Search Publications
IC 4406: A Radio-Infrared View
Hora, Joseph L.; Trigilio, Corrado; Cerrigone, Luciano +1 more
IC 4406 is a large (about 100'' × 30'') southern bipolar planetary nebula composed of two elongated lobes extending from a bright central region where there is evidence for the presence of a large torus of gas and dust. We show new observations of this source performed with IRAC (Spitzer Space Telescope) and the Australia Telescope Compact Array. …
SUBARU High-Dispersion Spectroscopy of Hα and [N II] 6583 Å Emission in the HH 46/47 Jet
Pyo, Tae-Soo; Takami, Michihiro; Hayashi, Masahiko +2 more
We present slit-scan observations of the Hα and [N II] 6583 Å emission lines toward the HH 46/47 jet with the Subaru Telescope. The spectral resolution of R = 3.6 × 104 allowed us to study the kinematics of individual features in unprecedented detail. The spectra show (1) the main jet component (VLSR ~ - 160 km s-1…
RX J1648.7+6109: Witnessing the Formation of a Massive Group/Poor Cluster and Its Brightest Galaxy
Mulchaey, John S.; Lubin, Lori M.; Jeltema, Tesla E.
Using deep Chandra and optical spectroscopic observations, we investigate an intriguing young massive group, RX J1648.7+6109, at z = 0.376, and we combine these observations with previous measurements to fit the scaling relations of intermediate-redshift groups and poor clusters. RX J1648 appears to be in an early stage of formation; while it foll…
A Search for Temperature and Density Variations in NGC 7027 with the Hubble Space Telescope
Bieging, John H.; Tielens, A. G. G. M.; Boley, Paul A. +1 more
We observed the young planetary nebula NGC 7027 with the HST Imaging Spectrograph (STIS) in long-slit mode at five slit positions along the major axis of the nebula, over the wavelength range from 3000 to ~10,000 Å. We used dereddened line ratios to determine line-of-sight average values for (1) He++ and He+ ionization fracti…
Multiwavelength Monitoring of the Dwarf Seyfert 1 Galaxy NGC 4395. IV. The Variable UV Absorption Lines
Laor, Ari; Baskin, Alexei
We report the detection of variable UV absorption lines in NGC 4395, based on UV observations with the HST STIS carried out in 2004 April and July as part of a reverberation-mapping campaign. Low-ionization lines of O I, N I, Si II, C II, and Fe II are present in the low-state spectra (2004 April) at a velocity vshift = - 250 km s-…
Rapid Cadence EUNIS-06 Observations of a He II Transient Brightening in the Quiet Sun
Brosius, Jeffrey W.; Thomas, Roger J.; Rabin, Douglas M.
We observed a transient brightening in the quiet Sun at rapid cadence (2.10 s) with the Extreme Ultraviolet Normal Incidence Spectrograph (EUNIS-06) sounding rocket instrument on 2006 April 12. The transient was visible only in He II at 303.78 Å (T ≈ 5 × 104 K), and its maximum temperature T was <4 × 105 K. Taking its line…
X-Ray Observations of Optically Selected Giant Elliptical-Dominated Galaxy Groups
Miller, Christopher J.; Nichol, Robert C.; Heitmann, Katrin +4 more
We present a combined optical and X-ray analysis of three optically selected X-ray-bright groups with giant elliptical galaxies in the center. These massive ellipticals were targeted for XMM-Newton X-ray observations on the basis of their large-velocity dispersions and their proximity to a nearby ROSAT X-ray source. In addition, these targets are …
Spatially Resolved Far-Ultraviolet Spectroscopy of the Nuclear Region of NGC 1068
Kriss, Gerard A.; Zheng, Wei; Wang, Jun-Xian +5 more
We carry out high-resolution FUSE spectroscopy of the nuclear region of NGC 1068. The first set of spectra was obtained with a 30'' square aperture that collected all emission from the narrow-line region. The data reveal a strong broad O VI component of FWHM ~3500 km s-1 and two narrow O VI λλ1031, 1037 components of ~350 km s-1
Ultrarelativistic Electrons in Jupiter's Inner Magnetosphere: First Observation of Angular Distributions in the 2.5 to 6 RJ Region
Armstrong, Thomas P.; Taherion, Saeed; Garrett, Henry B.
Jupiter has been recognized as a probable location of magnetically trapped ultrarelativistic electrons since its discovery as a source of polarized decimeter radio waves. A series of spacecraft (Pioneers 10 and 11, Voyagers 1 and 2, Ulysses, Cassini, and New Horizons) have flown by and orbited Jupiter with the goal of observing the trapped radiati…
Elemental Abundances of Energetic Particles within Magnetic Clouds Detected by Ulysses
Fränz, Markus; Krupp, Norbert; Woch, Joachim +1 more
The study of particles from the solar wind thermal population up to higher near-relativistic energies provides a tool to analyze and characterize the internal structure of magnetic clouds (MCs). In this work, we analyze the elemental composition of energetic particles at ~1 MeV nucleon-1. Statistically, using a data set of 40 MCs, we fi…