A5003797442- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Solar and Space Plasma Dynamics
- Astrophysics and Cosmic Phenomena
- Astro and Planetary Science
- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Astronomy and Astrophysical Research
- Calibration and Measurement Techniques
- Galaxies: Formation, Evolution, Phenomena
- Infrared Target Detection Methodologies
- Inorganic Fluorides and Related Compounds
- Geophysics and Gravity Measurements
- Geomagnetism and Paleomagnetism Studies
- Computer Graphics and Visualization Techniques
- Cardiovascular Disease and Adiposity
- Solid-state spectroscopy and crystallography
- Electron and X-Ray Spectroscopy Techniques
- Cephalopods and Marine Biology
- Material Science and Thermodynamics
- Advanced Semiconductor Detectors and Materials
- Advanced Chemical Physics Studies
- Neurobiology and Insect Physiology Research
Michigan State University
2021-2024
Campbell Collaboration
2022
University of Denver
2015-2021
Abstract Stripped-envelope supernovae (SESNe) represent a significant fraction of core-collapse supernovae, arising from massive stars that have shed their hydrogen and, in some cases, helium envelopes. The origins and explosion mechanisms SESNe remain topic active investigation. In this work, we employ radiative-transfer simulations to model the light curves spectra set explosions single, solar-metallicity, Wolf–Rayet with ejecta masses ranging 4 11 M ⊙ , which were computed...
We present the first results of a comprehensive supernova (SN) radiative-transfer (RT) code-comparison initiative (StaNdaRT), where emission from same set standardized test models is simulated by currently-used RT codes. A total ten codes have been run on four benchmark ejecta Type Ia supernovae. consider two sub-Chandrasekhar-mass ($M_\mathrm{tot} = 1.0$ M$_\odot$) toy with analytic density and composition profiles Chandrasekhar-mass delayed-detonation that are outcomes hydrodynamical...
Type Ia Supernovae (SNe Ia) are securely understood to come from the thermonuclear explosion of a white dwarf as result binary interaction, but nature that interaction and secondary object is uncertain. Recently, double model known dynamically driven double-degenerate double-detonation (D6) has become promising explanation for these events. One realization this scenario predicts companion may survive reside within remnant fast moving ($V_{peculiar} >1000$ km s$^{-1}$), overluminous ($L > 0.1...
Using results from the Herschel Astrophysical Terrahertz Large-Area Survey (H-ATLAS) and Galaxy Mass Assembly (GAMA) project, we show that, for galaxy masses above ≃ 108 M⊙, 51 per cent of stellar mass-density in local Universe is early-type galaxies (ETGs; Sérsic n > 2.5) while 89 rate production occurring late-type (LTGs; < 2.5). From this zero-redshift benchmark, have used a calorimetric technique to quantify importance morphological transformation over history Universe. The extragalactic...
We present the first visual orbit for nitrogen-rich Wolf-Rayet binary, WR 133 (WN5o + O9I) based on observations made with CHARA Array and MIRC-X combiner. This represents a WN star only third orbit. The has period of 112.8 d, moderate eccentricity 0.36, separation $a$= 0.79 mas sky. combine an SB2 Gaia parallax to find that derived masses component stars are $M_{\rm WR}$ = $9.3\pm1.6 M_\odot$ O}$ $22.6\pm 3.2 M_\odot$, large errors owing nearly face-on geometry system combined in...
Abstract Wolf–Rayet stars have strong, hot winds, with mass-loss rates at least a factor of 10 greater than their O-star progenitors, although terminal wind speeds are similar. In this paper, we use the technique multiband linear polarimetry to extract information on global asymmetry in sample 47 bright Galactic WR stars. Our observations also include time-dependent 17 sample. The path our goal includes removing dominating component wavelength-dependent interstellar polarization (ISP), which...
Abstract Type Ia supernovae (SNe) remain poorly understood despite decades of investigation. Massive computationally intensive hydrodynamic simulations have been developed and run to model an ever-growing number proposed progenitor channels. Further complicating the matter, a large subtypes SNe identified in recent decades. Due massive computational load required, inference internal structure ejecta directly from observations using has previously intractable. However, deep-learning emulators...
Abstract Manual fits to spectral times series of Type Ia supernovae have provided a method reconstructing the explosion from parametric model but due lack information about uncertainties or parameter degeneracies direct comparison between theory and observation is difficult. In order mitigate this important problem we present new way probabilistically reconstruct outer ejecta normal supernova SN 2002bo. A single epoch spectrum, taken 10 days before maximum light, fit by 13-parameter...
Type Ia supernovae remain poorly understood despite decades of investigation. Massive computationally intensive hydrodynamic simulations have been developed and run to model an ever-growing number proposed progenitor channels. Further complicating the matter, a large sub-types identified in recent decades. Due massive computational load required, inference internal structure ejecta directly from observations using has previously intractable. However, deep-learning emulators for radiation...
ABSTRACT We study the polarization produced by scattering from dust in a bow shock-shaped region of enhanced density surrounding stellar source, using Monte Carlo radiative transfer code SLIP. Bow shocks are structures formed interaction winds fast-moving stars with interstellar medium. Our previous focused on these electron scattering; we showed that is highly dependent inclination angle and multiple changes shape degree polarization. In contrast to scattering, wavelength-dependent, which...
Massive star binaries are critical laboratories for measuring masses and stellar wind mass-loss rates. A major challenge is inferring viewing inclination extracting information about the colliding interaction (CWI) region. Polarimetric variability from electron scattering in highly ionized winds provides important diagnostic system geometry. We combine first time well-known generalized treatment of \citet{brown_polarisation_1978} variable polarization with semi-analytic solution geometry...
ABSTRACT Near-infrared (NIR) observations of normal Type Ia supernovae (SNe Ia) obtained between 150 and 500 d past maximum light reveal the existence an extended plateau. Here, we present underluminous, 1991bg-like SN 2021qvv. Early, ground-based optical NIR show that 2021qvv is similar to 2006mr, making it one dimmest, fastest evolving SNe date. Late-time (170–250 d) Hubble Space Telescope no sign a An extrapolation these backwards earlier-phase 2006mr suggests complete absence plateau, at...
Abstract Understanding the evolution of massive binary stars requires accurate estimates their masses. This understanding is critically important because star can potentially lead to gravitational-wave sources such as black holes or neutron stars. For Wolf–Rayet (WR) with optically thick stellar winds, masses only be determined inclination angle from systems which have spectroscopic <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>M</mml:mi>...
We analyse 45 spectropolarimetric observations of the eclipsing, interacting binary star V356 Sgr, obtained over a period ∼21 yr, to characterize geometry system's circumstellar material. After removing interstellar polarization from these data, we find that system exhibits large intrinsic signature arising electron scattering. In addition, lack repeatable eclipses in phase curves indicates presence substantial pool scatterers not occulted by either star. suggest form circumbinary disc...
We present a general surface brightness correction method for compact extended sources imaged in the slow-scan pointed observation mode of Far-Infrared Surveyor (FIS) aboard AKARI Infrared Astronomical Satellite. Our recovers correct distribution maps by re-scaling archived raw FIS using surface-brightness-dependent inverse response function. The flux target source is then automatically corrected as simple sum brightnesses within adopted contour encircling perimeter (i.e., photometry). This...
The AKARI Infrared Astronomical Satellite produced the all-sky survey (AFASS) maps in far-IR at roughly arc-minute spatial resolution, enabling us to investigate whole sky for objects having surface brightnesses greater than a few couple of dozen MJy/sr. While AFASS are absolutely calibrated against large-scale diffuse emission, it was uncertain whether or not an additional flux correction point sources necessary. Here, we verify that calibration point-source photometry is proper. With...
Stripped-envelope supernovae (SESNe) represent a significant fraction of core-collapse supernovae, arising from massive stars that have shed their hydrogen and, in some cases, helium envelopes. The origins and explosion mechanisms SESNe remain topic active investigation. In this work, we employ radiative-transfer simulations to model the light curves spectra set explosions single, solar-metallicity, Wolf-Rayet (WR) with ejecta masses ranging 4 11 Msun, were computed turbulence-aided...
We present new spectropolarimetric data for WR 42 collected over 6 months at the 11-m Southern African Large Telescope (SALT) using Robert Stobie Spectrograph.
Abstract The AKARI Far-IR All-Sky Survey (AFASS) maps produced by the Infrared Astronomical Satellite enabled us to probe far-IR sky for objects having surface brightnesses greater than a few couple of dozen MJy sr −1 . Recently, we have verified that, if AFASS-measured fluxes are properly corrected using aperture correction method based on empirical point-spread-function templates derived directly from AFASS maps, point-source photometry measured reproduces in bright source catalogue (BSC)....
The far-IR all-sky mapping data obtained by the AKARI Astronomical Satellite were released to public in January 2015. These maps are expected provide us with further insights into our understanding of universe for first time since IRAS, especially extended objects. While calibrated against diffuse background emission and a flux correction scheme point sources is provided, it not necessarily obvious how one flux-corrects sources. Here, we briefly summarize new flux-correction method objects...