A5017722240- Galaxies: Formation, Evolution, Phenomena
- Gamma-ray bursts and supernovae
- Astronomy and Astrophysical Research
- Cosmology and Gravitation Theories
- Astrophysics and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Pulsars and Gravitational Waves Research
- Dark Matter and Cosmic Phenomena
- Scientific Research and Discoveries
- Remote Sensing in Agriculture
- Advanced Vision and Imaging
- Radio Astronomy Observations and Technology
- Impact of Light on Environment and Health
- Computational Physics and Python Applications
- Astrophysics and Star Formation Studies
- Plant Water Relations and Carbon Dynamics
- Astrophysical Phenomena and Observations
- Relativity and Gravitational Theory
- Black Holes and Theoretical Physics
- Electron and X-Ray Spectroscopy Techniques
- Particle Detector Development and Performance
- Advanced Thermodynamics and Statistical Mechanics
- Medical Imaging Techniques and Applications
- Leaf Properties and Growth Measurement
- Anomaly Detection Techniques and Applications
University of Copenhagen
2015-2024
Kavli Institute for Particle Astrophysics and Cosmology
2014-2018
Stanford University
2015-2018
SLAC National Accelerator Laboratory
2014-2018
Centre for Cosmology and Particle Physics Phenomenology
2014-2015
Nicolaus Copernicus Astronomical Center
2007-2010
Jagiellonian University
2005-2006
The historic detection of gravitational waves from a binary neutron star merger (GW170817) and its electromagnetic counterpart led to the first accurate (sub-arcsecond) localization gravitational-wave event. transient was found be $\sim$10" nucleus S0 galaxy NGC 4993. We report here luminosity distance this using two independent methods. (1) Based on our MUSE/VLT measurement heliocentric redshift ($z_{\rm helio}=0.009783\pm0.000023$) we infer systemic recession velocity 4993 group galaxies...
Time domain science has undergone a revolution over the past decade, with tens of thousands new supernovae (SNe) discovered each year. However, several observational domains, including SNe within days or hours explosion and faint, red transients, are just beginning to be explored. Here, we present Young Supernova Experiment (YSE), novel optical time-domain survey on Pan-STARRS telescopes. Our is designed obtain well-sampled $griz$ light curves for transient events up $z \approx 0.2$. This...
We present the Young Supernova Experiment Data Release 1 (YSE DR1), comprised of processed multi-color Pan-STARRS1 (PS1) griz and Zwicky Transient Facility (ZTF) gr photometry 1975 transients with host-galaxy associations, redshifts, spectroscopic/photometric classifications, additional data products from 2019 November 24 to 2021 December 20. YSE DR1 spans discoveries observations young fast-rising supernovae (SNe) that persist for over a year, redshift distribution reaching z~0.5. relative...
We study the kinematics of satellites around isolated galaxies selected from Sloan Digital Sky Survey spectroscopic catalogue. Using a model phase-space density previously measured for haloes Λ cold dark matter (ΛCDM) cosmological simulations, we determine properties halo mass distribution and orbital anisotropy as function colour-based morphological type stellar central host galaxy. place constraints on concentration parameter satellite number profiles. obtain concentration–mass relation...
This article is the second in a series which we perform an extensive comparison of various galaxy-based cluster mass estimation techniques that utilise positions, velocities and colours galaxies. Our aim to quantify scatter, systematic bias completeness masses derived from diverse set 25 methods using two contrasting mock galaxy catalogues based on sophisticated halo occupation model semi-analytic model. Analysing 968 clusters, find wide range RMS errors log M200c delivered by different...
This paper is the first in a series which we perform an extensive comparison of various galaxy-based cluster mass estimation techniques that utilise positions, velocities and colours galaxies. Our primary aim to test performance these on diverse set models will increase complexity. We begin by providing participating methods with data from simple model delivers idealised clusters, enabling us quantify underlying scatter intrinsic techniques. The mock catalogue based Halo Occupation...
We reanalyse observations of type Ia supernovae (SNe) and Cepheids used in the local determination Hubble constant find strong evidence that SN standardisation calibration sample (galaxies with observed Cepheids) require a steeper slope colour correction than cosmological flow). The is consistent being entirely due to an extinction dust properties similar Milky Way (R_B~4.6+/-0.4) there no for intrinsic scatter peak magnitudes. An immediate consequence this finding measurement becomes...
Supernovae (SNe) that have been multiply-imaged by gravitational lensing are rare and powerful probes for cosmology. Each detection is an opportunity to develop the critical tools methodologies needed as sample of lensed SNe increases orders magnitude with upcoming Vera C. Rubin Observatory Nancy Grace Roman Space Telescope. The latest such discovery quadruply-imaged Type Ia SN 2022qmx (aka, "SN Zwicky") at $z=0.3544$. Zwicky was discovered Transient Facility (ZTF) in spatially unresolved...
ABSTRACT The currently used standardization of Type Ia supernovae results in Hubble residuals whose physical origin is unaccounted for. Here, we present a complete interpretation the based on novel Bayesian hierarchical model which latent variables describing intrinsic and extrinsic (dust related) supernova properties originate from two populations. Fitting to SALT2 light-curve parameters flow find strong (4σ) evidence for presence overlapping, but distinct, populations differentiated...
We analyse kinematic data of 41 nearby (z < 0.1) relaxed galaxy clusters in terms the projected phase-space density using a phenomenological, fully anisotropic model distribution function. apply Markov Chain Monte Carlo approach to place constraints on total mass approximated by universal Navarro, Frenk and White (NFW) profile anisotropy orbits. find normalization mean mass–concentration relation is c= 6.9+0.6−0.7 at virial Mv= 5 × 1014 M⊙. By comparison with calibration from cosmological...
The increasing precision in the determination of Hubble parameter has reached a per cent level at which large-scale cosmic flows induced by inhomogeneities matter distribution become non-negligible. Here we use cosmological N-body simulations to study statistical properties local as measured observers. We show that depends not only on scale inhomogeneities, but also how one defines positions observers web and what reference frame is used. Observers located random dark haloes measure average...
Strongly lensed supernovae can be detected as multiply imaged or highly magnified transients. In order to compare the performances of these two observational strategies, we calculate expected discovery rates a function survey depth in five grizy filters and for different classes (Ia, IIP, IIL, Ibc IIn). We find that detections via magnification is only effective strategy relatively shallow pre-LSST surveys. For depths about LSST capacity, both strategies yield comparable numbers supernovae....
Persistent tension between low-redshift observations and the Cosmic Microwave Background radiation (CMB), in terms of two fundamental distance scales set by sound horizon $r_d$ Hubble constant $H_0$, suggests new physics beyond Standard Model or residual systematics. We examine recently updated calibrations from Cepheids, gravitational lensing time-delay observations, Tip Red Giant Branch. Calibrating Baryon Acoustic Oscillations (BAO) Type Ia supernovae with combinations indicators, we...
We present a new calibration of the peak absolute magnitude SNe Type Ia based on Surface Brightness Fluctuations (SBF) method, aimed at measuring value Hubble constant. build sample calibrating anchors consisting 24 hosted in galaxies having SBF distance measurements. Applying hierarchical Bayesian approach, we calibrate luminosity and extend it into flow by using 96 redshift range $0.02 < z 0.075$, extracted from Combined Pantheon Sample. estimate $H_0 = 70.50 \pm 2.37(stat) 3.38(sys)$...
Aims. The aim of this paper is to study the efficiency different approaches interloper treatment in dynamical modelling galaxy clusters.
We study the distribution function (DF) of dark matter particles in haloes mass range 10^{14}--10^{15}\Msun. In numerical part this work we measure DF for a sample relaxed formed simulation standard \LambdaCDM model. The is expressed as energy E and absolute value angular momentum L, form suitable comparison with theoretical models. By proper scaling obtain results that do not depend on virial haloes. demonstrate can be separated into components propose phenomenological model...
Abstract The Hubble constant H 0 and matter density Ω m of the universe are measured using latest γ -ray attenuation results from Fermi -LAT Cerenkov telescopes. This methodology is based upon fact that extragalactic background light supplies opacity for very high energy photons via photon–photon interaction. amount along line sight depends on expansion rate content universe. novel strategy in a value <?CDATA ${H}_{0}={67.4}_{-6.2}^{+6.0}$?> km s −1 Mpc ${{\rm{\Omega...
While gravitational wave (GW) standard sirens from neutron star (NS) mergers have been proposed to offer good measurements of the Hubble constant, we show in this paper how a variation expanding photosphere method (EPM) or spectral-fitting atmosphere method, applied kilonovae (KNe) associated with mergers, can provide an independent distance measurement individual that is potentially accurate within few percent. There are four reasons why KN-EPM overcomes major uncertainties commonly...
We study the mass distribution in six nearby (z<0.06) relaxed Abell clusters of galaxies A0262, A0496, A1060, A2199, A3158 and A3558. Given dominance dark matter galaxy we approximate their total density by NFW formula characterized virial concentration. also assume that anisotropy galactic orbits is reasonably well described a constant traces density. Using velocity position data for 120-420 per cluster calculate, after removal interlopers, profiles lowest-order even moments, dispersion...
The mass measurement of galaxy clusters is an important tool for the determination cosmological parameters describing matter and energy content Universe. However, standard methods rely on various assumptions about shape or level equilibrium cluster. We present a novel method measuring cluster masses. It complementary to most other methods, since it only uses kinematical information from outside virialized Our identifies objects, as sheets filaments, in outer region, infers by modeling how...
In the standard approach to studying cosmological structure formation, overall expansion of Universe is assumed be homogeneous, with gravitational effect inhomogeneities encoded entirely in a Newtonian potential. A topic ongoing debate what degree this fully captures dynamics dictated by general relativity, especially era precision cosmology. To quantitatively assess this, we directly compare N-body calculations full numerical solutions Einstein equations, for cold matter various magnitude...
With the advent of wide-field cosmological surveys, we are approaching samples hundreds thousands galaxy clusters. While such large numbers will help reduce statistical uncertainties, control systematics in cluster masses is crucial. Here examine effects an important source systematic uncertainty galaxy-based mass estimation techniques: presence significant dynamical substructure. Dynamical substructure manifests as dynamically distinct subgroups phase-space, indicating 'unrelaxed' state....
The primary difficulty in measuring dynamical masses of galaxy clusters from data lies the separation between true cluster members interloping galaxies along line sight. We study impact membership contamination and incompleteness on mass estimates obtained with 25 commonly used techniques applied to nearly 1000 mock clusters. show that all methods overestimate or underestimate when contaminated incomplete samples respectively. This appears be main source intrinsic scatter scaling relation....