Search Publications
A Droplet Model of Quiescent Prominence Downflows
Berger, T.; Haerendel, G.
Observations of quiescent prominences with the Solar Optical Telescope on the Hinode satellite have revealed the ubiquitous existence of downflows forming coherent thin and highly structured vertically oriented threads with velocities between 10 and 20 km s-1. Their widths range between 300 and 500 km. They are often initiated at the to…
Super-Chandrasekhar SNe Ia Strongly Prefer Metal-poor Environments
Stanek, K. Z.; Prieto, J. L.; Stoll, R. +1 more
We discuss the emerging trend that super-Chandrasekhar Type Ia Supernovae (SCSNe) with progenitor mass estimates significantly exceeding ~1.4 M sun tend to explode in metal-poor environments. While Taubenberger et al. noted that some of the SCSNe host galaxies are relatively metal-poor, we focus quantitatively on their locations in the …
Comparison Between Observation and Simulation of Magnetic Field Changes Associated with Flares
Jing, Ju; Wang, Haimin; Fan, Yuhong +1 more
It has been a long-standing question in solar physics how magnetic field structure changes with eruptive events (e.g., flares and coronal mass ejections). In this Letter, we present the eruption-associated changes in the magnetic inclination angle, the horizontal component of magnetic field vectors, and the Lorentz force. The analysis is based on …
Probing the Star Formation History and Initial Mass Function of the z ~ 2.5 Lensed Galaxy SMM J163554.2+661225 with Herschel
Papovich, Casey; Finkelstein, Steven L.; Egami, Eiichi +6 more
We present the analysis of Herschel Spectral and Photometric Imaging Receiver far-infrared (FIR) observations of the z = 2.515 lensed galaxy SMM J163554.2+661225. Combining new 250, 350, and 500 µm observations with existing data, we make an improved fit to the FIR spectral energy distribution of this galaxy. We find a total infrared (IR) lu…
Direct Measurements of Magnetic Twist in the Solar Corona
Longcope, D. W.; Malanushenko, A.; Yusuf, M. H.
In the present work, we study the evolution of magnetic helicity in the solar corona. We compare the rate of change of a quantity related to the magnetic helicity in the corona to the flux of magnetic helicity through the photosphere and find that the two rates are similar. This gives observational evidence that helicity flux across the photospher…
Multi-wavelength Probes of Obscuration Toward the Narrow-line Region in Seyfert Galaxies
Turner, T. J.; Kraemer, S. B.; Crenshaw, D. M. +4 more
We present a study of reddening and absorption toward the narrow line regions (NLRs) in active galactic nuclei (AGNs) selected from the Revised Shapley-Ames, 12 µm, and Swift/Burst Alert Telescope samples. For the sources in host galaxies with inclinations of b/a > 0.5, we find that the mean ratio of [O III] λ5007, from ground-based obser…
Spitzer Observations of Supernova Remnants. II. Physical Conditions and Comparison with HH7 and HH54
Yuan, Yuan; Neufeld, David A.
We have studied the shock-excited molecular regions associated with four supernova remnants (SNRs)—IC443C, W28, W44, and 3C391—and two Herbig-Haro objects—HH7 and HH54—using Spitzer's Infrared Spectrograph (IRS). The physical conditions within the observed areas (roughly ~1' × 1' in size) are inferred from spectroscopic data obtained from IRS and …
Extended X-Ray Emission in the Vicinity of the Microquasar LS 5039: Pulsar Wind Nebula?
Pavlov, George G.; Kargaltsev, Oleg; Garmire, Gordon P. +2 more
LS 5039 is a high-mass binary with a period of 4 days, containing a compact object and an O-star, one of the few high-mass binaries detected in γ-rays. Our Chandra Advanced CCD Imaging Spectrometer observation of LS 5039 provided a high-significance (≈10σ) detection of extended emission clearly visible for up to 1' from the point source. The spect…
Merging Galaxy Cluster A2255 in Mid-infrared
Goto, Tomotsugu; Kim, Seong Jin; Hwang, Narae +11 more
We present the mid-infrared (MIR) observation of a nearby galaxy cluster, A2255, by the AKARI space telescope. Using AKARI's continuous wavelength coverage between 3 and 24 µm and the wide field of view, we investigate the properties of cluster member galaxies to see how the infall of the galaxies, the cluster substructures, and the cluster-…
Observed Damping of the Slow Magnetoacoustic Mode
Marsh, M. S.; De Moortel, I.; Walsh, R. W.
Spectroscopic and stereoscopic imaging observations of slow magnetoacoustic wave propagation within a coronal loop are investigated to determine the decay length scale of the slow magnetoacoustic mode in three dimensions and the density profile within the loop system. The slow wave is found to have an e-folding decay length scale of 20,000+40…