Search Publications
The Implications of Local Fluctuations in the Galactic Midplane for Dynamical Analysis in the Gaia Era
Hogg, David W.; Laporte, Chervin F. P.; Ness, Melissa K. +6 more
Orbital properties of stars, computed from their six-dimensional phase-space measurements and an assumed Galactic potential, are used to understand the structure and evolution of the Galaxy. Stellar actions, computed from orbits, have the attractive quality of being invariant under certain assumptions and are therefore used as quantitative labels …
The Fornax 3D project: dust mix and gas properties in the centre of early-type galaxy FCC 167
Viaene, S.; Morelli, L.; Pinna, F. +15 more
Galaxies continuously reprocess their interstellar material. We can therefore expect changing dust grain properties in galaxies that have followed different evolutionary pathways. Determining the intrinsic dust grain mix of a galaxy helps in reconstructing its evolutionary history. Early-type galaxies occasionally display regular dust lanes in the…
3.8 µm Imaging of 400-600 K Brown Dwarfs and Orbital Constraints for WISEP J045853.90+643452.6AB
Apai, D.; Rieke, Marcia; Marley, Mark S. +10 more
Half of the energy emitted by late-T- and Y-type brown dwarfs emerges at 3.5 ≤ λ µm ≤ 5.5. We present new L‧ (3.43 ≤ λ µm ≤ 4.11) photometry obtained at the Gemini North telescope for nine late-T and Y dwarfs, and synthesize L‧ from spectra for an additional two dwarfs. The targets include two binary systems that were imaged at a resol…
The GALAH survey: co-orbiting stars and chemical tagging
Lewis, Geraint F.; Ting, Yuan-Sen; Casey, Andrew R. +24 more
We present a study using the second data release of the GALAH survey of stellar parameters and elemental abundances of 15 pairs of stars identified by Oh et al. They identified these pairs as potentially co-moving pairs using proper motions and parallaxes from Gaia DR1. We find that 11 very wide (>1 pc) pairs of stars do in fact have similar Ga…
A closer look at the deep radio sky: Multi-component radio sources at 3 GHz VLA-COSMOS
Bondi, M.; Finoguenov, A.; Magnelli, B. +20 more
Context. Given the unprecedented depth achieved in current large radio surveys, we are starting to probe populations of radio sources that have not been studied in the past. However, identifying and categorising these objects, differing in size, shape and physical properties, is becoming a more difficult task.
Aims: In this data paper we pres…
Formation of cometary O2 ice and related ice species on grain surfaces in the midplane of the pre-solar nebula
Walsh, Catherine; Eistrup, Christian
Context. Detection of abundant O2 at 1-10% relative to H2O ice in the comae of comets 1P/Halley and 67P/Churyumov-Gerasimenko has motivated attempts to explain the origin of the high O2 ice abundance. Recent chemical modelling of the outer, colder regions of a protoplanetary disk midplane has shown production of O<…
A high-mass planetary nebula in a Galactic open cluster
Zijlstra, A. A.; Parker, Q. A.; Fragkou, V. +2 more
Planetary nebulae are the ionized ejected envelopes surrounding the remnant cores of dying stars. Theory predicts that main-sequence stars of one to about eight solar masses may eventually form planetary nebulae. Until now, this has not been confirmed at the higher end of the mass range. Here we report that the planetary nebula BMP J1613-5406 is a…
Fundamental parameters and evolutionary status of the magnetic chemically peculiar stars HD 188041 (V1291 Aquilae), HD 111133 (EP Virginis), and HD 204411: spectroscopy versus interferometry
Shulyak, D.; Ryabchikova, T.; Perraut, K. +4 more
The determination of fundamental parameters of stars is one of the main tasks of astrophysics. For magnetic chemically peculiar stars, this problem is complicated by the anomalous chemical composition of their atmospheres, which requires special analysis methods. We present the results of the effective temperature, surface gravity, abundance, and …
Mid-infrared evolution of η Carinae from 1968 to 2018
Gull, T. R.; Hillier, D. J.; Asmus, D. +6 more
η Car is one of the most luminous and massive stars in our Galaxy and is the brightest mid-IR source in the sky outside our solar system. Since the late 1990s, the central source has dramatically brightened at UV and optical wavelengths. This might be explained by a decrease in circumstellar dust extinction. We aim to establish the mid-IR flux evo…
H.E.S.S. and Suzaku observations of the Vela X pulsar wind nebula
Santangelo, A.; Quirrenbach, A.; Bregeon, J. +222 more
Context. Pulsar wind nebulae (PWNe) represent the most prominent population of Galactic very-high-energy gamma-ray sources and are thought to be an efficient source of leptonic cosmic rays. Vela X is a nearby middle-aged PWN, which shows bright X-ray and TeV gamma-ray emission towards an elongated structure called the cocoon.
Aims: Since TeV …