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VLA Observations of Z CMa: The Orientation and Origin of the Thermal Jet

Velázquez, P. F.; Rodríguez, L. F.

We present sensitive, high angular resolution (~0.45'') Very Large Array observations made at 6 and 3.5 cm toward the thermal jet associated with the young star Z CMa. We found that the position angle of the axis of the thermal jet is coincident within error with the orientation of the optical jet and the orientation of the CO bipolar outflow. The…

The Parameters of Galactic Kinematics Determined from Total Least Squares

Branham, R. L., Jr.

Problems of Galactic kinematics have usually been solved by the method of least squares, but this may lead to biased results because least squares assume that error resides only in the observations, not in the equations of condition. The latter, however, generally incorporate error, at least in some of the columns of the data matrix. Total least s…

A Multifrequency Catalog of LINERs

Masegosa, J.; Dultzin-Hacyan, D.; Carrillo, R. +1 more

Spectroscopy and Direct Imaging of the Planetary Nebula IC 4593.

Olguín, L.; Bohigas, J.

Spectroscopy of the planetary nebula IC 4593 leads to helium, oxygen, carbon, sulfur and argon abundances which are typical of non-type I planetaries. Nitrogen abundance is normal when UV data is used. Neon might be underabundant by a factor of 2. Images in various emission lines show that the nebula is composed of two internal structures dominate…

The Spatial Intensity Distribution of the UV Light in HH Objects. Revisited

Raga, A. C.; Noriega-Crespo, A.; Moro-Martin, A. +1 more

Simple kinematical bow shock models have successfully explained many of the observed features in Herbig-Haro objects. It is shown that similar models can be applied to the spatial intensity distribution of the UV lines observed by IUE. Archival IUE spectra have been used for the HH 1, HH 2(H+A^'), HH 2(G+B), HH 24A, HH 32A, HH 43(A+B+C),…

LM1-64: a high excitation planetary nebula with WR nucleus in the LMC.

Torres-Peimbert, S.; Ruiz, M. T.; Peña, M. +1 more

The authors present optical and UV spectra of the planetary nebula LM1-64 in the LMC. This is a high excitation planetary nebula which shows evidence of having a WC central star. Broad and complex stellar emission at λ4650 (due to C III and C IV) is detected in the optical spectrum. The authors have measured all the emission line fluxes available …

The star-formation history of GR8 with HST imagery.

Dufour, R. J.; Wyatt, R. J.

The authors report the results of a deep imaging study of the nearby irregular galaxy GR8 using the Wide-Field Camera on the Hubble Space Telescope. These data enable them to perform photometry on stars as faint as R ≡ 24.5 with spatial resolution superior to ground-based observations. Color-magnitude diagrams in the "BVR" filters are presented an…

Structure, motion, and composition of the Orion Nebula.

O'Dell, C. R.

The author reviews the large scale structure of the Orion Nebula, incorporating recent results from 21 cm absorption studies, optical emission line investigations, and Hubble Space Telescope imaging. The ionization structure at the brightest ionization front is clearly defined and demonstrates a well organized flow away from the front. The ionized…

Comparisons of IUE & HST ultraviolet spectra of extragalactic H II regions.

Terlevich, E.; Terlevich, R.; Garnett, D. R. +5 more

The authors compare recently obtained HST FOS and IUE SWP ultraviolet spectra of two extragalactic H II regions: SBS 0335-052 and 30 Doradus in the LMC. They also present IUE SWP NEWSIPS processed spectra of I Zw 18, which show significant improvements in the data quality, suggesting that reprocessed IUE archival spectra will offer enhanced scienc…

HST FOC/48 UV imagery of GR8.

Dufour, R. J.; Wyatt, R. J.; Patterson, B.

Imagery observations of GR8 were made in July 1991 with the Hubble Space Telescope. The Wide Field Camera imaged the entire galaxy at 5500 Å (F555W), 4390 Å (F439W), and 3360 Å (F336W); and two smaller fields around the H II regions HL5 and HL19 were imaged at 1400 Å (F150W) with the Faint Object Camera. B and V magnitudes for these stars are from…