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Ion Temperatures in the Quiet Solar Corona
Landi, E.
We measure the upper and lower limits of the temperatures Ti for a number of ions observed in the quiescent solar corona from 1996 to 2000, in order to compare with the measured electron temperature Te and test the assumption Ti=Te commonly adopted to measure the plasma nonthermal velocity vnth
Time-Distance Helioseismology: Sensitivity of f-mode Travel Times to Flows
Birch, A. C.; Duvall, T. L., Jr.; Gizon, L. +1 more
Time-distance helioseismology has shown that f-mode travel times contain information about horizontal flows in the Sun. The purpose of this study is to provide a simple interpretation of these travel times. We study the interaction of surface gravity waves with horizontal flows in an incompressible, plane-parallel solar atmosphere. We show that fo…
Bulges and Disklike Components in the Host Galaxies of Low-Redshift 3CR Sources: A Near-Infrared View of Their Radial Brightness Profiles
Marchesini, Danilo; Chiaberge, Marco; Capetti, Alessandro +3 more
We analyze the near-infrared luminosity profiles and photometric parameters of the host galaxies of 3CR radio sources with z<0.3, to investigate their physical nature. Our sample includes 82 galaxies, of which 22 (27%) are FR Is and 60 (73%) are FR IIs. Using near-infrared data taken both with NICMOS on board the Hubble Space Telescope and from…
Magnetic Interaction: An Erupting Filament and a Remote Coronal Hole
Yang, Liheng; Shen, Yuandeng; Jiang, Yunchun +1 more
For the first time, we present a rare observation of direct magnetic interaction between an erupting filament and a coronal hole (CH). The small active region filament obliquely erupted toward the CH getting in the way, met and interacted with it, and then was deflected back. The erupting filament thus underwent a distinct to-and-fro motion in the…
A Quadrupolar Preplanetary Nebula: IRAS 19475+3119
Sahai, Raghvendra; Sánchez Contreras, Carmen; Morris, Mark +1 more
Our imaging of the preplanetary nebula IRAS 19475+3119 (hereafter I19475) at 0.43 and 0.6 µm with HST reveals a quadrupolar nebula of size about 10.5''×4.7'', with two bipolar elongated lobes emanating from the center of the nebula. One of the bipolar lobes shows detailed point-symmetric structure with respect to the ce…
Coronal and Chromospheric Dimmings during a Halo-Type CME Event
Yang, Liheng; Jiang, Yunchun; Li, Kejun +1 more
We present complementary solar observations of a filament eruption occurring in association with a halo-type coronal mass ejection (CME) on 2006 July 6 in AR 10898. This eruption was followed by an M2.5 flare and has led to the formation of a pair of dimmings, observed in Hα, over network patterns in regions of opposite magnetic polarities located…
The X-Ray Structure and Spectrum of the Pulsar Wind Nebula Surrounding PSR B0540-69.3
Safi-Harb, S.; Holt, S. S.; Williams, R. M. +2 more
We present the first spatially resolved spectral study of an extragalactic pulsar wind nebula (PWN), that surrounding the 50 ms pulsar B0540-69.3 in the Large Magellanic Cloud, using the ACIS instrument on board the Chandra X-ray Observatory. The spectral properties of the PWN change at a radius of ~5", corresponding to a shell detected optically …
Elemental Abundances of Nearby Galaxies through High Signal-to-Noise Ratio XMM-Newton Observations of Ultraluminous X-Ray Sources
Reynolds, Christopher S.; Mushotzky, Richard F.; Winter, Lisa M.
In this paper we examined XMM-Newton EPIC spectra of 14 ultraluminous X-ray sources (ULXs) in addition to the XMM-Newton RGS spectra of two sources (Holmberg II X-1 and Holmberg IX X-1). We determined oxygen and iron abundances of the host galaxy's ISM using K-shell (O) and L-shell (Fe) X-ray photoionization edges toward these ULXs. We found that …
A Galaxy in Transition: Structure, Globular Clusters, and Distance of the Star-Forming S0 Galaxy NGC 1533 in Dorado
Meurer, Gerhardt R.; Blakeslee, John P.; Putman, Mary E. +1 more
We use two-band imaging data from the Advanced Camera for Surveys onboard the Hubble Space Telescope for a detailed study of NGC 1533, an SB0 galaxy in the Dorado group surrounded by a ring of H I. NGC 1533 appears to be completing a transition from late to early type: it is red, but not quite dead. Faint spiral structure becomes visible following…
GQ Lup B Visible and Near-Infrared Photometric Analysis
Macintosh, Bruce; Barman, Travis; Marois, Christian
We have reanalyzed archival HST and Subaru data of the recently discovered planetary mass companion (PMC) GQ Lup B. With these we produce the first R- and I-band photometry of the companion and fit a radius and effective temperature using detailed model atmospheres. We find an effective temperature of 2335+/-100 K, a radius of 0.38+/-0.05 Rso…