Search Publications
Gaia DR2 in 6D: searching for the fastest stars in the Galaxy
Rossi, E. M.; Brown, A. G. A.; Marchetti, T.
We search for the fastest stars in the subset of stars with radial velocity measurements of the second data release (DR2) of the European Space Agency mission Gaia. Starting from the observed positions, parallaxes, proper motions, and radial velocities, we construct the distance and total velocity distribution of more than 7 million stars in our M…
The eye of Gaia on globular clusters kinematics: internal rotation
Hilker, M.; Baumgardt, H.; Sollima, A.
We derived the three-dimensional velocities of individual stars in a sample of 62 Galactic globular clusters using proper motions from the second data release of the Gaia mission together with the most comprehensive set of line-of-sight velocities with the aim of investigating the rotation pattern of these stellar systems. We detect the unambiguou…
The Milky Way bar/bulge in proper motions: a 3D view from VIRAC and Gaia
Smith, Leigh C.; Gerhard, Ortwin; Wegg, Christopher +3 more
We have derived absolute proper motions of the entire Galactic bulge region from VVV Infrared Astrometric Catalogue (VIRAC) and Gaia. We present these both as integrated on-sky maps and, after isolating standard candle red clump (RC) stars, as a function of distance using RC magnitude as a proxy. These data provide a new global, 3D view of the Mil…
Accounting for incompleteness due to transit multiplicity in Kepler planet occurrence rates
Christiansen, Jessie L.; Zink, Jon K.; Hansen, Bradley M. S.
We investigate the role that planet detection order plays in the Kepler planet detection pipeline. The Kepler pipeline typically detects planets in order of descending signal strength (MES). We find that the detectability of transits experiences an additional 5.5 per cent and 15.9 per cent efficiency loss, for periods <200 days and >200 days…
Observable tests of self-interacting dark matter in galaxy clusters: BCG wobbles in a constant density core
Massey, Richard; Harvey, David; Robertson, Andrew +1 more
Models of cold dark matter (CDM) predict that the distribution of dark matter in galaxy clusters should be cuspy, centrally concentrated. Constant density cores would be strong evidence for beyond CDM physics, such as self-interacting dark matter (SIDM). An observable consequence would be oscillations of the brightest cluster galaxy (BCG) in other…
Swift spectra of AT2018cow: a white dwarf tidal disruption event?
Wu, Kinwah; Cenko, S. Bradley; Levan, Andrew +19 more
The bright transient AT2018cow has been unlike any other known type of transient. Its high brightness, rapid rise and decay, and initially nearly featureless spectrum are unprecedented and difficult to explain using models for similar burst sources. We present evidence for faint γ-ray emission continuing for at least 8 d, and featureless spectra i…
From the far-ultraviolet to the far-infrared - galaxy emission at 0 ≤ z ≤ 10 in the SHARK semi-analytic model
Obreschkow, Danail; Driver, Simon P.; Robotham, Aaron S. G. +8 more
We combine the SHARK semi-analytic model of galaxy formation with the PROSPECT software tool for spectral energy distribution (SED) generation to study the multiwavelength emission of galaxies from the far-ultraviolet (FUV) to the far-infrared (FIR) at 0 ≤ z ≤ 10. We produce a physical model for the attenuation of galaxies across cosmic time by co…
The GALAH survey and Gaia DR2: Linking ridges, arches, and vertical waves in the kinematics of the Milky Way
Lewis, Geraint F.; Ting, Yuan-Sen; Buder, Sven +17 more
Gaia DR2 has revealed new small-scale and large-scale patterns in the phase-space distribution of stars in the Milky Way. In cylindrical Galactic coordinates (R,φ ,z), ridge-like structures can be seen in the (R,V_φ) plane and asymmetric arch-like structures in the (V_R,V_φ) plane. We show that the ridges are also clearly present when the third di…
Surface localization of gas sources on comet 67P/Churyumov-Gerasimenko based on DFMS/COPS data
Altwegg, Kathrin; Rubin, Martin; Läuter, Matthias +1 more
We reconstruct the temporal evolution of the source distribution for the four major gas species H2O, CO2, CO, and O2 on the surface of comet 67P/Churyumov-Gerasimenko during its 2015 apparition. The analysis applies an inverse coma model and fits to data between 2014 August 6 and 2016 September 5 measured with the …
Fundamental parameter accuracy of DA and DB white dwarfs in Gaia Data Release 2
Tremblay, P. -E.; Hollands, M. A.; Cunningham, T. +2 more
We report on a comparison of spectroscopic analyses for hydrogen (DA) and helium atmosphere (DB) white dwarfs with Gaia Data Release 2 (DR2) parallaxes and photometry. We assume a reddening law and a mass-radius relation to connect the effective temperatures (Teff) and surface gravities (log g) to masses and radii. This allows the compa…