Search Publications
Trapped orbits and solar-neighbourhood kinematics
Binney, James
Torus mapping yields constants of motion for stars trapped at a resonance. Each such constant of motion yields a system of contours in velocity space at the Sun and neighbouring points. If Jeans' theorem applied to resonantly trapped orbits, the density of stars in velocity space would be equal at all intersections of any two contours. A quantitat…
Measuring the local dark matter density with LAMOST DR5 and Gaia DR2
Mao, Shude; Liu, Chao; Xue, Xiang-Xiang +3 more
We apply the vertical Jeans equation to the kinematics of Milky Way stars in the solar neighbourhood to measure the local dark matter density. More than 90 000 G- and K-type dwarf stars are selected from the cross-matched sample of LAMOST (Large Sky Area Multi-Object Fibre Spectroscopic Telescope) fifth data release and Gaia second data release fo…
LEGO - II. A 3 mm molecular line study covering 100 pc of one of the most actively star-forming portions within the Milky Way disc
Weiss, A.; Evans, N. J.; Goldsmith, P. F. +20 more
The current generation of (sub)mm-telescopes has allowed molecular line emission to become a major tool for studying the physical, kinematic, and chemical properties of extragalactic systems, yet exploiting these observations requires a detailed understanding of where emission lines originate within the Milky Way. In this paper, we present 60 arcs…
Planet Hunters TESS I: TOI 813, a subgiant hosting a transiting Saturn-sized planet on an 84-day orbit
Aigrain, S.; Fridlund, M.; Barragán, O. +47 more
We report on the discovery and validation of TOI 813 b (TIC 55525572 b), a transiting exoplanet identified by citizen scientists in data from NASA's Transiting Exoplanet Survey Satellite (TESS) and the first planet discovered by the Planet Hunters TESS project. The host star is a bright (V = 10.3 mag) subgiant (R\star - 1.94 R⊙
The single-sided pulsator CO Camelopardalis
Handler, G.; Vanderburg, A.; Giarrusso, M. +10 more
CO Cam (TIC 160268882) is the second 'single-sided pulsator' to be discovered. These are stars where one hemisphere pulsates with a significantly higher amplitude than the other side of the star. CO Cam is a binary star comprised of an Am δ Sct primary star with Teff = 7070 ± 150 K, and a spectroscopically undetected G main-sequence sec…
Age dating the Galactic bar with the nuclear stellar disc
Kawata, Daisuke; Baba, Junichi
From the decades of the theoretical studies, it is well known that the formation of the bar triggers the gas funnelling into the central sub-kpc region and leads to the formation of a kinematically cold nuclear stellar disc (NSD). We demonstrate that this mechanism can be used to identify the formation epoch of the Galactic bar, using an N-body/hy…
MUSE-ALMA haloes V: physical properties and environment of z ≤ 1.4 H I quasar absorbers
Pettini, Max; York, Donald G.; Hamanowicz, Aleksandra +11 more
We present results of the MUSE-ALMA haloes, an ongoing study of the circumgalactic medium (CGM) of low-redshift galaxies (z ≤ 1.4), currently comprising 14 strong H I absorbers in 5 quasar fields. We detect 43 galaxies associated with absorbers down to star formation rate (SFR) limits of 0.01-0.1 M⊙ yr-1, found within impact …
Double dark matter vision: twice the number of compact-source lenses with narrow-line lensing and the WFC3 grism
Brammer, G.; Treu, T.; Fassnacht, C. D. +9 more
The magnifications of compact-source lenses are extremely sensitive to the presence of low-mass dark matter haloes along the entire sightline from the source to the observer. Traditionally, the study of dark matter structure in compact-source strong gravitational lenses has been limited to radio-loud systems, as the radio emission is extended and …
The Gaia DR2 parallax zero-point: hierarchical modelling of red clump stars
Bovy, Jo; Chan, Victor C.
The systematic offset of Gaia parallaxes has been widely reported with Gaia's second data release, and it is expected to persist in future Gaia data. In order to use Gaia parallaxes to infer distances to high precision, we develop a hierarchical probabilistic model to determine the Gaia parallax zero-point offset along with the calibration of an e…
Discovery and astrophysical properties of Galactic open clusters in dense stellar fields using Gaia DR2
Corradi, W. J. B.; Ferreira, F. A.; Maia, F. F. S. +2 more
We report the discovery of 25 new open clusters resulting from a search in dense low Galactic latitude fields. We also provide, for the first time, structural and astrophysical parameters for the new findings and 34 other recently discovered open clusters using Gaia Data Release 2 (DR2) data. The candidates were confirmed by jointly inspecting the…