Search Publications
Analysis of Helium-rich White Dwarfs Polluted by Heavy Elements in the Gaia Era
Bergeron, P.; Dufour, P.; Allard, N. F. +4 more
We present an analysis of 1023 DBZ/DZ(A) and 319 DQ white dwarf stars taken from the Montreal White Dwarf Database. This represents a significant increase over the previous comprehensive studies on these types of objects. We use new trigonometric parallax measurements from the Gaia second data release, together with photometry from the Sloan Digit…
Ingredients for solar-like systems: protostar IRAS 16293-2422 B versus comet 67P/Churyumov-Gerasimenko
van Dishoeck, Ewine F.; Drozdovskaya, Maria N.; Jørgensen, Jes K. +2 more
Our modern day Solar System has 4.6 × 109 yr of evolution behind it with just a few relics of its birth conditions remaining. Comets are thought to be some of the most pristine tracers of the initial ingredients that were combined to produce the Earth and the other planets. Other low-mass protostars may be analogous to our proto-Sun and…
Carbon, oxygen, and iron abundances in disk and halo stars. Implications of 3D non-LTE spectral line formation
Skúladóttir, Á.; Amarsi, A. M.; Nissen, P. E.
The abundances of carbon, oxygen, and iron in late-type stars are important parameters in exoplanetary and stellar physics, as well as key tracers of stellar populations and Galactic chemical evolution. However, standard spectroscopic abundance analyses can be prone to severe systematic errors, based on the assumption that the stellar atmosphere i…
The Hubble Legacy Field GOODS-S Photometric Catalog
Franx, Marijn; Mowla, Lamiya; Labbé, Ivo +12 more
This manuscript describes the public release of the Hubble Legacy Fields (HLF) project photometric catalog for the extended GOODS-South region from the Hubble Space Telescope (HST) archival program AR-13252. The analysis is based on the version 2.0 HLF data release that now includes all ultraviolet (UV) imaging, combining three major UV surveys. T…
Hyades tidal tails revealed by Gaia DR2
Goldman, Bertrand; Röser, Siegfried; Schilbach, Elena
Aims: Within a 200 pc sphere around the Sun, we search for the Hyades tidal tails in the Gaia DR2 dataset.
Methods: We used a modified convergent-point method to search for stars with space velocities close to the space velocity of the Hyades cluster.
Results: We find a clear indication for the existence of the Hyades tidal tails, a…
The origin of galactic metal-rich stellar halo components with highly eccentric orbits
Springel, Volker; Grand, Robert J. J.; Gómez, Facundo A. +6 more
Using the astrometry from the ESA's Gaia mission, previous works have shown that the Milky Way stellar halo is dominated by metal-rich stars on highly eccentric orbits. To shed light on the nature of this prominent halo component, we have analysed 28 Galaxy analogues in the Auriga suite of cosmological hydrodynamics zoom-in simulations. Some three…
A Temporary Epoch of Stalled Spin-down for Low-mass Stars: Insights from NGC 6811 with Gaia and Kepler
Agüeros, Marcel A.; Curtis, Jason Lee; Douglas, Stephanie T. +1 more
Stellar rotation was proposed as a potential age diagnostic that is precise, simple, and applicable to a broad range of low-mass stars (≤slant 1 {M}⊙ ). Unfortunately, rotation period ({P}{{rot}}) measurements of low-mass members of open clusters have undermined the idea that stars spin down with a common age dependence (i.e.…
The GALAH survey: An abundance, age, and kinematic inventory of the solar neighbourhood made with TGAS
Freeman, K. C.; Skúladóttir, Á.; Rix, H. -W. +32 more
The overlap between the spectroscopic Galactic Archaeology with HERMES (GALAH) survey and Gaia provides a high-dimensional chemodynamical space of unprecedented size. We present a first analysis of a subset of this overlap, of 7066 dwarf, turn-off, and sub-giant stars. These stars have spectra from the GALAH survey and high parallax precision from…
YBC: a stellar bolometric corrections database with variable extinction coefficients. Application to PARSEC isochrones
Fu, Xiaoting; Girardi, Léo; Marigo, Paola +7 more
We present the YBC database of stellar bolometric corrections, in which we homogenise widely used theoretical stellar spectral libraries and provide BCs for many popular photometric systems, including Gaia filters. The database can easily be extended to additional photometric systems and stellar spectral libraries. The web interface allows users t…
Black Hole Mass Scaling Relations for Early-type Galaxies. I. M BH-M *, sph and M BH-M *,gal
Graham, Alister W.; Davis, Benjamin L.; Sahu, Nandini
Analyzing a sample of 84 early-type galaxies (ETGs) with directly measured supermassive black hole masses -- nearly doubling the sample size of such galaxies with multicomponent decompositions -- a symmetric linear regression on the reduced (merger-free) sample of 76 galaxies reveals MBH ∝ M*,sph1.27+/-0.07 with a …