Search Publications
Understanding the Links among the Magnetic Fields, Filament, Bipolar Bubble, and Star Formation in RCW 57A Using NIR Polarimetry
Tamura, M.; Nishiyama, S.; Wang, Jia-Wei +10 more
The influence of magnetic fields (B-fields) on the formation and evolution of bipolar bubbles, due to the expanding ionization fronts (I-fronts) driven by the H II regions that are formed and embedded in filamentary molecular clouds, has not been well-studied yet. In addition to the anisotropic expansion of I-fronts into a filament, B-fields are e…
Finite-frequency Sensitivity Kernels in Spherical Geometry for Time-Distance Helioseismology
Mandal, Krishnendu; Hanasoge, Shravan M.; Bhattacharya, Jishnu +1 more
The inference of internal properties of the Sun from surface measurements of wave travel times is the goal of time-distance helioseismology. A critical step toward the accurate interpretation of shifts in travel time is the computation of sensitivity functions linking seismic measurements to internal structure. Here we calculate finite-frequency s…
Recombining Plasma and Gamma-Ray Emission in the Mixed-morphology Supernova Remnant 3C 400.2
Fukui, Y.; Sano, H.; Sezer, A. +2 more
3C 400.2 belongs to the mixed-morphology supernova remnant class, showing center-filled X-ray and shell-like radio morphology. We present a study of 3C 400.2 with archival Suzaku and Fermi-LAT observations. We find recombining plasma (RP) in the Suzaku spectra of north-east and south-east regions. The spectra of these regions are well described by…
Sunward-propagating Solar Energetic Electrons inside Multiple Interplanetary Flux Ropes
Temmer, Manuela; Veronig, Astrid; Dresing, Nina +8 more
On 2013 December 2 and 3, the SEPT and STE instruments on board STEREO-A observed two solar energetic electron events with unusual sunward-directed fluxes. Both events occurred during a time interval showing typical signatures of interplanetary coronal mass ejections (ICMEs). The electron timing and anisotropies, combined with extreme-ultraviolet …
Stacked Average Far-infrared Spectrum of Dusty Star-forming Galaxies from the Herschel/SPIRE Fourier Transform Spectrometer
Pearson, Chris; Clements, David L.; Valtchanov, Ivan +13 more
We present stacked average far-infrared spectra of a sample of 197 dusty star-forming galaxies (DSFGs) at 0.005< z< 4 using about 90% of the Herschel Space Observatory SPIRE Fourier Transform Spectrometer (FTS) extragalactic data archive based on 3.5 years of science operations. These spectra explore an observed-frame 447-1568 GHz frequency …
Detection of Extraplanar Diffuse Ionized Gas in M83
Gallagher, J. S., III; Boettcher, Erin; Zweibel, Ellen G.
We present the first kinematic study of extraplanar diffuse ionized gas (eDIG) in the nearby, face-on disk galaxy M83 using optical emission-line spectroscopy from the Robert Stobie Spectrograph on the Southern African Large Telescope. We use a Markov Chain Monte Carlo method to decompose the [N II]λ λ 6548, 6583, Hα, and [S II]λ λ 6717, 6731 emis…
Time-dependent Ionization in a Steady Flow in an MHD Model of the Solar Corona and Wind
Reeves, Katharine K.; Raymond, John C.; Linker, Jon A. +3 more
Time-dependent ionization is important for diagnostics of coronal streamers and pseudostreamers. We describe time-dependent ionization calculations for a three-dimensional magnetohydrodynamic (MHD) model of the solar corona and inner heliosphere. We analyze how non-equilibrium ionization (NEI) influences emission from a pseudostreamer during the W…
Comparing Coronal and Heliospheric Magnetic Fields over Several Solar Cycles
Mursula, K.; Koskela, J. S.; Virtanen, I. I.
Here we use the PFSS model and photospheric data from Wilcox Solar Observatory, SOHO/MDI, SDO/HMI, and SOLIS to compare the coronal field with heliospheric magnetic field measured at 1 au, compiled in the NASA/NSSDC OMNI 2 data set. We calculate their mutual polarity match and the power of the radial decay, p, of the radial field using different s…
Spatially Resolved Patchy Lyα Emission within the Central Kiloparsec of a Strongly Lensed Quasar Host Galaxy at z = 2.8
Acharyya, Ayan; Rigby, Jane R.; Bian, Fuyan +10 more
We report the detection of extended Lyα emission from the host galaxy of SDSS J2222+2745, a strongly lensed quasar at z = 2.8. Spectroscopic follow-up clearly reveals extended Lyα in emission between two images of the central active galactic nucleus (AGN). We reconstruct the lensed quasar host galaxy in the source plane by applying a strong lens m…
A Complete Census of Hα Emitters in NGC 6397
Pallanca, Cristina; Mucciarelli, Alessio; Ferraro, Francesco R. +3 more
We used a data set of archival Hubble Space Telescope images obtained through the F555W, F814W, and F656N filters to perform a complete search for objects showing {{H}}α emission in the globular cluster NGC 6397. As a photometric diagnostic, we used the {(V-{{H}}α )}0 color excess in the {(V-{{H}}α )}0-{(V-I)}0 col…