Search Publications
Sleuthing the Dynamo. II. Hubble Space Telescope Goddard High Resolution Spectrograph Observations of Solar-Type Dwarfs in Young Galactic Clusters
Ayres, Thomas R.
Far-ultraviolet (1150-1670 Å) spectra of three solar-type dwarfs in the young galactic clusters α Persei and the Pleiades were obtained with the Hubble Space Telescope Goddard High-Resolution Spectrograph (G140L mode). Time series of Si IV λ1393 show erratic variability on timescales of tens of minutes. An X-ray/C IV flux-flux diagram displays a p…
Development and Effects of Turbulence in Connection with CIRs
Horbury, T. S.; Schmidt, J. M.
We present an overview of the properties of magnetohydrodynamic turbulence within corotating interaction regions (CIRs) and its effects on energetic particles. We stress the importance of both the population of fluctuations in the inner heliosphere and the changing local environment in determining their properties at larger heliospheric distances.…
The carbon star IRAS 15194-5115: circumstellar CO radio and FIR rotational lines
Ryde, N.; Olofsson, H.; Schöier, F. L.
We have modelled radio and far-infrared rotational lines of 12CO and 13CO obtained from the circumstellar envelope of the infrared-bright carbon star
The Luminosity Function of omega Centauri
de Marchi, Guido
Deep Hubble Space Telescope (HST) Wide Field Planetary Camera 2 observations of the stellar population in the globular cluster omega Cen (NGC 5139) have been used to measure the luminosity function of main-sequence stars at the low-mass end. Two fields have been investigated, located ~4.6‧ and ~7', respectively, away from the cluster center or nea…
Whole Sun Month at solar minimum: An introduction
Kohl, John L.; Galvin, Antoinette B.
The Whole Sun Month was a collaborative project of the IACG Campaign 4 and the SOHO Joint Observing Programs to characterize and model the structure of the global corona during solar minimum conditions. This introduction provides a brief description of the campaign objectives, the missions, and observatories involved and highlights some of the sci…
Multiwavelength Superoutburst Observations of T Leonis
Szkody, Paula; Howell, Steve B.; Ciardi, David R. +5 more
We present results of simultaneous superoutburst observations in the X-ray, EUV, optical, and IR bands of the tremendous outburst amplitude dwarf novae T Leonis. Near peak luminosity, a single blackbody represents a good fit to T Leo's observed continuum in the EUV spectral region, yielding a boundary layer temperature of 71,000-97,000 K. Inclusio…
Pictor A (PKS 0518-45): From Nucleus to Lobes
Simkin, S. M.; Tingay, S. J.; Sadler, E. M. +2 more
We present a variety of new imaging and kinematic data for the double-lobed radio galaxy Pictor A. The new optical data include Hubble Space Telescope (HST) continuum and [O III], emission-line images (at a resolution of 25-100 mas) and ground-based imaging and spectroscopy (at a resolution of ~1.5"). The ground-based images show Hα filaments and …
Search for Signatures of a Coronal Hole in Transition Region Lines Near Disk Center
Bocchialini, K.; Wilhelm, K.; Lemaire, P. +2 more
The analysis of data taken by SUMER near disk center, where a small coronal hole is observed in EIT images, is performed. From the measurements of Doppler non-thermal velocities and intensities, we search for the diagnostics and the signature of small scale structures in the coronal hole using transition region lines. Transition region lines in th…
Neutral gas and dust in the central region of the ultraluminous infrared galaxy Mrk273
Mundell, C. G.; Holloway, A. J.; Pedlar, A. +1 more
We have used MERLIN to observe neutral hydrogen absorption against the central region of the ultraluminous infrared galaxy (ULIRG) galaxy Mrk273 with an angular resolution of 0.2arcsec. This represents a factor of 5 increase in resolution compared with previous work. Absorption has been resolved against two of three radio continuum components. A H…
Combined Ulysses solar wind and SOHO coronal observations of several west limb coronal mass ejections
Schwenn, R.; Forsyth, R. J.; Riley, P. +4 more
From October 1996 to January 1997, Ulysses was situated roughly above the west limb of the Sun as observed from Earth at a heliocentric distance of about 4.6 AU and a latitude of about 25°. This presents the first opportunity to compare Solar and Heliospheric Observatory (SOHO) limb observations of coronal mass ejections (CMEs) directly with their…