Search Publications
Evidence for Centrifugal Breakout around the Young M Dwarf TIC 234284556
Montet, Benjamin T.; Hartman, Joel D.; Feinstein, Adina D. +5 more
Magnetospheric clouds have been proposed as explanations for depth-varying dips in the phased light curves of young, magnetically active stars such as σ Ori E and RIK-210. However, the stellar theory that first predicted magnetospheric clouds also anticipated an associated mass-balancing mechanism known as centrifugal breakout for which there has …
The Internal Proper Motion Kinematics of NGC 346: Past Formation and Future Evolution
Anderson, J.; Lennon, D. J.; Sabbi, E. +6 more
We investigate the internal kinematics of the young star-forming region NGC 346 in the Small Magellanic Cloud (SMC). We used two epochs of deep F555W and F814W Hubble Space Telescope Advanced Camera for Surveys observations with an 11 yr baseline to determine proper motions and study the kinematics of different populations, as identified by their …
New Constraints on Cosmic Particle Populations at the Galactic Center Using X-Ray Observations of the Molecular Cloud Sagittarius B2
Zhang, Shuo; Clavel, Maïca; Perez, Kerstin +2 more
The Sagittarius B2 (Sgr B2) molecular cloud complex is an X-ray reflection nebula whose nonthermal X-ray emissions have continued to decrease since 2001 as it reprocesses one or more past energetic outbursts from the supermassive black hole Sagittarius A* at the Galactic Center. The X-ray reflection model explains the observed time variability of …
Acceleration and Expansion of a Coronal Mass Ejection in the High Corona: Role of Magnetic Reconnection
Temmer, Manuela; Lugaz, Noé; Zhuang, Bin +2 more
The important role played by magnetic reconnection in the early acceleration of coronal mass ejections (CMEs) has been widely discussed. However, as CMEs may have expansion speeds comparable to their propagation speeds in the corona, it is not clear whether and how reconnection contributes to the true acceleration and expansion separately. To addr…
A Long-period Pre-ELM System Discovered from the LAMOST Medium-resolution Survey
Liu, Jifeng; Bai, Yu; Gu, Wei-Min +16 more
We present LAMOST J041920.07+072545.4 (hereafter J0419), a close binary consisting of a bloated, extremely low mass pre-white dwarf (pre-ELM WD) and a compact object with an orbital period of 0.607189 days. The large-amplitude ellipsoidal variations and the evident Balmer and He I emission lines suggest a filled Roche lobe and ongoing mass transfe…
Evolution of Plasma Composition in an Eruptive Flux Rope
Long, D. M.; van Driel-Gesztelyi, L.; Démoulin, P. +8 more
Magnetic flux ropes are bundles of twisted magnetic field enveloping a central axis. They harbor free magnetic energy and can be progenitors of coronal mass ejections (CMEs). However, identifying flux ropes on the Sun can be challenging. One of the key coronal observables that has been shown to indicate the presence of a flux rope is a peculiar br…
Deep Learning Based Solar Flare Forecasting Model. II. Influence of Image Resolution
Liu, Sixuan; Xu, Long; Zhao, Zhongrui +3 more
Due to the accumulation of solar observational data and the development of data-driven algorithms, deep learning methods are widely applied to build a solar flare forecasting model. Most of the works focus on how to design or select proper deep networks for the forecasting task. Nevertheless, the influence of image resolution on the learning based…
3D-DASH: The Widest Near-infrared Hubble Space Telescope Survey
van Dokkum, Pieter G.; Franx, Marijn; Muzzin, Adam +15 more
The 3D-Drift And SHift (3D-DASH) program is a Hubble Space Telescope (HST) WFC3 F160W imaging and G141 grism survey of the equatorial COSMOS field. 3D-DASH extends the legacy of HST near-infrared imaging and spectroscopy to degree-scale swaths of the sky, enabling the identification and study of distant galaxies (z > 2) that are rare or in shor…
Kiloparsec-scale Imaging of the CO(1-0)-traced Cold Molecular Gas Reservoir in a z 3.4 Submillimeter Galaxy
van der Werf, Paul; Walter, Fabian; Narayanan, Desika +9 more
We present a high-resolution study of the cold molecular gas as traced by CO(1-0) in the unlensed z ~ 3.4 submillimeter galaxy SMM J13120+4242, using multiconfiguration observations with the Karl G. Jansky Very Large Array (JVLA). The gas reservoir, imaged on 0.″39 (~3 kpc) scales, is resolved into two components separated by ~11 kpc with a total …
Li Distribution, Kinematics, and Detailed Abundance Analysis among Very Metal-poor Stars in the Galactic Halo from the HESP-GOMPA Survey
Beers, Timothy C.; Sivarani, Thirupathi; Pandey, Jeewan C. +3 more
We present a study on the detailed elemental abundances of newly identified, bright, very metal-poor stars with the detection of lithium, initially observed as part of the SDSS/MARVELS pre-survey. These stars were selected for high-resolution spectroscopic follow-up as part of the HESP-GOMPA survey. In this work, we discuss the Li abundances detec…