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Chapter and Conference Paper
Local Group Census: The Dwarf Irregular Galaxy NGC6822
In the framework of the Local Group Census (LGC), an imaging programme to search for emission line objects in the Local Group, we present the detection of 13 new candidate planetary nebulae (PNe) and follow-up...
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Chapter and Conference Paper
Local Group Census: The Dwarf Irregular Galaxy NGC6822
In the framework of the Local Group Census (LGC), an imaging programme to search for emission line objects in the Local Group, we present the detection of 13 new candidate planetary nebulae (PNe) and follow-up...
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Chapter
Are Microstructures in the Outer Shells of PNe Fossil Condensations of the AGB Wind?
Some planetary nebulae (PNe) show microstructures of low ionization located in their outer regions, i.e. external to the bright rim defined by the fast vs. slow wind interaction region. Morphological and kinem...
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Chapter and Conference Paper
Multiwavelength Kinematics of the PNe Humason 1–2 and NGC 7662
The conventional interpretation of the “Wilson effect”is based on the fact that, in a simple photoionization model of a thick shell in free expansion, the elements with a high ionization potential are found in...
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Chapter
Shock Modelling of Planetary Nebulae
The kinematics of Planetary Nebulae are analyzed in terms of the solutions to the equations of hydrodynamic equilibrium developed by J. Cantó. We apply our analysis to the Planetary Nebulae NGC 6905 and NGC 65...
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Chapter and Conference Paper
Kinematics of the Planetary Nebula Hb 5.
The planetary nebula Hubble 5 shows a very striking bi-symmetry; a 180° rotation around its center would bring the object into fair coincidence. Similar to this nebula is NGC 6537 and, to a lesser degree, NGC ...
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Chapter and Conference Paper
An Infrared Search for New Planetary Nebulae
We present the first results of a large scale infrared search for new planetary nebulae. More than 1000 unidentified sources were selected from the IRS PSC having infrared colours similar to those of known PN’...
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Chapter and Conference Paper
High Velocity Outflows in Post-Main Sequence Nebulae
We have observed a broad range of post-main-sequence, type I and irregular nebulae using the intermediate dispersion spectrograph of the Isaac Newton Telescope (La Palma, Spain). Many of these show evidence fo...
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Chapter and Conference Paper
The Halos of NGC 6543 and NGC 6826
Long slit low resolution (3.4 A) spectra of the planetary nebulae NGC 6543 and NGC 6826, obtained using the 2.5-m Isaac Newton Telescope (La Palma) with the Image Photon Counting System (IPCS), indicate differ...
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Chapter and Conference Paper
High Resolution Long-Slit Spectroscopy of A78
High spectral resolution bidimensional spectroscopy of A78 in the He II λ4686 A, H λ4861 A, [O III] λ4959 A and [O III] λ5007 A lines is reported, confirming the different morphology of the nebula in these lin...
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Chapter and Conference Paper
Low Resolution Spectroscopy of 13 Low Surface Brightness PN’s
We have obtained long-slit low resolution spectra (7.5 A resolution) of a sample of 13 low surface brightness planetary nebulae using the 2.5-m Isaac Newton Telescope (La Palma) with the Image Photon Counting ...
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Chapter and Conference Paper
The prevalence of neutral gas in massive post-main-sequence nebulae
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Chapter and Conference Paper
A CO search for molecular gas in high mass post-main-sequence nebulae
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Chapter and Conference Paper
Efforts by the Instituto de Astrophisica de Canarias to Publicise Astronomy
The Institute provides facilities for school and group visits and these have also included “Astronomical Weeks” (held on more than one of the islands in the group) and yearly open days. In 1985 the formal open...
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Chapter and Conference Paper
Radio Map** of Type I Post-Main-Sequence Nebulae
Type I post-main-sequence nebulae appear to be characterised by a range of unusual, and in certain cases extreme physical characteristics, including high velocity (and possibly high mass) outflows, and anomalo...
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Chapter and Conference Paper
Shell Formation and Mass Loss in the Planetary Nebulae A78
High resolution bidimensional spectroscopy of A78 in the He II 4685 Å, Hβ λ 4861 Å, [OIII] γ 4959 Å and [OIII] λ 5007 Å lines was obtained at the Observatorio del Roque de los Muchachos (La Palma), using the 2...
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Chapter and Conference Paper
Spectroscopic Study of Gas Outflows in the Bipolar Nebula S106
High resolution bidimensional optical spectroscopy in Hα, [NII] λλ 6548, 6583 υ and [SII] λλ 6717, 6713 Å lines of the bipolar nebula S 106 are reported. The resulting Hα velocity maps show strong variations i...
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Chapter and Conference Paper
Near Infrared-IRAS Candidates for Molecular Outflows in Lynds Clouds
Near infrared observations of cold IRAS sources associated with Lynds dark clouds allowed the detection of 13 objects which, in some cases, could represent young embedded stars energizing molecular outflows.
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Chapter
Hydrogen Deficient Planetary Nebulae: Preliminary Results
New spectra of A78 and A58 at different positions in the nebulae are presented. An abundance gradient is found in A78, extending quite close to the center. Similarly the nebulous knot near the center of A58 ha...
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Chapter and Conference Paper
Near Infrared Emission from the Solar Corona
During the summers of 1973 and 1979 the F Corona was observed from ground in the near infrared at 2,2μ and 3,5μ in an attempt to measure the thermal emission peaks predicted by Peterson (1963) and found experi me...
