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Hubble space telescope observations of BL Lacertae environments
Urry, C. Megan; O'Dowd, Matthew; Scarpa, Riccardo +3 more
We analyze images of BL Lacertae objects obtained with the Hubble Space Telescope WFPC2 and the F814W filter. The nine objects cover a redshift range of 0.19 to 0.997. The relatively deep images are sufficient to detect galaxies at least one magnitude below MI* (-21.4) and in most cases to three magnitudes below M*. Galaxy enhancement o…
CCD astrometry of faint compact extragalactic radio sources. III.
Costa, E.
Optical positions relative to the Hipparcos Catalogue (ESA 1997) have been obtained for the optical counterparts of 38 faint (B ~ 20-24) southern compact extragalactic radio sources (CERS). Many of these sources are not detectable - or their coordinates not adequately measurable - by means of direct photography with a wide-field telescope, so the …
Geomagnetic storms with H 400nT during 1979-99
Kumar, Santosh; Pratap Yadav, Mahendra
The effect of solar features on geospheric conditions leading to ninety nine geomagnetic storms (GMSs) with H400nT and Ap20 have been investigated using interplanetary magnetic field (IMF), solar wind plasma (SWP) and solar geophysical data (SGD) during the period 1979-99. H, X-ray solar o o flares occured within lower latitudinal zone i.e., 30 N-…
HST imaging of radio galaxies at /z=0.2: a comparison with quasar hosts and normal ellipticals
McLure, R. J.; Dunlop, J. S.; Hughes, D. H. +3 more
We summarise the results of our recently completed HST R-band study of low-redshift (0.1< z<0.25) FRII radio galaxies along with the host galaxies of quasars of similar redshifts. We find that, like radio galaxies, the hosts of radio-loud quasars and all but the least luminous radio-quiet quasars are massive elliptical galaxies with relative…
Multiple-loop structure of a solar flare from Microwave, EUV and X-ray Imaging Data
Kundu, M. R.; Garaimov, V. I.
We present the results of an analysis of a flare event of importance M2.8 that occurred at 00:56 UT 28 August 1999. The analysis is based upon observations made with the Nobeyama radioheliograph (NoRH) and polarimeters (NoRP), TRACE, SOHO/MDI, EIT, and Yohkoh/SXT. The images show a very complex flaring region. Pre-flare TRACE and EIT images at 00:…
Information from the Kinematics of F and G Stars in the Solar Neighborhood
Zhao, Gang; Shi, Jian-Rong; Chen, Yu-Qin
We have calculated the orbital parameters for 90 stars in Chen et al. and updated the kinematic data for stars in Edvardsson et al. by using the accurate Hipparcos parallaxes and proper motions, and recalculated the α-element abundances in Edvardsson et al. in a way consistent with Chen et al. The two sets of data are combined in a study of stella…
Two jets from the Orion nebula (M42) `proplyds': kinematics, morphologies and origins
Redman, M. P.; Meaburn, J.; Graham, M. F.
A spatially unresolved velocity feature, with an approaching radial velocity of ~100 km s-1 with respect to the systemic radial velocity, in a position-velocity array of [OIII] 5007-Å line profiles is identified as the kinematical counterpart of a jet from the proplyd LV 5 (158-323) in the core of the Orion nebula. The only candidate in…
Interplanetary lyman alpha observations of swan during the rising phase of the 23rd solar cycle
Schmidt, W.; Bertaux, J. -L.; Lallement, R. +5 more
In this work we show the development of the intensity pattern of the interplanetary Lyman α sky background radiation between 1996 and 1999 as measured by the SWAN instrument. The results show that the intensity pattern has changed considerably in three years. The pattern with two maxima in the northern and southern hemispheres observed in 1996 has…
The nuclear dust disks of five nearby 3CR elliptical galaxies
Sparks, W. B.; Baum, S. A.; Biretta, J. A. +3 more
We present broad- and narrow-band WFPC2 images of the nuclear dust disks and rings of five low- z elliptical galaxies hosting 3C radio sources: NGC 383 (3C 31)/NGC 382, NGC 3862 (3C 264), NGC 4261 (3C 270), UGC 12064 (3C 449), and NGC 7720 (3C 465)/NGC 7720A. We detect resolved line emission in all the disks. In NGC 383, the line emission consists…
Galaxy Morphology in the Rich Cluster Abell 2390
Saintonge, A.; Hutchings, J. B.; Schade, D. +1 more
We have analyzed images of the field of Abell 2390 obtained with the Canada-France-Hawaii Telescope and the Hubble Space Telescope. The analysis fits models to bulge and disk components of several hundred galaxies, with about equal samples from the cluster and field. We also have assessed and graded asymmetries in the images. The cluster galaxies …