Search Publications
Synthesis of the morphological description of cometary dust at comet 67P/Churyumov-Gerasimenko
Lasue, J.; Langevin, Y.; Krüger, H. +28 more
Before Rosetta, the space missions Giotto and Stardust shaped our view on cometary dust, supported by plentiful data from Earth based observations and interplanetary dust particles collected in the Earth's atmosphere. The Rosetta mission at comet 67P/Churyumov-Gerasimenko was equipped with a multitude of instruments designed to study cometary dust…
Mass and Mass Scalings of Super-Earths
Wu, Yanqin
The majority of the transiting planets discovered by the Kepler mission (called super-Earths here, includes the so-called “sub-Neptunes”) orbit close to their stars. As such, photoevaporation of their hydrogen envelopes etches sharp features in an otherwise bland space spanned by planet radius and orbital period. This, in turn, can be exploited to…
Potential kick velocity distribution of black hole X-ray binaries and implications for natal kicks
Maccarone, T. J.; Chaty, S.; Miller-Jones, J. C. A. +14 more
We use very long baseline interferometry to measure the proper motions of three black hole X-ray binaries (BHXBs). Using these results together with data from the literature and Gaia DR2 to collate the best available constraints on proper motion, parallax, distance, and systemic radial velocity of 16 BHXBs, we determined their three-dimensional Ga…
Effect of galaxy mergers on star-formation rates
Wang, L.; van der Tak, F. F. S.; Holwerda, B. W. +8 more
Context. Galaxy mergers and interactions are an integral part of our basic understanding of how galaxies grow and evolve over time. However, the effect that galaxy mergers have on star-formation rates (SFRs) is contested, with observations of galaxy mergers showing reduced, enhanced, and highly enhanced star formation.
Aims: We aim to determi…
Characterization and history of the Helmi streams with Gaia DR2
Helmi, Amina; Koppelman, Helmer H.; Massari, Davide +2 more
Context. The halo of the Milky Way has long been hypothesized to harbour significant amounts of merger debris. For more than a decade this view has been supported by wide-field photometric surveys which have revealed the outer halo to be lumpy.
Aims: The recent release of Gaia DR2 is allowing us to establish that mergers also have been import…
ACCESS: a featureless optical transmission spectrum for WASP-19b from Magellan/IMACS
Fortney, Jonathan J.; López-Morales, Mercedes; Jordán, Andrés +13 more
The short-period (0.94-d) transiting exoplanet WASP-19b is an exceptional target for transmission spectroscopy studies, due to its relatively large atmospheric scale height (∼500 km) and equilibrium temperature (∼2100 K). Here, we report on six precise spectroscopic Magellan/IMACS observations, five of which target the full optical window from 0.4…
The pattern speed of the Milky Way bar from transverse velocities
Evans, N. Wyn; Sanders, Jason L.; Smith, Leigh
We use the continuity equation to derive a method for measuring the pattern speed of the Milky Way's bar/bulge from proper motion data. The method has minimal assumptions but requires complete coverage of the non-axisymmetric component in two of the three Galactic coordinates. We apply our method to the proper motion data from a combination of Gai…
The GREATS H β + [O III] luminosity function and galaxy properties at z ∼ 8: walking the way of JWST
Oesch, P. A.; Bouwens, R. J.; Illingworth, G. D. +5 more
The James Webb Space Telescope will allow to spectroscopically study an unprecedented number of galaxies deep into the reionization era, notably by detecting [O III]λλ4959, 5007, and H β nebular emission lines. To efficiently prepare such observations, we photometrically select a large sample of galaxies at z ∼ 8 and study their rest-frame optical…
Planetary system around the nearby M dwarf GJ 357 including a transiting, hot, Earth-sized planet optimal for atmospheric characterization
Tamura, M.; Nagel, E.; Amado, P. J. +73 more
We report the detection of a transiting Earth-size planet around GJ 357, a nearby M2.5 V star, using data from the Transiting Exoplanet Survey Satellite (TESS). GJ 357 b (TOI-562.01) is a transiting, hot, Earth-sized planet (Teq = 525 ± 11 K) with a radius of Rb = 1.217 ± 0.084 R⊕ and an orbital period of Pb
Surface Rotation and Photometric Activity for Kepler Targets. I. M and K Main-sequence Stars
García, R. A.; Pinsonneault, M. H.; Mathur, S. +5 more
Brightness variations due to dark spots on the stellar surface encode information about stellar surface rotation and magnetic activity. In this work, we analyze the Kepler long-cadence data of 26,521 main-sequence stars of spectral types M and K in order to measure their surface rotation and photometric activity level. Rotation-period estimates ar…