Search Publications
Separating extended disc features from the protoplanet in PDS 70 using VLT/SINFONI
Pinte, C.; Quanz, S. P.; Casassus, S. +12 more
Transition discs are prime targets to look for protoplanets and study planet-disc interactions. We present VLT/SINFONI observations of PDS 70, a transition disc with a recently claimed embedded protoplanet. We take advantage of the angular and spectral diversity present in our data for an optimal PSF modelling and subtraction using principal compo…
Partly burnt runaway stellar remnants from peculiar thermonuclear supernovae
Geier, S.; Hermes, J. J.; Gänsicke, B. T. +13 more
We report the discovery of three stars that, along with the prototype LP 40-365, form a distinct class of chemically peculiar runaway stars that are the survivors of thermonuclear explosions. Spectroscopy of the four confirmed LP 40-365 stars finds ONe-dominated atmospheres enriched with remarkably similar amounts of nuclear ashes of partial O- an…
HST/WFC3 grism observations of z ∼ 1 clusters: the cluster versus field stellar mass-size relation and evidence for size growth of quiescent galaxies from minor mergers
Demarco, R.; Brammer, G. B.; Matharu, J. +13 more
Minor mergers are thought to be responsible for the size growth of quiescent field galaxies with decreasing redshift. We test this hypothesis using the cluster environment as a laboratory. Satellite galaxies in clusters move at high velocities, making mergers between them rare. The stellar mass-size relation in 10 clusters and in the field is meas…
Diagnosing solar wind origins using in situ measurements in the inner heliosphere
Matteini, L.; Horbury, T. S.; Stansby, D.
Robustly identifying the solar sources of individual packets of solar wind measured in interplanetary space remains an open problem. We set out to see if this problem is easier to tackle using solar wind measurements closer to the Sun than 1 au, where the mixing and dynamical interaction of different solar wind streams is reduced. Using measuremen…
A discontinuity in the Teff-radius relation of M-dwarfs
Jordán, Andrés; Espinoza, Néstor; Brahm, Rafael +7 more
We report on 13 new high-precision measurements of stellar diameters for low-mass dwarfs obtained by means of near-infrared long-baseline interferometry with PIONIER at the Very Large Telescope Interferometer. Together with accurate parallaxes from Gaia DR2, these measurements provide precise estimates for their linear radii, effective temperature…
Clouds in arms
Belokurov, Vasily A.; Erkal, Denis
We use astrometry and broad-band photometry from Data Release 2 of the ESA's Gaia mission to map out low surface-brightness features in the stellar density distribution around the Large and Small Magellanic Clouds. The LMC appears to have grown two thin and long stellar streams in its Northern and Southern regions, highly reminiscent of spiral arm…
Rotational modulation in TESS B stars
Handler, G.; Wade, G. A.; Cantiello, M. +6 more
Light curves and periodograms of 160 B stars observed by the Transiting Exoplanet Survey Satellite (TESS) space mission and 29 main-sequence B stars from Kepler and K2 were used to classify the variability type. There are 114 main-sequence B stars in the TESS sample, of which 45 are classified as possible rotational variables. This confirms previo…
The spiral pattern rotation speed of the Galaxy and the corotation radius with Gaia DR2
Dias, W. S.; Monteiro, H.; Lépine, J. R. D. +1 more
In this work we revisit the issue of the rotation speed of the spiral arms and the location of the corotation radius of our Galaxy. This research was performed using homogeneous data set of young open clusters (age < 50 Myr) determined from Gaia Data Release 2 (DR2) data. The stellar astrometric membership was determined using proper motions an…
Disentangling the spatial substructure of Cygnus OB2 from Gaia DR2
Lennon, D. J.; Herrero, A.; Wright, N. J. +2 more
For the first time, we have explored the spatial substructure of the Cygnus OB2 association using parallaxes from the recent second Gaia data release. We find significant line-of-sight substructure within the association, which we quantify using a parametrized model that reproduces the observed parallax distribution. This inference approach is nec…
Galaxy structure with strong gravitational lensing: decomposing the internal mass distribution of massive elliptical galaxies
Tam, Sut-Ieng; Nightingale, James W.; Cooper, Andrew P. +4 more
We investigate how strong gravitational lensing can test contemporary models of massive elliptical (ME) galaxy formation, by combining a traditional decomposition of their visible stellar distribution with a lensing analysis of their mass distribution. As a proof of concept, we study a sample of three ME lenses, observing that all are composed of …