Search Publications
Gemini-LIGHTS: Herbig Ae/Be and Massive T Tauri Protoplanetary Disks Imaged with Gemini Planet Imager
Monnier, John D.; Kraus, Stefan; Oppenheimer, Rebecca +20 more
We present the complete sample of protoplanetary disks from the Gemini- Large Imaging with the Gemini Planet Imager Herbig/T Tauri Survey, which observed bright Herbig Ae/Be stars and T Tauri stars in near-infrared polarized light to search for signatures of disk evolution and ongoing planet formation. The 44 targets were chosen based on their nea…
Flux rope and dynamics of the heliospheric current sheet. Study of the Parker Solar Probe and Solar Orbiter conjunction of June 2020
Fedorov, A.; Parenti, S.; Lavraud, B. +19 more
Context. Solar Orbiter and Parker Solar Probe jointly observed the solar wind for the first time in June 2020, capturing data from very different solar wind streams: calm, Alfvénic wind and also highly dynamic large-scale structures. Context. Our aim is to understand the origin and characteristics of the highly dynamic solar wind observed by the t…
Theory of solar oscillations in the inertial frequency range: Linear modes of the convection zone
Gizon, Laurent; Cameron, Robert H.; Bekki, Yuto
Context. Several types of global-scale inertial modes of oscillation have been observed on the Sun. These include the equatorial Rossby modes, critical-latitude modes, and high-latitude modes. However, the columnar convective modes (predicted by simulations and also known as banana cells or thermal Rossby waves) remain elusive.
Aims: We aim t…
Star-spots and magnetism: testing the activity paradigm in the Pleiades and M67
Pinsonneault, Marc H.; Cao, Lyra
We measure star-spot filling fractions for 240 stars in the Pleiades and M67 open star clusters using APOGEE high-resolution H-band spectra. For this work, we developed a modified spectroscopic pipeline which solves for star-spot filling fraction and star-spot temperature contrast. We exclude binary stars, finding that the large majority of binari…
Milky Way mass with K giants and BHB stars using LAMOST, SDSS/SEGUE, and Gaia: 3D spherical Jeans equation and tracer mass estimator
Bird, Sarah A.; Zhao, Gang; Tian, Hai-Jun +8 more
We measure the enclosed Milky Way mass profile to Galactocentric distances of ~70 and ~50 kpc using the smooth, diffuse stellar halo samples of Bird et al. The samples are Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) and Sloan Digital Sky Survey/Sloan Extension for Galactic Understanding and Exploration (SDSS/SEGUE) K giants …
Solar coronal heating from small-scale magnetic braids
Barczynski, K.; Peter, H.; Chitta, L. P. +19 more
Relaxation of braided coronal magnetic fields through reconnection is thought to be a source of energy to heat plasma in active region coronal loops. However, observations of active region coronal heating associated with an untangling of magnetic braids remain sparse. One reason for this paucity could be the lack of coronal observations with a suf…
Detecting low-mass haloes with strong gravitational lensing I: the effect of data quality and lensing configuration
White, Simon D. M.; Fassnacht, Christopher D.; Rizzo, Francesca +5 more
This paper aims to quantify how the lowest halo mass that can be detected with galaxy-galaxy strong gravitational lensing depends on the quality of the observations and the characteristics of the observed lens systems. Using simulated data, we measure the lowest detectable NFW mass at each location of the lens plane, in the form of detailed sensit…
Testing White Dwarf Age Estimates Using Wide Double White Dwarf Binaries from Gaia EDR3
Hermes, J. J.; van Saders, Jennifer L.; El-Badry, Kareem +4 more
White dwarf (WD) stars evolve simply and predictably, making them reliable age indicators. However, self-consistent validation of the methods for determining WD total ages has yet to be widely performed. This work uses 1565 wide (>100 au) WD+WD binaries and 24 new triples containing at least two WDs to test the accuracy and validity of WD total…
Rotation Distributions around the Kraft Break with TESS and Kepler: The Influences of Age, Metallicity, and Binarity
Pan, Kaike; van Saders, Jennifer L.; Claytor, Zachary R. +6 more
Stellar rotation is a complex function of mass, metallicity, and age and can be altered by binarity. To understand the importance of these parameters in main-sequence stars, we have assembled a sample of observations that spans a range of these parameters using a combination of observations from The Transiting Exoplanet Survey Satellite (TESS) and…
The extreme properties of the nearby hyper-Eddington accreting active galactic nucleus in IRAS 04416+1215
Ho, Luis C.; Ricci, Claudio; Tombesi, Francesco +6 more
The physical properties of the accretion flow and of the X-ray emitting plasma, in supermassive black holes accreting at extreme Eddington rates, are still very unclear. Here we present the analysis of simultaneous XMM-Newton and NuSTAR observations of the hyper-Eddington Seyfert 1 galaxy IRAS 04416+1215, carried out in 2020. The main goal of thes…