Search Publications
A Multiwavelength Study of PSR B0628-28: The First Overluminous Rotation-powered Pulsar?
Becker, Werner; Jessner, Axel; Kramer, Michael +2 more
The ROSAT source RX J0630.8-2834 was suggested by positional coincidence to be the X-ray counterpart of the pulsar PSR B0628-28. This association, however, was regarded to be unlikely on the basis of the computed energetics of the putative X-ray counterpart. In this paper we report on multiwavelength observations of PSR B0628-28 made with the ESO …
Discovery of Multiple Coaxial Rings in the Quadrupolar Planetary Nebula NGC 6881
Kwok, Sun; Su, Kate Y. L.
We report the discovery of multiple two-dimensional rings in the quadrupolar planetary nebula NGC 6881. As many as four pairs of rings are seen in the bipolar lobes, and three rings are seen in the central torus. While the rings in the lobes have the same axis as one pair of the bipolar lobes, the inner rings are aligned with the other pair. The t…
Supersolar Metallicity in the NLS1 Galaxy Markarian 1044
Pogge, Richard W.; Nicastro, Fabrizio; Mathur, Smita +3 more
We present measurements of the metallicity of the circumnuclear gas in the narrow-line Seyfert 1 (NLS1) galaxy Markarian 1044 using O VI column density measurements from the Far Ultraviolet Spectroscopic Explorer (FUSE) together with C IV, N V, and H I measurements from the Hubble Space Telescope (HST). From the absorption lines we find that the c…
The Lens Galaxy in PG 1115+080 is an Ellipse
Kochanek, Christopher S.; Falco, Emilio E.; Yoo, Jaiyul +1 more
We use the structure of the Einstein ring image of the quasar host galaxy in the four-image quasar lens PG 1115+080 to determine the angular structure of the gravitational potential of the lens galaxy. We find that it is well described as an ellipsoid and that the best-fit nonellipsoidal models are consistent with the ellipsoidal model. We find up…
The Reverse Shock of SNR 1987A at 18 Years after Outburst
Smith, Nathan; Zhekov, Svetozar A.; Heng, Kevin +3 more
We use low-dispersion spectra obtained at the Magellan Observatory to study the broad Hα emission from the reverse shock of the infant supernova remnant SNR 1987A. These spectra demonstrate that the spatiokinematic structure of the reverse shock can be distinguished from that of the circumstellar ring and hot spots, even at ground-based spatial re…
Multialtitude Observations of a Coronal Jet during the Third Whole Sun Month Campaign
Mason, H. E.; Thompson, B. J.; Raymond, J. C. +11 more
On 1999 August 26, a coronal jet occurred at the northwest limb near a sigmoid active region (AR 8668) that was the target for a joint observation plan (SOHO joint observing program 106) during the third Whole Sun Month Campaign. This jet was observed by several instruments at the limb (SOHO/CDS, SOHO/EIT, TRACE, and Mauna Loa Solar Observatory CH…
Correlation Heights of the Sources of Solar Ultraviolet Emission Lines in a Quiet-Sun Region
Wilhelm, Klaus; Marsch, Eckart; Wang, Jing-Xiu +4 more
The radiance and Doppler-velocity maps of the emission lines of Si II, C IV, and Ne VIII obtained in a quiet region of the Sun by SUMER (Solar Ultraviolet Measurements of Emitted Radiation) are correlated with the vertical component, Bz, of the magnetic field vector as extrapolated, by means of a force-free field model, from the photosp…
Faint Fuzzies and the Formation of Lenticular Galaxies
Brodie, Jean; Burkert, Andreas; Larsen, Soeren
We investigate the dynamical state of a new class of extended star clusters known as ``faint fuzzies,'' which were discovered in two nearby S0 galaxies, NGC 1023 and NGC 3384. It is shown that the faint fuzzies of NGC 1023 lie in a fast-rotating ringlike structure within the galactic disk with mean radius of 5 kpc, rotational velocity of 200 km s<…
Integral Field Spectroscopy of the Central Regions of 3C 120: Evidence of a Past Merging Event
Christensen, L.; García-Lorenzo, B.; Mediavilla, E. +2 more
Optical integral field spectroscopy (IFS), combined with Hubble Space Telescope (HST) WFPC imaging, was used to characterize the central regions of the Seyfert 1 radio galaxy 3C 120. We carried out the analysis of the data, deriving intensity maps of different emission lines and the continua at different wavelengths from the observed spectra. Appl…
A Study of Flare-associated X-Ray Plasma Ejections. I. Association with Coronal Mass Ejections
Cho, K. -S.; Moon, Y. -J.; Park, Y. D. +2 more
We have made a comprehensive statistical study of the relationship between flare-associated X-ray plasma ejections and coronal mass ejections (CMEs). For this we considered all flare-mode data in Yohkoh SXT observations from 1999 April to 2001 March and then selected 279 limb flares seen at longitudes greater than 60°. For these events, we identif…