Search Publications
Effect of binary evolution on the inferred initial and final core masses of hydrogen-rich, Type II supernova progenitors
Smith, N.; Renzo, M.; Zapartas, E. +3 more
The majority of massive stars, which are the progenitors of core-collapse supernovae (SNe), are found in close binary systems. In a previous work, we modeled the fraction of hydrogen-rich, Type II SN progenitors whose evolution is affected by mass exchange with their companion, finding this to be between ≈1/3 and 1/2 for most assumptions. Here we …
The R-Process Alliance: Chemodynamically Tagged Groups of Halo r-process-enhanced Stars Reveal a Shared Chemical-evolution History
Beers, Timothy C.; Holmbeck, Erika M.; Hansen, Terese T. +11 more
We derive dynamical parameters for a large sample of 446 r-process-enhanced (RPE) metal-poor stars in the halo and disk systems of the Milky Way, based on data releases from the R-Process Alliance, supplemented by additional literature samples. This sample represents more than a 10-fold increase in size relative to that previously considered by Ro…
White dwarf-main-sequence binaries from Gaia EDR3: the unresolved 100 pc volume-limited sample
Althaus, L. G.; Solano, E.; Rebassa-Mansergas, A. +6 more
We use the data provided by the Gaia Early Data Release 3 to search for a highly complete volume-limited sample of unresolved binaries consisting of a white dwarf and a main-sequence companion (i.e. WDMS binaries) within 100 pc. We select 112 objects based on their location within the Hertzsprung-Russell diagram, of which 97 are new identification…
ML-MOC: Machine Learning (kNN and GMM) based Membership determination for Open Clusters
Vaidya, Kaushar; Rao, Khushboo K.; Agarwal, Manan +1 more
The existing open-cluster membership determination algorithms are either prior dependent on some known parameters of clusters or are not automatable to large samples of clusters. In this paper, we present ML-MOC, a new machine-learning-based approach to identify likely members of open clusters using the Gaia DR2 data and no a priori information ab…
Ultraviolet spectra of extreme nearby star-forming regions: Evidence for an overabundance of very massive stars
Charlot, Stéphane; Chevallard, Jacopo; Stark, Daniel P. +3 more
As deep spectroscopic campaigns extend to higher redshifts and lower stellar masses, the interpretation of galaxy spectra depends increasingly upon models for very young stellar populations. Here we present new HST/COS ultraviolet spectroscopy of seven nearby (<120 Mpc) star-forming regions hosting very young stellar populations (~4-20 Myr) wit…
Light Elements in the Universe
Magrini, Laura; Randich, Sofia
Due to their production sites, as well as to how they are processed and destroyed in stars, the light elements are excellent tools to investigate a number of crucial issues in modern astrophysics: from stellar structure and non-standard processes at work in stellar interiors to age dating of stars; from pre-main sequence evolution to the star form…
Exploring the foundations of the physical universe with space tests of the equivalence principle
Métris, Gilles; Rodrigues, Manuel; Loriani, Sina +34 more
We present the scientific motivation for future space tests of the equivalence principle, and in particular the universality of free fall, at the 10− 17 level or better. Two possible mission scenarios, one based on quantum technologies, the other on electrostatic accelerometers, that could reach that goal are briefly discussed. This pub…
Spitzer Phase-curve Observations and Circulation Models of the Inflated Ultrahot Jupiter WASP-76b
Deming, Drake; Fortney, Jonathan J.; Stevenson, Kevin B. +15 more
The large radii of many hot Jupiters can only be matched by models that have hot interior adiabats, and recent theoretical work has shown that the interior evolution of hot Jupiters has a significant impact on their atmospheric structure. Due to its inflated radius, low gravity, and ultrahot equilibrium temperature, WASP-76b is an ideal case study…
TIC 172900988: A Transiting Circumbinary Planet Detected in One Sector of TESS Data
Kostov, Veselin B.; Powell, Brian P.; Torres, Guillermo +85 more
We report the first discovery of a transiting circumbinary planet detected from a single sector of Transiting Exoplanet Survey Satellite (TESS) data. During Sector 21, the planet TIC 172900988b transited the primary star and then five days later it transited the secondary star. The binary is itself eclipsing, with a period P ≈ 19.7 days and an ecc…
Ultra-low-frequency gravitational waves from cosmological and astrophysical processes
Moore, Christopher J.; Vecchio, Alberto
Gravitational waves at ultra-low frequencies (≲100 nHz) are key to understanding the assembly and evolution of astrophysical black hole binaries with masses ~106-109 M⊙ at low redshifts1-3. These gravitational waves also offer a unique window into a wide variety of cosmological processes4-11. …