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Distance and absorption features in the CG 30/CG 31/CG 38 complex
Knude, J.; Nielsen, A. S.
We report a possible confirmation of the short 200 pc distance to the cometary globules CG 30/31/38 suggested by a previously discussed (V - I) - V diagram to Vlim ~ 20 mag. New 2 magnitudes deeper V and I photometry centered on CG 31A indicate the presence of visual extinction A_V = 5\fm6 at 200 pc. In addition, we may have measured an…
Kinematics versus X-ray luminosity segregation in the Hyades
Makarov, V. V.
State of the art Tycho-2 proper motions of bona fide Hyades members are used in combination with the ROSAT X-ray survey of this open cluster in Stern et al. (1995) to study the internal velocity dispersion versus X-ray luminosity by the classical convergent point method. It is shown in this paper for the Hyades members with B-V below 0.7 mag that …
17 µm imaging of eta Carinaea: an onion-like structure for the lobes?
Pantin, E.; Le Mignant, D.
We have obtained a 17 mu m image of the eta Carinae nebula with a signal to noise ratio never reached before. Once deconvolved, the spatial resolution is of the order of 0.5\arcsec. The ring and arclike structures seen at 17 mu m are very similar to those observed at 12.5 mu m; however the intensity maximum is located elsewhere in a dense cold str…
Line-profile variation in tau Herculis
Masuda, Seiji; Hirata, Ryuko
Based on a time series of high-resolution spectra at He I lambda 4471 and Mg Ii lambda 4481, we have detected the line-profile variation of
The UV (IUE) spectrum of the planetary nebula PC 11 (HD 149427)
Pottasch, S. R.; de Martino, D.; García-Lario, P. +2 more
The UV spectrum of PC 11 is found to show variations in the strength of the O III] 1666Ä , N III] 1750Ä and C III] 1909Ä emission lines. The detection of continuum emission in the wavelength interval 2650Ä to 3200Ä indicates that the central star of PC 11 has an early F-type dwarf companion. The very low level of UV continuum in the wavelength int…
The Fe II excitation mechanism in KQ Puppis
Johansson, S. G.; Redfors, A.
We discuss different excitation processes behind the Fe II emission lines in the IUE spectrum of KQ Puppis (Boss 1985), a VV Cephei type of spectroscopic binary. Several papers have been published on the subject suggesting a number of processes behind the strong Fe II emission lines. We propose that there are two processes operating: selective pho…
ISO far-infrared observations of rich galaxy clusters. III. Abell 2029, Abell 2052, Abell 2142
Nørgaard-Nielsen, H. U.; Pedersen, K.; Hansen, L. +3 more
A sample of five rich galaxy clusters has been mapped by ISO at 60 mu m, 100 mu m, 135 mu m, and 200 mu m using the PHT-C camera. In previous papers Abell 2670 and Sérsic 159-03 were discussed. Here we present the results for Abell 2029, Abell 2052, and Abell 2142. The conclusion of the survey is that the relatively small fields (~60 square arc mi…
Emission lines of O bt III in the optical and ultraviolet spectra { } of planetary nebulae
Feibelman, W. A.; Keenan, F. P.; Aller, L. H. +3 more
Recent R-matrix calculations of electron impact excitation rates in O Iii are used to calculate electron temperature and density-dependent emission line ratios R1 = I(4363 Å) / I(4960 Å+ 5007 Å), R2 = I(1661 Å+ 1667 Å) / I(4960 Å+ 5007 Å) and R3 = I(2322 Å) / I(1661 Å+ 1667 Å), for a range of electron temperatures …
Far-infrared [C Ii]/continuum ratio toward the central kiloparsecs of M31. Comparison with that of our Galaxy
Mochizuki, K.
We observed the nearby spiral galaxy M31 with the Long-Wavelength Spectrometer on board the Infrared Space Observatory. Far-infrared line-to-continuum ratios of [C II] / 100 µ m =~ 6 x 10-3 were obtained for the central kiloparsec region along the major axis of the galaxy. These ratios are 2-3 times higher than those in the Galact…
QSO mass constraints from gravitational lensing studies of quasar pairs. The cases of Q1548+114 A & B and Q1148+0055 A & B
Surdej, J.; Sluse, D.; Claeskens, J. -F. +2 more
New constraints on the mass of quasars are derived from gravitational lensing studies of the QSO pairs Q1548+114 A & B and Q1148+0055 A & B, for which new ground-based and Hubble Space Telescope (HST) direct imagery have been obtained. In the case of Q1548+114 A & B, QSO A has been resolved into its host galaxy and a close companion. T…