Search Publications
Astrometry and exoplanets in the Gaia era: a Bayesian approach to detection and parameter recovery
Ranalli, P.; Lindegren, L.; Hobbs, D.
The Gaia mission is expected to make a significant contribution to the knowledge of exoplanet systems, both in terms of their number and of their physical properties. We develop Bayesian methods and detection criteria for orbital fitting, and revise the detectability of exoplanets in light of the in-flight properties of Gaia. Limiting ourselves to…
A New Generation of Cool White Dwarf Atmosphere Models. II. A DZ Star with Collision-induced Absorption
Dufour, P.; Allard, N. F.; Blouin, S. +1 more
In the first paper of this series, we presented our upgraded cool white dwarf atmosphere code. In this second paper, we use our new models to analyze SDSS J080440.63+223948.6 (J0804+2239), the first DZ star to show collision-induced absorption (CIA). This object provides a crucial test for our models, since previous versions of our code were unabl…
Dynamics and Formation of the Near-resonant K2-24 System: Insights from Transit-timing Variations and Radial Velocities
Deming, Drake; Gorjian, Varoujan; Fulton, Benjamin J. +8 more
While planets between the size of Uranus and Saturn are absent within the solar system, the star K2-24 hosts two such planets, K2-24b and c, with radii equal to 5.4 {R}\oplus and 7.5 {R}\oplus , respectively. The two planets have orbital periods of 20.9 days and 42.4 days, residing only 1% outside the nominal 2:1 mean-motion…
Shock Connectivity and the Late Cycle 24 Solar Energetic Particle Events in July and September 2017
Luhmann, J. G.; Odstrcil, D.; Cohen, C. M. S. +7 more
As solar activity steadily declined toward the cycle 24 minimum in the early months of 2017, the expectation for major solar energetic particle (SEP) events diminished with the sunspot number. It was thus surprising (though not unprecedented) when a new, potentially significant active region rotated around the East limb in early July that by midmo…
K2-260 b: a hot Jupiter transiting an F star, and K2-261 b: a warm Saturn around a bright G star
Kuzuhara, M.; Tamura, M.; Alonso, R. +45 more
We present the discovery and confirmation of two new transiting giant planets from the Kepler extended mission K2. K2-260 b is a hot Jupiter transiting a V = 12.7 F6V star in K2 Field 13, with a mass and radius of M⋆ = 1.39_{-0.06}^{+0.05} M_{⊙} and R⋆ = 1.69 ± 0.03 R_{⊙}. The planet has an orbital period of P = 2.627 d, and …
ALMA 26 arcmin2 Survey of GOODS-S at One-millimeter (ASAGAO): X-Ray AGN Properties of Millimeter-selected Galaxies
Ivison, R. J.; Taniguchi, Y.; Yun, M. S. +33 more
We investigate the X-ray active galactic nucleus (AGN) properties of millimeter galaxies in the Great Observatories Origins Deep Survey South (GOODS-S) field detected with the Atacama Large Millimeter/submillimeter Array (ALMA), by utilizing the Chandra 7-Ms data, the deepest X-ray survey to date. Our millimeter galaxy sample comes from the ASAGAO…
Magnetic seismology of interstellar gas clouds: Unveiling a hidden dimension
Tassis, Konstantinos; Tritsis, Aris
Stars and planets are formed inside dense interstellar molecular clouds by processes imprinted on the three-dimensional (3D) morphology of the clouds. Determining the 3D structure of interstellar clouds remains challenging because of projection effects and difficulties measuring the extent of the clouds along the line of sight. We report the detec…
Non-damping oscillations at flaring loops
Li, D.; Zhang, Q. M.; Ning, Z. J. +3 more
Context. Quasi-periodic oscillations are usually detected as spatial displacements of coronal loops in imaging observations or as periodic shifts of line properties (i.e., Doppler velocity, line width and intensity) in spectroscopic observations. They are often applied for remote diagnostics of magnetic fields and plasma properties on the Sun.
The Origin of Double-peaked Narrow Lines in Active Galactic Nuclei. IV. Association with Galaxy Mergers
Newman, Jeffrey A.; Stemo, Aaron; Comerford, Julia M. +4 more
Double-peaked narrow emission lines in active galactic nucleus (AGN) spectra can be produced by AGN outflows, rotation, or dual AGNs, which are AGN pairs in ongoing galaxy mergers. Consequently, double-peaked narrow AGN emission lines are useful tracers of the coevolution of galaxies and their supermassive black holes, as driven by AGN feedback an…
Searching for the weakest detectable magnetic fields in white dwarfs. Highly-sensitive measurements from first VLT and WHT surveys
Bagnulo, S.; Landstreet, J. D.
Our knowledge of the magnetism in white dwarfs is based on an observational dataset that is biased in favour of stars with very strong magnetic fields. Most of the field measurements available in the literature have a relatively low sensitivity, while current instruments allow us to detect magnetic fields of white dwarfs with sub-kG precision. Wit…