Search Publications
Revisiting the Impact of Dust Production from Carbon-rich Wolf-Rayet Binaries
Sakon, Itsuki; Williams, Peredur M.; Lau, Ryan M. +3 more
We present a dust spectral energy distribution (SED) and binary stellar population analysis revisiting the dust production rates (DPRs) in the winds of carbon-rich Wolf-Rayet (WC) binaries and their impact on galactic dust budgets. DustEM SED models of 19 Galactic WC "dustars" reveal DPRs of ${\dot{M}}_{d}\sim {10}^{-10}\mbox{--}{10}^{-6}$ M⊙…
Gaia-DR2 extended kinematical maps. II. Dynamics in the Galactic disk explaining radial and vertical velocities
Wang, H. -F.; López-Corredoira, M.; Chang, J. +5 more
Context. In our Paper I, by using statistical deconvolution methods, extended kinematics maps of Gaia-DR2 data have been produced in a range of heliocentric distances that are a factor of two to three larger than those analyzed previously by the Gaia Collaboration with the same data. It added the range of Galactocentric distances between 13 kpc an…
TOI-481 b and TOI-892 b: Two Long-period Hot Jupiters from the Transiting Exoplanet Survey Satellite
Trifonov, Trifon; Henning, Thomas; Bieryla, Allyson +75 more
We present the discovery of two new 10 day period giant planets from the Transiting Exoplanet Survey Satellite mission, whose masses were precisely determined using a wide diversity of ground-based facilities. TOI-481 b and TOI-892 b have similar radii (0.99 ± 0.01 ${R}_{{\rm{J}}}$ and 1.07 ± 0.02 ${R}_{{\rm{J}}}$ , respectively), and orbital peri…
Discovery of Two Pulsating Extremely Low-mass Pre-white Dwarf Candidates in the TESS Eclipsing Binaries
Zhang, Xiaobin; Wang, Kun; Dai, Min
We report the discovery of two new pulsating extremely low-mass pre-white dwarf (pre-ELMV) candidates in the Transiting Exoplanet Survey Satellite (TESS) eclipsing binaries, TIC 149160359 and TIC 416264037. Their light curves show a typical feature of EL CVn-type binaries. The light-curve modeling indicates that they are both detached systems with…
Chemical abundances of 1111 FGK stars from the HARPS-GTO planet search sample. III. Sulfur
Tsantaki, M.; Costa Silva, A. R.; Delgado Mena, E.
Context. Elemental abundances are of prime importance to help us reconstruct the origin and evolution of stars and galaxies in our Universe. Sulfur abundances have not been as heavily studied as other elements, so some details regarding their behaviour are still unclear.
Aims: We aim to investigate [S/Fe] ratios in stars of the solar neighbou…
First Results on Dark Matter Substructure from Astrometric Weak Lensing
Van Tilburg, Ken; Weiner, Neal; Taki, Anna-Maria +1 more
Low-mass structures of dark matter (DM) are expected to be entirely devoid of light-emitting regions and baryons. Precisely because of this lack of baryonic feedback, small-scale substructures of the Milky Way are a relatively pristine testing ground for discovering aspects of DM microphysics and primordial fluctuations on subgalactic scales. In t…
The Milky Way's stellar streams and globular clusters do not align in a Vast Polar Structure
Riley, Alexander H.; Strigari, Louis E.
There is increasing evidence that a substantial fraction of Milky Way satellite galaxies align in a rotationally supported plane of satellites, a rare configuration in cosmological simulations of galaxy formation. It has been suggested that other Milky Way substructures (namely young halo globular clusters and stellar/gaseous streams) similarly te…
Cosmological Insights into the Early Accretion of r-process-enhanced Stars. I. A Comprehensive Chemodynamical Analysis of LAMOST J1109+0754
Zhao, Gang; Beers, Timothy C.; Placco, Vinicius M. +11 more
This study presents a comprehensive chemodynamical analysis of LAMOST J1109+0754, a bright (V = 12.8), extremely metal-poor ([Fe/H] = -3.17) star, with a strong r-process enhancement ([Eu/Fe] = +0.94 ± 0.12). Our results are based on the 7D measurements supplied by Gaia and the chemical composition derived from a high-resolution (R ∼ 110,000), hig…
Effective J -factors for Milky Way dwarf spheroidal galaxies with velocity-dependent annihilation
Pace, Andrew B.; Kumar, Jason; Runburg, Jack +2 more
We calculate the effective J -factors, which determine the strength of indirect detection signals from dark matter annihilation, for 25 dwarf spheroidal galaxies (dSphs). We consider several well-motivated assumptions for the relative velocity dependence of the dark matter annihilation cross section: σAv : s -wave (velocity independent)…
NGC 4993, the shell galaxy host of GW170817: constraints on the recent galactic merger
Ebrová, I.; Bílek, M.; Yıldız, M. K. +1 more
Context. NGC 4993 is the shell galaxy host of the GRB170817A short gamma-ray burst and the GW170817 gravitational-wave event produced during a binary-neutron-star coalescence.
Aims: The galaxy shows signs, including the stellar shells, that it has recently accreted a smaller, late-type galaxy. The accreted galaxy might be the original host of…