Search Publications

New white dwarf envelope models and diffusion. Application to DQ white dwarfs
DOI: 10.1051/0004-6361/202037530 Bibcode: 2020A&A...635A.103K

Kepler, S. O.; Koester, D.; Irwin, A. W.

Context. Recent studies of the atmospheres of carbon-rich (DQ) white dwarfs have demonstrated the existence of two different populations that are distinguished by the temperature range, but more importantly, by the extremely high masses of the hotter group. The classical DQ below 10 000 K are well understood as the result of dredge-up of carbon by…

2020 Astronomy and Astrophysics
Gaia 58
The Regulation of Galaxy Growth along the Size-Mass Relation by Star Formation, as Traced by Hα in KMOS3D Galaxies at 0.7 ≲ z ≲ 2.7
DOI: 10.3847/1538-4357/ab7914 Bibcode: 2020ApJ...892....1W

Übler, Hannah; van Dokkum, Pieter; Momcheva, Ivelina +24 more

We present half-light sizes measured from Hα emission tracing star formation in 281 star-forming galaxies from the KMOS3D survey at 0.7≲ z ≲ 2.7. Sizes are derived by fitting 2D exponential disk models, with bootstrap errors averaging 20%. Hα sizes are a median (mean) of 1.19 (1.26) times larger than those of the stellar continuum—which…

2020 The Astrophysical Journal
eHST 58
An Information Theoretic Framework for Classifying Exoplanetary System Architectures
DOI: 10.3847/1538-3881/ab8e3c Bibcode: 2020AJ....159..281G

Fabrycky, Daniel C.; Gilbert, Gregory J.

We propose several descriptive measures to characterize the arrangements of planetary masses, periods, and mutual inclinations within exoplanetary systems. These measures are based on complexity theory and capture the global, system-level trends of each architecture. Our approach considers all planets in a system simultaneously, facilitating both …

2020 The Astronomical Journal
Gaia 57
TRAPPIST-1: Global results of the Spitzer Exploration Science Program Red Worlds
DOI: 10.1051/0004-6361/201937392 Bibcode: 2020A&A...640A.112D

Queloz, D.; Agol, E.; Delrez, L. +18 more

Context. With more than 1000 h of observation from Feb. 2016 to Oct. 2019, the Spitzer Exploration Program Red Worlds (ID: 13067, 13175 and 14223) exclusively targeted TRAPPIST-1, a nearby (12 pc) ultracool dwarf star, finding that it is orbited by seven transiting Earth-sized planets. At least three of these planets orbit within the classical hab…

2020 Astronomy and Astrophysics
eHST 57
Three-component Kinematics of Multiple Stellar Populations in Globular Clusters with Gaia and VLT
DOI: 10.3847/1538-4357/ab5aee Bibcode: 2020ApJ...889...18C

Milone, A. P.; Cordoni, G.; Marino, A. F. +5 more

The internal dynamics of multiple stellar populations in globular clusters (GCs) provides unique constraints on the physical processes responsible for their formation. Specifically, the present-day kinematics of cluster stars, such as rotation and velocity dispersion, could be related to the initial configuration of the system. In recent work, we …

2020 The Astrophysical Journal
Gaia 57
Phase II of the LAMOST-Kepler/K2 Survey. I. Time Series of Medium-resolution Spectroscopic Observations
DOI: 10.3847/1538-4365/abbb2d Bibcode: 2020ApJS..251...15Z

Tian, Hao; Shi, Jianrong; Zhang, Yong +20 more

Phase II of the Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST)-Kepler/K2 survey (LK-MRS), initiated in 2018, aims at collecting medium-resolution spectra (R ∼ 7500; hereafter MRS) for more than 50,000 stars with multiple visits (∼60 epochs) over a period of 5 yr (2018 September to 2023 June). We selected 20 footprints distribut…

2020 The Astrophysical Journal Supplement Series
Gaia 57
Two Directly Imaged, Wide-orbit Giant Planets around the Young, Solar Analog TYC 8998-760-1
DOI: 10.3847/2041-8213/aba27e Bibcode: 2020ApJ...898L..16B

Ginski, Christian; Kenworthy, Matthew A.; Mamajek, Eric E. +9 more

Even though tens of directly imaged companions have been discovered in the past decades, the number of directly confirmed multiplanet systems is still small. Dynamical analysis of these systems imposes important constraints on formation mechanisms of these wide-orbit companions. As part of the Young Suns Exoplanet Survey we report the detection of…

2020 The Astrophysical Journal
Gaia Hipparcos 57
New Conductive Opacities for White Dwarf Envelopes
DOI: 10.3847/1538-4357/ab9e75 Bibcode: 2020ApJ...899...46B

Blouin, Simon; Saumon, Didier; Shaffer, Nathaniel R. +1 more

Thanks to their continuous cooling and relative simplicity, white dwarf stars are routinely used to measure the ages of stellar populations. The usefulness of white dwarfs as cosmochronometers depends on the availability of accurate cooling models. A key ingredient of those models is conductive opacities, which largely govern the cooling rate. In …

2020 The Astrophysical Journal
Gaia 57
WASP-127b: a misaligned planet with a partly cloudy atmosphere and tenuous sodium signature seen by ESPRESSO
DOI: 10.1051/0004-6361/202039234 Bibcode: 2020A&A...644A.155A

Bouchy, F.; Rebolo, R.; Zapatero Osorio, M. R. +46 more

Context. The study of exoplanet atmospheres is essential for understanding the formation, evolution, and composition of exoplanets. The transmission spectroscopy technique is playing a significant role in this domain. In particular, the combination of state-of-the-art spectrographs at low- and high-spectral resolution is key to our understanding o…

2020 Astronomy and Astrophysics
Gaia eHST 57
A large catalogue of molecular clouds with accurate distances within 4 kpc of the Galactic disc
DOI: 10.1093/mnras/staa235 Bibcode: 2020MNRAS.493..351C

Wang, H. -F.; Huang, Y.; Chen, B. -Q. +6 more

We present a large, homogeneous catalogue of molecular clouds within 4 kpc from the Sun at low Galactic latitudes (|b| < 10°) with unprecedented accurate distance determinations. Based on the 3D dust reddening map and estimates of colour excesses and distances of over 32 million stars presented in Chen et al., we have identified 567 dust/molecu…

2020 Monthly Notices of the Royal Astronomical Society
Gaia 57