Search Publications
Radio Pulsation Search and Imaging Study of SGR J1935+2154
Manoharan, P. K.; Surnis, Mayuresh. P.; Joshi, Bhal Chandra +3 more
We present the results obtained from imaging observations and a search for radio pulsations toward the magnetar SGR J1935+2154 made using the Giant Metrewave Radio Telescope and the Ooty Radio Telescope. We present the high-resolution radio image of the supernova remnant (SNR) G57.2+0.8, which is positionally associated with SGR J1935+2154. We did…
A Data-driven Analytic Model for Proton Acceleration by Large-scale Solar Coronal Shocks
Schwadron, Nathan A.; Kozarev, Kamen A.
We have recently studied the development of an eruptive filament-driven, large-scale off-limb coronal bright front (OCBF) in the low solar corona, using remote observations from the Solar Dynamics Observatory’s Advanced Imaging Assembly EUV telescopes. In that study, we obtained high-temporal resolution estimates of the OCBF parameters regulating …
Jets, Coronal “Puffs,” and a Slow Coronal Mass Ejection Caused by an Opposite-polarity Region within an Active Region Footpoint
Morgan, H.; Alzate, N.
During a period of three days beginning 2013 January 17, twelve recurrent reconnection events occur within a small region of opposing flux embedded within one footpoint of an active region, accompanied by flares and jets observed in EUV and fast and faint structureless “puffs” observed by coronagraphs. During the same period a slow structured CME …
An Analysis of Interplanetary Solar Radio Emissions Associated with a Coronal Mass Ejection
Magdalenić, J.; Eastwood, J. P.; Davies, J. A. +13 more
Coronal mass ejections (CMEs) are large-scale eruptions of magnetized plasma that may cause severe geomagnetic storms if Earth directed. Here, we report a rare instance with comprehensive in situ and remote sensing observations of a CME combining white-light, radio, and plasma measurements from four different vantage points. For the first time, we…
Star Cluster Formation and Destruction in the Merging Galaxy NGC 3256
Whitmore, B. C.; Chandar, R.; Mulia, A. J.
We use the Advanced Camera for Surveys on the Hubble Space Telescope to study the rich population of young massive star clusters in the main body of NGC 3256, a merging pair of galaxies with a high star formation rate (SFR) and SFR per unit area (ΣSFR). These clusters have luminosity and mass functions that follow power laws, dN/dL ∝ L …
On the Nature of the Enigmatic Object IRAS 19312+1950: A Rare Phase of Massive Star Formation?
Justtanont, K.; Tielens, A. G. G. M.; Boogert, A. C. A. +7 more
IRAS 19312+1950 is a peculiar object that has eluded firm characterization since its discovery, with combined maser properties similar to an evolved star and a young stellar object (YSO). To help determine its true nature, we obtained infrared spectra of IRAS 19312+1950 in the range 5-550 µm using the Herschel and Spitzer space observatories…
The Compact Star-forming Complex at the Heart of NGC 253
Davidge, T. J.
We discuss integral field spectra of the compact star-forming complex that is the brightest near-infrared (NIR) source in the central regions of the starburst galaxy NGC 253. The spectra cover the H and K passbands and were recorded with the Gemini NIR Spectrograph during subarcsecond seeing conditions. Absorption features in the spectrum of the s…
A NuSTAR Observation of the Gamma-ray-emitting X-ray Binary and Transitional Millisecond Pulsar Candidate 1RXS J154439.4-112820
Bogdanov, Slavko
I present a 40 ks Nuclear Spectroscopic Telescope Array observation of the recently identified low-luminosity X-ray binary and transitional millisecond pulsar (tMSP) candidate 1RXS J154439.4-112820, which is associated with the high-energy γ-ray source 3FGL J1544.6-1125. The system is detected up to ∼30 keV with an extension of the same power-law …
Pixel Color Magnitude Diagrams for Semi-resolved Stellar Populations: The Star Formation History of Regions within the Disk and Bulge of M31
van Dokkum, Pieter G.; Conroy, Charlie
The analysis of stellar populations has, by and large, been developed for two limiting cases: spatially resolved stellar populations in the color-magnitude diagram, and integrated light observations of distant systems. In between these two extremes lies the semi-resolved regime, which encompasses a rich and relatively unexplored realm of observati…
The Inner Structure of the TW Hya Disk as Revealed in Scattered Light
Debes, John H.; Schneider, Glenn; Jang-Condell, Hannah
We observe a significant change in the TW Hya disk interior to 40 au via archival unpolarized multi-wavelength Hubble Space Telescope/STIS and NICMOS images with an inner working angle of 0.″4 (22 au). Our images show the outer edge of a clearing at every wavelength with similar behavior, demonstrating that the feature is structural, rather than d…