Search Publications
Oblique Electrostatic Solitary and Supersolitary Waves in Earth's Magnetosheath
Singh, Kuldeep; Varghese, Steffy Sara; Saini, Nareshpal Singh +1 more
Nonlinear electrostatic solitary waves (ESWs) are routinely detected at various regions of Earth's magnetosphere using the Wideband Data plasma wave receivers mounted on board the Cluster satellite(s). This mission has facilitated the observation and analysis of ESW characteristics, such as amplitude and temporal duration within the magnetosheath,…
A Rapidly Accreting Active Galactic Nucleus Hidden in a Dust-obscured Galaxy at z ∼ 0.8
Brandt, William N.; Yu, Zhibo; Zou, Fan +3 more
Dust-obscured galaxies (DOGs) containing central supermassive black holes (SMBHs) that are rapidly accreting (i.e., having high Eddington ratios, λ Edd) may represent a key phase closest to the peak of both the black hole and galaxy growth in the coevolution framework for SMBHs and galaxies. In this work, we present a 68 ks XMM-Newton o…
Distance Estimate Method for Asymptotic Giant Branch Stars Using Infrared Spectral Energy Distributions
Stroh, Michael C.; Sahai, Raghvendra; Sjouwerman, Loránt O. +8 more
We present a method to estimate distances to asymptotic giant branch (AGB) stars in the Galaxy, using spectral energy distributions (SEDs) in the near- and mid-infrared. By assuming that a given set of source properties (initial mass, stellar temperature, composition, and evolutionary stage) will provide a typical SED shape and brightness, sources…
The Dependence of Joy's Law and Mean Tilt as a Function of Flux Emergence Phase
Will, Lucy W.; Norton, Aimee A.; Hoeksema, Jon Todd
Data from the Michelson Doppler Imager (MDI) and Helioseismic and Magnetic Imager (HMI) are analyzed from 1996 to 2023 to investigate tilt angles (γ) of bipolar magnetic regions and Joy's law for Solar Cycles 23 and 24 and a portion of Cycle 25. The HMI radial magnetic field (B r ) and MDI magnetogram (B los) data are used t…
Using the Cartwheel CME to Predict Off-limb Observations of CMEs for New and Upcoming UV and EUV Spectrometers
Landi, E.; Manchester, W. B.; Wraback, E. M.
Coronal mass ejections (CMEs) expel multithermal, magnetized plasma from the Sun, and when directed toward Earth, can cause extensive damage to space and ground-based electronics. To better understand the triggering, acceleration, and evolution of CMEs, it is critical to study CME plasma properties close to the Sun. High-resolution ultraviolet and…
How Does the Critical Torus Instability Height Vary with the Solar Cycle?
van Driel-Gesztelyi, Lidia; Green, Lucie M.; Barnes, Graham +2 more
The ideal magnetohydrodynamic torus instability can drive the eruption of coronal mass ejections. The critical threshold of magnetic field strength decay for the onset of the torus instability occurs at different heights in different solar active regions, and understanding this variation could therefore improve space weather prediction. In this wo…
Direct Evidence of the Hybrid Nature of Extreme-ultraviolet Waves and the Reflection of the Fast-mode Wave
Chen, P. F.; Chandra, Ramesh; Devi, Pooja
We performed an analysis of the extreme-ultraviolet (EUV) wave event on 2022 March 31. The event originated from active region (AR) 12975 located at N13W52 in the field of view of the Atmospheric imaging Assembly (AIA) and exactly at the west limb viewed by the EUV Imager (EUVI) of the Solar Terrestrial Relations Observatory-Ahead (STEREO-A) satel…
Magnetic Fields Observed along the East–West Outflow of IRAS 16293-2422
Pattle, Kate; Sadavoy, Sarah; Looney, Leslie W. +6 more
Magnetic fields likely play an important role in the formation of young protostars. Multiscale and multiwavelength dust polarization observations can reveal the inferred magnetic field from scales of the cloud to core to protostar. We present continuum polarization observations of the young protostellar triple system IRAS 16293-2422 at 89 µm…
Rotation and Hα Emission in a Young SMC Cluster: A Spectroscopic View of NGC 330
Dupree, Andrea K.; Milone, Antonino P.; Dotter, Aaron +4 more
We present an analysis of high-resolution optical spectra recorded for 30 stars of the split extended main-sequence turnoff of the young (∼40 Myr) Small Magellanic Cloud globular cluster NGC 330. Spectra were obtained with the Michigan/Magellan Fiber System and Magellan Inamori Kyocera Echelle spectrographs located on the Magellan-Clay 6.5 m teles…
Tidal Disruption Event AT2020ocn: Early Time X-Ray Flares Caused by a Possible Disk Alignment Process
Jonker, P. G.; Zabludoff, A. I.; Pasham, D. R. +3 more
A tidal disruption event (TDE) may occur when a star is torn apart by the tidal force of a black hole (BH). Eventually, an accretion disk is thought to form out of stellar debris falling back toward the BH. If the star's orbital angular momentum vector prior to disruption is not aligned with the BH spin angular momentum vector, the disk will be ti…