M. Kowalski
A5036614721- Astrophysics and Cosmic Phenomena
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Radio Astronomy Observations and Technology
- Particle physics theoretical and experimental studies
- Astronomy and Astrophysical Research
- Pulsars and Gravitational Waves Research
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Face recognition and analysis
- Galaxies: Formation, Evolution, Phenomena
- Particle Detector Development and Performance
- Atomic and Subatomic Physics Research
- Atmospheric Ozone and Climate
- Solar and Space Plasma Dynamics
- Particle accelerators and beam dynamics
- 3D Shape Modeling and Analysis
- Radio Wave Propagation Studies
- Generative Adversarial Networks and Image Synthesis
- Adaptive optics and wavefront sensing
- Computational Physics and Python Applications
- Ionosphere and magnetosphere dynamics
- Cosmology and Gravitation Theories
Humboldt-Universität zu Berlin
2016-2025
Deutsches Elektronen-Synchrotron DESY
2015-2025
Southern University and Agricultural and Mechanical College
2013-2024
Clark Atlanta University
2012-2024
The University of Texas at Arlington
2018-2024
University of Alaska Anchorage
2008-2024
Providence College
2007-2024
Lawrence Berkeley National Laboratory
2005-2024
Uppsala University
2002-2024
UCLouvain
2023
We present Advanced Camera for Surveys, NICMOS, and Keck adaptive-optics-assisted photometry of 20 Type Ia supernovae (SNe Ia) from the Hubble Space Telescope (HST) Cluster Supernova Survey. The SNe were discovered over redshift interval 0.623 < z 1.415. Of these Ia, 14 pass our strict selection cuts are used in combination with world's sample to derive best current constraints on dark energy. new 10 beyond = 1, thereby nearly doubling statistical weight HST-discovered this redshift. Our...
The Zwicky Transient Facility (ZTF) is a new optical time-domain survey that uses the Palomar 48 inch Schmidt telescope. A custom-built wide-field camera provides 47 deg2 field of view and 8 s readout time, yielding more than an order magnitude improvement in speed relative to its predecessor survey, Factory. We describe design implementation observing system. ZTF data system at Infrared Processing Analysis Center near-real-time reduction identify moving varying objects. outline analysis...
We present a new compilation of Type Ia supernovae (SNe Ia), dataset low-redshift nearby-Hubble-flow SNe and analysis procedures to work with these heterogeneous compilations. This ``Union'' 414 SN Ia, which reduces 307 after selection cuts, includes the recent large samples from Supernova Legacy Survey ESSENCE Survey, older datasets, as well recently extended distant observed HST. A single, consistent blind procedure is used for all various subsamples, implemented that consistently weights...
We report on work to increase the number of well-measured Type Ia supernovae (SNe Ia) at high redshifts. Light curves, including signal-to-noise Hubble Space Telescope data, and spectra six SNe that were discovered during 2001, are presented. Additionally, for two with z > 1, we present ground-based J-band photometry from Gemini Very Large Telescope. These among most distant which near-IR observations have been obtained. add these together other data sets recently become available in...
The Zwicky Transient Facility (ZTF), a public-private enterprise, is new time domain survey employing dedicated camera on the Palomar 48-inch Schmidt telescope with 47 deg$^2$ field of view and 8 second readout time. It well positioned in development astronomy, offering operations at 10% scale style Large Synoptic Survey Telescope (LSST) single 1-m class telescope. public surveys will cover observable northern sky every three nights g r filters visible Galactic plane night r. Alerts...
We have remotely mapped optical scattering and absorption in glacial ice at the South Pole for wavelengths between 313 560 nm depths 1100 2350 m. used pulsed continuous light sources embedded with AMANDA neutrino telescope, an array of more than six hundred photomultiplier tubes buried deep ice. At greater 1300 m, both coefficient absorptivity follow vertical variations concentration dust impurities, which are seen cores from other Antarctic sites track climatological changes. The varies by...
Recent work on Neural Radiance Fields (NeRF) showed how neural networks can be used to encode complex 3D environments that rendered photorealistically from novel viewpoints. Rendering these images is very computationally demanding and recent improvements are still a long way enabling interactive rates, even high-end hardware. Motivated by scenarios mobile mixed reality devices, we propose FastNeRF, the first NeRF-based system capable of rendering high fidelity photorealistic at 200Hz...
The Zwicky Transient Facility (ZTF) Observing System (OS) is the data collector for ZTF project to study astrophysical phenomena in time domain. OS based upon 48-inch aperture Schmidt-type design Samuel Oschin Telescope at Palomar Observatory Southern California. It incorporates new telescope aspheric corrector optics, dome and drives, a large-format exposure shutter, flat-field illumination system, robotic bandpass filter exchanger, key element: 47-square-degree, 600 megapixel cryogenic CCD...
Previously we used the Nearby Supernova Factory sample to show that Type Ia supernovae (SNe Ia) having locally star-forming environments are dimmer than SNe passive environments. Here use Constitution together with host galaxy data from GALEX independently confirm result. The effect is seen using both SALT2 and MLCS2k2 lightcurve fitting standardization methods, brightness differences of 0.094 ± 0.037 mag for 0.155 0.041 RV = 2.5. When combined our previous measurement 0.025 SALT2. If ratio...
As part of an on-going effort to identify, understand and correct for astrophysics biases in the standardization Type Ia supernovae (SNIa) cosmology, we have statistically classified a large sample nearby SNeIa into those located predominantly younger or older environments. This classification is based on specific star formation rate measured within projected distance 1kpc from each SN location (LsSFR). important refinement compared using local directly as it provides normalization relative...
The origins of the high-energy cosmic neutrino flux remain largely unknown. Recently, one was associated with a tidal disruption event (TDE). Here we present AT2019fdr, an exceptionally luminous TDE candidate, coincident another neutrino. Our observations, including bright dust echo and soft late-time x-ray emission, further support origin this flare. probability finding two such events by chance is just 0.034%. We evaluate several models for production show that AT2019fdr capable producing...
Abstract The Ultraviolet Transient Astronomy Satellite (ULTRASAT) is scheduled to be launched geostationary orbit in 2027. It will carry a telescope with an unprecedentedly large field of view (204 deg 2 ) and near-ultraviolet (NUV; 230–290 nm) sensitivity (22.5 mag, 5 σ , at 900 s). ULTRASAT conduct the first wide-field survey transient variable NUV sources revolutionize our ability study hot Universe. explore new parameter space energy timescale (months-long light curves minutes cadence),...
ABSTRACT The origin of cosmic high-energy neutrinos remains largely unexplained. For neutrino alerts from IceCube, a coincidence with time-variable emission has been seen for three different types accreting black holes: (1) gamma-ray flare blazar (TXS 0506+056), (2) an optical transient following stellar tidal disruption event (TDE; AT2019dsg), and (3) outburst active galactic nucleus (AGN; AT2019fdr). the latter two sources, infrared follow-up observations revealed powerful reverberation...
Context. Type Ia supernova (SN Ia) cosmology studies will soon be dominated by systematic, uncertainties, rather than statistical ones. Thus, it is crucial to understand the unknown phenomena potentially affecting their luminosity that may remain, such as astrophysical biases. For accurate application in studies, SN magnitudes need standardised; namely, they must corrected for correlation with light-curve width and colour. Aims. Here, we investigate how standardisation procedure used reduce...
The nearby supernova SN 2011fe can be observed in unprecedented detail. Therefore, it is an important test case for Type Ia (SN Ia) models, which may bring us closer to understanding the physical nature of these objects. Here, we explore how available and expected future observations used constrain explosion scenarios. We base our discussion on three-dimensional simulations a delayed detonation Chandrasekhar-mass white dwarf violent merger two dwarfs-realizations models appropriate most...
We present 32 epochs of optical (3300-9700 \AA) spectrophotometric observations the nearby quintessential "normal" type Ia supernova (SN Ia) SN 2011fe in galaxy M101, extending from -15 to +97 d with respect B-band maximum, obtained by Nearby Supernova Factory collaboration. is closest (\mu = 29.04) and brightest (Bmax 9.94 mag) observed since advent modern large scale programs for intensive periodic followup supernovae. Both synthetic light curve measurements spectral feature analysis...
We examine the relationship between Type Ia supernova (SN Ia) Hubble residuals and properties of their host galaxies using a sample 115 SNe from Nearby Supernova Factory. use galaxy stellar masses specific star formation rates fitted photometry for all hosts, as well gas-phase metallicities subset 69 star-forming (non-active galactic nucleus) to show that SN correlate with each these properties. With data we find new evidence correlation intrinsic color metallicity. When combine our those...
We present a sample of normal Type Ia supernovae (SNe Ia) from the Nearby Supernova Factory data set with spectrophotometry at sufficiently late phases to estimate ejected mass using bolometric light curve. measure 56Ni masses peak luminosity, then compare luminosity in 56Co-decay tail expected rate radioactive energy release ejecta given mass. infer Bayesian context semi-analytic model ejecta, incorporating constraints contemporary numerical models as priors on density structure and...
(Abridged) We study the host galaxy regions in close proximity to Type Ia supernovae (SNe Ia) analyze relations between properties of SN events and environments most similar where their progenitors formed. focus on local H\alpha\ emission as an indicator young environments. The Nearby Supernova Factory has obtained flux-calibrated spectral timeseries for SNe using integral field spectroscopy, allowing simultaneous measurement its immediate vicinity. For 89 we measure tracing ongoing star...
LiveScan3D is a free, open source system for live, 3D data acquisition using multiple Kinect v2 sensors. It allows the user to place any number of sensors in physical configuration and start gathering at real time speed. The freedom placing many possible scenarios such as: capturing single object from viewpoints or creating panoramas with devices located close each other. Thanks off-the-shelf sensor both accurate inexpensive, opening up more recipients. In paper we describe our algorithms it...