Search Publications
Long-lasting X-Ray Emission from Type IIb Supernova 2011dh and Mass-loss History of the Yellow Supergiant Progenitor
Katsuda, Satoru; Fukazawa, Yasushi; Terada, Yukikatsu +2 more
Type IIb supernova (SN) 2011dh, with conclusive detection of an unprecedented yellow supergiant (YSG) progenitor, provides an excellent opportunity to deepen our understanding on the massive star evolution in the final centuries toward the SN explosion. In this paper, we report on detection and analyses of thermal X-ray emission from SN IIb 2011dh…
A Broadband X-Ray Study of the Geminga Pulsar with NuSTAR and XMM-Newton
An, Hongjun; Hailey, Charles J.; Mori, Kaya +14 more
We report on the first hard X-ray detection of the Geminga pulsar above 10 keV using a 150 ks observation with the Nuclear Spectroscopic Telescope Array (NuSTAR) observatory. The double-peaked pulse profile of non-thermal emission seen in the soft X-ray band persists at higher energies. Broadband phase-integrated spectra over the 0.2-20 keV band w…
Observations of a Hybrid Double-streamer/Pseudostreamer in the Solar Corona
Seaton, D. B.; Bethge, C.; Yeates, A. R. +2 more
We report on the first observation of a single hybrid magnetic structure that contains both a pseudostreamer and a double streamer. This structure was originally observed by the SWAP instrument on board the PROBA2 satellite between 2013 May 5 and 10. It consists of a pair of filament channels near the south pole of the Sun. On the western edge of …
Ulysses Observations of Magnetic Waves Due to Newborn Interstellar Pickup Ions. II. Application of Turbulence Concepts to Limiting Wave Energy and Observability
Isenberg, Philip A.; Murphy, Neil; Cannon, Bradford E. +4 more
The low-frequency magnetic waves that arise from the isotropization of newborn interstellar pickup ions (PUIs) are reasonably well described by linear and quasi-linear kinetic theory in so far as those theories predict the wave frequency and polarization in the spacecraft frame. Those theories fail to describe the scarce observability of the waves…
Preliminary Analysis of SOHO/STEREO Observations of Sungrazing Comet ISON (C/2012 S1) around Perihelion
Knight, Matthew M.; Battams, Karl
We present photometric and morphological analysis of the behavior of sungrazing comet C/2012 S1 ISON in Solar and Heliospheric Observatory (SOHO) and Solar TErrestrial RElations Observatory (STEREO) images around its perihelion on 2013 November 28.779 UT. ISON brightened gradually November 20-26 with a superimposed outburst on November 21.3-23.5. …
Untangling the Nature of Spatial Variations of Cold Dust Properties in Star Forming Galaxies
Kirkpatrick, Allison; Calzetti, Daniela; Dale, Daniel +7 more
We investigate the far-infrared (IR) dust emission for 20 local star forming galaxies from the Key Insights on Nearby Galaxies: A Far-IR Survey with Herschel (KINGFISH) sample. We model the far-IR/submillimeter spectral energy distribution (SED) using images from Spitzer Space Telescope and Herschel Space Observatory. We calculate the cold dust te…
A Spectroscopic Survey of WISE-selected Obscured Quasars with the Southern African Large Telescope
Myers, Adam D.; Hainline, Kevin N.; Hickox, Ryan C. +3 more
We present the results of an optical spectroscopic survey of a sample of 40 candidate obscured quasars identified on the basis of their mid-infrared emission detected by the Wide-Field Infrared Survey Explorer (WISE). Optical spectra for this survey were obtained using the Robert Stobie Spectrograph on the Southern African Large Telescope. Our sam…
Evidence of Very Low Metallicity and High Ionization State in a Strongly Lensed, Star-forming Dwarf Galaxy at z= 3.417
Castellano, M.; Pentericci, L.; Merlin, E. +6 more
We investigate the gas-phase metallicity and Lyman continuum (LyC) escape fraction of a strongly gravitationally lensed, extreme emission-line galaxy at z = 3.417, J1000+0221S, recently discovered by the CANDELS team. We derive ionization- and metallicity-sensitive emission-line ratios from H+K band Large Binocular Telescope (LBT)/LUCI medium reso…
Comparison of Extreme Ultraviolet Imaging Spectrometer Observations of Solar Coronal Loops with Alfvén Wave Turbulence Models
van Ballegooijen, A. A.; Imada, S.; Asgari-Targhi, M.
The observed non-thermal widths of coronal emission lines could be due to Alfvén wave turbulence. To test this idea, we examine and analyze the dynamics of an active region observed on 2012 September 7. We use spectral line profiles of Fe XII, Fe XIII, Fe XV, and Fe XVI obtained by the Extreme-ultraviolet Imaging Spectrometer on the it Hinode spac…
The Properties of Lyα Nebulae: Gas Kinematics from Nonresonant Lines
Davé, Romeel; Yang, Yujin; Zabludoff, Ann +1 more
With the Very Large Telescope/X-shooter, we obtain optical and near-infrared spectra of six Lyα blobs at z ~ 2.3. For a total sample of eight Lyα blobs (including two that we have previously studied), the majority (6/8) have broadened Lyα profiles with shapes ranging from a single peak to symmetric or asymmetric double-peaked. The remaining two sy…