David Matthews
A5015032746- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Astronomical Observations and Instrumentation
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Advanced X-ray and CT Imaging
- Adaptive optics and wavefront sensing
- Optical Systems and Laser Technology
- Laser-Plasma Interactions and Diagnostics
- Solar and Space Plasma Dynamics
- Advanced Optical Sensing Technologies
- Ionosphere and magnetosphere dynamics
- Particle Accelerators and Free-Electron Lasers
- Scientific Measurement and Uncertainty Evaluation
- Radio Astronomy Observations and Technology
- Legume Nitrogen Fixing Symbiosis
- Magnetic confinement fusion research
- Soybean genetics and cultivation
- Cardiac Arrest and Resuscitation
- Superconducting and THz Device Technology
- Galaxies: Formation, Evolution, Phenomena
- Ocular and Laser Science Research
- LGBTQ Health, Identity, and Policy
Centre for Addiction and Mental Health
2024
University of California, Berkeley
2022-2023
Northwestern University
2021-2022
Queen's University Belfast
1982
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...
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...
For the first $\sim3$ years after binary neutron star merger event GW 170817 radio and X-ray radiation has been dominated by emission from a structured relativistic off-axis jet propagating into low-density medium with n $< 0.01\,\rm{cm^{-3}}$. We report on observational evidence for an excess of at $\delta t>900$ days merger. With $L_x\approx5\times 10^{38}\,\rm{erg\,s^{-1}}$ 1234 days, recently detected represents $\ge 3.2\,\sigma$ (Gaussian equivalent) deviation universal post jet-break...
We present multiwavelength observations of the Type II SN 2020pni. Classified at $\sim 1.3$ days after explosion, object showed narrow (FWHM $<250\,\textrm{km}\,\textrm{s}^{-1}$) recombination lines ionized helium, nitrogen, and carbon, as typically seen in flash-spectroscopy events. Using non-LTE radiative transfer code CMFGEN to model our first high resolution spectrum, we infer a progenitor mass-loss rate $\dot{M}=(3.5-5.3)\times10^{-3}$ M$_{\odot}$ yr$^{-1}$ (assuming wind velocity...
Abstract We present deep X-ray and radio observations of the fast blue optical transient (FBOT) AT 2020xnd/ZTF 20acigmel at z = 0.2433 from 13 days to 269 after explosion. 2020xnd belongs category optically luminous FBOTs with similarities archetypal event 2018cow. shows emission reaching L ν ≈ 8 × 10 29 erg s −1 Hz 20 GHz 75 post-explosion, accompanied by rapidly fading soft peaking X 6 42 . Interpreting in context synchrotron radiation explosion’s shock interaction environment, we find...
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...
Abstract We present a new photometric pipeline for the detection of pre-supernova (pre-SN) emission in Young Supernova Experiment (YSE) sky survey. The method described is applied to SN 2020tlf, type II with precursor last ~100 days before first light. re-analyze YSE griz -band light curves 2020tlf and provide revised pre-explosion photometry that includes robust list confident limiting magnitudes. Compared results W. V. Jacobson-Galán et al., this analysis yields fewer total r / i z pre-SN...
Abstract Luminous interacting supernovae (SNe) are a class of stellar explosions whose progenitors underwent vigorous mass loss in the years prior to core collapse. While mechanism by which this material is ejected still debated, obtaining full density profile circumstellar medium (CSM) could reveal more about process. Here, we present an extensive multiwavelength study PS1-11aop, luminous and slowly declining Type IIn SNe discovered Pan-STARRS Medium Deep Survey. PS1-11aop had peak r -band...
Abstract We present the X-ray monitoring campaign of AT2022tsd in time range δ t rest = 23–116 days rest-frame since discovery. With an initial 0.3–10 keV luminosity L x ≈ 10 44 erg s −1 at 23 days, is most luminous FBOT to date and rivals GRBs. find no statistical evidence for spectral evolution. The average spectrum well-described by absorbed simple power-law model with best-fitting photon index <?CDATA ${\rm{\Gamma }}={1.89}_{-0.08}^{+0.09}$?> <mml:math...
Abstract We present the results from a multiyear radio campaign of superluminous supernova (SLSN) SN 2017ens, which yielded earliest detection an SLSN to date at age ∼3.3 yr after explosion. 2017ens was not detected frequencies in first ∼300 days but reached L ν ≈ 10 28 erg s −1 cm −2 Hz ∼ 6 GHz, ∼1250 post Interpreting observations context synchrotron radiation shock interaction with circumstellar medium (CSM), we infer effective mass-loss rate <mml:math...
Abstract We report multiwavelength observations and characterization of the ultraluminous transient AT 2021lwx (ZTF20abrbeie; aka “Barbie”) identified in alert stream Zwicky Transient Facility (ZTF) using a Recommender Engine For Intelligent Tracking filter on ANTARES broker. From spectroscopically measured redshift 0.995, we estimate peak-observed pseudo-bolometric luminosity log( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow>...
We present UV/optical observations and models of supernova (SN) 2023ixf, a type II 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 photo-ionization dense, close-in circumstellar material (CSM) around progenitor star prior to shock breakout. These electron-scattering broadened line profiles persist for $\sim$8 days respect...
SUMMARY Soya-bean plants were grown for 40 days in a range of root temperatures from 10 to 25°C either medium containing N but uninoculated or N-free inoculated with Rhizobium japonicum . Low temperature restricted growth both cases the depending solely on symbiotic N-fixation much more affected. At CC failed nodulate nodulation and nitrogen fixation increased greatly 15–25°C. It is concluded that soya beans sown cool soils would benefit applied at sowing time.
We report on new Very Long Baseline Interferometry radio measurements of supernova 2014C in the spiral galaxy NGC 7331, made with European VLBI Network ~5 yr after explosion, as well flux density Jansky Large Array (VLA). SN was an unusual supernova, initially Type Ib, but over course ~1 it developed strong H$\alpha$ lines, implying onset interaction some H-rich circumstellar medium (CSM). The expanding shock-front interacted a dense shell material during first year, has now emerged from and...
Introduction Transgender and gender diverse (TGD) people are disproportionately negatively impacted by gaps in several social determinants of health (SDH) domains.
Luminous interacting supernovae are a class of stellar explosions whose progenitors underwent vigorous mass loss in the years prior to core-collapse. While mechanism by which this material is ejected still debated, obtaining full density profile circumstellar medium (CSM) could reveal more about process. Here, we present an extensive multi-wavelength study PS1-11aop, luminous and slowly declining Type IIn SN discovered PanSTARRS Medium Deep Survey. PS1-11aop had peak r-band magnitude...
We present pre-explosion 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 mid-IR...
We present the results from a multi-year radio campaign of superluminous supernova (SLSN) 2017ens, which yielded earliest detection SLSN to date at age $\sim$3.3 years after explosion. SN2017ens was not detected frequencies in first $\sim$300\,d evolution but reached $L_{\nu}\approx 10^{28}\,\rm{erg\,s^{-1}\,cm^{-2}}$ $\nu\sim 6$ GHz, $\sim1250$ days post-explosion. Interpreting observations context synchrotron radiation shock interaction with circumstellar medium (CSM), we infer an...