Search Publications
Elevated ionizing photon production efficiency in faint high-equivalent-width Lyman-α emitters
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…
Is multiphase gas cloudy or misty?
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…
The first six months of the Advanced LIGO's and Advanced Virgo's third observing run with GRANDMA
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…
Unlocking Galactic Wolf-Rayet stars with Gaia DR2 - I. Distances and absolute magnitudes
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 …
Disks Around T Tauri Stars with SPHERE (DARTTS-S). II. Twenty-one new polarimetric images of young stellar disks
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…
The CARMENES search for exoplanets around M dwarfs. Two planets on opposite sides of the radius gap transiting the nearby M dwarf LTT 3780
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 …
The Milky Way Cepheid Leavitt law based on Gaia DR2 parallaxes of companion stars and host open cluster populations
Mérand, Antoine; Riess, Adam G.; Breuval, Louise +12 more
Aims: Classical Cepheids provide the foundation for the empirical extragalactic distance ladder. Milky Way Cepheids are the only stars in this class accessible to trigonometric parallax measurements. However, the parallaxes of Cepheids from the second Gaia data release (GDR2) are affected by systematics because of the absence of chromaticity …
Observed sizes of planet-forming disks trace viscous spreading
van Dishoeck, E. F.; Rosotti, G.; Trapman, L. +2 more
Context. The evolution of protoplanetary disks is dominated by the conservation of angular momentum, where the accretion of material onto the central star is fed by the viscous expansion of the outer disk or by disk winds extracting angular momentum without changing the disk size. Studying the time evolution of disk sizes therefore allows us to di…
The population of hot subdwarf stars studied with Gaia. III. Catalogue of known hot subdwarf stars: Data Release 2
Geier, S.
In light of substantial new discoveries of hot subdwarfs by ongoing spectroscopic surveys and the availability of new all-sky data from ground-based photometric surveys and the Gaia mission Data Release 2, we compiled an updated catalogue of the known hot subdwarf stars. The catalogue contains 5874 unique sources including 528 previously unknown h…
Interpreting the Spitzer/IRAC colours of 7 ≤ z ≤ 9 galaxies: distinguishing between line emission and starlight using ALMA
Laporte, N.; Ellis, R. S.; Roberts-Borsani, G. W.
Prior to the launch of JWST, Spitzer/IRAC photometry offers the only means of studying the rest-frame optical properties of z >7 galaxies. Many such high-redshift galaxies display a red [3.6]-[4.5] micron colour, often referred to as the 'IRAC excess', which has conventionally been interpreted as arising from intense [O III]+H β emission within…