A5023589580- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Star Formation Studies
- Pulsars and Gravitational Waves Research
- SAS software applications and methods
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Astro and Planetary Science
- Adaptive optics and wavefront sensing
- Advanced X-ray and CT Imaging
- Particle Detector Development and Performance
- CCD and CMOS Imaging Sensors
- Nuclear Physics and Applications
- Radio Astronomy Observations and Technology
- Calibration and Measurement Techniques
- Neural and Behavioral Psychology Studies
- Cosmology and Gravitation Theories
- Atmospheric Ozone and Climate
- Scientific Research and Discoveries
- Geophysics and Gravity Measurements
- History and Developments in Astronomy
- Solar and Space Plasma Dynamics
University of Copenhagen
2016-2025
DAWN Center for Independent Living
2019-2024
Kennedy Center
2018-2024
Brera Astronomical Observatory
2022
Technical University of Denmark
2018-2019
Kazan Federal University
2018
Czech Technical University in Prague
2018
Centre for Cosmology and Particle Physics Phenomenology
2015
University of Warwick
2010-2014
Center for Astrophysics Harvard & Smithsonian
2013
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...
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...
We present deep spectroscopy of 17 very low mass (M⋆ ≃ 2.0 × 106–1.4 109 M⊙) and luminosity (MUV −13.7 to −19.9) gravitationally lensed galaxies in the redshift range z 1.5-3.0. Deep rest-frame ultraviolet spectra reveal large equivalent width emission from numerous lines (N iv], O iii], C iv, Si iii]) which are rarely seen individual more massive star-forming galaxies. iii] is detected 16 low-mass systems with widths as 13.5 Å. Nebular iv most extreme emitters, requiring an ionizing source...
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...
Primordial neutral atomic gas, mostly composed of hydrogen, is the raw material for star formation in galaxies. However, there are few direct constraints on amount hydrogen (H i ) galaxies at early cosmic times. We analyzed James Webb Space Telescope (JWST) near-infrared spectroscopy distant galaxies, redshifts ≳8. From a sample 12 we identified three that show strong damped Lyman-α absorption due to H their local surroundings. The located spectroscopic 8.8, 10.2, and 11.4, corresponding 400...
The exceptionally high luminosities of gamma-ray bursts (GRBs), gradually emerging as extremely useful probes star formation, make them promising tools for exploration the high-redshift Universe. Here we present a carefully selected sample Swift GRBs, intended to estimate in an unbiased way GRB mean redshift (), constraints on fraction and upper limit heavily obscured afterglows. We find that at least 7% GRBs originate . In addition, consistent with pre-Swift observations, most 20%...
The nature of galaxies selected at submillimeter wavelengths (SMGs, S_850 > 3 mJy), some the bolometrically most luminous objects high redshifts, is still elusive. In particular their star formation histories and source emission are not accurately constrained. this paper we introduce a new approach to analyse SMG data. Namely, present first self-consistent UV-to-radio spectral energy distribution fits 76 SMGs with spectroscopic redshifts using all photometric datapoints from ultraviolet...
The <i>Swift</i> X-ray Telescope (XRT) is designed to make astrometric, spectroscopic, and photometric observations of emission from Gamma-ray Bursts their afterglows in the energy band 0.2-10 keV. In order provide rapid-response, automated these randomly occurring objects without ground intervention, XRT must be able observe covering some seven orders magnitude flux, extracting maximum possible science each one. This requires a variety readout modes optimise information collected response...
We report on the detection by Swift of GRB 080913, and subsequent optical/near-infrared follow-up observations GROND, which led to discovery its optical/NIR afterglow recognition high-z nature via a spectral break between i' z' bands. Spectroscopy obtained at ESO-VLT revealed continuum extending down λ = 9400 Å, zero flux for 7500 Å<λ < we interpret as onset Gunn–Peterson trough z 6.695± 0.025 (95.5% confidence level), making 080913 highest-redshift gamma-ray burst (GRB) date, more distant...
Aims.We present early optical spectroscopy of the afterglow gamma-ray burst GRB 060206 with aim determining metallicity absorber and physical conditions in circumburst medium. We also discuss how GRBs may be important complementary probes cosmic chemical evolution.