Search Publications
The rocky road to quiescence: compaction and quenching of quasar host galaxies at z ∼ 2
Ivison, R. J.; Vegetti, S.; McKean, J. P. +6 more
We resolve the host galaxies of seven gravitationally lensed quasars at redshift 1.5-2.8 using observations with the Atacama Large (sub)Millimetre Array. Using a visibility plane lens modelling technique, we create pixellated reconstructions of the dust morphology, and CO line morphology and kinematics. We find that the quasar hosts in our sample …
The proper motion of Andromeda from Gaia EDR3: confirming a nearly radial orbit
Reylé, C.; Famaey, B.; Ibata, R. +4 more
We present an analysis of the proper motion of the Andromeda galaxy (M31), based on the Early Third Data Release of the Gaia mission. We use the Gaia photometry to select young blue main-sequence stars and apply several quality cuts to obtain clean samples of these tracers. After correcting the proper motion measurements for the internal rotation …
Orbital misalignment of the super-Earth π Men c with the spin of its star
Kunovac Hodžić, Vedad; Triaud, Amaury H. M. J.; Cegla, Heather M. +2 more
Planet-planet scattering events can leave an observable trace of a planet's migration history in the form of orbital misalignment with respect to the stellar spin axis, which is measurable from spectroscopic time-series taken during transit. We present high-resolution spectroscopic transits observed with ESPRESSO of the close-in super-Earth π Men …
The Pristine survey - XII. Gemini-GRACES chemo-dynamical study of newly discovered extremely metal-poor stars in the Galaxy
Sestito, Federico; Navarro, Julio F.; Martin, Nicolas F. +16 more
High-resolution optical spectra of 30 metal-poor stars selected from the Pristine survey are presented, based on observations taken with the Gemini Observatory GRACES spectrograph. Stellar parameters Teff and log g are determined using a Gaia DR2 colour-temperature calibration and surface gravity from the Stefan-Boltzmann equation. GRAC…
Stellar flares detected with the Next Generation Transit Survey
Jackman, James A. G.; Wheatley, Peter J.; Bayliss, Daniel +19 more
We present the results of a search for stellar flares in the first data release from the Next Generation Transit Survey (NGTS). We have found 610 flares from 339 stars, with spectral types between F8 and M6, the majority of which belong to the Galactic thin disc. We have used the 13-s cadence NGTS light curves to measure flare properties such as t…
Infrared emission of z ∼ 6 galaxies: AGN imprints
Ferrara, A.; Vito, F.; Pallottini, A. +6 more
We investigate the infrared (IR) emission of high-redshift (z ∼ 6), highly star-forming ( ${{\rm SFR}\gt 100\,{\rm M}_{\odot }\, {\rm yr}^{-1}}$ ) galaxies, with/without active galactic nuclei (AGN), using a suite of cosmological simulations featuring dust radiative transfer. Synthetic spectral energy distributions (SEDs) are used to quantify the …
Action-based distribution function modelling for constraining the shape of the Galactic dark matter halo
Hattori, Kohei; Vasiliev, Eugene; Valluri, Monica
We estimate the 3D density profile of the Galactic dark matter (DM) halo within r ≲ 30 kpc from the Galactic centre by using the astrometric data for halo RR Lyrae stars from Gaia DR2. We model both the stellar halo distribution function and the Galactic potential, fully taking into account the survey selection function, the observational errors, …
TOI-431/HIP 26013: a super-Earth and a sub-Neptune transiting a bright, early K dwarf, with a third RV planet
Henning, Thomas; Barclay, Thomas; Gorjian, Varoujan +125 more
We present the bright (Vmag = 9.12), multiplanet system TOI-431, characterized with photometry and radial velocities (RVs). We estimate the stellar rotation period to be 30.5 ± 0.7 d using archival photometry and RVs. Transiting Exoplanet Survey Satellite (TESS) objects of Interest (TOI)-431 b is a super-Earth with a period of 0.49 d, a…
The origin of metal-poor stars on prograde disc orbits in FIRE simulations of Milky Way-mass galaxies
Faucher-Giguère, Claude-André; El-Badry, Kareem; Wetzel, Andrew +3 more
In hierarchical structure formation, metal-poor stars in and around the Milky Way (MW) originate primarily from mergers of lower mass galaxies. A common expectation is therefore that metal-poor stars should have isotropic, dispersion-dominated orbits that do not correlate strongly with the MW disc. However, recent observations of stars in the MW s…
X-ray spectral components of the blazar and binary black hole candidate OJ 287 (2005-2020)
Ciprini, S.; Nowak, M. A.; Komossa, S. +12 more
We present a comprehensive analysis of all XMM-Newton spectra of OJ 287 spanning 15 yr of X-ray spectroscopy of this bright blazar. We also report the latest results from our dedicated Swift UVOT and XRT monitoring of OJ 287, which started in 2015, along with all earlier public Swift data since 2005. During this time interval, OJ 287 was caught in…