485 citations · 1.2k across the 42 of their papers we have counts for
15 papers · 1 filter
Strontium and helium in the kilonova AT2017gfo: Origin of the 1μm feature constrained via NLTE calculations
Aayush Arya, Rasmus Damgaard, Albert Sneppen +4
Mergers of neutron stars are believed to be one of the primary sites for the synthesis of the universe's heavy elements via the rapid neutron capture process. AT2017gfo, the kilono…
Electron impact excitation of Te IV and V and Level Resolved R-matrix Photoionization of Te I - IV with application to modelling of AT2017gfo
Leo P. Mulholland, Catherine A. Ramsbottom, Connor P. Ballance +2
Spectral modelling of kilonovae (KNe) require large amounts of collisional excitation and photoionization atomic data for lowly ionised (neutral, singly and doubly ionised) species…
Light Travel Time Effects in Kilonova Models
F. McNeill, S. A. Sim, C. E. Collins +4
The extremely rapid evolution of kilonovae results in spectra that change on an hourly basis. These spectra are key to understanding the processes occurring within the event, but t…
JWST Spectroscopy of GRB 250702B: An Extremely Rare and Exceptionally Energetic Burst in a Dusty, Massive Galaxy at
Benjamin P. Gompertz, Andrew J. Levan, Tanmoy Laskar +25
We present follow-up observations of the day-long, repeating GRB 250702B with the Near Infrared Spectrograph (NIRSpec) on board the James Webb Space Telescope (JWST). Through the i…
JWST reveals a supernova following a gamma-ray burst at z 7.3
A. J. Levan, B. Schneider, E. Le Floc'h +50
The majority of energetic long-duration gamma-ray bursts (GRBs) are thought to arise from the collapse of massive stars, making them powerful tracers of star formation across cosmi…
The day-long, repeating GRB 250702BDE / EP250702a: A unique extragalactic transient
Andrew J. Levan, Antonio Martin-Carrillo, Tanmoy Laskar +42
Gamma-ray bursts (GRBs) are singular outbursts of high-energy radiation with durations typically lasting from milliseconds to minutes and, in extreme cases, a few hours. They are a…
The optical constants and grain sizes of interstellar dust measured directly using the dust scattered x-ray halo of GRB 221009A
Albert Sneppen, Darach Watson
X-ray scattering is a powerful probe of the optical constants and grain size distribution of interstellar dust. Bright, transient sources are excellent tools for this, since they f…
Helium as an Indicator of the Neutron-Star Merger Remnant Lifetime and its Potential for Equation of State Constraints
Albert Sneppen, Oliver Just, Andreas Bauswein +9
The time until black hole formation in a binary neutron-star (NS) merger contains invaluable information about the nuclear equation of state (EoS) but has thus far been difficult t…
Helium features are inconsistent with the spectral evolution of the kilonova AT2017gfo
Albert Sneppen, Rasmus Damgaard, Darach Watson +3
The spectral features observed in kilonovae (KNe) reveal the elemental composition and the velocity structures of matter ejected from neutron star mergers. In the spectra of the ki…
Emergence hour-by-hour of -process features in the kilonova AT2017gfo
Albert Sneppen, Darach Watson, Rasmus Damgaard +4
The spectral features in the optical/near-infrared counterparts of neutron star mergers (kilonovae, KNe), evolve dramatically on hour timescales. To examine the spectral evolution…
Kilonova evolution -- the rapid emergence of spectral features
Albert Sneppen, Darach Watson, James H. Gillanders +1
Kilonovae (KNe) are one of the fastest types of optical transients known, cooling rapidly in the first few days following their neutron-star merger origin. We show here that KN spe…
Towards inferring the geometry of kilonovae
Christine E. Collins, Luke J. Shingles, Andreas Bauswein +11
Recent analysis of the kilonova, AT2017gfo, has indicated that this event was highly spherical. This may challenge hydrodynamics simulations of binary neutron star mergers, which u…
Discovery of a 760 nm P Cygni line in AT2017gfo: Identification of yttrium in the kilonova photosphere
Albert Sneppen, Darach Watson
Neutron star mergers are believed to be a major cosmological source of rapid neutron-capture elements. The kilonovae associated with neutron star mergers have to date yielded only…
On the Blackbody Spectrum of Kilonovae
Albert Sneppen
The early spectra of the kilonova AT2017gfo have a remarkably smooth blackbody continuum, which reveals information on the thermal properties and radioactive heating within the eje…
Spherical symmetry in the kilonova AT2017gfo/GW170817
Albert Sneppen, Darach Watson, Andreas Bauswein +5
The mergers of neutron stars expel a heavy-element enriched fireball which can be observed as a kilonova. The kilonova's geometry is a key diagnostic of the merger and is dictated…