Search Publications
A Detailed Kinematic Map of Cassiopeia A's Optical Main Shell and Outer High-velocity Ejecta
Milisavljevic, Dan; Fesen, Robert A.
We present three-dimensional (3D) kinematic reconstructions of optically emitting material in the young Galactic supernova remnant Cassiopeia A (Cas A). These Doppler maps have the highest spectral and spatial resolutions of any previous survey of Cas A and represent the most complete catalog of its optically emitting material to date. We confirm …
The Formation of IRIS Diagnostics. III. Near-ultraviolet Spectra and Images
De Pontieu, B.; Leenaarts, J.; Carlsson, M. +2 more
The Mg II h&k lines are the prime chromospheric diagnostics of NASA's Interface Region Imaging Spectrograph (IRIS). In the previous papers of this series, we used a realistic three-dimensional radiative magnetohydrodynamics model to calculate the h&k lines in detail and investigated how their spectral features relate to the underlying atmo…
Nuclear Activity is More Prevalent in Star-forming Galaxies
Berta, S.; Magnelli, B.; Nordon, R. +14 more
We explore the question of whether low and moderate luminosity active galactic nuclei (AGNs) are preferentially found in galaxies that are undergoing a transition from active star formation (SF) to quiescence. This notion has been suggested by studies of the UV-optical colors of AGN hosts, which find them to be common among galaxies in the so-call…
Global Helioseismic Evidence for a Deeply Penetrating Solar Meridional Flow Consisting of Multiple Flow Cells
Roth, M.; Schad, A.; Timmer, J.
We use a novel global helioseismic analysis method to infer the meridional flow in the deep Solar interior. The method is based on the perturbation of eigenfunctions of Solar p modes due to meridional flow. We apply this method to time series obtained from Dopplergrams measured by the Michelson Doppler Imager aboard the Solar and Heliospheric Obse…
Embedded Protostars in the Dust, Ice, and Gas In Time (DIGIT) Herschel Key Program: Continuum SEDs, and an Inventory of Characteristic Far-infrared Lines from PACS Spectroscopy
Herczeg, Gregory J.; Lee, Jeong-Eun; Dunham, Michael M. +18 more
We present 50-210 µm spectral scans of 30 Class 0/I protostellar sources, obtained with Herschel-PACS, and 0.5-1000 µm spectral energy distributions, as part of the Dust, Ice, and Gas in Time Key Program. Some sources exhibit up to 75 H2O lines ranging in excitation energy from 100 to 2000 K, 12 transitions of OH, and CO rot…
Forecasting a Coronal Mass Ejection's Altered Trajectory: ForeCAT
Kay, C.; Opher, M.; Evans, R. M.
To predict whether a coronal mass ejection (CME) will impact Earth, the effects of the background on the CME's trajectory must be taken into account. We develop a model, ForeCAT (Forecasting a CME's Altered Trajectory), of CME deflection due to magnetic forces. ForeCAT includes CME expansion, a three-part propagation model, and the effects of drag…
The First Hi-GAL Observations of the Outer Galaxy: A Look at Star Formation in the Third Galactic Quadrant in the Longitude Range 216.°5 <~ l <~ 225.°5
Rygl, K. L. J.; Schneider, N.; Benedettini, M. +17 more
We present the first Herschel PACS and SPIRE photometric observations in a portion of the outer Galaxy (216.°5 <~ l <~ 225.°5 and -2° <~ b <~ 0°) as a part of the Hi-GAL survey. The maps between 70 and 500 µm, the derived column density and temperature maps, and the compact source catalog are presented. NANTEN CO(1-0) line observ…
A Comprehensive Analysis of Fermi Gamma-Ray Burst Data. III. Energy-dependent T 90 Distributions of GBM GRBs and Instrumental Selection Effect on Duration Classification
Lin, Lin; Zhang, Bing; Liang, En-Wei +8 more
The durations (T 90) of 315 gamma-ray bursts (GRBs) detected with Fermi/GBM (8-1000 keV) up to 2011 September are calculated using the Bayesian Block method. We compare the T 90 distributions between this sample and those derived from previous/current GRB missions. We show that the T 90 distribution of this GRB sam…
Mapping Dust through Emission and Absorption in Nearby Galaxies
Gordon, Karl D.; Johnson, Benjamin D.; Hunt, Leslie K. +13 more
Dust has long been identified as a barrier to measuring inherent galaxy properties. However, the link between dust and attenuation is not straightforward and depends on both the amount of dust and its distribution. Herschel imaging of nearby galaxies undertaken as part of the KINGFISH project allows us to map the dust as seen in emission with unpr…
Early Stages of Cluster Formation: Fragmentation of Massive Dense Cores down to <~ 1000 AU
Fuente, Asunción; Zhang, Qizhou; Palau, Aina +11 more
In order to study the fragmentation of massive dense cores, which constitute the cluster cradles, we observed the continuum at 1.3 mm and the CO (2-1) emission of four massive cores with the Plateau de Bure Interferometer in the most extended configuration. We detected dust condensations down to ~0.3 M ⊙ and separate millimeter sources …