Search Publications
High-speed Bullet Ejections during the AGB-to-Planetary Nebula Transition: HST Observations of the Carbon Star, V Hydrae
Sahai, R.; Morris, M. R.; Scibelli, S.
The well-studied carbon star, V Hya, showing evidence for high-speed, collimated outflows and dense equatorial structures, is a key object in the study of the poorly understood transition of AGB stars into aspherical planetary nebulae. Using the Space Telescope Imaging Spectrograph instrument on board the Hubble Space Telescope, we have obtained h…
Structure of Prominence Legs: Plasma and Magnetic Field
Schmieder, B.; Labrosse, N.; López Ariste, A. +1 more
We investigate the properties of a “solar tornado” observed on 2014 July 15, and aim to link the behavior of the plasma to the internal magnetic field structure of the associated prominence. We made multi-wavelength observations with high spatial resolution and high cadence using SDO/AIA, the Interface Region Imaging Spectrograph (IRIS) spectrogra…
Axion Decay and Anisotropy of Near-IR Extragalactic Background Light
Gong, Yan; Cooray, Asantha; Mitchell-Wynne, Ketron +3 more
The extragalactic background light (EBL) is composed of the cumulative radiation from all galaxies and active galactic nuclei over cosmic history. In addition to point sources, the EBL also contains information from diffuse sources of radiation. The angular power spectra of the near-infrared intensities could contain additional signals, and a comp…
On the Misalignment between Chromospheric Features and the Magnetic Field on the Sun
Martínez-Sykora, Juan; De Pontieu, Bart; Hansteen, Viggo +1 more
Observations of the upper chromosphere show an enormous amount of intricate fine structure. Much of this comes in the form of linear features, which are most often assumed to be well aligned with the direction of the magnetic field in the low plasma β regime that is thought to dominate the upper chromosphere. We use advanced radiative magnetohydro…
Detection of Three Gamma-ray Burst Host Galaxies at z ∼ 6
Stocke, J. T.; Shull, J. M.; Bremer, M. +17 more
Long-duration gamma-ray bursts (GRBs) allow us to pinpoint and study star-forming galaxies in the early universe, thanks to their orders of magnitude brighter peak luminosities compared to other astrophysical sources, and their association with the deaths of massive stars. We present Hubble Space Telescope Wide Field Camera 3 detections of three S…
Boron Abundances Across the “Li-Be Dip” in the Hyades Cluster
Deliyannis, Constantine P.; Somers, Garrett; Pinsonneault, Marc H. +3 more
Dramatic deficiencies of Li in the mid-F dwarf stars of the Hyades cluster were discovered by Boesgaard & Tripicco. Boesgaard & King discovered corresponding, but smaller, deficiencies in Be in the same narrow temperature region in the Hyades. Using the Space Telescope Imaging Spectrograph on the Hubble Space Telescope, we investigate B ab…
A Comparison and Joint Analysis of Sunyaev-Zel’dovich Effect Measurements from Planck and Bolocam for a Set of 47 Massive Galaxy Clusters
Pierpaoli, Elena; Merten, Julian; Sayers, Jack +7 more
We measure the Sunyaev-Zel’dovich (SZ) signal toward a set of 47 clusters with a median mass of 9.5 × 1014 M ⊙ and a median redshift of 0.40 using data from Planck and the ground-based Bolocam receiver. When Planck XMM-like masses are used to set the scale radius {θ }{{s}}, we find consistency between the integrate…
X-Ray and Optical Correlation of Type I Seyfert NGC 3516 Studied with Suzaku and Japanese Ground-based Telescopes
Kawabata, Koji; Fukazawa, Yasushi; Makishima, Kazuo +23 more
From 2013 April to 2014 April, we performed X-ray and optical simultaneous monitoring of the type 1.5 Seyfert galaxy NGC 3516. We employed Suzaku and five Japanese ground-based telescopes—the Pirka, Kiso Schmidt, Nayuta, MITSuME, and the Kanata telescopes. The Suzaku observations were conducted seven times with various intervals ranging from days …
First NuSTAR Observations of the BL Lac-type Blazar PKS 2155-304: Constraints on the Jet Content and Distribution of Radiating Particles
Harrison, F. A.; Hornstrup, A.; Hailey, C. +35 more
We report the first hard X-ray observations with NuSTAR of the BL Lac-type blazar PKS 2155-304, augmented with soft X-ray data from XMM-Newton and γ-ray data from the Fermi Large Area Telescope, obtained in 2013 April when the source was in a very low flux state. A joint NuSTAR and XMM spectrum, covering the energy range 0.5-60 keV, is best descri…
Quasi-periodic Fluctuations and Chromospheric Evaporation in a Solar Flare Ribbon Observed by Hinode/EIS, IRIS, and RHESSI
Brosius, Jeffrey W.; Inglis, Andrew R.; Daw, Adrian N.
The Hinode/Extreme-ultraviolet Imaging Spectrometer (EIS) obtained rapid cadence (11.2 s) EUV stare spectra of an M7.3 flare ribbon in AR 12036 on 2014 April 18. Quasi-periodic (P ≈ 75.6 ± 9.2 s) intensity fluctuations occurred in emission lines of O IV, Mg VI, Mg vii, Si vii, Fe xiv, and Fe xvi during the flare's impulsive rise, and ended when th…