Discovery of the optical and radio counterpart to the fast X-ray transient EP240315a
ArXiv 2404.1066 (2024)
A lanthanide-rich kilonova in the aftermath of a long gamma-ray burst.
Nature 626:8000 (2024) 742-745
Abstract:
Observationally, kilonovae are astrophysical transients powered by the radioactive decay of nuclei heavier than iron, thought to be synthesized in the merger of two compact objects1-4. Over the first few days, the kilonova evolution is dominated by a large number of radioactive isotopes contributing to the heating rate2,5. On timescales of weeks to months, its behaviour is predicted to differ depending on the ejecta composition and the merger remnant6-8. Previous work has shown that the kilonova associated with gamma-ray burst 230307A is similar to kilonova AT2017gfo (ref. 9), and mid-infrared spectra revealed an emission line at 2.15 micrometres that was attributed to tellurium. Here we report a multi-wavelength analysis, including publicly available James Webb Space Telescope data9 and our own Hubble Space Telescope data, for the same gamma-ray burst. We model its evolution up to two months after the burst and show that, at these late times, the recession of the photospheric radius and the rapidly decaying bolometric luminosity (Lbol ∝ t-2.7±0.4, where t is time) support the recombination of lanthanide-rich ejecta as they cool.GW190425: Pan-STARRS and ATLAS coverage of the skymap and limits on optical emission associated with FRB 20190425A
Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 528:2 (2024) 2299-2307
Exploring the Impact of the Ejecta Velocity Profile on the Evolution of Kilonova: Diversity of the Kilonova Lightcurves
The Astrophysical Journal American Astronomical Society 958:2 (2023) 121
Modelling the spectra of the kilonova AT2017gfo – II: Beyond the photospheric epochs
Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) (2023) stad3688