Search Publications
Evidence of a plume on Europa from Galileo magnetic and plasma wave signatures
Khurana, Krishan K.; Kivelson, Margaret G.; Jia, Xianzhe +1 more
The icy surface of Jupiter's moon, Europa, is thought to lie on top of a global ocean1-4. Signatures in some Hubble Space Telescope images have been associated with putative water plumes rising above Europa's surface5,6, providing support for the ocean theory. However, all telescopic detections reported were made at the limit…
Using the full power of the cosmic microwave background to probe axion dark matter
Hložek, Renée; Grin, Daniel; Marsh, David J. E.
The cosmic microwave background (CMB) places stringent constraints on models of dark matter (DM), and on the initial conditions of the Universe. The full Planck data set is used to test the possibility that some fraction of the DM is composed of ultralight axions (ULAs). This represents the first use of CMB lensing to test the ULA model. We find n…
Direct mapping of the temperature and velocity gradients in discs. Imaging the vertical CO snow line around IM Lupi
Pinte, C.; Ménard, F.; Duchêne, G. +14 more
Accurate measurements of the physical structure of protoplanetary discs are critical inputs for planet formation models. These constraints are traditionally established via complex modelling of continuum and line observations. Instead, we present an empirical framework to locate the CO isotopologue emitting surfaces from high spectral and spatial …
Empirical Accurate Masses and Radii of Single Stars with TESS and Gaia
Stassun, Keivan G.; Corsaro, Enrico; Gaudi, B. Scott +1 more
We present a methodology for the determination of empirical masses of single stars through the combination of three direct observables with Gaia and Transiting Exoplanet Survey Satellite (TESS): (i) the surface gravity via granulation-driven variations in the TESS light curve, (ii) the bolometric flux at Earth via the broadband spectral energy dis…
Estimating stellar birth radii and the time evolution of Milky Way's ISM metallicity gradient
Recio-Blanco, A.; de Laverny, P.; Hayden, M. +14 more
We present a semi-empirical, largely model-independent approach for estimating Galactic birth radii, rbirth, for Milky Way disc stars. The technique relies on the justifiable assumption that a negative radial metallicity gradient in the interstellar medium (ISM) existed for most of the disc lifetime. Stars are projected back to their bi…
Extreme magnification of an individual star at redshift 1.5 by a galaxy-cluster lens
Pérez-González, Pablo G.; Weiner, Benjamin J.; Richard, Johan +42 more
Galaxy-cluster gravitational lenses can magnify background galaxies by a total factor of up to 50. Here we report an image of an individual star at redshift z = 1.49 (dubbed MACS J1149 Lensed Star 1) magnified by more than ×2,000. A separate image, detected briefly 0.26″ from Lensed Star 1, is probably a counterimage of the first star demagnified …
Open cluster kinematics with Gaia DR2
Castro-Ginard, A.; Jordi, C.; Casamiquela, L. +16 more
Context. Open clusters are very good tracers of the evolution of the Galactic disc. Thanks to Gaia, their kinematics can be investigated with an unprecedented precision and accuracy.
Aims: The distribution of open clusters in the 6D phase space is revisited with Gaia DR2.
Methods: The weighted mean radial velocity of open clusters was de…
The Atacama Cosmology Telescope: The Two-season ACTPol Sunyaev-Zel’dovich Effect Selected Cluster Catalog
Hilton, Matt; Hasselfield, Matthew; Sifón, Cristóbal +41 more
We present a catalog of 182 galaxy clusters detected through the Sunyaev-Zel’dovich (SZ) effect by the Atacama Cosmology Telescope in a contiguous 987.5 deg2 field. The clusters were detected as SZ decrements by applying a matched filter to 148 GHz maps that combine the original ACT equatorial survey with data from the first two observi…
The abundance, distribution, and physical nature of highly ionized oxygen O VI, O VII, and O VIII in IllustrisTNG
Torrey, Paul; Vogelsberger, Mark; Genel, Shy +8 more
We explore the abundance, spatial distribution, and physical properties of the O VI, O VII, and O VIII ions of oxygen in circumgalactic and intergalactic media (the CGM, IGM, and WHIM). We use the TNG100 and TNG300 large volume cosmological magnetohydrodynamical simulations. Modelling the ionization states of simulated oxygen, we find good agreeme…
Gaia DR2 study of Herbig Ae/Be stars
Mendigutía, I.; Baines, D.; Vioque, M. +2 more
Aims: We use Gaia Data Release 2 (DR2) to place 252 Herbig Ae/Be stars in the Hertzsprung-Russell diagram and investigate their characteristics and properties.
Methods: For all known Herbig Ae/Be stars with parallaxes in Gaia DR2, we collected their atmospheric parameters and photometric and extinction values from the literature. To thes…