Search Publications
A dusty filament and turbulent CO spirals in HD 135344B - SAO 206462
Dong, Ruobing; Baruteau, Clément; Pinte, Christophe +16 more
Planet-disc interactions build up local pressure maxima that may halt the radial drift of protoplanetary dust, and pile it up in rings and crescents. ALMA observations of the HD 135344B disc revealed two rings in the thermal continuum stemming from ~mm-sized dust. At higher frequencies the inner ring is brighter relative to the outer ring, which i…
The stellar distribution function and local vertical potential from Gaia DR2
Widrow, Lawrence M.; Li, Haochuan
We develop a novel method to simultaneously determine the vertical potential, force, and stellar z-vz phase space distribution function (DF) in our local patch of the Galaxy. We assume that the Solar Neighbourhood can be treated as a one-dimensional (1D) system in dynamical equilibrium and directly fit the number density in the z-v…
Star formation in 'the Brick': ALMA reveals an active protocluster in the Galactic centre cloud G0.253+0.016
Ho, Luis C.; Jackson, James M.; Lu, Xing +16 more
G0.253+0.016, aka 'the Brick', is one of the most massive (>105 M⊙) and dense (>104 cm-3) molecular clouds in the Milky Way's Central Molecular Zone. Previous observations have detected tentative signs of active star formation, most notably a water maser that is associated with a dust continuum sou…
Towards constraining warm dark matter with stellar streams through neural simulation-based inference
Bertone, Gianfranco; Banik, Nilanjan; Weniger, Christoph +2 more
A statistical analysis of the observed perturbations in the density of stellar streams can in principle set stringent constraints on the mass function of dark matter subhaloes, which in turn can be used to constrain the mass of the dark matter particle. However, the likelihood of a stellar density with respect to the stream and subhaloes parameter…
The large-scale magnetic field of Proxima Centauri near activity maximum
Donati, Jean-François; Bonfils, Xavier; Delfosse, Xavier +5 more
We report the detection of a large-scale magnetic field at the surface of the slowly rotating fully convective (FC) M dwarf Proxima Centauri. 10 circular polarization spectra, collected from 2017 April to July with the HARPS-Pol spectropolarimeter, exhibit rotationally modulated Zeeman signatures suggesting a stellar rotation period of 89.8 ± 4.0 …
Search for dormant black holes in ellipsoidal variables I. Revisiting the expected amplitudes of the photometric modulation
Gomel, Roy; Faigler, Simchon; Mazeh, Tsevi
Ellipsoidal variables present light-curve modulations caused by stellar distortion, induced by tidal interaction with their companions. An analytical approximated model of the ellipsoidal modulation is given as a discrete Fourier series by Morris & Naftilan. Based on numerical simulations using the PHOEBE code, we present here updated amplitud…
Gaia EDR3 in 6D: searching for unbound stars in the galaxy
Marchetti, Tommaso
The early third data release (EDR3) of the European Space Agency satellite Gaia provides coordinates, parallaxes, and proper motions for ∼1.47 billion sources in our Milky Way, based on 34 months of observations. The combination of Gaia DR2 radial velocities with the more precise and accurate astrometry provided by Gaia EDR3 makes the best data se…
A quantitative in-depth analysis of the prototype sdB+BD system SDSS J08205+0008 revisited in the Gaia era
Geier, S.; Dhillon, V. S.; Heber, U. +8 more
Subdwarf B stars are core-helium-burning stars located on the extreme horizontal branch (EHB). Extensive mass loss on the red giant branch is necessary to form them. It has been proposed that substellar companions could lead to the required mass loss when they are engulfed in the envelope of the red giant star. J08205+0008 was the first example of…
Proplyds in the flame nebula NGC 2024
Hines, Dean C.; Stapelfeldt, Karl R.; Clarke, Cathie J. +5 more
A recent survey of the inner 0.35 × 0.35 pc of the NGC 2024 star-forming region revealed two distinct millimetre continuum disc populations that appear to be spatially segregated by the boundary of a dense cloud. The eastern (and more embedded) population is ~0.2-0.5 Myr old, with an ALMA mm continuum disc detection rate of about $45\,$ per cent. …
New star clusters discovered towards the Galactic bulge direction using Gaia DR2
Corradi, W. J. B.; Ferreira, F. A.; Maia, F. F. S. +2 more
We report the discovery of 34 new open clusters and candidates as a result of a systematic search carried out in 200 adjacent fields of 1 × 1 deg2 area projected towards the Galactic bulge, using Gaia DR2 data. The objects were identified and characterized by a joint analysis of their photometric, kinematic, and spatial distribution tha…