Search Publications

The dark matter interpretation of the 3.5-keV line is inconsistent with blank-sky observations
DOI: 10.1126/science.aaw3772 Bibcode: 2020Sci...367.1465D

Safdi, Benjamin R.; Dessert, Christopher; Rodd, Nicholas L.

Observations of nearby galaxies and galaxy clusters have reported an unexpected x-ray emission line around 3.5 kilo-electron volts (keV). Proposals to explain this line include decaying dark matter—in particular, that the decay of sterile neutrinos with a mass around 7 keV could match the available data. If this interpretation is correct, the 3.5-…

2020 Science
XMM-Newton 98
A naked-eye triple system with a nonaccreting black hole in the inner binary
DOI: 10.1051/0004-6361/202038020 Bibcode: 2020A&A...637L...3R

Rivinius, Th.; Baade, D.; Klement, R. +2 more

Several dozen optical echelle spectra demonstrate that HR 6819 is a hierarchical triple. A classical Be star is in a wide orbit with an unconstrained period around an inner 40 d binary consisting of a B3 III star and an unseen companion in a circular orbit. The radial-velocity semi-amplitude of 61.3 km s-1 of the inne…

2020 Astronomy and Astrophysics
IUE 98
NIHAO-UHD: the properties of MW-like stellar discs in high-resolution cosmological simulations
DOI: 10.1093/mnras/stz3241 Bibcode: 2020MNRAS.491.3461B

Ostriker, Jeremiah P.; Buck, Tobias; Minchev, Ivan +3 more

Simulating thin and extended galactic discs has long been a challenge in computational astrophysics. We introduce the NIHAO-UHD suite of cosmological hydrodynamical simulations of Milky Way (MW) mass galaxies and study stellar disc properties such as stellar mass, size, and rotation velocity which agree well with observations of the MW and local g…

2020 Monthly Notices of the Royal Astronomical Society
Gaia eHST 97
Quenching as a Contest between Galaxy Halos and Their Central Black Holes
DOI: 10.3847/1538-4357/ab9633 Bibcode: 2020ApJ...897..102C

Barro, Guillermo; Bell, Eric F.; Ferguson, Henry C. +27 more

Existing models of galaxy formation have not yet explained striking correlations between structure and star formation activity in galaxies, notably the sloped and moving boundaries that divide star-forming from quenched galaxies in key structural diagrams. This paper uses these and other relations to "reverse engineer" the quenching process for ce…

2020 The Astrophysical Journal
eHST 97
Observational constraints on the optical and near-infrared emission from the neutron star-black hole binary merger candidate S190814bv
DOI: 10.1051/0004-6361/202037669 Bibcode: 2020A&A...643A.113A

Covino, S.; D'Avanzo, P.; Campana, S. +151 more

Context. Gravitational wave (GW) astronomy has rapidly reached maturity, becoming a fundamental observing window for modern astrophysics. The coalescences of a few tens of black hole (BH) binaries have been detected, while the number of events possibly including a neutron star (NS) is still limited to a few. On 2019 August 14, the LIGO and Virgo i…

2020 Astronomy and Astrophysics
Gaia 97
The origin of the escape of Lyman α and ionizing photons in Lyman continuum emitters
DOI: 10.1051/0004-6361/202038096 Bibcode: 2020A&A...639A..85G

Chisholm, J.; Schaerer, D.; Verhamme, A. +2 more

Context. Identifying the physical mechanisms driving the escape of Lyman continuum (LyC) photons is crucial for the search of Lyman continuum emitter (LCE) candidates.
Aims: To understand the physical properties involved in the leakage of LyC photons, we investigate the connection between the H I covering fraction, H I velocity width, the Lym…

2020 Astronomy and Astrophysics
eHST 97
Discovery of a nearby 1700 km s-1 star ejected from the Milky Way by Sgr A*
DOI: 10.1093/mnras/stz3081 Bibcode: 2020MNRAS.491.2465K

Lewis, Geraint F.; Boubert, Douglas; Erkal, Denis +18 more

We present the serendipitous discovery of the fastest main-sequence hyper-velocity star (HVS) by the Southern Stellar Stream Spectroscopic Survey (S5). The star S5-HVS1 is a ∼2.35 M A-type star located at a distance of ∼9 kpc from the Sun and has a heliocentric radial velocity of 1017 ± 2.7 km s^{-1} without any signature of…

2020 Monthly Notices of the Royal Astronomical Society
Gaia 97
A remnant planetary core in the hot-Neptune desert
DOI: 10.1038/s41586-020-2421-7 Bibcode: 2020Natur.583...39A

Latham, David W.; Gandhi, Siddharth; Brogi, Matteo +92 more

The interiors of giant planets remain poorly understood. Even for the planets in the Solar System, difficulties in observation lead to large uncertainties in the properties of planetary cores. Exoplanets that have undergone rare evolutionary processes provide a route to understanding planetary interiors. Planets found in and near the typically bar…

2020 Nature
Gaia 97
Dynamical traceback age of the β Pictoris moving group
DOI: 10.1051/0004-6361/202038765 Bibcode: 2020A&A...642A.179M

Miret-Roig, N.; Bouy, H.; Figueras, F. +7 more

Context. The β Pictoris moving group is one of the most well-known young associations in the solar neighbourhood and several members are known to host circumstellar discs, planets, and comets. Measuring its age precisely is essential to the study of several astrophysical processes, such as planet formation and disc evolution, which are strongly ag…

2020 Astronomy and Astrophysics
Gaia 97
Is HR 6819 a triple system containing a black hole?. An alternative explanation
DOI: 10.1051/0004-6361/202038682 Bibcode: 2020A&A...641A..43B

Shenar, T.; Sana, H.; Hawcroft, C. +10 more

Context. HR 6819 was recently proposed to be a triple system consisting of an inner B-type giant plus black hole (BH) binary with an orbital period of 40 d and an outer Be tertiary. This interpretation is mainly based on two inferences: that the emission attributed to the outer Be star is stationary and that the inner star, which is used as mass c…

2020 Astronomy and Astrophysics
Gaia IUE 97