Search Publications
The impact of stellar clustering on the observed multiplicity of super-earth systems: outside-in cascade of orbital misalignments initiated by stellar flybys
Rodet, Laetitia; Lai, Dong
A recent study suggests that the observed multiplicity of super-Earth (SE) systems is correlated with stellar overdensities: field stars in high phase-space density environments have an excess of single-planet systems compared to stars in low-density fields. This correlation is puzzling as stellar clustering is expected to influence mostly the out…
Improved hydrodynamic pulsation models for the pulsating extreme helium star V652 Herculis
Saio, Hideyuki; Jeffery, C. Simon; Montañés-Rodríguez, Pilar
New non-linear hydrodynamic models have been constructed to simulate the radial pulsations observed in the extreme helium star V652 Her. These use a finer zoning to allow higher radial resolution than in previous simulations. Models incorporate updated OPAL and OP opacity tables and adopt a composition based on the best atmospheric analyses to dat…
Doubling of minute-long quasi-periodic pulsations from super-flares on a low-mass star
Ramsay, Gavin; Irawati, Puji; Dhillon, Vik S. +5 more
Using the ULTRASPEC instrument mounted on the 2.4-m Thai National Telescope, we observed two large flares, each with a total energy close to 1034 erg with sub-second cadence. A combination of a wavelet analysis, a Fourier transform plus an empirical mode decomposition, reveals quasi-periodic pulsations (QPPs) that exhibit an apparent do…
On the nature of the X-ray pulsar XTE J1859+083 and its broad-band properties
Gromadzki, Mariusz; Buckley, David A. H.; Tsygankov, Sergey S. +5 more
This work is devoted to the study of the broad-band 0.8-79 keV spectral and timing properties of the poorly studied X-ray pulsar XTE J1859+083 during its 2015 outburst based on the data from the NuSTAR and Swift observatories. We show that the source pulse profile has complex shape that depends on the energy band. Pulse fraction of XTE J1859+083 h…
L-GALAXIES 2020: the formation and chemical evolution of stellar haloes in Milky Way analogues and galaxy clusters
Yates, Robert M.; Mohamed, Shazrene S.; Murphy, Geoff G.
We present an analysis of the formation and chemical evolution of stellar haloes around (a) Milky Way analogue (MWA) galaxies and (b) galaxy clusters in the L-GALAXIES 2020 semi-analytic model of galaxy evolution. Observed stellar halo properties are better reproduced when assuming a gradual stripping model for the removal of cold gas and stars fr…
An estimate of the mass of the Milky Way from the Magellanic Stream
Baum, Stefi; Chakrabarti, Sukanya; Craig, Peter A. +1 more
We present a model for the formation of the Magellanic Stream (MS) due to ram pressure stripping. We model the history of the Small and Large Magellanic Clouds in the recent cosmological past in a static Milky Way (MW) potential with diffuse halo gas, using observationally motivated orbits for the Magellanic Clouds derived from HST proper motions …
Deep near-infrared survey towards the W40 and Serpens South region in the Aquila Rift: A comprehensive catalogue of young stellar objects
Wang, Hongchi; Gutermuth, Robert A.; Ma, Yuehui +5 more
Active star-forming regions are excellent laboratories for studying the origins and evolution of young stellar object (YSO) clustering. The W40-Serpens South region is such a region, and we compile a large near- and mid-infrared catalogue of point sources in it, based on deep near-infrared observations of Canada-France-Hawaii Telescope (CFHT) in c…
Analysis of eight magnetic chemically peculiar stars with rotational modulation
Paunzen, E.; Bowman, D. M.; Shultz, M. E. +9 more
Since the end of 2018, the Transiting Exoplanet Survey Satellite (TESS) has provided stellar photometry to the astronomical community. We have used TESS data to study rotational modulation in the light curves of a sample of chemically peculiar stars with measured large-scale magnetic fields (mCP stars). In general, mCP stars show inhomogeneous dis…
HORuS transmission spectroscopy and revised planetary parameters of KELT-7 b
Rebolo, R.; del Burgo, C.; Montes, D. +7 more
We report on the high-resolution spectroscopic observations of two planetary transits of the hot Jupiter KELT-7b (Mp = 1.28 ± 0.17MJup, Teq = 2028 K) observed with the High Optical Resolution Spectrograph (HORuS) mounted on the 10.4-m Gran Telescopio Canarias (GTC). A new set of stellar parameters are obtained for …
RELICS: small lensed z ≥ 5.5 galaxies selected as potential Lyman continuum leakers
Treu, Tommaso; Bradač, Maruša; Strait, Victoria +8 more
We present size measurements of 78 high-redshift (z ≥ 5.5) galaxy candidates from the Reionization Lensing Cluster Survey (RELICS). These distant galaxies are well resolved due to the gravitational lensing power of foreground galaxy clusters, imaged by the Hubble Space Telescope and the Spitzer Space Telescope. We compute sizes using the forward-m…