Search Publications

Chemo-dynamics of outer halo dwarf stars, including Gaia-Sausage and Gaia-Sequoia candidates
DOI: 10.1093/mnras/staa1995 Bibcode: 2020MNRAS.497.1236M

Monty, Stephanie; Venn, Kim A.; Lane, James M. M. +2 more

The low-metallicity, kinematically interesting dwarf stars studied by Stephens & Boesgaard (2002, SB02) are re-examined using Gaia DR2 astrometry, and updated model atmospheres and atomic line data. New stellar parameters are determined based on the Gaia DR2 parallactic distances and Dartmouth Stellar Evolution Database isochrones. These are i…

2020 Monthly Notices of the Royal Astronomical Society
Gaia 67
Mitigation of LEO Satellite Brightness and Trail Effects on the Rubin Observatory LSST
DOI: 10.3847/1538-3881/abba3e Bibcode: 2020AJ....160..226T

Yoachim, Peter; Tyson, J. Anthony; Ivezić, Željko +8 more

We report studies on the mitigation of optical effects of bright low-Earth-orbit (LEO) satellites on Vera C. Rubin Observatory and its Legacy Survey of Space and Time (LSST). These include options for pointing the telescope to avoid satellites, laboratory investigations of bright trails on the Rubin Observatory LSST camera sensors, algorithms for …

2020 The Astronomical Journal
Gaia 67
A transition between the hot and the ultra-hot Jupiter atmospheres
DOI: 10.1051/0004-6361/201937394 Bibcode: 2020A&A...639A..36B

Désert, Jean-Michel; Mansfield, Megan; Parmentier, Vivien +6 more

A key hypothesis in the field of exoplanet atmospheres is the trend of atmospheric thermal structure with planetary equilibrium temperature. We explore this trend and report here the first statistical detection of a transition in the near-infrared atmospheric emission between hot and ultra-hot Jupiters. We measure this transition using secondary e…

2020 Astronomy and Astrophysics
eHST 67
X-shooter survey of disk accretion in Upper Scorpius. I. Very high accretion rates at age > 5 Myr
DOI: 10.1051/0004-6361/202037949 Bibcode: 2020A&A...639A..58M

Lodato, G.; Pascucci, I.; Fedele, D. +14 more

Determining the mechanisms that drive the evolution of protoplanetary disks is a necessary step toward understanding how planets form. For this work, we measured the mass accretion rate for young stellar objects with disks at age > 5 Myr, a critical test for the current models of disk evolution. We present the analysis of the spectra of 36 targ…

2020 Astronomy and Astrophysics
Gaia 67
Elevated ionizing photon production efficiency in faint high-equivalent-width Lyman-α emitters
DOI: 10.1093/mnras/staa622 Bibcode: 2020MNRAS.493.5120M

Bacon, Roland; Inami, Hanae; Brinchmann, Jarle +16 more

While low-luminosity galaxies dominate number counts at all redshifts, their contribution to cosmic reionization is poorly understood due to a lack of knowledge of their physical properties. We isolate a sample of 35 z ≈ 4-5 continuum-faint Lyman-α emitters from deep VLT/MUSE spectroscopy and directly measure their H α emission using stacked Spitz…

2020 Monthly Notices of the Royal Astronomical Society
eHST 67
Is multiphase gas cloudy or misty?
DOI: 10.1093/mnrasl/slaa033 Bibcode: 2020MNRAS.494L..27G

Gronke, Max; Oh, S. Peng

Cold T ∼ 104 K gas morphology could span a spectrum ranging from large discrete clouds to a fine 'mist' in a hot medium. This has myriad implications, including dynamics and survival, radiative transfer, and resolution requirements for cosmological simulations. Here, we use 3D hydrodynamic simulations to study the pressure-driven fragme…

2020 Monthly Notices of the Royal Astronomical Society
eHST 66
The first six months of the Advanced LIGO's and Advanced Virgo's third observing run with GRANDMA
DOI: 10.1093/mnras/stz3142 Bibcode: 2020MNRAS.492.3904A

Bertin, E.; Kann, D. A.; Berthier, J. +74 more

We present the Global Rapid Advanced Network Devoted to the Multi-messenger Addicts (GRANDMA). The network consists of 21 telescopes with both photometric and spectroscopic facilities. They are connected together thanks to a dedicated infrastructure. The network aims at coordinating the observations of large sky position estimates of transient eve…

2020 Monthly Notices of the Royal Astronomical Society
INTEGRAL 66
Unlocking Galactic Wolf-Rayet stars with Gaia DR2 - I. Distances and absolute magnitudes
DOI: 10.1093/mnras/stz3614 Bibcode: 2020MNRAS.493.1512R

Crowther, Paul A.; Rate, Gemma

We obtain distances to 383 Galactic Wolf-Rayet (WR) stars from Gaia DR2 parallaxes and Bayesian methods, with a prior based on H II regions and dust extinction. Distances agree with those from Bailer-Jones et al. for stars up to 2 kpc from the Sun, though deviate thereafter due to differing priors, leading to modest reductions in luminosities for …

2020 Monthly Notices of the Royal Astronomical Society
Gaia 66
Disks Around T Tauri Stars with SPHERE (DARTTS-S). II. Twenty-one new polarimetric images of young stellar disks
DOI: 10.1051/0004-6361/201936946 Bibcode: 2020A&A...633A..82G

van der Plas, G.; Quanz, S. P.; Avenhaus, H. +8 more

Context. Near-IR polarimetric images of protoplanetary disks enable us to characterize substructures that might be due to the interaction with (forming) planets. The available census is strongly biased toward massive disks around old stars, however.
Aims: The DARTTS program aims at alleviating this bias by imaging a large number of T Tauri st…

2020 Astronomy and Astrophysics
Gaia 66
The CARMENES search for exoplanets around M dwarfs. Two planets on opposite sides of the radius gap transiting the nearby M dwarf LTT 3780
DOI: 10.1051/0004-6361/202037867 Bibcode: 2020A&A...642A.173N

Tamura, M.; Nagel, E.; Amado, P. J. +97 more

We present the discovery and characterisation of two transiting planets observed by the Transiting Exoplanet Survey Satellite (TESS) orbiting the nearby (d ≈ 22 pc), bright (J ≈ 9 mag) M3.5 dwarf LTT 3780 (TOI-732). We confirm both planets and their association with LTT 3780 via ground-based photometry and determine their masses using …

2020 Astronomy and Astrophysics
Gaia 66