Search Publications
Gravitationally lensed quasars in Gaia - III. 22 new lensed quasars from Gaia data release 2
McMahon, Richard G.; Auger, Matthew W.; Lemon, Cameron A.
We report the discovery and spectroscopic confirmation of 22 new gravitationally lensed quasars found using Gaia data release 2. The selection was made using several techniques: multiple Gaia detections around objects in quasar candidate catalogues, modelling of unWISE coadd pixels using Gaia astrometry, and Gaia detections offset from photometric…
Gaia Cepheid parallaxes and 'Local Hole' relieve H0 tension
Metcalfe, N.; Shanks, T.; Hogarth, L. M.
There is an ≈9 ± 2.5 per cent tension between the value of Hubble's Constant, H0 = 67.4 ± 0.5 km s-1 Mpc-1, implied by the Planck microwave background power spectrum and that given by the distance scale of H0 = 73.4 ± 1.7 km s-1Mpc-1. But with a plausible assumption about a Gaia DR2…
On the slow solar wind with high Alfvénicity: from composition and microphysics to spectral properties
D'Amicis, Raffaella; Bruno, Roberto; Matteini, Lorenzo
Alfvénic fluctuations are very common features in the solar wind and are found especially within the main portion of fast-wind streams while the slow wind usually is less Alfvénic and more variable. In general, the fast and slow winds show many differences, which span from the large-scale structure to small-scale phenomena, including also a differ…
The spatial relation between young star clusters and molecular clouds in M51 with LEGUS
Tosi, M.; Gallagher, J. S.; Dale, D. A. +21 more
We present a study correlating the spatial locations of young star clusters with those of molecular clouds in NGC 5194, in order to investigate the time-scale over which clusters separate from their birth clouds. The star cluster catalogues are from the Legacy ExtraGalactic UV Survey (LEGUS) and the molecular clouds from the Plateau de Bure Intere…
Quantifying the impact of variable BLR diffuse continuum contributions on measured continuum interband delays
Korista, K. T.; Goad, M. R.
We investigate the contribution of reprocessed continuum emission (1000-10 000 Å) originating in broad-line region (BLR) gas, the diffuse continuum (DC), to the wavelength-dependent continuum delays measured in AGN disc reverberation mapping experiments. Assuming a spherical BLR geometry, we adopt a Local Optimally emitting Cloud (LOC) model for t…
Gone after one orbit: How cluster environments quench galaxies
Dolag, Klaus; Biviano, Andrea; Burkert, Andreas +2 more
The effect of galactic orbits on a galaxy's internal evolution within a galaxy cluster environment has been the focus of heated debate in recent years. To understand this connection, we use both the (0.5 Gpc)3 and the Gpc3 boxes from the cosmological hydrodynamical simulation set Magneticum Pathfinder. We investigate the velo…
The unbiased frequency of planetary signatures around single and binary white dwarfs using Spitzer and Hubble
Gänsicke, Boris T.; Wilson, Thomas G.; Farihi, Jay +1 more
This paper presents combined Spitzer IRAC and Hubble COS results for a double-blind survey of 195 single and 22 wide binary white dwarfs for infrared excesses and atmospheric metals. The selection criteria include cooling ages in the range 9 to 300 Myr, and hydrogen-rich atmospheres so that the presence of atmospheric metals can be confidently lin…
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…