Search Publications
New Insights into the Spectral Variability and Physical Conditions of the X-Ray Absorbers in NGC 4151
Turner, T. J.; Kraemer, S. B.; Crenshaw, D. M. +1 more
We investigate the relationship between the long-term X-ray spectral variability in the Seyfert 1.5 galaxy NGC 4151 and its intrinsic absorption, by comparing the 2014 simultaneous ultraviolet/X-ray observations taken with Hubble STIS Echelle and Chandra HETGS with archival observations from Chandra, XMM-Newton, and Suzaku. The observations are di…
Morphological Properties of Lyα Emitters at Redshift 4.86 in the Cosmos Field: Clumpy Star Formation or Merger?
Koekemoer, Anton M.; Kajisawa, Masaru; Nagao, Tohru +7 more
We investigate morphological properties of 61 Lyα emitters (LAEs) at z = 4.86 identified in the COSMOS field, based on Hubble Space Telescope Advanced Camera for Surveys (ACS) imaging data in the F814W band. Out of the 61 LAEs, we find the ACS counterparts for 54 LAEs. Eight LAEs show double-component structures with a mean projected separation of…
The Quest for the Largest Depleted Galaxy Core: Supermassive Black Hole Binaries and Stalled Infalling Satellites
Graham, Alister W.; Bonfini, Paolo
Partially depleted cores are practically ubiquitous in luminous early-type galaxies (M B ≲ -20.5 mag) and are typically smaller than 1 kpc. In one popular scenario, supermassive black hole (SMBH) binaries—established during dry (I.e., gas-poor) galaxy mergers—kick out the stars from a galaxy’s central region via three-body interaction…
The Effect of Unresolved Binaries on Globular Cluster Proper-motion Dispersion Profiles
Anderson, J.; Schinnerer, E.; van der Marel, R. P. +5 more
High-precision kinematic studies of globular clusters (GCs) require an accurate knowledge of all possible sources of contamination. Among other sources, binary stars can introduce systematic biases in the kinematics. Using a set of Monte Carlo cluster simulations with different concentrations and binary fractions, we investigate the effect of unre…
Protoplanetary Disks in the Hostile Environment of Carina
Tsamis, Y. G.; Henney, W. J.; Mesa-Delgado, A. +2 more
We report the first direct imaging of protoplanetary disks in the star-forming region of Carina, the most distant massive cluster in which disks have been imaged. Using the Atacama Large Millimeter/sub-millimeter Array (ALMA), the disks are observed around two young stellar objects (YSOs) that are embedded inside evaporating gaseous globules and e…
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 …