Search Publications
Large Silicon Abundance in Photodissociation Regions
Nakagawa, Takao; Onaka, Takashi; Tomono, Daigo +3 more
We have made one-dimensional raster scan observations of the ρ Oph and σ Sco star-forming regions with two spectrometers (SWS and LWS) on board the ISO. In the ρ Oph region, [Si II] 35 µm, [O I] 63 µm, 146 µm, [C II] 158 µm, and the H2 pure rotational transition lines S(0) to S(3) are detected, and the photodisso…
Adaptive-Optics-Assisted Near-Infrared Spectroscopy of SVS 13 and Its Jet
Smith, M. D.; Ray, T. P.; Nisini, B. +5 more
We present long-slit H- and K-band spectroscopy of the low-mass outflow source SVS 13, obtained with the adaptive-optics-assisted imager-spectrometer NACO on the VLT. With a spatial resolution of <0.25" and a pixel scale of 0.027", we precisely establish the relative offsets of H2, [Fe II], CO, H I, and Na I components from the sourc…
Discovery of a 3.6 hr Eclipsing Luminous X-Ray Binary in the Galaxy NGC 4214
Tennant, Allyn F.; Swartz, Douglas A.; Ghosh, Kajal K. +3 more
We report the discovery of an eclipsing X-ray binary with a 3.62 hr period within 24" of the center of the dwarf starburst galaxy NGC 4214. The orbital period places interesting constraints on the nature of the binary and allows for a few very different interpretations. The most likely possibility is that the source lies within NGC 4214 and has an…
The Einstein Ring 0047-2808 Revisited: A Bayesian Inversion
Brewer, B. J.; Lewis, G. F.
In a previous paper, we outlined a new Bayesian method for inferring the properties of extended gravitational lenses given data in the form of resolved images. This method holds the most promise for optimally extracting information from the observed image, while providing reliable uncertainties in all parameters. Here, we apply the method to the w…
Doppler Shift Correlations in the Solar Transition Region
Doschek, G. A.
I investigate dynamical correlations between the lower transition region and the upper transition region using spectra from the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) spectrometer on the Solar and Heliospheric Observatory (SOHO) spacecraft. The measured quantity is the Doppler shift (mostly solar radial) along the line of sigh…
Suzaku Reveals Helium-burning Products in the X-Ray-emitting Planetary Nebula BD +30 3639
Hamaguchi, K.; Matsushita, K.; Hayashida, K. +7 more
BD +30 3639, the brightest planetary nebula at X-ray energies, was observed with Suzaku, an X-ray observatory launched on 2005 July 10. Using the X-ray Imaging Spectrometer, the K lines from C VI, O VII, and O VIII were resolved for the first time, and the C/O, N/O, and Ne/O abundance ratios were determined. The C/O and Ne/O abundance ratios excee…
A Flare of AE Aquarii Observed with XMM-Newton
Dotani, Tadayasu; Choi, Chul-Sung
We present the results of analyzing the XMM-Newton data obtained in 2001 November 7-8. A flare is observed simultaneously in X-ray and UV together with a quiescence. We find that during the flare event X-ray flux varies with UV with no significant time lag, indicating a close correlation of flux variation for X-ray and UV flares. An upper limit of…
Luminous Compact Blue Galaxies in Intermediate-Redshift Galaxy Clusters: A Significant but Extreme Butcher-Oemler Population
Bershady, M. A.; Hoessel, J. G.; Crawford, S. M. +1 more
We identify a population of luminous compact blue galaxies (LCBGs) in two galaxy clusters: MS 0451.6-0305 (z=0.54) and Cl 1604+4304 (z=0.9). LCBGs are identified via photometric characteristics and photometric redshifts derived from broad- and narrowband images taken with the WIYN telescope and the Hubble Space Telescope (HST). We analyze their su…
The Spitzer View of Low-Metallicity Star Formation. I. Haro 3
Hunt, Leslie K.; Sauvage, Marc; Thuan, Trinh X. +1 more
We present Spitzer observations of the blue compact dwarf galaxy Haro 3, with an oxygen abundance of 12+log(O/H)=8.32. These data are part of a larger study of star formation and dust in low-metallicity environments. The IRS spectrum of Haro 3 shows strong narrow PAH emission, with high equivalent widths. Gaseous nebular fine-structure lines are a…
Traveling Convective Modes in the Sun's Subsurface Shear Layer
Kosovichev, A. G.; Green, C. A.
Observations reveal that supergranular convective cells on the Sun rotate faster than the plasma on the solar surface. Recent time-distance helioseismology results from the Solar and Heliospheric Observatory Michelson Doppler Imager suggest that supergranulation has properties of traveling waves. We consider the idea that these properties are rela…