Search Publications

New evidence for the ubiquity of prominent polar dust emission in AGN on tens of parsec scales
DOI: 10.1093/mnras/stz2289 Bibcode: 2019MNRAS.489.2177A

Asmus, D.

The key ingredient of active galactic nuclei (AGN) unification, the dusty obscuring torus was so far held responsible for the observed mid-infrared (MIR) emission of AGN. However, the best studied objects with Very Large Telescope Interferometer (VLTI)/MID-infrared Interferometric instrument (MIDI) show that instead a polar dusty wind is dominatin…

2019 Monthly Notices of the Royal Astronomical Society
ISO 67
A Deep View into the Nucleus of the Sagittarius Dwarf Spheroidal Galaxy with MUSE. I. Data and Stellar Population Characterization
DOI: 10.3847/1538-4357/ab1b2c Bibcode: 2019ApJ...886...57A

Kacharov, N.; Böker, T.; Kamann, S. +9 more

The center of the Sagittarius dwarf spheroidal galaxy (Sgr dSph) hosts a nuclear star cluster (NSC), M54, which is the only galaxy nucleus that can be resolved into individual stars at optical wavelengths. It is thus a key target for understanding the formation of NSCs and their relation to globular clusters (GCs). We present a large Multi-Unit Sp…

2019 The Astrophysical Journal
eHST 67
Damping of slow magnetoacoustic oscillations by the misbalance between heating and cooling processes in the solar corona
DOI: 10.1051/0004-6361/201936072 Bibcode: 2019A&A...628A.133K

Nakariakov, V. M.; Kolotkov, D. Y.; Zavershinskii, D. I.

Context. Rapidly decaying slow magnetoacoustic waves are regularly observed in the solar coronal structures, offering a promising tool for a seismological diagnostics of the coronal plasma, including its thermodynamical properties.
Aims: The effect of damping of standing slow magnetoacoustic oscillations in the solar coronal loops is investig…

2019 Astronomy and Astrophysics
SOHO 67
The CIDA Variability Survey of Orion OB1. II. Demographics of the Young, Low-mass Stellar Populations
DOI: 10.3847/1538-3881/aaf79b Bibcode: 2019AJ....157...85B

Berlind, Perry; Mateo, Mario; Bailey, John I., III +11 more

We present results of our large-scale, optical, multi-epoch photometric survey across ∼180 square degrees in the Orion OB1 association, complemented with extensive follow-up spectroscopy. Our focus is mapping and characterizing the off-cloud, low-mass, pre-main-sequence (PMS) populations. We report 2062 K- and M-type confirmed T Tauri members; 59%…

2019 The Astronomical Journal
Gaia 67
Multiplicity of Galactic Cepheids and RR Lyrae stars from Gaia DR2. I. Binarity from proper motion anomaly
DOI: 10.1051/0004-6361/201834210 Bibcode: 2019A&A...623A.116K

Mérand, Antoine; Gieren, Wolfgang; Gallenne, Alexandre +8 more

Context. Classical Cepheids (CCs) and RR Lyrae stars (RRLs) are important classes of variable stars used as standard candles to estimate galactic and extragalactic distances. Their multiplicity is imperfectly known, particularly for RRLs. Astoundingly, to date only one RRL has convincingly been demonstrated to be a binary, TU UMa, out of tens of t…

2019 Astronomy and Astrophysics
Gaia Hipparcos 67
Interpretation and diversity of exoplanetary material orbiting white dwarfs
DOI: 10.1093/mnras/stz2337 Bibcode: 2019MNRAS.490..202S

Redfield, Seth; Hollands, Mark; Gänsicke, Boris T. +5 more

Nine metal-polluted white dwarfs are observed with medium-resolution optical spectroscopy, where photospheric abundances are determined and interpreted by comparison with Solar system objects. An improved method for making such comparisons is presented, which overcomes potential weaknesses of prior analyses, with numerous sources of error consider…

2019 Monthly Notices of the Royal Astronomical Society
Gaia eHST 67
The Canada-France Imaging Survey: Reconstructing the Milky Way Star Formation History from Its White Dwarf Population
DOI: 10.3847/1538-4357/ab5521 Bibcode: 2019ApJ...887..148F

Lewis, Geraint F.; Gwyn, Stephen D. J.; McConnachie, Alan W. +15 more

As the remnants of stars with initial masses ≲8 M , white dwarfs contain valuable information on the formation histories of stellar populations. In this paper, we use deep, high-quality, u-band photometry from the Canada-France Imaging Survey, griz photometry from Pan-STARRS1, as well as proper motions from Gaia DR2, to select 25,156 w…

2019 The Astrophysical Journal
Gaia 67
The K2-HERMES Survey: age and metallicity of the thick disc
DOI: 10.1093/mnras/stz2861 Bibcode: 2019MNRAS.490.5335S

Lewis, Geraint F.; Ting, Yuan-Sen; Huber, Daniel +34 more

Asteroseismology is a promising tool to study Galactic structure and evolution because it can probe the ages of stars. Earlier attempts comparing seismic data from the Kepler satellite with predictions from Galaxy models found that the models predicted more low-mass stars compared to the observed distribution of masses. It was unclear if the misma…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 67
Spatial variations in the Milky Way disc metallicity-age relation
DOI: 10.1093/mnras/stz2221 Bibcode: 2019MNRAS.489.1742F

Feuillet, Diane K.; Lind, Karin; García-Hernández, D. A. +5 more

Stellar ages are a crucial component to studying the evolution of the Milky Way. Using Gaia DR2 distance estimates, it is now possible to estimate stellar ages for a larger volume of evolved stars through isochrone matching. This work presents [M/H]-age and [α/M]-age relations derived for different spatial locations in the Milky Way disc. These re…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 66
Astrometry with the Wide-Field Infrared Space Telescope
DOI: 10.1117/1.JATIS.5.4.044005 Bibcode: 2019JATIS...5d4005W

Casertano, Stefano; Lu, Jessica R.; Anderson, Jay +15 more

The Wide-Field Infrared Space Telescope (WFIRST) will be capable of delivering precise astrometry for faint sources over the enormous field of view of its main camera, the Wide-Field Imager (WFI). This unprecedented combination will be transformative for the many scientific questions that require precise positions, distances, and velocities of sta…

2019 Journal of Astronomical Telescopes, Instruments, and Systems
Gaia 66