A5012957683- 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
- Astro and Planetary Science
- Nuclear Physics and Applications
- Galaxies: Formation, Evolution, Phenomena
- Astronomical Observations and Instrumentation
- Geophysics and Gravity Measurements
- Cosmology and Gravitation Theories
- Spectroscopy Techniques in Biomedical and Chemical Research
- Spectroscopy and Laser Applications
- CCD and CMOS Imaging Sensors
- Particle Detector Development and Performance
- Advanced Power Generation Technologies
- Particle Accelerators and Free-Electron Lasers
- Mitochondrial Function and Pathology
- Neutrino Physics Research
- Influenza Virus Research Studies
- Radio Astronomy Observations and Technology
- Laser Design and Applications
- Spacecraft and Cryogenic Technologies
- History and Developments in Astronomy
Lancaster University
2024
Centre National de la Recherche Scientifique
2024
Aix-Marseille Université
2024
Austin Peay State University
2024
University of Zurich
2024
National Central University
2020-2024
Ludwig-Maximilians-Universität München
2024
American Public University System
2024
Stanford University
2024
Oak Ridge National Laboratory
2024
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...
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,...
We present the results of a Palomar Transient Factory (PTF) archival search for blue transients which lie in magnitude range between "normal" core-collapse and superluminous supernovae (i.e. with $-21\,{\leq}M_{R\,(peak)}\,{\leq}-19$). Of six events found after excluding all interacting Type~IIn Ia-CSM supernovae, three (PTF09ge, 09axc 09djl) are coincident centers their hosts, one (10iam) is offset from center, two (10nuj 11glr) precise can not be determined. All central have similar rise...
Stellar Explosions Stars that are born with masses greater than eight times of the Sun end their lives in luminous explosions known as supernovae. Over past decade, access to improved sky surveys has revealed rare types supernovae much more any those were before. Gal-Yam (p. 927 ) reviews these superluminous events and groups them into three classes share common observational physical characteristics. Gamma-ray bursts another type extreme explosive related death massive stars, which occur...
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...
We report the results of a three-year-long dedicated monitoring campaign restless luminous blue variable (LBV) in NGC 7259. The object, named SN 2009ip, was observed photometrically and spectroscopically optical near-infrared domains. monitored number erupting episodes past few years, increased density our observations during eruptive episodes. In this paper, we present full historical data set from 2009 to 2012 with multi-wavelength dense coverage two high-luminosity events between August...
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 an improved measurement of the Hubble constant (H_0) using 'inverse distance ladder' method, which adds information from 207 Type Ia supernovae (SNe Ia) Dark Energy Survey (DES) at redshift 0.018 < z 0.85 to existing measurements 122 low (z 0.07) SNe (Low-z) and Baryon Acoustic Oscillations (BAOs). Whereas traditional H_0 with use a ladder parallax Cepheid variable stars, inverse relies on absolute BAOs calibrate intrinsic magnitude Ia. find = 67.8 +/- 1.3 km s-1 Mpc-1...
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 Fast X-ray transients (FXTs) are extragalactic bursts of X-rays first identified in archival data and now routinely discovered real time by the Einstein Probe, which is continuously surveying night sky soft (0.5–4 keV) regime. In this Letter, we report discovery second optical counterpart (AT 2024gsa) to an FXT (EP 240414a). EP 240414a located at a projected radial separation 27 kpc from its likely host galaxy z = 0.4018 ± 0.0010. The light curve AT 2024gsa displays three distinct...
On May 31, 2011 UT a supernova (SN) exploded in the nearby galaxy M51 (the Whirlpool Galaxy). We discovered this event using small telescopes equipped with CCD cameras, as well by Palomar Transient Factory (PTF) survey, and rapidly confirmed it to be Type II supernova. Our early light curve spectroscopy indicates that PTF11eon resulted from explosion of relatively compact progenitor star evidenced rapid shock-breakout cooling seen curve, low temperature early-time spectra prompt appearance...
Owing to their utility for measurements of cosmic acceleration, Type Ia supernovae (SNe) are perhaps the best-studied class SNe, yet progenitor systems these explosions largely remain a mystery. A rare subclass SNe show evidence strong interaction with circumstellar medium (CSM), and in particular, hydrogen-rich CSM; we refer them as Ia-CSM. In first systematic search such systems, have identified 16 Ia-CSM, here present new spectra 13 them. Six Ia-CSM been well-studied previously, three...
The nearby Type Ia supernova (SN Ia) SN 2011fe in M101 (cz = 241 km s−1) provides a unique opportunity to study the early evolution of "normal" Ia, its compositional structure, and elusive progenitor system. We present 18 high signal-to-noise spectra during first month beginning 1.2 days post-explosion with an average cadence 1.8 days. This gives clear picture how various line-forming species are distributed within outer layers ejecta, including that unburned material (C+O). follow C ii...
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,...
We present spectroscopic observations of the host galaxies 82 low-redshift Type Ia supernovae (SNe Ia) discovered by Palomar Transient Factory. determine star formation rates, gas-phase/stellar metallicities, and stellar masses ages these objects. As expected, strong correlations between SN light-curve width (stretch) age/mass/metallicity are found: fainter, faster declining events tend to be hosted older/massive/metal-rich galaxies. There is some evidence that redder SNe explode in higher...
A key tracer of the elusive progenitor systems Type Ia supernovae (SNe Ia) is detection narrow blueshifted time-varying Na i D absorption lines, interpreted as evidence circumstellar material surrounding system. The origin this controversial, but simplest explanation that it results from previous mass-loss in a system containing white dwarf and non-degenerate companion star. We present new single-epoch intermediate-resolution spectra 17 low-redshift SNe taken with XShooter on European...
A spectral-energy distribution (SED) model for Type Ia supernovae (SNe Ia) is a critical tool measuring precise and accurate distances across large redshift range constraining cosmological parameters. We present an improved framework, SALT3, which has several advantages over current models including the leading SALT2 (SALT2.4). While SALT3 similar philosophy, it differs from by having estimation of uncertainties, better separation color light-curve stretch, publicly available training code....
We describe catalog-level simulations of Type Ia supernova (SN~Ia) light curves in the Dark Energy Survey Supernova Program (DES-SN), and low-redshift samples from Center for Astrophysics (CfA) Carnegie Project (CSP). These are used to model biases selection effects curve analysis, determine bias corrections SN~Ia distance moduli that measure cosmological parameters. To generate realistic curves, simulation uses a detailed model, incorporates information observations (PSF, sky noise, zero...