Search Publications
H0LiCOW - IX. Cosmographic analysis of the doubly imaged quasar SDSS 1206+4332 and a new measurement of the Hubble constant
Treu, T.; Fassnacht, C. D.; Meylan, G. +15 more
We present a blind time-delay strong lensing (TDSL) cosmographic analysis of the doubly imaged quasar SDSS 1206+4332 . We combine the relative time delay between the quasar images, Hubble Space Telescope imaging, the Keck stellar velocity dispersion of the lensing galaxy, and wide-field photometric and spectroscopic data of the field to constrain …
Vertical waves in the solar neighbourhood in Gaia DR2
Bovy, Jo; Bennett, Morgan
The vertical structure and dynamics of stars in our local Galactic neighbourhood contains much information about the local distribution of visible and dark matter and of perturbations to the Milky Way disc. We use data on the positions and velocities of stars in the solar neighbourhood from Gaia Data Release 2 (DR2) and large spectroscopic surveys…
Gaia-2MASS 3D maps of Galactic interstellar dust within 3 kpc
Arenou, F.; Babusiaux, C.; Katz, D. +5 more
Gaia stellar measurements are currently revolutionizing our knowledge of the evolutionary history of the Milky Way. 3D maps of the interstellar dust provide complementary information and are a tool for a wide range of uses. We built 3D maps of the dust in the Local arm and surrounding regions. To do so, Gaia DR2 photometric data were combined with…
Cosmological Constraints from the Hubble Diagram of Quasars at High Redshifts
Lusso, E.; Risaliti, G.
The concordance model (Λ cold dark matter (ΛCDM) model, where Λ is the cosmological constant) reproduces the main current cosmological observations1-4 assuming the validity of general relativity at all scales and epochs and the presence of CDM and of Λ, equivalent to dark energy with a constant density in space and time. However, the ΛC…
The total mass of the Large Magellanic Cloud from its perturbation on the Orphan stream
Li, T. S.; Evans, N. W.; Belokurov, V. +14 more
In a companion paper by Koposov et al., RR Lyrae from Gaia Data Release 2 are used to demonstrate that stars in the Orphan stream have velocity vectors significantly misaligned with the stream track, suggesting that it has received a large gravitational perturbation from a satellite of the Milky Way. We argue that such a mismatch cannot arise due …
The fourth data release of the Kilo-Degree Survey: ugri imaging and nine-band optical-IR photometry over 1000 square degrees
Sutherland, W.; Heymans, C.; Hoekstra, H. +20 more
Context. The Kilo-Degree Survey (KiDS) is an ongoing optical wide-field imaging survey with the OmegaCAM camera at the VLT Survey Telescope, specifically designed for measuring weak gravitational lensing by galaxies and large-scale structure. When completed it will consist of 1350 square degrees imaged in four filters (ugri).
Aims: Here we pr…
Kinematics in Young Star Clusters and Associations with Gaia DR2
Sills, Alison; Feigelson, Eric D.; Hillenbrand, Lynne A. +2 more
The Gaia mission has opened a new window into the internal kinematics of young star clusters at the sub-km s-1 level, with implications for our understanding of how star clusters form and evolve. We use a sample of 28 clusters and associations with ages from ∼1-5 Myr, where lists of members are available from previous X-ray, optical, an…
How to Constrain Your M Dwarf. II. The Mass-Luminosity-Metallicity Relation from 0.075 to 0.70 Solar Masses
Gaidos, Eric; Rizzuto, Aaron C.; Kraus, Adam L. +11 more
The mass-luminosity relation for late-type stars has long been a critical tool for estimating stellar masses. However, there is growing need for both a higher-precision relation and a better understanding of systematic effects (e.g., metallicity). Here we present an empirical relationship between {M}{KS} and M * sp…
Exoplanetary Atmospheres: Key Insights, Challenges, and Prospects
Madhusudhan, Nikku
Exoplanetary science is on the verge of an unprecedented revolution. The thousands of exoplanets discovered over the past decade have most recently been supplemented by discoveries of potentially habitable planets around nearby low-mass stars. Currently, the field is rapidly progressing toward detailed spectroscopic observations to characterize th…
An Improved Distance to NGC 4258 and Its Implications for the Hubble Constant
Riess, A. G.; Reid, M. J.; Pesce, D. W.
NGC 4258 is a critical galaxy for establishing the extragalactic distance scale and estimating the Hubble constant ({H}0). Water masers in the nucleus of the galaxy orbit about its supermassive black hole, and very long baseline interferometric observations of their positions, velocities, and accelerations can be modeled to give a geome…