Search Publications
A search for red giant solar-like oscillations in all Kepler data
García, Rafael A.; Sharma, Sanjib; Stello, Dennis +4 more
The recently published Kepler mission Data Release 25 (DR25) reported on ∼197 000 targets observed during the mission. Despite this, no wide search for red giants showing solar-like oscillations have been made across all stars observed in Kepler's long-cadence mode. In this work, we perform this task using custom apertures on the Kepler pixel file…
CO observations of major merger pairs at z = 0: molecular gas mass and star formation
Yun, Min S.; Gao, Yu; Domingue, Donovan L. +4 more
We present CO observations of 78 spiral galaxies in local merger pairs. These galaxies represent a subsample of a Ks-band-selected sample consisting of 88 close major-merger pairs (HKPAIRs), 44 spiral-spiral (S+S) pairs, and 44 spiral-elliptical (S+E) pairs, with separation <20 h-1 kpc and mass ratio <2.5. For all objec…
The K2 Galactic Caps Project - going beyond the Kepler field and ageing the Galactic disc
Khan, S.; Valentini, M.; García, R. A. +21 more
Analyses of data from spectroscopic and astrometric surveys have led to conflicting results concerning the vertical characteristics of the Milky Way. Ages are often used to provide clarity, but typical uncertainties of >40 per cent from photometry restrict the validity of the inferences made. Using the Kepler APOKASC sample for context, we expl…
Accretion Kinematics in the T Tauri Binary TWA 3A: Evidence for Preferential Accretion onto the TWA 3A Primary
Johns-Krull, Christopher M.; Tofflemire, Benjamin M.; Mathieu, Robert D.
We present time-series, high-resolution optical spectroscopy of the eccentric T Tauri binary TWA 3A. Our analysis focuses on variability in the strength and structure of the accretion-tracing emission lines Hα and He I 5876 Å. We find emission line strengths to display the same orbital phase-dependent behavior found with time-series photometry, na…
Jellyfish: Ram Pressure Stripping As a Diagnostic Tool in Studies of Cluster Collisions
Ebeling, Harald; Kalita, Boris S.
Prompted by the discovery of A1758N_JFG1, a spectacular case of ram pressure stripping (RPS) in the galaxy cluster A1758N, we investigate the properties of other galaxies suspected to undergo RPS in this equal-mass, post-collision merger. Exploiting constraints derived from Hubble Space Telescope images and Keck longslit spectroscopy, our finding …
Constraining the properties of HD 206893 B. A combination of radial velocity, direct imaging, and astrometry data
Aigrain, S.; Rouan, D.; Meunier, N. +25 more
Context. High contrast imaging enables the determination of orbital parameters for substellar companions (planets, brown dwarfs) from the observed relative astrometry and the estimation of model and age-dependent masses from their observed magnitudes or spectra. Combining astrometric positions with radial velocity gives direct constraints on the o…
Multispacecraft Analysis of Electron Holes
Russell, C. T.; Vaivads, A.; Khotyaintsev, Yu. V. +4 more
Electron holes (EHs) are nonlinear electrostatic structures in plasmas. Most previous in situ studies of EHs have been limited to single- and two-spacecraft methods. We present statistics of EHs observed by Magnetospheric Multiscale on the magnetospheric side of the magnetopause during October 2016 when the spacecraft separation was around 6 km. E…
Investigating ULX accretion flows and cyclotron resonance in NGC 300 ULX1
Haberl, F.; Buchner, J.; Vasilopoulos, G. +2 more
Aims: We investigate accretion models for the newly discovered pulsating ultraluminous X-ray source (ULX) NGC 300 ULX1.
Methods: We analyzed broadband XMM-Newton and NuSTAR observations of NGC 300 ULX1, performing phase-averaged and phase-resolved spectroscopy. Using the Bayesian framework, we compared two physically motivated models for…
The VMC survey - XXXIV. Morphology of stellar populations in the Magellanic Clouds
Girardi, Léo; de Grijs, Richard; Ripepi, Vincenzo +11 more
The Magellanic Clouds are nearby dwarf irregular galaxies whose morphologies show different properties when traced by different stellar populations, making them an important laboratory for studying galaxy morphologies. We study the morphology of the Magellanic Clouds using data from the Visible and Infrared Survey Telescope for Astronomy survey of…
From Scattered-light to Millimeter Emission: A Comprehensive View of the Gigayear-old System of HD 202628 and its Eccentric Debris Ring
Hughes, A. Meredith; Wilner, David J.; Stapelfeldt, Karl R. +13 more
We present here new observations of the eccentric debris ring surrounding the Gyr-old solar-type star HD 202628: at millimeter wavelengths with ALMA, at far-infrared wavelengths with Herschel, and in scattered light with the Hubble Space Telescope (HST). The ring inner edge is found to be consistent between ALMA and HST data. As radiation pressure…