Search Publications
TESS Hunt for Young and Maturing Exoplanets (THYME). III. A Two-planet System in the 400 Myr Ursa Major Group
Gagliano, Robert; Kristiansen, Martti H.; LaCourse, Daryll M. +51 more
Exoplanets can evolve significantly between birth and maturity, as their atmospheres, orbits, and structures are shaped by their environment. Young planets (<1 Gyr) offer an opportunity to probe the critical early stages of this evolution, where planets evolve the fastest. However, most of the known young planets orbit prohibitively faint stars…
Direct confirmation of the radial-velocity planet β Pictoris c
Genzel, R.; Sturm, E.; Tacconi, L. J. +92 more
Context. Methods used to detect giant exoplanets can be broadly divided into two categories: indirect and direct. Indirect methods are more sensitive to planets with a small orbital period, whereas direct detection is more sensitive to planets orbiting at a large distance from their host star. This dichotomy makes it difficult to combine the two t…
Meridional flow in the Sun’s convection zone is a single cell in each hemisphere
Gizon, Laurent; Cameron, Robert H.; Liang, Zhi-Chao +4 more
The Sun’s magnetic field is generated by subsurface motions of the convecting plasma. The latitude at which the magnetic field emerges through the solar surface (as sunspots) drifts toward the equator over the course of the 11-year solar cycle. We use helioseismology to infer the meridional flow (in the latitudinal and radial directions) over two …
A dynamic black hole corona in an active galaxy through X-ray reverberation mapping
Fabian, Andrew C.; Middleton, Matthew J.; Walton, Dominic J. +18 more
X-ray reverberation echoes are assumed to be produced in the strongly distorted spacetime around accreting supermassive black holes. This signal allows us to spatially map the geometry of the inner accretion flow1,2—a region that cannot yet be spatially resolved by any telescope—and provides a direct measure of the black hole mass and s…
The Lyman Continuum Escape Survey. II. Ionizing Radiation as a Function of the [O III]/[O II] Line Ratio
Tang, Mengtao; Stark, Daniel P.; Ellis, Richard S. +2 more
We discuss the rest-frame optical emission line spectra of a large (∼50) sample of z ∼ 3.1 Lyα emitting galaxies (LAEs) whose physical properties suggest such sources are promising analogs of galaxies in the reionization era. Reliable Lyman continuum (LyC) escape fractions have now been determined for a large sample of such LAEs from the LymAn Con…
Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. XI. Accretion Disk Reverberation Mapping of Mrk 142
Ho, Luis C.; Barth, Aaron J.; Horne, Keith +15 more
We performed an intensive accretion disk reverberation mapping campaign on the high accretion rate active galactic nucleus Mrk 142 in early 2019. Mrk 142 was monitored with the Neil Gehrels Swift Observatory for four months in X-rays and six different UV/optical filters. Ground-based photometric monitoring was obtained from the Las Cumbres Observa…
Initiation and Early Kinematic Evolution of Solar Eruptions
Inhester, B.; Cheng, X.; Ding, M. D. +5 more
We investigate the initiation and early evolution of 12 solar eruptions, including six active-region hot channel and six quiescent filament eruptions, which were well observed by the Solar Dynamics Observatory, as well as by the Solar Terrestrial Relations Observatory for the latter. The sample includes one failed eruption and 11 coronal mass ejec…
Structure of Brightest Cluster Galaxies and Intracluster Light
Brosch, N.; Schmidt, M.; Bender, R. +6 more
Observations of 170 local (z ≲ 0.08) galaxy clusters in the northern hemisphere have been obtained with the Wendelstein Telescope Wide Field Imager (WWFI). We correct for systematic effects such as point-spread function broadening, foreground star contamination, relative bias offsets, and charge persistence. Background inhomogeneities induced by s…
Magnetic Reconnection in the Space Sciences: Past, Present, and Future
Hesse, M.; Cassak, P. A.
Magnetic reconnection converts, often explosively, stored magnetic energy to particle energy in space and in the laboratory. Through processes operating on length scales that are tiny, it facilitates energy conversion over dimensions of, in some cases, hundreds of Earth radii. In addition, it is the mechanism behind large current disruptions in fu…
The accretion rates and mechanisms of Herbig Ae/Be stars
Mendigutía, I.; Vioque, M.; Oudmaijer, R. D. +3 more
This work presents a spectroscopic study of 163 Herbig Ae/Be stars. Amongst these, we present new data for 30 objects. Stellar parameters such as temperature, reddening, mass, luminosity, and age are homogeneously determined. Mass accretion rates are determined from Hα emission line measurements. Our data is complemented with the X-Shooter sample …