Search Publications
Parallel Plasma Loops and the Energization of the Solar Corona
Tiwari, Sanjiv K.; Golub, Leon; Winebarger, Amy R. +15 more
The outer atmosphere of the Sun is composed of plasma heated to temperatures well in excess of the visible surface. We investigate short cool and warm (<1 MK) loops seen in the core of an active region to address the role of field-line braiding in energizing these structures. We report observations from the High-resolution Coronal imager (Hi-C)…
CWISE J014611.20-050850.0AB: The Widest Known Brown Dwarf Binary in the Field
Shkolnik, Evgenya; Meisner, Aaron M.; Cushing, Michael C. +17 more
While stars are often found in binary systems, brown dwarf binaries are much rarer. Brown dwarf-brown dwarf pairs are typically difficult to resolve because they often have very small separations. Using brown dwarfs discovered with data from the Wide-field Infrared Survey Explorer (WISE) via the Backyard Worlds: Planet 9 citizen science project, w…
Is the Core-cusp Problem a Matter of Perspective? Jeans Anisotropic Modeling against Numerical Simulations
Tian, Hao; Grand, Robert J. J.; Wang, Wenting +14 more
Mock member stars for 28 dwarf galaxies are constructed from the cosmological AURIGA simulation, which reflects the dynamical status of realistic stellar tracers. Axisymmetric Jeans Anisotropic Multi-Gaussian Expansion (JAM) modeling is applied to 6000 star particles for each system to recover the underlying matter distribution. The stellar or dar…
Estimating the Convective Turnover Time
Henry, Todd J.; Wright, Nicholas J.; Jao, Wei-Chun +2 more
The introduction of the Rossby number (R0), which incorporates the convective turnover time (τ), in 1984 was a pioneering idea for understanding the correlation between stellar rotation and activity. The convective turnover time, which cannot be measured directly, is often inferred using existing τ-mass or τ-color relations, typically e…
Circular Polarization Observations of Type II Solar Radio Bursts and the Coronal Magnetic Field
Ramesh, R.; Kathiravan, C.; Chellasamy, E. Ebenezer
It is well known that magnetic field strength (B) in the solar corona can be calculated using the Alfvén Mach number (M A ) and Alfvén speed (v A ) of the magnetohydrodynamic shock waves associated with coronal type II radio bursts. We show that observations of weak circularly polarized emission associated with the harmonic…
Distributed YSOs in the Perseus Molecular Cloud from the Gaia and LAMOST Surveys
Fang, Min; Herczeg, Gregory J.; Gao, Yu +5 more
Identifying the young optically visible population in a star-forming region is essential for fully understanding the star formation event. In this paper, we identify 211 candidate members of the Perseus molecular cloud based on Gaia astrometry. We use LAMOST spectra to confirm that 51 of these candidates are new members, bringing the total census …
Termination Shocks and the Extended X-Ray Emission in Mrk 78
Elvis, Martin; Gandhi, Poshak; Maksym, W. Peter +4 more
Subarcsecond imaging of the X-ray emission in the type 2 active galactic nucleus (AGN) Mrk 78 with Chandra shows complex structure with spectral variations on scales from ~200 pc to ~2 kpc. Overall the X-ray emission is aligned E-W with the radio (3.6 cm) and narrow emission line region as mapped in [O III], with a marked E-W asymmetry. The easter…
Blanco DECam Bulge Survey (BDBS). VII. Multiple Populations in Globular Clusters of the Galactic Bulge
Clarkson, William I.; Rich, R. Michael; Kunder, Andrea +9 more
We present photometric evidence for multiple stellar populations (MPs) in 14 globular clusters (GCs) toward the southern Galactic bulge. The photometric data come as part of the Blanco DECam Bulge Survey, which is a deep, wide-field near-UV-near-IR (ugrizY) survey of the southern Galactic bulge. Here, we present the first systematic study of bulge…
A Dearth of Close-in Planets around Rapidly Rotating Stars or a Dearth of Data?
De Medeiros, J. R.; Leão, I. C.; Canto Martins, B. L. +4 more
A dearth of close-in planets orbiting rapid rotators was reported almost a decade ago. According to this view, only slowly spinning stars with rotation periods longer than 5-10 days would host planets with orbital periods shorter than 2 or 3 days. This Letter brings an enlarged and more detailed analysis that led us to the question: Is there reall…
A Low-mass Pre-main-sequence Eclipsing Binary in Lower Centaurus Crux Discovered with TESS
Torres, Guillermo; Feliz, Dax L.; Stassun, Keivan G. +5 more
We report the discovery of 2M1222-57 as a low-mass, pre-main-sequence (PMS) eclipsing binary (EB) in the Lower Centaurus Crux (LCC) association for which, using Gaia parallaxes and proper motions with a neural net age estimator, we determine an age of 16.2 ± 2.2 Myr. The broadband spectral energy distribution (SED) shows clear excess at ≳10 µ…