A5001557702- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- SAS software applications and methods
- Astrophysical Phenomena and Observations
- Galaxies: Formation, Evolution, Phenomena
- Astronomical Observations and Instrumentation
- Pulsars and Gravitational Waves Research
- Astrophysics and Cosmic Phenomena
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Adaptive optics and wavefront sensing
- Cosmology and Gravitation Theories
- Geophysics and Gravity Measurements
- CCD and CMOS Imaging Sensors
- Statistical Mechanics and Entropy
- Solar and Space Plasma Dynamics
- Calibration and Measurement Techniques
- Scientific Research and Discoveries
- Advanced X-ray and CT Imaging
- Neutrino Physics Research
- Microbial Metabolites in Food Biotechnology
- Statistical and numerical algorithms
- Radio Astronomy Observations and Technology
- Particle Detector Development and Performance
University of Copenhagen
2016-2025
Aarhus University
1979-2020
National Bureau of Investigation
2019
Joint Research Centre
1998-2019
Instituto de Astrofísica de Andalucía
2018
Centre for Cosmology and Particle Physics Phenomenology
2011-2012
University of Iceland
2009-2011
European Space Astronomy Centre
2009
AlbaNova
2009
University of Oslo
2009
X-shooter is the first 2nd generation instrument of ESO Very Large Telescope(VLT). It a very efficient, single-target, intermediate-resolution spectrograph that was installed at Cassegrain focus UT2 in 2009. The covers, single exposure, spectral range from 300 to 2500 nm. designed maximize sensitivity this through dichroic splitting three arms with optimized optics, coatings, dispersive elements and detectors. operates intermediate resolution (R~4,000 - 17,000, depending on wavelength slit...
Abstract We report the discovery and monitoring of near-infrared counterpart (AT2017gfo) a binary neutron-star merger event detected as gravitational wave source by Advanced Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo (GW170817) short gamma-ray burst Fermi Gamma-ray Burst Monitor (GBM) Integral SPI-ACS (GRB 170817A). The evolution transient light is consistent with predictions for behavior “kilonova/macronova” powered radioactive decay massive neutron-rich nuclides...
Gamma-ray bursts (GRBs) serve as powerful probes of the early Universe, with their luminous afterglows revealing locations and physical properties star forming galaxies at highest redshifts, potentially locating first generation (Population III) stars. Since GRB have intrinsically very simple spectra, they allow robust redshifts from low signal to noise spectroscopy, or photometry. Here we present a photometric redshift z~9.4 for Swift-detected 090429B based on deep observations...
Variable X-ray and gamma-ray emission is characteristic of the most extreme physical processes in Universe, studying sources these energetic photons has been a major driver astronomy for past 50 years. Here we present multiwavelength observations unique selected transient, discovered by Swift, which was accompanied bright across electromagnetic spectrum, whose properties are unlike any previously observed source. We pinpoint event to center small, star-forming galaxy at redshift z=0.3534....
We have gathered optical photometry data from the literature on a large sample of Swift-era gamma-ray burst (GRB) afterglows including GRBs up to September 2009, for total 76 GRBs, and present an additional three pre-Swift not included in earlier sample. Furthermore, we publish 840 new points 42 GRB afterglows, sets 050319, 050408, 050802, 050820A, 050922C, 060418, 080413A 080810. analyzed light curves all derived spectral energy distributions with best quality, allowing us estimate host...
(Abridged). We present a sample of 77 optical afterglows (OAs) Swift detected GRBs for which spectroscopic follow-up observations have been secured. provide linelists and equivalent widths all lines redward Ly-alpha. discuss to what extent the current bursts with OA spectroscopy is biased subsample GRBs. For that purpose we define an X-ray selected optimal conditions ground-based follow up from period March 2005 September 2008; 146 fulfill our criteria. derive redshift distribution this...
We present comprehensive multiwavelength observations of three gamma-ray bursts (GRBs) with durations several thousand seconds. demonstrate that these events are extragalactic transients; in particular we resolve the long-standing conundrum distance GRB 101225A (the "Christmas-day burst"), finding it to have a redshift z=0.847, and showing two apparently similar (GRB 111209A 121027A) lie at z=0.677 z=1.773 respectively. The systems show extremely unusual X-ray optical lightcurves, very...
In 1964, Refsdal hypothesized that a supernova whose light traversed multiple paths around strong gravitational lens could be used to measure the rate of cosmic expansion. We report discovery such system. Hubble Space Telescope imaging, we have found four images single forming an Einstein cross configuration redshift z=0.54 elliptical galaxy in MACS J1149.6+2223 cluster. The cluster's potential also creates z=1.49 spiral host galaxy, and future appearance elsewhere cluster field is expected....
The double explosion of SN 2009ip in 2012 raises questions about our understanding the late stages massive star evolution. Here we present a comprehensive study during its remarkable rebrightenings. High-cadence photometric and spectroscopic observations from GeV to radio band obtained variety ground-based space facilities (including Very Large Array, Swift, Fermi, Hubble Space Telescope, XMM) constrain be low energy (E ∼ 1050 erg for an ejecta mass ∼0.5 M☉) asymmetric complex medium shaped...
We present an analysis of 15 Type Ia supernovae (SNe Ia) at redshift z > 1 (9 1.5 < 2.3) recently discovered in the CANDELS and CLASH Multi-Cycle Treasury programs using WFC3 on Hubble Space Telescope. combine these SNe with a new compilation 1050 Ia, jointly calibrated corrected for simulated survey biases to produce accurate distance measurements. unbiased constraints expansion rate six redshifts range 0.07 based only this combined SN sample. The added leverage our sample leads factor ~3...
Superluminous supernovae (SLSNe) are very bright explosions that were only discovered recently and show a preference for occurring in faint dwarf galaxies. Understanding why stellar evolution yields different types of these environments is fundamental order to both uncover the elusive progenitors SLSNe study star formation In this paper, we present first results our project SUperluminous Supernova Host galaxIES, focusing on sample which have obtained spectroscopy. We SLSNe-I SLSNe-R...
We present observations of the optical afterglow GRB\,170817A, made by {\it Hubble Space Telescope}, between February and August 2018, up to one year after neutron star merger, GW170817. The shows a rapid decline beyond $170$~days, confirms jet origin for observed outflow, in contrast more slowly declining expectations `failed-jet' scenarios. show here that broadband (radio, optical, X-ray) is consistent with structured outflow where an ultra-relativistic jet, Lorentz factor...
We present panchromatic observations and modeling of supernova (SN) 2020tlf, the first normal type II-P/L SN with confirmed precursor emission, as detected by Young Supernova Experiment transient survey Pan-STARRS1 telescope. Pre-explosion emission was in $riz-$bands at 130 days prior to 2020tlf persisted relatively constant flux until light. Soon after discovery, "flash" spectroscopy revealed prominent narrow symmetric lines ($v_w < 300$ km s$^{-1}$) that resulted from photo-ionization...
The mergers of binary compact objects such as neutron stars and black holes are central interest to several areas astrophysics, including the progenitors gamma-ray bursts (GRBs), sources high-frequency gravitational waves likely production sites for heavy element nucleosynthesis via rapid capture (the r-process). These elements include some great geophysical, biological cultural importance, thorium, iodine gold. Here we present observations exceptionally bright burst GRB 230307A. We show...
Ultraviolet light from early galaxies is thought to have ionized gas in the intergalactic medium. However, there are few observational constraints on this epoch because of faintness those and redshift their optical into infrared. We report observation, JWST imaging, a distant galaxy that magnified by gravitational lensing. spectroscopy galaxy, at rest-frame wavelengths, detects strong nebular emission lines attributable oxygen hydrogen. The measured z = 9.51 ± 0.01, corresponding 510 million...