Search Publications
Jet- and Wind-driven Ionized Outflows in the Superbubble and Star-forming Disk of NGC 3079
Filippenko, Alexei V.; Veilleux, Sylvain; Bland-Hawthorn, Joss +1 more
Hubble Space Telescope WFPC2 images are presented that span the inner ~19 kpc diameter of the edge-on galaxy NGC 3079; they are combined with optical, emission-line imaging spectrophotometry and VLA images of radio polarization vectors and rotation measures. Ionized gas filaments within 9 kpc diameter project up to 3 kpc above the disk, with the b…
Clustering Segregation with Ultraviolet Luminosity in Lyman Break Galaxies at z~3 and Its Implications
Dickinson, Mark; Giavalisco, Mauro
We report on the clustering properties of Lyman break galaxies (LBGs) at z~3. The correlation length of flux-limited samples of LBGs depends on their rest-frame ultraviolet (UV) luminosity at λ~1700 Å, with fainter galaxies being less strongly clustered in space. We have used three samples with progressively fainter flux limits: two extracted from…
Magnetic Energy Release and Transients in the Solar Flare of 2000 July 14
Kosovichev, A. G.; Zharkova, V. V.
High-resolution observations of a large solar flare on 2000 July 14 (``Bastille Day Flare'') from the Michelson Doppler Imager instrument on the SOHO spacecraft reveal rapid variations of the magnetic field in the lower solar atmosphere during the flare. Some of these variations were irreversible, occurred in the vicinity of magnetic neutral lines…
A Faint Star-forming System Viewed through the Lensing Cluster Abell 2218: First Light at z~=5.6?
Ellis, Richard; Kneib, Jean-Paul; Kuijken, Konrad +1 more
We discuss the physical nature of a remarkably faint pair of Lyα-emitting images discovered close to the giant cD galaxy in the lensing cluster Abell 2218 (z=0.18) during a systematic survey for highly magnified star-forming galaxies beyond z=5. A well-constrained mass model suggests the pair arises via a gravitationally lensed source viewed at hi…
Is the Gas in Cooling Flows Multiphase?
Molendi, Silvano; Pizzolato, Fabio
Employing XMM-Newton EPIC data we perform a detailed comparison between different spectral models to test whether the gas in cooling flows is multiphase or not. Our findings all point in the same direction, namely, that gas in cooling flows does not show the wide distribution of temperatures expected from standard multiphase models. This result ha…
The Coronal Mass Ejection of 1998 April 20: Direct Imaging at Radio Wavelengths
Pick, M.; Kerdraon, A.; Vourlidas, A. +2 more
We observed the fast coronal mass ejection (CME) of 1998 April 20 with the radioheliograph at Nançay, France, between 164 and 432 MHz. Spectroscopic data were obtained between 40 and 800 MHz by the spectrometer at Tremsdorf, Germany, and between 20 kHz and 14 MHz with the WAVES instrument on board the Wind spacecraft. Energetic particle data were …
Evolution of Two EIT/Hα Moreton Waves
Vršnak, B.; Hanslmeier, A.; Aurass, H. +1 more
Since the discovery of EIT waves, questions have remained about the driver of these disturbances and their association with the chromospheric Moreton waves. In order to resolve some of these issues, two flare-associated transient events (1997 November 3 and 1998 May 2) observed simultaneously in Hα and EIT are analyzed. The cospatiality of Moreton…
Coronal Mass Ejections Associated with Impulsive Solar Energetic Particle Events
Kahler, S. W.; Reames, D. V.; Sheeley, N. R., Jr.
An impulsive solar energetic particle (SEP) event observed on the Wind spacecraft on 2000 May 1 was associated with an impulsive solar active region M1 X-ray flare. The timing and position of a fast (v=960 km s-1), narrow CME observed in the LASCO coronagraph on SOHO make clear the connection between the CME and the flare and SEP event.…
Chandra X-Ray Observations of Pictor A: High-Energy Cosmic Rays in a Radio Galaxy
Young, A. J.; Wilson, A. S.; Shopbell, P. L.
We report X-ray observations of the nearby, powerful radio galaxy Pictor A with the Chandra Observatory and optical and near-UV observations of its western radio hot spot with the Hubble Space Telescope. X-ray emission is detected from the nucleus, a 1.9‧ (110 kpc) long jet to the west of the nucleus, the western radio hot spot some 4.2‧ (240 kpc)…
Material Outflows from Coronal Intensity ``Dimming Regions'' during Coronal Mass Ejection Onset
Harra, Louise K.; Sterling, Alphonse C.
One signature of expulsion of coronal mass ejections (CMEs) from the solar corona is the appearance of transient intensity dimmings in coronal images. These dimmings have generally been assumed to be due to discharge of CME material from the corona, and thus the ``dimming regions'' are thought of as an important signature of the sources of CMEs. W…