D. A. Coulter
A5069608139- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Stellar, planetary, and galactic studies
- Pulsars and Gravitational Waves Research
- Astrophysics and Cosmic Phenomena
- Astronomy and Astrophysical Research
- Astronomical Observations and Instrumentation
- Galaxies: Formation, Evolution, Phenomena
- Astro and Planetary Science
- Neutrino Physics Research
- CCD and CMOS Imaging Sensors
- Calibration and Measurement Techniques
- Geophysics and Gravity Measurements
- Solar and Space Plasma Dynamics
- History and Developments in Astronomy
- Astrophysics and Star Formation Studies
- Adaptive optics and wavefront sensing
- Cosmology and Gravitation Theories
- Advanced Sensor Technologies Research
- Sensor Technology and Measurement Systems
- Methane Hydrates and Related Phenomena
- Particle Detector Development and Performance
- Nuclear Issues and Defense
- Remote-Sensing Image Classification
- Advanced optical system design
University of California, Santa Cruz
2017-2024
Space Telescope Science Institute
2024
American Association of Variable Star Observers
2022
Goddard Space Flight Center
2017
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$_0=73.5\pm1.1$...
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,...
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...
Photons from a gravitational wave event Two neutron stars merging together generate signal and have also been predicted to emit electromagnetic radiation. When the GW170817 was detected, astronomers rushed search for source using conventional telescopes (see Introduction by Smith). Coulter et al. describe how One-Meter Two-Hemispheres (1M2H) collaboration first locate source. Drout present 1M2H measurements of its optical infrared brightness, Shappee report their spectroscopy event, which is...
We present panchromatic observations and modeling of supernova (SN) 2020tlf, the first normal type II-P/L SN with confirmed precursor emission, as detected by Young Supernova Experiment transient survey Pan-STARRS1 telescope. Pre-explosion emission was in $riz-$bands at 130 days prior to 2020tlf persisted relatively constant flux until light. Soon after discovery, "flash" spectroscopy revealed prominent narrow symmetric lines ($v_w < 300$ km s$^{-1}$) that resulted from photo-ionization...
Abstract We present UV and/or optical observations and models of SN 2023ixf, a type II supernova (SN) located in Messier 101 at 6.9 Mpc. Early time ( flash ) spectroscopy obtained primarily Lick Observatory, reveals emission lines H i , He i/ii C iv N iii/iv/v with narrow core broad, symmetric wings arising from the photoionization dense, close-in circumstellar material (CSM) around progenitor star prior to shock breakout. These electron-scattering broadened line profiles persist for ∼8 days...
Abstract We present preexplosion optical and infrared (IR) imaging at the site of type II supernova (SN II) 2023ixf in Messier 101 6.9 Mpc. astrometrically registered a ground-based image SN to archival Hubble Space Telescope (HST), Spitzer (Spitzer), near-IR images. A single point source is detected position consistent with wavelengths ranging from HST R band 4.5 μ m. Fitting blackbody red supergiant (RSG) spectral energy distributions (SEDs), we find that anomalously cool significant...
Abstract We present ultraviolet/optical/near-infrared observations and modeling of Type II supernovae (SNe II) whose early time ( δ t < 2 days) spectra show transient, narrow emission lines from shock ionization confined r 10 15 cm) circumstellar material (CSM). The observed electron-scattering broadened line profiles (i.e., IIn-like) H i , He i/ii C iv N iii/iv/v the CSM persist on a characteristic timescale IIn ) that marks transition to lower-density emergence Doppler-broadened...
Abstract The discovery and localization of FRB 20240209A by the Canadian Hydrogen Intensity Mapping Fast Radio Burst (CHIME/FRB) experiment marks first repeating localized with CHIME/FRB Outriggers adds to small sample FRBs associated host galaxies. Here we present Keck Gemini observations that reveal a redshift z = 0.1384 ± 0.0004. We perform stellar population modeling jointly fit optical through mid-IR data infer median mass log( M * / ⊙ ) 11.35 0.01 mass-weighted age ~11 Gyr,...
Abstract The JWST Advanced Deep Extragalactic Survey (JADES) is a multicycle program that has taken among the deepest near- and mid-infrared images to date (down ∼30 AB mag) over ∼25 arcmin 2 in GOODS-S field two sets of observations with 1 yr separation. This presented first opportunity systematically search for transients, mostly supernovae (SNe), out z > 2. We found 79 SNe: 38 at < 2, 23 3, 8 3 4, 7 4 5, undetermined redshifts, where redshifts are predominantly based on...
The Foundation Supernova Survey aims to provide a large, high-fidelity, homogeneous, and precisely-calibrated low-redshift Type Ia supernova (SN Ia) sample for cosmology. calibration of the current SN is largest component systematic uncertainties cosmology, new data are necessary make progress. We present motivation, survey design, observation strategy, implementation, first results Survey. using Pan-STARRS telescope obtain photometry up 800 SNe at z < 0.1. This strategy has several unique...
Abstract The merging neutron star gravitational-wave event GW170817 has been observed throughout the entire electromagnetic spectrum from radio waves to γ -rays. resulting energetics, variability, and light curves are shown be consistent with originating merger of two stars, in all likelihood followed by prompt gravitational collapse massive remnant. available -ray, X-ray, data provide a clear probe for nature relativistic ejecta non-thermal processes occurring within, while ultraviolet,...
ABSTRACT We present observations of ASASSN-19dj, a nearby tidal disruption event (TDE) discovered in the post-starburst galaxy KUG 0810+227 by All-Sky Automated Survey for Supernovae (ASAS-SN) at distance d ≃ 98 Mpc. observed ASASSN-19dj from −21 to 392 relative peak ultraviolet (UV)/optical emission using high-cadence, multiwavelength spectroscopy and photometry. From ASAS-SN g-band data, we determine that TDE began brighten on 2019 February 6.8 first 16 rise was consistent with flux ∝t2...
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 present extensive optical photometry of the afterglow GRB~221009A. Our data cover $0.9 - 59.9$\,days from time \textit{Swift} and \textit{Fermi} GRB detections. Photometry in $rizy$-band filters was collected primarily with Pan-STARRS supplemented by multiple 1- to 4-meter imaging facilities. analyzed Swift X-ray found a single decline rate power-law $f(t) \propto t^{-1.556\pm0.002}$ best describes light curve. In addition high foreground Milky Way dust extinction along this line sight,...
The modern study of astrophysical transients has been transformed by an exponentially growing volume data. Within the last decade, transient discovery rate increased a factor ~20, with associated survey data, archival and metadata also increasing number discoveries. To manage data at this rate, we require new tools. Here present YSE-PZ, management platform that ingests multiple live streams alerts, identifies host galaxies those transients, downloads coincident retrieves photometry spectra...
Abstract The nearby type II supernova, SN 2023ixf in M101 exhibits signatures of early time interaction with circumstellar material the first week postexplosion. This may be consequence prior mass loss suffered by progenitor, which possibly manifested form a detectable presupernova outburst. We present an analysis long-baseline preexplosion photometric data g , w r i z and y filters from Pan-STARRS as part Young Supernova Experiment, spanning ∼5000 days. find no significant detections light...
Abstract Supernova (SN) SN H0pe is a gravitationally lensed, triply imaged, Type Ia (SN Ia) discovered in James Webb Space Telescope imaging of the PLCK G165.7+67.0 cluster galaxies. Well-observed multiply imaged SNe provide rare opportunity to constrain Hubble constant ( H 0 ), by measuring relative time delay between images and modeling foreground mass distribution. located at z = 1.783 first with sufficient light-curve sampling long enough delays for an inference. Here we present...
Abstract A bright ( m F150W,AB = 24 mag), z 1.95 supernova (SN) candidate was discovered in JWST/NIRCam imaging acquired on 2023 November 17. The SN is quintuply imaged as a result of strong gravitational lensing by foreground galaxy cluster, detected three locations, and remarkably the second lensed found same host galaxy. previous called “Requiem,” therefore new named “Encore.” This makes MACS J0138.0−2155 cluster first known system to produce more than one multiply SN. Moreover, both...
Abstract Supernova (SN) 2018oh (ASASSN-18bt) is the first spectroscopically confirmed Type Ia supernova (SN Ia) observed in Kepler field. The data revealed an excess emission its early light curve, allowing us to place interesting constraints on progenitor system. Here we present extensive optical, ultraviolet, and near-infrared photometry, as well dense sampling of optical spectra, for this object. SN relatively normal photometric evolution, with a rise time 18.3 ± 0.3 days Δ m 15 ( B ) =...
Abstract We present an analysis of the host-galaxy environment Swope Supernova Survey 2017a (SSS17a), discovery electromagnetic counterpart to a gravitational-wave source, GW170817. SSS17a occurred 1.9 kpc (in projection; 10.″2) from nucleus NGC 4993, S0 galaxy at distance 40 Mpc. Hubble Space Telescope ( HST ) pre-trigger image Magellan optical spectroscopy 4993 and location SSS17a, broadband UV-through-IR photometry 4993. The spectrum spectral-energy distribution indicate that has stellar...
Abstract We present panchromatic observations and modeling of the Calcium-rich supernova (SN) 2019ehk in star-forming galaxy M100 ( d ≈ 16.2 Mpc) starting 10 hr after explosion continuing for ∼300 days. SN shows a double-peaked optical light curve peaking at t = 3 15 The first peak is coincident with luminous, rapidly decaying Swift-XRT–discovered X-ray emission <?CDATA ${L}_{{\rm{x}}}\approx {10}^{41}\,\mathrm{erg}\,{{\rm{s}}}^{-1}$?> days; L x ∝ −3 ), Shane/Kast spectral detection narrow H...