Search Publications
On the UV compactness and morphologies of typical Lyman α emitters from z ∼ 2 to z ∼ 6
Sobral, David; Matthee, Jorryt; Paulino-Afonso, Ana +8 more
We investigate the rest-frame UV morphologies of a large sample of Lyman α emitters (LAEs) from z ∼ 2 to z ∼ 6, selected in a uniform way with 16 different narrow and medium bands over the full COSMOS field. We use 3045 LAEs with Hubble Space Telescope coverage in a stacking analysis and find that they have MUV ∼ -20, below M_UV^\ast at…
Gaia reveals evidence for merged white dwarfs
Hambly, N. C.; Rowell, N.; Genest-Beaulieu, C. +2 more
We use Gaia Data Release 2 to identify 13 928 white dwarfs (WDs) within 100 pc of the Sun. The exquisite astrometry from Gaia reveals for the first time a bifurcation in the observed WD sequence in both Gaia and the Sloan Digital Sky Survey (SDSS) passbands. The latter is easily explained by a helium atmosphere WD fraction of 36 per cent. However,…
The dusty progenitor star of the Type II supernova 2017eaw
Kilpatrick, Charles D.; Foley, Ryan J.
We present pre-explosion photometry of the likely progenitor star of the Type II supernova (SN II) 2017eaw in NGC 6946. We use a Hubble Space Telescope (HST) image of SN 2017eaw to perform relative astrometry with HST and Spitzer Space Telescope (Spitzer) imaging, finding a single point source consistent with its position. We detect the progenitor…
Venus Interior Structure and Dynamics
Sotin, Christophe; Smrekar, Suzanne E.; Davaille, Anne
No two rocky bodies offer a better laboratory for exploring the conditions controlling interior dynamics than Venus and Earth. Their similarities in size, density, distance from the sun, and young surfaces would suggest comparable interior dynamics. Although the two planets exhibit some of the same processes, Venus lacks Earth's dominant process f…
The XUV environments of exoplanets from Jupiter-size to super-Earth
Kirk, James; Wheatley, Peter J.; Louden, Tom +8 more
Planets that reside close-in to their host star are subject to intense high-energy irradiation. Extreme-ultraviolet (EUV) and X-ray radiation (together, XUV) is thought to drive mass-loss from planets with volatile envelopes. We present XMM-Newton observations of six nearby stars hosting transiting planets in tight orbits (with orbital period, P
StarGO: A New Method to Identify the Galactic Origins of Halo Stars
Kang, Xi; Chang, Jiang; Han, Jiaxin +3 more
We develop a new method, Stars’ Galactic Origin (StarGO), to identify the galactic origins of halo stars using their kinematics. Our method is based on a self-organizing map (SOM), which is one of the most popular unsupervised learning algorithms. STARGO combines SOM with a novel adaptive group identification algorithm with essentially no free par…
Analysis of the SFR-M∗ plane at z < 3: single fitting versus multi-Gaussian decomposition
Koekemoer, A.; Caputi, K. I.; Bisigello, L. +1 more
The analysis of galaxies on the star formation rate-stellar mass (SFR-M∗) plane is a powerful diagnostic for galaxy evolution at different cosmic times. We consider a sample of 24 463 galaxies from the CANDELS/GOODS-S survey to conduct a detailed analysis of the SFR-M∗ relation at redshifts re than three dex in stellar mass. …
Bending waves in the Milky Way's disc from halo substructure
Widrow, Lawrence M.; Chequers, Matthew H.; Darling, Keir
We use N-body simulations to investigate the excitation of bending waves in a Milky Way-like disc-bulge-halo system. The dark matter halo consists of a smooth component and a population of subhaloes, while the disc is composed of thin and thick components. Also, considered is a control simulation where all of the halo mass is smoothly distributed.…
Galaxy and Quasar Fueling Caught in the Act from the Intragroup to the Interstellar Medium
Bouché, Nicolas; Marino, Raffaella A.; Maseda, Michael V. +11 more
We report the discovery of six spatially extended (10-100 kpc) line-emitting nebulae in the z ≈ 0.57 galaxy group hosting PKS 0405-123, one of the most luminous quasars at z < 1. The discovery is enabled by the Multi Unit Spectroscopic Explorer and provides tantalizing evidence connecting large-scale gas streams with nuclear activity on scales …
A Gaia DR2 Mock Stellar Catalog
Rix, Hans-Walter; Fouesneau, Morgan; Andrae, René +3 more
We present a mock catalog of Milky Way stars, matching in volume and depth the content of the Gaia data release 2 (GDR2). We generated our catalog using Galaxia, a tool to sample stars from a Besançon Galactic model, together with a realistic 3D dust extinction map. The catalog mimics the complete GDR2 data model and contains most of the entries i…