Search Publications
Discovery of a Strongly Lensed Galaxy at z=3.9 behind a z=0.83 Galaxy Cluster
Kodama, Tadayuki; Tanaka, Ichi; Umetsu, Keiichi +4 more
We report on the discovery and spectroscopic confirmation of three gravitationally-lensed images of a galaxy at z=3.9 in the background of a distant, rich cluster of galaxies at z=0.83, on the basis of observations with Faint Object Camera And Spectrograph on the Subaru telescope. We construct a simple lens model of the cluster mass distribution b…
Dust Morphology and Composition in FU Orionis Systems
Woodward, Charles E.; Russell, Ray W.; Telesco, C. M. +7 more
FU Orionis stars are a small group of pre-main-sequence stars known for large-amplitude optical variability. These objects also exhibit multiwavelength phenomena suggestive of active accretion from a circumstellar disk. We present high spatial resolution mid-IR imaging and spectroscopy, submillimeter photometry, and 3-4 µm photometry of four…
Narrowband Z-mode emissions interior to Saturn's plasma torus
Gurnett, D. A.; Kurth, W. S.; Kaiser, M. L. +3 more
During Cassini's close approach to Saturn, on 1 July 2004, a set of narrow bandwidth plasma emissions were detected by the Radio and Plasma Wave Science (RPWS) instrument in the inner magnetosphere. These discrete tones were detected between 3 and 70 kHz, with individual tone bandwidths as low as a few hundred Hertz. The tones persisted for long t…
The EUV variability of the luminous QSO HS 1700+6416
Shull, J. M.; Kriss, G. A.; Reimers, D. +2 more
We report on the first observations of variations in UV (intrinsic EUV 330 Å) flux of the luminous QSO HS 1700+6416 (z = 2.72) over a decade. The amplitude of variations increases from ±0.1 mag in the optical (R) to up to a factor of 3 at 1250 Å. This is apparently an extension of the increase in amplitude of variations towards shorter wavelengths…
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…