Search Publications
High-resolution observations of molecular emission lines toward the CI Tau proto-planetary disc: planet-carved gaps or shadowing?
Ilee, John D.; Facchini, Stefano; Tazzari, Marco +4 more
Recent observations have revealed that most proto-planetary discs show a pattern of bright rings and dark gaps. However, most of the high-resolution observations have focused only on the continuum emission. In this paper, we present high-resolution ALMA band 7 (0.89 mm) observations of the disc around the star CI Tau in the 12CO & <…
The Swift bulge survey: motivation, strategy, and first X-ray results
Maccarone, T. J.; Degenaar, N.; Wijnands, R. +12 more
Very faint X-ray transients (VFXTs) are X-ray transients with peak X-ray luminosities (LX) of L$_X \lesssim 10^{36}$ erg s-1, which are not well understood. We carried out a survey of 16 deg2 of the Galactic Bulge with the Swift Observatory, using short (60 s) exposures, and returning every 2 weeks for 19 epochs in…
Did Sgr cause the vertical waves in the solar neighbourhood?
Bovy, Jo; Bennett, Morgan
The vertical distribution of stars in the solar neighbourhood is not in equilibrium but contains a wave signature in both density and velocity space originating from a perturbation. With the discovery of the phase-space spiral in Gaia data release (DR) 2, determining the origin of this perturbation has become even more urgent. We develop and test …
The orbit and stellar masses of the archetype colliding-wind binary WR 140
Corcoran, Michael F.; Couperus, Andrew; Moffat, Anthony F. J. +33 more
We present updated orbital elements for the Wolf-Rayet (WR) binary WR 140 (HD 193793; WC7pd + O5.5fc). The new orbital elements were derived using previously published measurements along with 160 new radial velocity measurements across the 2016 periastron passage of WR 140. Additionally, four new measurements of the orbital astrometry were collect…
3D spectroscopic analysis of helium-line white dwarfs
Ludwig, Hans-Günter; Bergeron, Pierre; Tremblay, Pier-Emmanuel +3 more
In this paper, we present corrections to the spectroscopic parameters of DB and DBA white dwarfs with -10.0 ≤ log (H/He) ≤ -2.0, 7.5 ≤ log g ≤ 9.0, and $12\, 000$ ≲ Teff $\lesssim 34\, 000\,\mathrm{ K}$ , based on 282 3D atmospheric models calculated with the CO5BOLD radiation-hydrodynamics code. These corrections arise due t…
Galactic bar resonances inferred from kinematically hot stars in Gaia EDR3
Cropper, Mark; Ciucă, Ioana; Seabroke, George +5 more
Using a numerical simulation of an isolated barred disc galaxy, we first demonstrate that the resonances of the inner bar structure induce more prominent features in the action space distribution for the kinematically hotter stars, which are less sensitive to the local perturbation, such as the transient spiral arms. Then, we analyse the action di…
CoBiToM project - I. Contact binaries towards merging
Hakala, P.; Liakos, A.; Zola, S. +6 more
Binary and multiple stellar systems are numerous in our solar neighbourhood with 80 per cent of the solar-type stars being members of systems with high order multiplicity. The Contact Binaries Towards Merging (CoBiToM) Project is a programme that focuses on contact binaries and multiple stellar systems, as a key for understanding stellar nature. T…
The IRX-β relation of high-redshift galaxies
Faucher-Giguère, Claude-André; Hayward, Christopher C.; Narayanan, Desika +5 more
The relation between infrared excess (IRX) and UV spectral slope (βUV) is an empirical probe of dust properties of galaxies. The shape, scatter, and redshift evolution of this relation are not well understood, however, leading to uncertainties in estimating the dust content and star formation rates (SFRs) of galaxies at high redshift. I…
The ZTF Source Classification Project - II. Periodicity and variability processing metrics
Duev, Dmitry A.; Riddle, Reed; Mróz, Przemek +22 more
The current generation of all-sky surveys is rapidly expanding our ability to study variable and transient sources. These surveys, with a variety of sensitivities, cadences, and fields of view, probe many ranges of time-scale and magnitude. Data from the Zwicky Transient Facility (ZTF) yields an opportunity to find variables on time-scales from mi…
The census of dense cores in the Serpens region from the Herschel Gould Belt Survey
Arzoumanian, D.; Könyves, V.; Bontemps, S. +13 more
The Herschel Gould Belt survey mapped the nearby (d < 500 pc) star-forming regions to understand better how the prestellar phase influences the star formation process. Here, we report a complete census of dense cores in a ~15 deg2 area of the Serpens star-forming region located between d ~ 420 and 484 pc. The PACS and SPIRE cameras i…