Search Publications
Evidence of Flaring in a Transequatorial Loop on the Sun
Harra, Louise K.; Matthews, Sarah A.; van Driel-Gesztelyi, Lidia
We present evidence of flaring behavior in a transequatorial loop (TEL) that lights up in soft X-rays on 2000 July 13. The large loop structure connects NOAA Active Regions 9070/9066 in the northern hemisphere and AR 9069/9068 in the southern hemisphere. We follow the loop systems for 2 days and observe several pieces of evidence strongly suggesti…
What Do the Hubble Space Telescope and Chandra Tell Us about the Jet and the Nuclear Region of the Radio Galaxy 3C 270?
Sparks, William B.; Chiaberge, Marco; Capetti, Alessandro +2 more
The Hubble Space Telescope (HST)/Space Telescope Imaging Spectrograph ultraviolet image of the FR I radio galaxy 3C 270 shows the presence of a jetlike structure emerging from the position of the nucleus. This feature, which represents the first jetlike component ever detected in the UV in a radio galaxy with jets lying almost on the plane of the …
Warm Molecular Hydrogen and Ionized Neon in the HH 2 Outflow
Cernicharo, J.; Noriega-Crespo, A.; Cesarsky, D. +3 more
We report on spectro-imaging observations of the Herbig-Haro 2 outflow with the ISOCAM camera on board the Infrared Space Observatory. The [Ne II] 12.81 µm and [Ne III] 15.55 µm lines are detected only toward the jet working surface (HH 2H), consistent with the high excitation of this knot in the optical range, while H2 pure…
Hubble Space Telescope Space Telescope Imaging Spectrograph Spectroscopy of the Intermediate Polar EX Hydrae
Szkody, Paula; Howell, Steve B.; Sion, Edward M. +2 more
We present the results of our analysis of six orbits of Hubble Space Telescope Space Telescope Imaging Spectrograph (HST/STIS) time-tagged spectroscopy of the intermediate polar, EX Hydrae. The high time and wavelength resolution of the HST/STIS spectra provided an excellent opportunity to study the UV properties of EX Hya. Measurements of the con…
The Kinematics and Physical Conditions of the Ionized Gas in Markarian 509. II. STIS Echelle Observations
Turner, T. J.; Kraemer, S. B.; Crenshaw, D. M. +5 more
We present observations of the UV absorption lines in the luminous Seyfert 1 galaxy Mrk 509, obtained with the medium-resolution (λ/Δλ~40,000) echelle gratings of the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. The spectra reveal the presence of eight kinematic components of absorption in Lyα, C IV, and N V, at radial veloc…
Variable Na I Absorption toward ρ Leonis: Biased Neutral Formation in the Diffuse Interstellar Medium?
Meyer, David M.; Lauroesch, J. T.
We present multiepoch KPNO coudé feed telescope observations of interstellar Na I and Ca II absorption toward the bright star ρ Leo. Comparisons of the Na I profiles observed over a period of 8 yr reveal significant temporal variations in the Na I column in at least one component, implying that there is ``structure'' at scales on the order of the …
The Collimated Wind in NGC 253
Sugai, H.; Davies, R. I.; Ward, M. J.
Near-infrared Fabry-Perot imaging has revealed H2 emission extended to about 130 pc from the disk of NGC 253. It is closely related to the hot plasma observed in soft X-rays: filamentary H2 features are found at the edges of the hot plasma. These are the places of direct interaction between a superwind and its surrounding mol…
Constraints on the Cluster Environments and Hot Spot Magnetic Field Strengths of the Radio Sources 3C 280 and 3C 254
Donahue, Megan; Daly, Ruth A.; Horner, Donald J.
We present new Chandra Observatory observations together with archival Hubble Space Telescope (HST) and radio observations of 3C 254, a radio quasar at z=0.734, and 3C 280, a radio galaxy at z=0.996. We report the detection of X-ray and possible HST optical counterparts to the radio hot spots in 3C 280 and the detection of an X-ray counterpart to …
Mass Motions and Plasma Properties in the 107 K Flare Solar Corona
Curdt, W.; Innes, D. E.; Landi, E. +1 more
In the present work, we analyze Solar Ultraviolet Measurement of Emitted Radiation (SUMER) observations of a solar limb flare that occurred on 1999 May 9. The analyzed data cover a time span of around 6.4 hr, during which an M-7.6 flare erupted and decayed in the field of view. Two selected regions along the SUMER slit have been considered for qua…
Discovery of Radio/X-Ray/Optical-resolved Supernova Remnants in the Center of the Andromeda Galaxy
Kong, A. K. H.; Garcia, M. R.; Williams, B. F. +2 more
We have detected a spatially resolved supernova remnant (SNR) in the center of the Andromeda galaxy, in radio, X-ray, and optical wavelengths. These observations provide the highest spatial resolution imaging of a radio/X-ray/optical SNR in that galaxy to date. The multiwavelength morphology, radio spectral index, X-ray colors, and narrowband opti…