Related papers: Probing the stellar initial mass function with hig…
The Transiting Exoplanet Survey Satellite (TESS) is the latest observational effort to find exoplanets and map bright transient optical phenomena. Supernovae (SN) are particularly interesting as cosmological standard candles for…
We investigate the detectability of single-event coalescing black hole binaries with total mass of $100-600 M_{\odot}$ at cosmological distances ($5 \lesssim z \lesssim 20$) with the next generation of terrestrial gravitational wave…
Supernovae characterized by enduring narrow optical hydrogen emission lines (SNe IIn) are believed to result primarily from the core-collapse of massive stars undergoing sustained interaction with a dense circumstellar medium (CSM). While…
The origin of high-redshift quasars and their supermassive black hole engines is unclear. One promising solution is the collapse of a primordial supermassive star. Observational confirmation of this scenario may be challenging, but a…
Evolutionary effects with redshift of core collapse supernovae and their application to cosmology have been studied based on an extensive grid of stellar models between 13 and 25 Mo, and their light curves after the explosion. With…
The formation of supermassive Population III stars with masses $\gtrsim$ 10,000 Msun in primeval galaxies in strong UV backgrounds at $z \sim$ 15 may be the most viable pathway to the formation of supermassive black holes by $z \sim$ 7.…
Supernovae that are strongly gravitationally lensed (gLSNe) by galaxies are powerful probes of astrophysics and cosmology that will be discovered systematically by next-generation wide-field, high-cadence imaging surveys such as the Zwicky…
The first direct detection of gravitational waves in 2015 marked the beginning of a new era for the study of compact objects. Upcoming detectors, such as the Einstein Telescope, are expected to add thousands of binary coalescences to the…
The formation of the Universe's first luminous stellar structures depends on the unique conditions at "Cosmic Dawn," which are set by the underlying cosmological model and early baryonic physics. Observations suggest that high-$z$ star…
We present the results of a systematic search for candidate quiescent galaxies in the distant Universe in eleven $JWST$ fields with publicly available observations collected during the first three months of operations and covering an…
Our search for high-redshift Type Ia supernovae discovered, in its first years, a sample of seven supernovae. Using a "batch" search strategy, almost all were discovered before maximum light and were observed over the peak of their light…
The masses and the evolutionary states of the progenitors of core-collapse supernovae are not well constrained by direct observations. Stellar evolution theory generally predicts that massive stars with initial masses less than about…
Supernova (SN) H0pe was discovered as a new transient in James Webb Space Telescope (JWST) NIRCam images of the galaxy cluster PLCK G165.7+67.0 taken as part of the "Prime Extragalactic Areas for Reionization and Lensing Science" (PEARLS)…
Population III (Pop III) stars formed out of metal free gas in minihalos at $z>20$. While their ignition ended the Dark Ages and begin enrichment of the IGM, their mass distribution remains unconstrained. To date, no confirmed Pop III star…
We model the number of detectable supernovae (SNe) as a function of redshift at different flux thresholds, making use of the observed properties of local SNe, such as their lightcurves, fiducial spectra, and peak magnitude distributions. We…
It has been well established from a variety of observations that red supergiants (RSGs) loose a lot of mass in stellar wind. Dust formed in this emitted gas over a few decades before core-collapse can lead to substantial extinction and…
We age-date the stellar populations associated with 12 historic nearby core-collapse supernovae (CCSNe) and 2 supernova impostors, and from these ages, we infer their initial masses and associated uncertainties. To do this, we have obtained…
The James Webb Space Telescope (JWST) is unveiling astounding results about the first few hundred million years of life of the Universe, delivering images of galaxies at very high redshifts. Here, we develop a UV luminosity function model…
We present photometry of 12 recent supernovae (SNe) recovered in a {\it Hubble Space Telescope} Snapshot program, and tie the measurements to earlier ground-based observations, in order to study the late-time evolution of the SNe. Many of…
Eclipse exoplanet spectroscopy has yielded detection of H_2O, CH_4, CO_2 and CO in the atmosphere of hot jupiters and neptunes. About 40 large terrestrial planets are announced or confirmed, two of which are transiting, and another deemed…