR lines, we delineate a picture of the morphology of the explosive burning ashes in SN 1987A. For MZAMS = 15−20 M⊙ progenitors exploding with ∼1.5 × 1051 erg, ejecta structures suitable to reproduce the observations involve a bulk asymmetry of the 56Ni of at least ∼400 km s−1 and a bulk velocity of at least 1500 km s−1. By adding constraints to reproduce the UVOIR bolometric light curve of SN 1987A up to 600 d, an ejecta mass around 14 M⊙ is favoured. We also investigate whether observed decay lines can constrain the neutron star (NS) kick velocity. The model grid provides a constraint VNS & Vredshift, and applying this to SN 1987A gives a NS kick of at least 500 km s−1. For Cas A, our single model provides a satisfactory fit to the NuSTAR observations and reinforces the result that current neutrino-driven core-collapse SN models achieve enough bulk asymmetry in the explosive burning material. Finally, we investigate the internal gamma-ray field and energy deposition, and compare the 3D models to 1D approximations.
Publisher: EDP Sciences
Date: 26-09-2017
Publisher: Oxford University Press (OUP)
Date: 29-10-2013
Publisher: Oxford University Press (OUP)
Date: 30-03-2018
DOI: 10.1093/MNRAS/STY820
Publisher: Oxford University Press (OUP)
Date: 27-02-2015
DOI: 10.1093/MNRAS/STV106
Publisher: Oxford University Press (OUP)
Date: 04-07-2016
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Anders Jerkstrand.