Search Publications
The kinematics of the Scorpius-Centaurus OB association from Gaia DR1
Wright, Nicholas J.; Mamajek, Eric E.
We present a kinematic study of the Scorpius-Centaurus (Sco-Cen) OB association (Sco OB2) using Gaia DR1 parallaxes and proper motions. Our goal is to test the classical theory that OB associations are the expanded remnants of dense and compact star clusters disrupted by processes such as residual gas expulsion. Gaia astrometry is available for 25…
The relationship between galaxy and dark matter halo size from z ∼ 3 to the present
Santini, Paola; Fontana, Adriano; Koekemoer, Anton M. +10 more
We explore empirical constraints on the statistical relationship between the radial size of galaxies and the radius of their host dark matter haloes from z ∼ 0.1-3 using the Galaxy And Mass Assembly (GAMA) and Cosmic Assembly Near Infrared Deep Extragalactic Legacy Survey (CANDELS) surveys. We map dark matter halo mass to galaxy stellar mass using…
The TESS-HERMES survey data release 1: high-resolution spectroscopy of the TESS southern continuous viewing zone
Casey, Andrew R.; Huber, Daniel; Buder, Sven +22 more
The Transiting Exoplanet Survey Satellite (TESS) will provide high-precision time series photometry for millions of stars with at least a half-hour cadence. Of particular interest are the circular regions of 12° radius centred around the ecliptic poles that will be observed continuously for a full year. Spectroscopic stellar parameters are desirab…
Dust attenuation in 2 < z < 3 star-forming galaxies from deep ALMA observations of the Hubble Ultra Deep Field
Scott, D.; van Kampen, E.; Rujopakarn, W. +12 more
We present the results of a new study of the relationship between infrared excess (IRX ≡ LIR/LUV), ultraviolet (UV) spectral slope (β) and stellar mass at redshifts 2 < z < 3, based on a deep Atacama Large Millimeter Array (ALMA) 1.3-mm continuum mosaic of the Hubble Ultra Deep Field. Excluding the most heavily obscured…
BAT AGN Spectroscopic Survey - XII. The relation between coronal properties of active galactic nuclei and the Eddington ratio
Treister, E.; Bauer, F. E.; Paltani, S. +12 more
The bulk of the X-ray emission in active galactic nuclei (AGNs) is produced very close to the accreting supermassive black hole (SMBH), in a corona of hot electrons which up scatters optical and ultraviolet photons from the accretion flow. The cut-off energy (EC) of the primary X-ray continuum emission carries important information on t…
A white dwarf catalogue from Gaia-DR2 and the Virtual Observatory
Solano, E.; Rebassa-Mansergas, A.; Torres, S. +4 more
We present a catalogue of 73 221 white dwarf candidates extracted from the astrometric and photometric data of the recently published Gaia-DR2 catalogue. White dwarfs were selected from the Gaia Hertzsprung-Russell diagram with the aid of the most updated population synthesis simulator. Our analysis shows that Gaia has virtually identified all whi…
Warp, waves, and wrinkles in the Milky Way
Schönrich, Ralph; Dehnen, Walter
We derive unbiased distance estimates for the Gaia-TGAS data set by correcting for the bias due to the distance dependence of the selection function, which we measure directly from the data. From these distances and proper motions, we estimate the vertical and azimuthal velocities, W and Vφ, and angular momentum Lz for stars …
Retrieval analysis of 38 WFC3 transmission spectra and resolution of the normalization degeneracy
Heng, Kevin; Fisher, Chloe
A comprehensive analysis of 38 previously published Wide Field Camera 3 (WFC3) transmission spectra is performed using a hierarchy of nested-sampling retrievals: with versus without clouds, grey versus non-grey clouds, isothermal versus non-isothermal transit chords, and with water, hydrogen cyanide, and/or ammonia. We revisit the `normalization d…
The origin of the Gaia phase-plane spiral
Binney, James; Schönrich, Ralph
A simple model is presented of the formation of the spiral in the (z, vz) phase plane of solar-neighbourhood stars that was recently discovered in Gaia data. The key is that the frequency Ωz at which stars oscillate vertically depends on angular momentum about the z-axis in addition to the amplitude of the star's vertical osc…
The internal rotation of globular clusters revealed by Gaia DR2
van der Marel, R. P.; Bellini, A.; Libralato, M. +5 more
Line-of-sight kinematic studies indicate that many Galactic globular clusters have a significant degree of internal rotation. However, three-dimensional kinematics from a combination of proper motions (PMs) and line-of-sight velocities are needed to unveil the role of angular momentum in the formation and evolution of these old stellar systems. He…