Search Publications
ASKAP observations of multiple rapid scintillators reveal a degrees-long plasma filament
Kaplan, David L.; Lenc, Emil; Murphy, Tara +5 more
We present the results from an Australian Square Kilometre Array Pathfinder search for radio variables on timescales of hours. We conducted an untargeted search over a 30 deg2 field, with multiple 10-h observations separated by days to months, at a central frequency of 945 MHz. We discovered six rapid scintillators from 15-min model-sub…
The HST large programme on ω Centauri - IV. Catalogue of two external fields
Salaris, M.; Apai, D.; Anderson, J. +9 more
In the fourth paper of this series, we present - and publicly release - the state-of-the-art catalogue and atlases for the two remaining parallel fields observed with the Hubble Space Telescope for the large programme on ω Centauri. These two fields are located at ~12 arcmin from the centre of the globular cluster (in the west and south-west direc…
An Improved Near-infrared Spectrum of the Archetype Y Dwarf WISEP J182831.08+265037.8
Cushing, Michael C.; Kirkpatrick, J. Davy; Gelino, Christopher R. +8 more
We present a Hubble Space Telescope/Wide-Field Camera 3 near-infrared spectrum of the archetype Y dwarf WISEP 182831.08+265037.8. The spectrum covers the 0.9-1.7 µm wavelength range at a resolving power of λ/Δλ ≈ 180 and is a significant improvement over the previously published spectrum because it covers a broader wavelength range and is un…
One Year in the Life of Young Suns: Data-constrained Corona-wind Model of κ1 Ceti
Kochukhov, Oleg; Güdel, Manuel; Jin, Meng +5 more
The young magnetically active solar-like stars are efficient generators of ionizing radiation in the form of X-ray and extreme-UV (EUV) flux, stellar wind, and eruptive events. These outputs are the critical factors affecting atmospheric escape and chemistry of (exo)planets around active stars. While X-ray fluxes and surface magnetic fields can be…
Optimized modelling of Gaia-Hipparcos astrometry for the detection of the smallest cold Jupiter and confirmation of seven low-mass companions
Butler, R. Paul; Vogt, Steven S.; Oppenheimer, Rebecca +6 more
To fully constrain the orbits of low-mass circumstellar companions, we conduct combined analyses of the radial velocity data and the Gaia and Hipparcos astrometric data for eight nearby systems. Our study shows that companion-induced position and proper motion differences between Gaia and Hipparcos are significant enough to constrain orbits of low…
On the Color-Metallicity Relation of the Red Clump and the Reddening toward the Magellanic Clouds
Riess, Adam G.; Yuan, Wenlong; Casagrande, Luca +2 more
The zero point of the reddening toward the Large Magellanic Cloud (LMC) has been the subject of some dispute. Its uncertainty propagates as a systematic error for methods that measure the extragalactic distance scale through knowledge of the absolute extinction of LMC stars. In an effort to resolve this issue, we used three different methods to ca…
The Gaia spectrophotometric standard stars survey - V. Preliminary flux tables for the calibration of Gaia DR2 and (E)DR3
Harrison, D. L.; Jordi, C.; Rainer, M. +15 more
We present the flux tables of the spectrophotometric standard stars (SPSS) used to calibrate in flux the Gaia DR2 and (E)DR3 data releases. The latest SPSS grid version contains 112 stars, whose flux tables agree to better than 1 per cent with the CALSPEC spectra of 11 flux standards for the calibration of the Hubble Space Telescope. The synthetic…
On the Contribution of the X-Ray Source to the Extended Nebular He II Emission in IZW18
Guerrero, M. A.; Ramos-Larios, G.; Kehrig, C. +1 more
Nebular He II emission implies the presence of energetic photons (E ≥ 54 eV). Despite the great deal of effort dedicated to understanding He II ionization, its origin has remained mysterious, particularly in metal-deficient star-forming (SF) galaxies. Unfolding He II-emitting, metal-poor starbursts at z ∼ 0 can yield insight into the powerful ioni…
Outflows, envelopes, and disks as evolutionary indicators in Lupus young stellar objects
de Gregorio-Monsalvo, I.; Lopez, C.; Fernández-López, M. +4 more
Context. The Lupus star-forming complex includes some of the closest low-mass star-forming regions, and together they house objects that span evolutionary stages from prestellar to premain sequence.
Aims: By studying seven objects in the Lupus clouds from prestellar to protostellar stages, we aim to test if a coherence exists between commonly…
Evidence Suggesting That 'Oumuamua Is the 30 Myr Old Product of a Molecular Cloud
Hsieh, Cheng-Han; Laughlin, Gregory; Arce, Héctor G.
The appearance of interstellar objects (ISOs) in the solar system-and specifically the arrival of 1I/'Oumuamua-points to a significant number density of free-floating bodies in the solar neighborhood. We review the details of 'Oumuamua's pre-encounter Galactic orbit, which intersected the solar system at very nearly its maximum vertical and radial…