Search Publications

Observable tests of self-interacting dark matter in galaxy clusters: cosmological simulations with SIDM and baryons
DOI: 10.1093/mnras/stz1815 Bibcode: 2019MNRAS.488.3646R

Massey, Richard; Jauzac, Mathilde; Harvey, David +5 more

We present BAHAMAS-SIDM, the first large-volume, (400 h^{-1} Mpc)3, cosmological simulations including both self-interacting dark matter (SIDM) and baryonic physics. These simulations are important for two primary reasons: (1) they include the effects of baryons on the dark matter distribution and (2) the baryon particles can be used to…

2019 Monthly Notices of the Royal Astronomical Society
eHST 111
The L 98-59 System: Three Transiting, Terrestrial-size Planets Orbiting a Nearby M Dwarf
DOI: 10.3847/1538-3881/ab2459 Bibcode: 2019AJ....158...32K

Kostov, Veselin B.; Barclay, Thomas; Moran, Sarah E. +112 more

We report the Transiting Exoplanet Survey Satellite (TESS) discovery of three terrestrial-size planets transiting L 98-59 (TOI-175, TIC 307210830)—a bright M dwarf at a distance of 10.6 pc. Using the Gaia-measured distance and broadband photometry, we find that the host star is an M3 dwarf. Combined with the TESS transits from three sectors, the c…

2019 The Astronomical Journal
Gaia 111
High Density Reflection Spectroscopy - II. The density of the inner black hole accretion disc in AGN
DOI: 10.1093/mnras/stz2326 Bibcode: 2019MNRAS.489.3436J

Fabian, Andrew C.; Reynolds, Christopher S.; Walton, Dominic J. +7 more

We present a high density disc reflection spectral analysis of a sample of 17 Seyfert 1 galaxies to study the inner disc densities at different black hole mass scales and accretion rates. All the available XMM-Newton observations in the archive are used. OM observations in the optical/UV band are used to estimate their accretion rates. We find tha…

2019 Monthly Notices of the Royal Astronomical Society
XMM-Newton 111
Close Companions around Young Stars
DOI: 10.3847/1538-3881/ab13b1 Bibcode: 2019AJ....157..196K

Bizyaev, Dmitry; Oravetz, Daniel; Pan, Kaike +26 more

Multiplicity is a fundamental property that is set early during stellar lifetimes, and it is a stringent probe of the physics of star formation. The distribution of close companions around young stars is still poorly constrained by observations. We present an analysis of stellar multiplicity derived from Apache Point Observatory Galactic Evolution…

2019 The Astronomical Journal
Gaia 111
White dwarf and subdwarf stars in the Sloan Digital Sky Survey Data Release 14
DOI: 10.1093/mnras/stz960 Bibcode: 2019MNRAS.486.2169K

Kepler, S. O.; Pelisoli, Ingrid; Romero, Alejandra D. +6 more

White dwarfs carry information on the structure and evolution of the Galaxy, especially through their luminosity function and initial-to-final mass relation. Very cool white dwarfs provide insight into the early ages of each population. Examining the spectra of all stars with 3σ proper motion in the Sloan Digital Sky Survey Data Release 14, we rep…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 110
Testing massive star evolution, star formation history, and feedback at low metallicity. Spectroscopic analysis of OB stars in the SMC Wing
DOI: 10.1051/0004-6361/201935365 Bibcode: 2019A&A...625A.104R

Hamann, W. -R.; Gallagher, J. S.; Oskinova, L. M. +6 more

Stars that start their lives with spectral types O and early B are the progenitors of core-collapse supernovae, long gamma-ray bursts, neutron stars, and black holes. These massive stars are the primary sources of stellar feedback in star-forming galaxies. At low metallicities, the properties of massive stars and their evolution are not yet fully …

2019 Astronomy and Astrophysics
eHST 110
A Cooling Anomaly of High-mass White Dwarfs
DOI: 10.3847/1538-4357/ab4989 Bibcode: 2019ApJ...886..100C

Cheng, Sihao; Cummings, Jeffrey D.; Ménard, Brice

Recently, the power of Gaia data has revealed an enhancement of high-mass white dwarfs (WDs) on the Hertzsprung-Russell diagram, called the Q branch. This branch is located at the high-mass end of the recently identified crystallization branch. Investigating its properties, we find that the number density and velocity distribution on the Q branch …

2019 The Astrophysical Journal
Gaia 110
A super-Earth and two sub-Neptunes transiting the nearby and quiet M dwarf TOI-270
DOI: 10.1038/s41550-019-0845-5 Bibcode: 2019NatAs...3.1099G

Vanderburg, Andrew; Latham, David W.; Quinn, Samuel N. +57 more

One of the primary goals of exoplanetary science is to detect small, temperate planets passing (transiting) in front of bright and quiet host stars. This enables the characterization of planetary sizes, orbits, bulk compositions, atmospheres and formation histories. These studies are facilitated by small and cool M dwarf host stars. Here we report…

2019 Nature Astronomy
Gaia 109
Constraining the Milky Way halo potential with the GD-1 stellar stream
DOI: 10.1093/mnras/stz1035 Bibcode: 2019MNRAS.486.2995M

Malhan, Khyati; Ibata, Rodrigo A.

We use ESA/Gaia astrometry together with SEGUE and LAMOST measurements of the GD-1 stellar stream to explore the improvement on the Galactic gravitational potential that these new data provide. Assuming a realistic universal model for the dark matter halo together with reasonable models of the baryonic components, we find that the orbital solution…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 109
Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS). II. A broadened sodium feature on the ultra-hot giant WASP-76b
DOI: 10.1051/0004-6361/201834776 Bibcode: 2019A&A...623A.166S

Heng, K.; Ségransan, D.; Deline, A. +18 more

High-resolution optical spectroscopy is a powerful tool to characterise exoplanetary atmospheres from the ground. The sodium D lines, with their large cross sections, are especially suited to studying the upper layers of atmospheres in this context. We report on the results from Hot Exoplanet Atmosphere Resolved with Transit Spectroscopy survey (H…

2019 Astronomy and Astrophysics
Gaia 109