Speaker
Description
Neutron star (NS) mergers are at the origin of gravitational waves (GW) detected by LIGO/Virgo interferometers. Such events produce a large amount of elements heavier than iron by a rapid neutron capture (r-process) nucleosynthesis. Among these elements, those belonging to the fifth row of the periodic table, in particular from Zr ($Z$ = 40) and Cd ($Z$ = 48), are the greatest contributors to the opacity affecting the kilonovae, after the lanthanides and actinides. In the present work, new atomic structures and radiative parameters (wavelengths and oscillator strengths) are reported for a large number of spectral lines in two selected elements, namely Nb ($Z$ = 41) and Ag ($Z$ = 47) from neutral to triply ionized states. These results were obtained through large-scale atomic structure calculations using the pseudo-relativistic Hartree–Fock method implemented in Cowan code. The results obtained were used to calculate the expansion opacities characterizing the kilonova signal observed resulting from the collision of two NS, for typical conditions corresponding to time after the merger t = 1 day, the temperature in the ejecta T $\le$ 15000 K, and a density of $\rho$ = $10^{−13}$ $\mathrm{g.cm^{−3}}$ . Comparisons with previously published experimental and theoretical studies have shown a good agreement. In terms of quantity and quality, the results presented in this work are the most complete currently available, concerning the atomic data and monochromatic opacities for niobium and silver and are useful for astrophysicists to interpret kilonova spectra.
| Presenting Author | BEN NASR Sirine |
|---|---|
| Presenting Author Email Address | sirinamarouan@gmail.com |
| Presenting Author Affiliation | Atomic physics and Astrophysics, Mons university – UMONS, B-7000 Mons, Belgium |
| Country | Belgium |
| Presenting Author Gender | Female |
