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ISO observations of the Wolf-Rayet galaxies NGC 5430, NGC 6764, Mrk 309 and VII Zw 19
McBreen, B.; Metcalfe, L.; O'Halloran, B. +2 more
Observations of four WR galaxies (NGC 5430, NGC 6764, Mrk 309 and VII Zw 19) using the Infrared Space Observatory are presented here. ISOCAM maps of NGC 5430, Mrk 309 and NGC 6764 revealed the location of star formation regions in each of these galaxies. ISOPHOT spectral observations from 4 to 12 µm detected the ubiquitous PAH bands in the n…
On I Line Emission in the Quasar PG 1116+215
Oyabu, Shinki; Matsuoka, Yoshiki; Yoshii, Yuzuru +2 more
By observing the near-infrared spectrum of the quasar PG 1116+215 at z = 0.176 and combining with the HST/FOS spectrum, we obtained the relative strengths of three permitted O I lines (λ1304, λ8446, and λ11287) in a quasar for the first time. The photon flux ratios of the O I lines of the quasar were compared with those previously measured in a Se…
Galaxy Evolution Explorer Observations of the Ultraviolet Surface Brightness and Color Profiles of the Local Group Elliptical Galaxy M32 (NGC 221)
Heckman, Timothy M.; Madore, Barry F.; Rich, R. Michael +22 more
M32, the compact elliptical galaxy companion to the Andromeda spiral galaxy, has been imaged by the Galaxy Evolution Explorer (GALEX) in two UV bands, centered at ~1500 (far-ultraviolet [FUV]) and 2300 Å (near-ultraviolet). The imaging data have been carefully decomposed so as to properly account for the complicated background contamination from t…
Precision Limits to Emission-Line Profile Measuring Experiments
Ireland, J.
Spectra, such as astrophysical spectra, can provide detailed diagnostics on the state of their emitting volume. Emission-line diagnostics are found by assuming a model for the spectral emission line and then fitting the model to the data. It is shown for Poisson noisy emission-line data, via the application of Cramér-Rao lower bounds, that there a…
Simulation Studies of High-Latitude Magnetospheric Boundary Dynamics
Zhang, H.; Zong, Q. -G.; Liu, Z. X. +5 more
Magnetic reconnection at the high-latitude magnetopause is studied using 2–1/2-dimensional (2‑1/2-D) Hall-MHD simulation. Concentric flow vortices and magnetic islands appear when both Hall effect and sheared flow are considered. Plasma mixing across the magnetopause occurs in the presence of the flow vortices. Reconnected structure generated in t…
Spitzer's large CO2 ice detection toward the L723 class 0 object
Dartois, E.; Thi, W. -F.; Muñoz Caro, G. M. +1 more
The L723 low mass class 0 protostellar object has been observed with the IRS low resolution spectrometer onboard Spitzer Space Telescope. A huge CO2 ice column density of 6.3 ± 1 × 1018 cm-2 is detected toward this extremely red object. We constructed the spectral energy distribution (SED) of L723 by combining the Spitzer spe…
Planetary foreshock radio emissions
Cairns, Iver H.; Kuncic, Zdenka
The electron foreshock regions upstream of Earth's bow shock and upstream of traveling interplanetary shocks are known to be propitious sites for a variety of energetic particle and plasma wave phenomena, including radio emissions. A quantitative theoretical model has been developed for radio emissions associated with the terrestrial foreshock and…
GRB 040403: A faint X-ray rich gamma-ray burst discovered by INTEGRAL
Frontera, F.; Hurley, K.; Götz, D. +13 more
GRB 040403 is one of the faintest gamma-ray bursts for which a rapid and accurate localization has been obtained. Here we report on the gamma-ray properties of this burst, based on observations with the IBIS instrument aboard INTEGRAL, and the results of searches for its optical afterglow. The steep spectrum (power law photon index = 1.9 in the 20…
The Infrared-dominated Jet of 3C 401
Axon, David J.; Chiaberge, Marco; Capetti, Alessandro +6 more
We present a Hubble Space Telescope image of the FR II radio galaxy 3C 401, obtained at 1.6 µm with NICMOS, in which we identify the infrared counterpart of the brightest region of the radio jet. The jet has a complex radio structure and brightens where bending occurs, most likely as a result of relativistic beaming. We analyze archival data…
Energetic Particles in the Magnetosphere of Saturn and a Comparison with Jupiter
Krupp, Norbert