A5027854924- Gamma-ray bursts and supernovae
- Pulsars and Gravitational Waves Research
- Astrophysics and Cosmic Phenomena
- Astronomy and Astrophysical Research
- SAS software applications and methods
- Astrophysical Phenomena and Observations
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Galaxies: Formation, Evolution, Phenomena
- Astro and Planetary Science
- Geophysics and Gravity Measurements
- Neutrino Physics Research
- Solar and Space Plasma Dynamics
- CCD and CMOS Imaging Sensors
- Geological and Geophysical Studies
- Atomic and Subatomic Physics Research
- Particle Accelerators and Free-Electron Lasers
- Particle physics theoretical and experimental studies
- Flood Risk Assessment and Management
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Adaptive optics and wavefront sensing
- Seismology and Earthquake Studies
- Geographic Information Systems Studies
- Underwater Vehicles and Communication Systems
- Particle Detector Development and Performance
University of Michigan–Ann Arbor
2006-2024
Australian National University
2012-2024
Lancaster University
2024
University of Zurich
2024
American Public University System
2024
Stanford University
2024
Oak Ridge National Laboratory
2024
Geoscience Australia
2018-2024
Ludwig-Maximilians-Universität München
2024
Centre National de la Recherche Scientifique
2024
We present the first data release (DR1) of SkyMapper Southern Survey, a hemispheric survey carried out with Telescope at Siding Spring Observatory in Australia. Here, we strategy, processing, catalogue construction and database schema. The DR1 dataset includes over 66,000 images from Shallow Survey component, covering an area 17,200 deg$^2$ all six passbands $uvgriz$, while full covered by any passband exceeds 20,000 deg$^2$. catalogues contain 285 million unique astrophysical objects,...
High-quality collections of Type II supernova (SN) light curves are scarce because they evolve for hundreds days, making follow-up observations time consuming and often extending over multiple observing seasons. In these difficulties, the diversity SNe is not fully understood. Here we present ultraviolet optical photometry 12 monitored by Las Cumbres Observatory Global Telescope Network during 2013 to 2014, compare them with previously studied having well-sampled curves. We explore SN...
We describe the derivation and validation of redshift distribution estimates their uncertainties for populations galaxies used as weak-lensing sources in Dark Energy Survey (DES) Year 1 cosmological analyses. The Bayesian Photometric Redshift (bpz) code is to assign four bins between z ≈ 0.2 ≈1.3, produce initial lensing-weighted distributions |$n^i_{\rm PZ}(z)\propto \mathrm{d}n^i/\mathrm{d}z$| members bin i. Accurate determination parameters depends critically on knowledge ni, but...
We assemble a sample of 24 hydrogen-poor super-luminous supernovae (SLSNe). Parameterizing the light curve shape through rise and decline timescales shows that two are highly correlated. Magnetar-powered models can reproduce correlation, with diversity in rates driven by diffusion timescale. Circumstellar interaction exhibit similar rise-decline relation, but only for narrow range densities, which may be problematic these models. find SLSNe approximately 3.5 magnitudes brighter have curves 3...
We present results from a study of the photometric redshift performance Dark Energy Survey (DES), using early data Science Verification period observations in late 2012 and 2013 that provided science-quality images for almost 200 sq. deg. at nominal depth survey. assess (photo-z) about 15 000 galaxies with spectroscopic redshifts available other surveys. These are used, different configurations, as calibration sample, photo-z's obtained studied most existing photo-z codes. A weighting method...
We calculate the volumetric rate of superluminous supernovae (SLSNe) based on 5 events discovered with ROTSE-IIIb telescope. gather light curves 19 from literature and our own unpublished data employ crude k-corrections to constrain pseudo-absolute magnitude distributions in rest frame (unfiltered) band pass for both hydrogen poor (SLSN-I) rich (SLSN-II) populations. find that peak magnitudes available SLSN-I are narrowly distributed ($M = -21.7 \pm 0.4$) unfiltered may suggest an even...
Abstract We present early photometric and spectroscopic observations of SN 2013ej, a bright Type IIP supernova (SN) in M74. 2013ej is one the closest SNe ever discovered. The available archive images discovery help to constrain nature its progenitor. earliest detection this explosion was on 2013 July 24.125 ut our monitoring with FLOYDS spectrographs began 27.7 ut, continuing almost daily for two weeks. Daily optical achieved 1 m telescopes Las Cumbres Observatory Global Telescope (LCOGT)...
We present ultraviolet, optical and near-infrared observations of the interacting transient SN 2009ip, covering period from start outburst in 2012 October until end observing season. The reached a peak magnitude MV = −17.7 mag, with total integrated luminosity 1.9 × 1049 erg over August–December. light curve fades rapidly, dropping by 4.5 mag V-band 100 d. spectra are dominated narrow emission lines broad electron scattering wings, signalling dense circumstellar environment, together...
We present two hydrogen-rich superluminous supernovae (SLSNe), namely SN2013hx and PS15br. These objects, together with SN2008es are the only SLSNe showing a distinct, broad Halpha feature during photospheric phase also do not show any sign of strong interaction between fast-moving ejecta circumstellar shells in their early spectra. Despite PS15br peak luminosity is fainter than other spectrophotometric evolution similar to different supernova space. group all them as II hence distinct from...
We describe the operation and performance of difference imaging pipeline (DiffImg) used to detect transients in deep images from Dark Energy Survey Supernova program (DES-SN) its first observing season 2013 August through 2014 February. DES-SN is a search for which ten 3 deg2 fields are repeatedly observed g, r, i, z passbands with cadence about 1 week. The strategy has been optimized measure high-quality light curves redshifts thousands Type Ia supernovae (SNe Ia) goal measuring dark energy...
OzDES is a five-year, 100-night, spectroscopic survey on the Anglo-Australian Telescope, whose primary aim to measure redshifts of approximately 2,500 Type Ia supernovae host galaxies over redshift range 0.1 < z 1.2, and derive reverberation-mapped black hole masses for 500 active galactic nuclei quasars 0.3 4.5. This treasure trove data forms major part follow-up Dark Energy Survey which we are also targeting cluster galaxies, radio strong lenses, unidentified transients, as well measuring...
We present the full Hubble diagram of photometrically-classified Type Ia supernovae (SNe Ia) from Dark Energy Survey supernova program (DES-SN). DES-SN discovered more than 20,000 SN candidates and obtained spectroscopic redshifts 7,000 host galaxies. Based on light-curve quality, we select 1635 photometrically-identified SNe with redshift 0.10$< z <$1.13, which is largest sample any single survey increases number known $z>0.5$ by a factor five. In companion paper, cosmological results...
Abstract We present the full Hubble diagram of photometrically classified Type Ia supernovae (SNe Ia) from Dark Energy Survey supernova program (DES-SN). DES-SN discovered more than 20,000 SN candidates and obtained spectroscopic redshifts 7000 host galaxies. Based on light-curve quality, we select 1635 identified SNe with redshift 0.10 < z 1.13, which is largest sample any single survey increases number known > 0.5 by a factor 5. In companion paper, cosmological results combined 194...
We report the discovery by Robotic Optical Transient Search Experiment (ROTSE-IIIb) telescope of SN 2008es, an overluminous supernova (SN) at z = 0.205 with a peak visual magnitude −22.2. present multiwavelength follow-up observations Swift satellite and several ground-based optical telescopes. The ROTSE-IIIb constrain time explosion to be 23 ± 1 rest-frame days before maximum. linear decay light curve, combination symmetric, broad Hα emission line profile P Cygni Hβ Na i λ5892 profiles, are...
We report on a complete set of early optical afterglows gamma-ray bursts (GRBs) obtained with the Robotic Optical Transient Search Experiment (ROTSE-III) telescope network from 2005 March through 2007 June. This is comprised 12 and Swift/X-Ray Telescope observations, median ROTSE-III response time 45 s after start γ-ray emission (8 GCN notice time). These span 4 orders magnitude in luminosity, contemporaneous X-ray detections allow multi-wavelength spectral analysis. Excluding flares,...
The Palomar Transient Factory (PTF) is an optical wide-field variability survey carried out using a camera with 7.8 square degree field of view mounted on the 48-in Oschin Schmidt telescope at Observatory. One key goals this to conduct high-cadence monitoring sky in order detect transient sources shortly after they occur. Here, we describe real-time capabilities PTF and our related rapid multiwavelength follow-up programs, extending from radio gamma-ray bands. We present as case study...
We present results for the first three years of OzDES, a six year programme to obtain redshifts objects in Dark Energy Survey (DES) supernova fields using 2dF fibre positioner and AAOmega spectrograph on Anglo-Australian Telescope. OzDES is multi-object spectroscopic survey targeting multiple types targets at epochs over multiyear baseline one surveys dynamically include transients into target list soon after their discovery. At end years, has spectroscopically confirmed almost 100...
The light curves of Type Ia supernovae (SNe Ia) are powered by the radioactive decay $^{56}$Ni to $^{56}$Co at early times, and $^{56}$Fe from ~60 days after explosion. We examine evolution [Co III] 5892 A emission complex during nebular phase for SNe with multiple spectra show that line flux follows square mass as a function time. This result indicates both efficient local energy deposition positrons produced in decay, long-term stability ionization state nebula. compile 77 25 SN literature...
We present multiband ultraviolet, optical, and near-infrared photometry, along with visual-wavelength spectroscopy, of supernova (SN) 2014G in the nearby galaxy NGC 3448 (25 Mpc). The early-phase spectra show strong emission lines high ionization species He ii/N iv/C iv during first 2–3 d after explosion, traces a metal-rich circumstellar material (CSM) probably due to pre-explosion mass-loss events. These disappear by day 9 spectral evolution then continues matching that normal Type II SNe....
We present optical and near-infrared (NIR) photometry for three gamma-ray burst supernovae (GRB-SNe): GRB 120729A, 130215A / SN 2013ez 130831A 2013fu. In the case of 2013ez, we also spectroscopy at t-t0=16.1 d, which covers rest-frame 3000-6250 Angstroms. Based on Fe II (5169) Si (II) (6355), our spectrum indicates an unusually low expansion velocity 4000-6350 km/s, lowest ever measured a GRB-SN. Additionally, determined brightness shape each accompanying relative to template supernova (SN...
We use numerical simulations to characterize the performance of a clustering-based method calibrate photometric redshift biases. In particular, we cross-correlate weak lensing (WL) source galaxies from Dark Energy Survey Year 1 (DES Y1) sample with redMaGiC (luminous red secure redshifts) estimate distribution former sample. The recovered distributions are used bias standard photo-$z$ methods applied same galaxy apply three codes run in our simulated data: Bayesian Photometric Redshift...
We present optical and near-infrared photometric spectroscopic observations of SN 2013ej, in galaxy M74, from 1 to 450 d after the explosion. 2013ej is a hydrogen-rich supernova, classified as Type IIL due its relatively fast decline following initial peak. It has high peak luminosity (absolute magnitude MV = −17.6) but small 56Ni production ∼0.023 M⊙. Its photospheric evolution similar other II SNe, with shallow absorption Hα profile typical for IIL. During transition radioactive decay tail...
ABSTRACT We present a description of the Australian Dark Energy Survey (OzDES) and summarize results from its 6 years operations. Using 2dF fibre positioner AAOmega spectrograph on 3.9-m Anglo-Australian Telescope, OzDES has monitored 771 active galactic nuclei, classified hundreds supernovae, obtained redshifts for thousands galaxies that hosted transient within 10 deep fields Survey. also second data release, containing almost 30 000 sources, some as faint rAB = 24 mag, 375 individual...
The technological landscape for managing big Earth observation (EO) data ranges from global solutions on large cloud infrastructures with web-based access to self-hosted implementations. EO cubes are a leading technology facilitating analysis and can be deployed different spatial scales: local, national, regional, or global. Several geographic focus ("local cubes") have been implemented. However, their alignment the Digital (DE) vision benefits trade-offs in creating maintaining them ought...
Swift triggered on a precursor to the main burst of GRB 061121 (z=1.314), allowing observations be made from optical gamma-ray bands. Many other telescopes, including Konus-Wind, XMM-Newton, ROTSE and Faulkes Telescope North, also observed burst. The gamma-ray, X-ray UV/optical emission all showed peak ~75s after trigger, although afterglow components appear early - before, or during, peak. Spectral evolution was seen throughout burst, with prompt showing clear positive correlation between...