A5016871217- Gamma-ray bursts and supernovae
- Astronomy and Astrophysical Research
- Astrophysics and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Astronomical Observations and Instrumentation
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Cosmology and Gravitation Theories
- Astrophysical Phenomena and Observations
- Neutrino Physics Research
- Pulsars and Gravitational Waves Research
- CCD and CMOS Imaging Sensors
- Dark Matter and Cosmic Phenomena
- Adaptive optics and wavefront sensing
- Particle Accelerators and Free-Electron Lasers
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Particle Detector Development and Performance
- Radio Astronomy Observations and Technology
- History and Developments in Astronomy
- Atomic and Subatomic Physics Research
- Particle accelerators and beam dynamics
- Gyrotron and Vacuum Electronics Research
University of Hawaii System
2020-2024
Lawrence Berkeley National Laboratory
2014-2023
University of Hawaiʻi at Mānoa
2020-2023
University of Hawaii–West Oahu
2020-2023
Space Telescope Science Institute
2016-2021
Michigan Science Center
2019
University of Liverpool
2018
Florida State University
2014-2015
University of California, Berkeley
2007-2015
Cornell University
1990-2002
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...
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...
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...
With Cosmicflows-4, distances are compiled for 55,877 galaxies gathered into 38,065 groups. Eight methodologies employed, with the largest numbers coming from correlations between photometric and kinematic properties of spiral (TF) elliptical (FP). Supernovae that arise degenerate progenitors (type Ia Sne) an important overlapping component. Smaller contributions come distance estimates surface brightness fluctuations luminosities expansion rates core collapse supernovae (SNII). Cepheid...
The DESI Collaboration have recently analyzed their first year of data, finding a preference for thawing dark energy scenarios when using parametrized equations state energy. We investigate whether this persists the data are within context well-studied field theory model energy, exponential quintessence. No over Lambda cold matter is found, and both models poorer fits to than Chevallier-Polarski-Linder ${w}_{0}\text{\ensuremath{-}}{w}_{a}$ parametrization. demonstrate that worse fit due lack...
The accelerating expansion of the universe is one most profound discoveries in modern cosmology, pointing to a which 70% mass-energy density has an unknown form spread uniformly across universe. This result been well established using combination cosmological probes (e.g., Planck Collaboration et al. 2016), resulting "standard model" cosmology that constant with cold dark matter and baryons. first compelling evidence for acceleration came late 1990's, when two independent teams studying type...
Type Ia supernovae (SNe Ia) were instrumental in establishing the acceleration of universe's expansion. By virtue their combination distance reach, precision, and prevalence, they continue to provide key cosmological constraints, complementing other probes. Individual SN surveys cover only over about a factor two redshift, so compilations multiple datasets are strongly beneficial. We assemble an updated "Union" compilation 2087 cosmologically useful SNe from 24 ("Union3"). take care put all...
We have performed intra- and extra-cavity microwave frequency (1–100 GHz) measurements on high quality Y1Ba2Cu3O7−x superconducting thin films (100) LaAlO3 substrates. The ∼0.3 μm fabricated by the pulsed laser deposition technique exhibit transition temperatures &gt;90 K, as determined resistivity ac susceptibility measurements, critical current densities of 5×106 A/cm2 at 77 K. Moreover, ion beam channeling minimum yields ∼3% were measured, indicating extremely crystalline grown...
We present weak gravitational lensing analysis of 22 high-redshift (z >~1) clusters based on Hubble Space Telescope images. Most in our sample provide significant signals and are well detected their reconstructed two-dimensional mass maps. Combining the current results previous weak-lensing studies five other high-z clusters, we compare masses these with observables. revisit question whether presence most massive is tension LambdaCDM structure formation paradigm. find that tightly correlated...
We present observations of SCP 06F6, an unusual optical transient discovered during the Hubble Space Telescope Cluster Supernova Survey. The brightened over a period ~100 days, reached peak magnitude ~21.0 in both i_775 and z_850, then declined similar timescale. There is no host galaxy or progenitor star detected at location to 3 sigma upper limit = 26.4 z_850 26.1, giving corresponding lower on flux increase factor ~120. Multiple spectra show five broad absorption bands between 4100 AA...
While recent supernova cosmology research has benefited from improved measurements, current analysis approaches are not statistically optimal and will prove insufficient for future surveys. This paper discusses the limitations of cosmological analyses in treating outliers, selection effects, shape- color-standardization relations, unexplained dispersion, heterogeneous observations. We present a new Bayesian framework, called UNITY (Unified Nonlinear Inference Type-Ia cosmologY), that...
We present observations of ZTF18abfcmjw (SN2019dge), a helium-rich supernova with fast-evolving light curve indicating an extremely low ejecta mass ($\approx 0.3\,M_\odot$) and kinetic energy 1.2\times 10^{50}\,{\rm erg}$). Early-time (<4 d after explosion) photometry reveal evidence shock cooling from extended envelope $\sim0.1\,M_\odot$ located at $\sim 3\times 10^{12}\,{\rm cm}$ the progenitor. He II line emission subsequent spectra show signatures interaction circumstellar material,...
In this paper, results are presented from a study of the hadronic final states in ${\mathit{e}}^{+}$${\mathit{e}}^{\mathrm{\ensuremath{-}}}$ annihilation at 29 GeV. The data were obtained with High Resolution Spectrometer (HRS) SLAC PEP colliding-beam facility. based on 6342 selected events corresponding to an integrated luminosity 19.6 ${\mathrm{pb}}^{\mathrm{\ensuremath{-}}1}$. distributions sphericity (S), thrust (T), and aplanarity (A) given compared other same energy range. We measure...
We present convincing evidence of unburned carbon at photospheric velocities in new observations 5 Type Ia supernovae (SNe Ia) obtained by the Nearby Supernova Factory. These SNe are identified examining 346 spectra from 124 before +2.5 d relative to maximum. Detections based on presence relatively strong C II 6580 absorption "notches" multiple each SN, aided automated fitting with SYNAPPS code. Four question otherwise spectroscopically unremarkable, ions and ejection typical Ia, but fifth...
Type Ia supernova cosmology depends on the ability to fit and standardize observations of magnitudes with an empirical model. We present here a series new models Supernova spectral time that capture greater amount diversity than possible are currently customary. These entitled SuperNova Empirical MOdels (\textsc{SNEMO}\footnote{https://snfactory.lbl.gov/snemo}). The constructed using spectrophotometric from $172$ individual supernovae Nearby Factory, comprising more $2000$ spectra. Using...
A large fraction of Type Ia supernova (SN Ia) observations over the next decade will be in near-infrared (NIR), at wavelengths beyond reach current standard light-curve model for SN cosmology, SALT3 ($\sim 2800$--8700$A$ central filter wavelength). To harness this new sample and reduce future standardization systematic uncertainties, we train NIR (SALT3-NIR) up to 2 $\mu$m with open-source model-training software SALTShaker, which can easily accommodate observations. Using simulated data...
We present the Spectroscopic Classification of Astronomical Transients (SCAT) survey, which is dedicated to spectrophotometric observations transient objects such as supernovae and tidal disruption events. SCAT uses SuperNova Integral-Field Spectrograph (SNIFS) on University Hawai'i 2.2-meter (UH2.2m) telescope. SNIFS was designed specifically for accurate spectrophotometry, including absolute flux calibration host-galaxy removal. describe data reduction pipeline spectral extraction,...
Abstract We present a new empirical Type Ia supernova (SN Ia) model with three chromatic flux variation templates: one phase dependent and two independent. No underlying dust extinction or patterns of intrinsic variability are assumed. Implemented S tan trained using spectrally binned Nearby Supernova Factory spectrophotometry, we examine this model's 2D, phase-independent space motivated basis representations. In both, the first template captures that appears dust-like, while second...
We present a study of the morphological fractions and color–magnitude relation (CMR) in most distant X-ray selected galaxy cluster currently known, XMMXCS J2215.9 − 1738 at z = 1.46, using combination optical imaging data obtained with Hubble Space Telescope Advanced Camera for Surveys, infrared from Multi-Object Infrared Spectrograph, mounted on 8.2 m Subaru telescope. find that mix population is similar to clusters ∼ 1. Within central 0.5 Mpc, approximately ∼62% galaxies identified as...
We present a new survey strategy to discover and study high-redshift Type Ia supernovae (SNe Ia) using the Hubble Space Telescope (HST). By targeting massive galaxy clusters at 0.9 < z 1.5, we obtain twofold improvement in efficiency of finding SNe compared an HST field factor 3 total yield SN detections relatively dust-free red-sequence galaxies. In total, sixteen were discovered z>0.95, nine which clusters. This provides sample that can be used decouple effects host-galaxy extinction...
We present a new measurement of the volumetric rate SNe Ia up to redshift 1.7, using HST GOODS data combined with an additional set covering GOODS-North field collected in 2004. employ novel technique that does not require spectroscopic for identifying (although measurements redshifts are used over half sample); instead, we Bayesian approach only photometric calculate probability object is SN Ia. This can easily be modified incorporate improved priors on properties, and it well-suited future...
We report the discovery of a redshift 1.71 supernova in GOODS North field. The Hubble Space Telescope (HST) ACS spectrum has almost negligible contamination from host or neighboring galaxies. Although rest frame sampled range is too blue to include any Si ii line, principal component analysis allows us confirm it as Type Ia with 92% confidence. A recent serendipitous archival HST WFC3 grism contributed key element confirmation by giving host-galaxy 1.713 +/- 0.007. In addition being most...
We present GIGA-Lens: a gradient-informed, GPU-accelerated Bayesian framework for modeling strong gravitational lensing systems, implemented in TensorFlow and JAX. The three components, optimization using multi-start gradient descent, posterior covariance estimation with variational inference, sampling via Hamiltonian Monte Carlo, all take advantage of information through automatic differentiation massive parallelization on graphics processing units (GPUs). test our pipeline large set...