A5037076997- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Astro and Planetary Science
- Pulsars and Gravitational Waves Research
- Geophysics and Sensor Technology
- Neutrino Physics Research
- Astrophysics and Cosmic Phenomena
- Adaptive optics and wavefront sensing
University of Toronto
2020-2025
Canadian Institute for Theoretical Astrophysics
2023-2024
The hydrogen-rich outer layers of massive stars can be removed by interactions with a binary companion. Theoretical models predict that this stripping produces population hot helium ~2 to 8 solar masses (M☉), however, only one such system has been identified thus far. We used ultraviolet photometry identify potential stripped then investigated 25 them using optical spectroscopy. high temperatures (~60,000 100,000 kelvin), surface gravities, and hydrogen-depleted surfaces; 16 also showed...
Abstract Massive stars (∼8–25 M ⊙ ) stripped of their hydrogen-rich envelopes via binary interaction are thought to be the main progenitors for merging neutron and stripped-envelope supernovae. We recently presented discovery first set such in a companion paper. Here, we fit spectra 10 with new atmosphere models order constrain stellar properties precisely. find that align well theoretical expectations from evolution helium-core burning envelope-stripped stars. The fits confirm have high...
Abstract In previous work, we identified a population of 38 cool and luminous variable stars in the Magellanic Clouds examined 11 detail order to classify them as either Thorne–Żytkow objects (TŻOs; red supergiants with neutron star cores) or super-asymptotic giant branch (sAGB) (the most massive that will not undergo core collapse). This includes HV 2112, peculiar previously considered other works be TŻO high-mass asymptotic (AGB) star. Here continue this investigation, using kinematic...
Stars stripped of their hydrogen-rich envelopes through binary interaction are thought to be responsible for both hydrogen-poor supernovae and the hard ionizing radiation observed in low-Z galaxies. A population these stars was recently first time, but prevalence remains unknown. In preparation such measurements, we estimate mass distribution hot, using a synthesis code that interpolates over detailed single stellar evolution tracks. We predict constant star formation rate $1 ,M_⊙$/yr...
Abstract Binary interaction can cause stellar envelopes to be stripped, which significantly reduces the radius of star. The orbit a binary composed stripped star and compact object therefore so tight that gravitational radiation system produces reaches frequencies accessible Laser Interferometer Space Antenna (LISA). Two such stars in orbits with white dwarfs are known far (ZTF J2130+4420 CD−30°11223), but many more expected exist. These binaries provide important constraints for evolution...
The theory of binary evolution predicts that many massive stars should lose their hydrogen-rich envelopes via interaction with a companion -- revealing hot helium masses $\sim$2--8M$_{\odot}$. However, only one candidate system had been identified, leaving large discrepancy between and observation. Here, we present new sample identified excess ultraviolet emission whose luminosities, colors, spectral morphologies are consistent predictions for the missing population. We detect radial...
Massive stars (~8-25Msun) stripped of their hydrogen-rich envelopes via binary interaction are thought to be the main progenitors for merging neutron and stripped-envelope supernovae. We recently presented discovery first set such in a companion paper. Here, we fit spectra ten with new atmosphere models order constrain stellar properties precisely. find that align well theoretical expectations from evolution helium-core burning envelope-stripped stars. The fits confirm have high effective...
Recent works have constrained the binary fraction of evolved populations massive stars in local galaxies such as red supergiants and Wolf-Rayet stars, but yellow (YSGs) Hertzsprung Gap remains unconstrained. Binary evolution theory predicts that is home to multiple systems with varied evolutionary histories. In this paper, we develop a method distinguish single YSGs from YSG plus O- or B-type main sequence binaries using optical ultraviolet photometry, then apply identify candidate...
Abstract Recent works have constrained the binary fraction of evolved populations massive stars in local galaxies such as red supergiants and Wolf–Rayet stars, but yellow (YSGs) Hertzsprung gap remains unconstrained. Binary evolution theory predicts that is home to multiple systems with varied evolutionary histories. In this paper, we develop a method distinguish single YSGs from YSG plus O- or B-type main-sequence binaries using optical ultraviolet photometry, then apply identify candidate...
Surveys in the Milky Way and Large Magellanic Cloud revealed that majority of massive stars will interact with companions during their lives. However, knowledge binary properties at low metallicity, which approaches conditions Early Universe, remains sparse. We present Binarity LOw Metallicity (BLOeM) campaign - an ESO large programme designed to obtain 25 epochs spectroscopy for 929 SMC lowest metallicity multiplicity is probed date (Z = 0.2 Zsun). BLOeM provide (i) fraction, (ii) orbital...
Stars stripped of their hydrogen-rich envelopes through binary interaction are thought to be responsible for both hydrogen-poor supernovae and the hard ionizing radiation observed in low-$Z$ galaxies. A population these stars was recently first time, but prevalence remains unknown. In preparation such measurements, we estimate mass distribution hot, using a synthesis code that interpolates over detailed single stellar evolution tracks. We predict constant star-formation rate $1 \,M_\odot$/yr...
In previous work we identified a population of 38 cool and luminous variable stars in the Magellanic Clouds examined 11 detail order to classify them as either Thorne-Żytkow Objects (TŻOs, red supergiants with neutron star cores) or super-AGB (the most massive that will not undergo core collapse). This includes HV\,2112, peculiar previously considered other works be TŻO high-mass AGB star. Here continue this investigation, using kinematic radio environments local formation history these...