- Gamma-ray bursts and supernovae
- Particle Detector Development and Performance
- Distributed and Parallel Computing Systems
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Astronomical Observations and Instrumentation
- Scientific Computing and Data Management
- Galaxies: Formation, Evolution, Phenomena
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Solar and Space Plasma Dynamics
- Adaptive optics and wavefront sensing
- Geophysics and Gravity Measurements
- Cosmology and Gravitation Theories
- CCD and CMOS Imaging Sensors
- Particle Accelerators and Free-Electron Lasers
- Calibration and Measurement Techniques
- Spectroscopy Techniques in Biomedical and Chemical Research
- Spectroscopy and Laser Applications
- Spacecraft and Cryogenic Technologies
- Neutrino Physics Research
- Nuclear Physics and Applications
Space Telescope Science Institute
2016-2025
Johns Hopkins University
2015-2025
Bloomberg (United States)
2024
Michigan Science Center
2023
Purdue University West Lafayette
2022
Durham University
2020
National Center for Supercomputing Applications
2020
University of Illinois Urbana-Champaign
2020
Harvard University
2007-2017
University of Hawaii System
2012
We present optical light curves, redshifts, and classifications for 365 spectroscopically confirmed Type Ia supernovae (SNe Ia) discovered by the Pan-STARRS1 (PS1) Medium Deep Survey. detail improvements to PS1 SN photometry, astrometry calibration that reduce systematic uncertainties in distances. combine subset of 279 ($0.03 < z 0.68$) with useful distance estimates from SDSS, SNLS, various low-z HST samples form largest combined sample consisting a total 1048 ranging $0.01 2.3$, which we...
Pan-STARRS1 has carried out a set of distinct synoptic imaging sky surveys including the $3π$ Steradian Survey and Medium Deep in 5 bands ($grizy_{P1}$). The mean 5$σ$ point source limiting sensitivities stacked 3$π$ $grizy_{P1}$ are (23.3, 23.2, 23.1, 22.3, 21.4) respectively. upper bound on systematic uncertainty photometric calibration across is 7-12 millimag depending bandpass. astrometric using Gaia frame comes from comparison results with Gaia: standard deviation median residuals ($...
We present UV, optical, and NIR photometry of the first electromagnetic counterpart to a gravitational wave source from Advanced LIGO/Virgo, binary neutron star merger GW170817. Our data set extends discovery optical at $0.47$ days $18.5$ post-merger, includes observations with Dark Energy Camera (DECam), Gemini-South/FLAMINGOS-2 (GS/F2), {\it Hubble Space Telescope} ({\it HST}). The spectral energy distribution (SED) inferred this $0.6$ is well described by blackbody model $T\approx 8300$...
We present constraints on the dark energy equation-of-state parameter, w=P/(rho c^2), using 60 Type Ia supernovae (SNe Ia) from ESSENCE supernova survey. derive a set of nature assuming flat Universe. By including (Omega_M, w) baryon acoustic oscillations, we obtain value for static parameter w=-1.05^{+0.13}_{-0.12} (stat; 1 sigma) +- 0.11 (sys) and Omega_M=0.274^{+0.033}_{-0.020} with best-fit chi^2/DoF 0.96. These results are consistent those reported by SuperNova Legacy Survey in similar...
We combine the CfA3 supernovae Type Ia (SN Ia) sample with samples from literature to calculate improved constraints on dark energy equation of state parameter, w. The is added Union set Kowalski et al. form Constitution and, combined a BAO prior, produces 1 + w = 0.013+0.066−0.068 (0.11 syst), consistent cosmological constant. addition makes cosmologically useful nearby SN between 2.6 and 2.9 times larger than before, reducing statistical uncertainty point where systematics play largest...
On 2017 August 17, gravitational waves were detected from a binary neutron star merger, GW170817, along with coincident short gamma-ray burst, GRB170817A. An optical transient source, Swope Supernova Survey 17a (SSS17a), was subsequently identified as the counterpart of this event. We present ultraviolet, and infrared light curves SSS17a extending 10.9 hours to 18 days post-merger. constrain radioactively-powered resulting ejection neutron-rich material. The fast rise curves, subsequent...
On 2017 August 17, the Laser Interferometer Gravitational-wave Observatory (LIGO) and Virgo interferometer detected gravitational waves emanating from a binary neutron star merger, GW170817. Nearly simultaneously, Fermi INTEGRAL telescopes gamma-ray transient, GRB 170817A. 10.9 hours after wave trigger, we discovered transient fading optical source, Swope Supernova Survey 2017a (SSS17a), coincident with SSS17a is located in NGC 4993, an S0 galaxy at distance of 40 megaparsecs. The precise...
We present constraints on cosmological parameters from the Pantheon+ analysis of 1701 light curves 1550 distinct Type Ia supernovae (SNe Ia) ranging in redshift $z=0.001$ to 2.26. This work features an increased sample size, span, and improved treatment systematic uncertainties comparison original Pantheon results a factor two improvement constraining power. For Flat$\Lambda$CDM model, we find $\Omega_M=0.334\pm0.018$ SNe alone. Flat$w_0$CDM measure $w_0=-0.90\pm0.14$ alone, H$_0=73.5\pm1.1$...
The first cosmological results from the ESSENCE supernova survey (Wood-Vasey and coworkers) are extended to a wider range of models including dynamical dark energy nonstandard models. We fold in greater number external data sets such as recent Higher-z release high-redshift supernovae (Riess coworkers), well several complementary probes. Model comparison statistics Bayesian Akaike information criteria applied gauge worth These favor that give good fit with fewer parameters. Based on this...
Abstract We present the Dark Energy Camera (DECam) discovery of optical counterpart first binary neutron star merger detected through gravitational-wave emission, GW170817. Our observations commenced 10.5 hr post-merger, as soon localization region became accessible from Chile. imaged 70 deg 2 in i and z bands, covering 93% initial integrated probability, to a depth necessary identify likely counterparts (e.g., kilonova). At 11.4 post-merger we bright transient located nucleus NGC 4993 at...
We present multiband photometry of 185 type-Ia supernovae (SNe Ia), with over 11,500 observations. These were acquired between 2001 and 2008 at the F. L. Whipple Observatory Harvard-Smithsonian Center for Astrophysics (CfA). This sample contains largest number homogeneously observed reduced nearby SNe Ia (z ≲ 0.08) published to date. It more than doubles sample, bringing SN cosmology point where systematic uncertainties dominate. Our natural system has a precision ≲0.02 mag in BVRIr'i' ≲0.04...
Here we present 1701 light curves of 1550 spectroscopically confirmed Type Ia supernovae (SNe Ia) that will be used to infer cosmological parameters as part the Pantheon+ SN analysis and SH0ES (Supernovae H0 for Equation State dark energy) distance-ladder analysis. This effort is one a series works perform an extensive review redshifts, peculiar velocities, photometric calibration, intrinsic-scatter models SNe Ia. The total number curves, which are compiled across 18 different surveys,...
We report extensive observational data for five of the lowest redshift Super-Luminous Type Ic Supernovae (SL-SNe Ic) discovered to date, namely PTF10hgi, SN2011ke, PTF11rks, SN2011kf and SN2012il. Photometric imaging transients at +50 +230 days after peak combined with host galaxy subtraction reveals a luminous tail phase four these SL-SNe. A high resolution, optical near infrared spectrum from xshooter provides detection broad He I $\lambda$10830 emission line in (+50d) SN2012il, revealing...
We present Very Large Array (VLA) and Atacama Millimeter/sub-millimeter ALMA radio observations of GW\,170817, the first Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo gravitational wave (GW) event from a binary neutron star merger GW with an electromagnetic (EM) counterpart. Our data include following discovery optical transient at both centimeter ($13.7$ hours post merger) millimeter ($2.41$ days bands. detect faint emission 6 GHz 19.47 39.23 after merger, but not in...
We present a near-infrared spectral sequence of the electromagnetic counterpart to binary neutron star merger GW170817 detected by Advanced LIGO/Virgo. Our dataset comprises seven epochs J+H spectra taken with FLAMINGOS-2 on Gemini-South between 1.5 and 10.5 days after merger. In initial epoch, spectrum is dominated smooth blue continuum due high-velocity, lanthanide-poor kilonova component. Starting following night, all subsequent instead show features that are similar those predicted in...
In the past decade, several rapidly evolving transients have been discovered whose timescales and luminosities are not easily explained by traditional supernovae (SNe) models. The sample size of these objects has remained small due, at least in part, to challenges detecting short timescale with survey cadences. Here we present results from a search within Pan-STARRS1 Medium Deep Survey (PS1-MDS) for luminous transients. We identify 10 new time above half-maximum (t1/2) less than 12 days...
On 2017 August 17, Swope Supernova Survey 2017a (SSS17a) was discovered as the optical counterpart of binary neutron star gravitational wave event GW170817. We report time-series spectroscopy SSS17a from 11.75 hours until 8.5 days after merger. Over first hour observations ejecta rapidly expanded and cooled. Applying blackbody fits to spectra, we measure photosphere cooling $11,000^{+3400}_{-900}$ K $9300^{+300}_{-300}$ K, determine a photospheric velocity roughly 30% speed light. The...
This paper describes the organization of database and catalog data products from Pan-STARRS1 $3\pi$ Steradian Survey. The are available in form an SQL-based relational MAST, Mikulski Archive for Space Telescopes at STScI. is described detail, including construction database, provenance data, schema, how tables related. Examples queries a range science goals included.
Using the Atacama Large Millimeter/submillimeter Array, we have conducted a blind redshift survey in 3 mm atmospheric transmission window for 26 strongly lensed dusty star-forming galaxies (DSFGs) selected with South Pole Telescope. The sources were to S1.4 > 20 mJy and dust-like spectrum and, remove low-z sources, not bright radio (S843 MHz < 6 mJy) or far-infrared counterparts (S100 μm 1 Jy, S60 200 mJy). We robustly detect 44 line features our survey, which identify as redshifted emission...
We present a detection-significance-limited catalog of 21 Sunyaev-Zel'dovich selected galaxy clusters. These clusters, along with 1 unconfirmed candidate, were identified in 178 deg^2 sky surveyed 2008 by the South Pole Telescope to depth 18 uK-arcmin at 150 GHz. Optical imaging from Blanco Cosmology Survey (BCS) and Magellan telescopes provided photometric (and some cases spectroscopic) redshift estimates, redshifts ranging z=0.15 z>1, median z = 0.74. Of confirmed three previously as...
Abstract We present optical and ultraviolet spectra of the first electromagnetic counterpart to a gravitational-wave (GW) source, binary neutron star merger GW170817. Spectra were obtained nightly between 1.5 9.5 days post-merger, using Southern Astrophysical Research Magellan telescopes; UV spectrum was with Hubble Space Telescope at 5.5 days. Our data reveal rapidly fading blue component ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>T</mml:mi>...