scholarly journals ISO-SWS observations of Planetary Nebulae

1997 ◽  
Vol 180 ◽  
pp. 145-150
Author(s):  
D.A. Beintema
Keyword(s):  
Solid State ◽  
Short Wavelength ◽  
Planetary Nebulae ◽  
Spectral Lines ◽  
Ngc 7027 ◽  
First Results

First results of the ISO1 Short-Wavelength Spectrometer on three bright planetary nebulae NGC 6543, NGC 7027 and NGC 6302 provide a wealth of information on solid-state features and spectral lines. Spectra from 2.4 to 45 μm are presented, at a reduced resolution of about 600.

scholarly journals The central stars of the Planetary Nebulae NGC 7027 and NGC 6543

1997 ◽  
Vol 180 ◽  
pp. 134-134
Author(s):  
P.A.M. Van Hoof ◽  
D. A. Beintema ◽  
F. Lahuis ◽  
S. R. Pottasch
Keyword(s):  
Infrared Spectra ◽  
Short Wavelength ◽  
Planetary Nebulae ◽  
Space Observatory ◽  
Infrared Space Observatory ◽  
Ngc 7027 ◽  
Photo Ionization ◽  
Central Stars

Infrared spectra of NGC 7027 and NGC 6543 ranging from 2.4 μm to 45 μm were obtained with the Short Wavelength Spectrometer on board the Infrared Space Observatory. A first analysis of these spectra, with the aid of photo-ionization models, is presented in Beintema et al. (1996).

scholarly journals First Results from a Panchromatic HST/WFC3 Imaging Study of the Young, Rapidly Evolving Planetary Nebulae NGC 7027 and NGC 6302

Galaxies ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 49
Author(s):  
Joel H. Kastner ◽  
Jesse Bublitz ◽  
Bruce Balick ◽  
Rodolfo Montez ◽  
Adam Frank ◽  
...  
Keyword(s):  
Hubble Space Telescope ◽  
Imaging Study ◽  
Planetary Nebulae ◽  
Wide Field ◽  
Space Telescope ◽  
Near Ir ◽  
Ngc 7027 ◽  
First Results ◽  
Initial Color ◽  
Line Imaging

We present the first results from comprehensive, near-UV-to-near-IR Hubble Space Telescope Wide Field Camera 3 (WFC3) emission-line imaging studies of two young planetary nebulae (PNe), NGC 7027 and NGC 6302. These two objects represent key sources for purposes of understanding PNe shaping processes. Both nebulae feature axisymmetric and point-symmetric (bipolar) structures and, despite hot central stars and high nebular excitation states, both harbor large masses of molecular gas and dust. The sweeping wavelength coverage of our Cycle 27 Hubble Space Telescope (HST)/WFC3 imaging surveys targeting these two rapidly evolving PNe will provide a battery of essential tests for theories describing the structural and chemical evolution of evolved star ejecta. Here, we present initial color overlays for selected images, and we highlight some of the first results gleaned from the surveys.

scholarly journals Internal Kinematics of the Planetary Nebulae

1958 ◽  
Vol 8 ◽  
pp. 1025-1029
Author(s):  
O. C. Wilson
Keyword(s):  
High Temperature ◽  
Planetary Nebula ◽  
Chemical Elements ◽  
Chemical Species ◽  
Planetary Nebulae ◽  
Spectral Lines ◽  
Ellipsoidal Shell ◽  
Ngc 7027 ◽  
Image Position

A common form of planetary nebula consists of a high temperature nuclear star surrounded by an ovoid or ellipsoidal shell of gas which has originated in some manner in the nucleus. The radiation from the nebula consists of the ordinary spectral lines and continua of hydrogen and helium plus the so-called forbidden lines of atoms and ions of oxygen, nitrogen, neon, argon, etc. It has become clear that, as in other cosmic bodies, the bulk of the nebula consists of hydrogen and helium, and the remainder of the chemical elements occur only as a slight admixture of impurities. For instance, recent data by Aller and Minkowski lead to relative numbers of atoms of various chemical species in a particular nebula (NGC 7027) as follows (oxygen arbitrarily taken as 104):

Current Status of Solid-State X-Ray Systems

1985 ◽  
Vol 43 ◽  
pp. 158-161
Author(s):  
Martin Peckerar ◽  
Anastasios Tousimis
Keyword(s):  
Solid State ◽  
Electric Fields ◽  
Spectral Lines ◽  
Current Status ◽  
Mobile Charge ◽  
Electron Hole ◽  
X Ray ◽  
Sensing Systems ◽  
Transmission Electron ◽  
Electron Microscopes

Solid state x-ray sensing systems have been used for many years in conjunction with scanning and transmission electron microscopes. Such systems conveniently provide users with elemental area maps and quantitative chemical analyses of samples. Improvements on these tools are currently sought in the following areas: sensitivity at longer and shorter x-ray wavelengths and minimization of noise-broadening of spectral lines. In this paper, we review basic limitations and recent advances in each of these areas. Throughout the review, we emphasize the systems nature of the problem. That is. limitations exist not only in the sensor elements but also in the preamplifier/amplifier chain and in the interfaces between these components.Solid state x-ray sensors usually function by way of incident photons creating electron-hole pairs in semiconductor material. This radiation-produced mobile charge is swept into external circuitry by electric fields in the semiconductor bulk.

scholarly journals AGN Spectra as Seen by the Infrared Space Observatory: First Results

1997 ◽  
Vol 159 ◽  
pp. 333-336
Author(s):  
D. Lutz ◽  
R. Genzel ◽  
E. Sturm ◽  
A.F.M. Moorwood ◽  
E. Oliva ◽  
...  
Keyword(s):  
Fine Structure ◽  
Short Wavelength ◽  
Molecular Hydrogen ◽  
Molecular Gas ◽  
Space Observatory ◽  
Infrared Space Observatory ◽  
First Results ◽  
External Galaxies ◽  
First Time ◽  
Fine Structure Lines

AbstractWe discuss 2.5–45 µm spectra of the Circinus galaxy and of Cen A, obtained with the Short Wavelength Spectrometer (SWS) on board the Infrared Space Observatory. The large number of detected ionic fine structure lines, observable also in visually obscured sources, provides strong constraints on the shape of the ionizing spectrum, which is found to exhibit a UV bump peaking at ~ 70 eV in the case of Circinus. Pure rotational emission of molecular hydrogen, directly probing warm molecular gas, can for the first time be detected in external galaxies.

Cooling Efficiencies of a NiTi-Based Cooling Process

2013 ◽  
Author(s):  
Marvin Schmidt ◽  
Andreas Schütze ◽  
Stefan Seelecke
Keyword(s):  
Solid State ◽  
Thermodynamic Analysis ◽  
Cooling System ◽  
Analysis Method ◽  
Efficiency Ratio ◽  
Cooling Process ◽  
First Results ◽  
Work Input ◽  
Underlying Mechanisms ◽  
The Impact

Energy saving and environmental protection are topics of growing interest. In the light of these aspects alternative refrigeration principles become increasingly important. Shape memory alloys (SMA), especially NiTi alloys, generate a large amount of latent heat during solid state phase transformations, which can lead to a significant cooling effect in the material. These materials do not only provide the potential for an energy-efficient cooling process, they also minimize the impact on the environment by reducing the need for conventional ozone-depleting refrigerants. Our paper, presenting first results obtained in a project within the DFG Priority Program SPP 1599 “Ferroic Cooling”, focuses on the thermodynamic analysis of a NiTi-based cooling system. We first introduce a suitable cooling process and subsequently illustrate the underlying mechanisms of the process in comparison with the conventional compression refrigeration system. We further introduce a graphical solution to calculate the energy efficiency ratio of the system. This thermodynamic analysis method shows the necessary work input and the heat absorption of the SMA in stress/strain- or temperature/entropy-diagrams, respectively. The results of the calculations underline the high potential of this solid-state cooling methodology.

Abundance Anomalies in the X‐Ray Spectra of Planetary Nebulae NGC 7027 and BD +30o3639

2003 ◽  
Vol 589 (1) ◽  
pp. 439-443 ◽  
Author(s):  
Holly L. Maness ◽  
Saeqa D. Vrtilek ◽  
Joel H. Kastner ◽  
Noam Soker
Keyword(s):  
Planetary Nebulae ◽  
X Ray ◽  
Ngc 7027 ◽  
Abundance Anomalies

scholarly journals SOLID-STATE MICROWAVE PROCESSOR FOR FOOD TREATMENT

2019 ◽  
Author(s):  
Marco Fiore ◽  
Nicola Di Modugno ◽  
Francesco Pellegrini ◽  
Mariagrazia Roselli
Keyword(s):  
Solid State ◽  
Food Processing ◽  
Hot Spots ◽  
Industrial Applications ◽  
Radiation Patterns ◽  
Modular Architecture ◽  
Food Treatment ◽  
Distributed Software ◽  
First Results ◽  
Uneven Heating

Uneven heating and hot spots, irregular matching conditions and deterioration of organoleptic qualities are typical drawbacks of magnetron-based food processing with microwave radiation. The proposed “Kopernicook” modular architecture, based on multiple solid-state generators governed by a distributed software platform, allows highly accurate parametric control, full customization of radiation patterns and dynamic self-regulating workflows. The first results, validated with industrial applications, show great flexibility of operation, optimal energy consumption and different ideas for future developments in terms of radiation patterns and feedback-triggered algorithms aimed at maximally efficient processes.

scholarly journals Photoionization modeling of the Galactic planetary nebulae Abell 39 and NGC 7027

2011 ◽  
Vol 7 (S283) ◽  
pp. 340-341 ◽  
Author(s):  
Ashkbiz Danehkar ◽  
David J. Frew ◽  
Quentin A. Parker ◽  
Orsola De Marco
Keyword(s):  
Planetary Nebula ◽  
Planetary Nebulae ◽  
Ngc 7027

AbstractWe estimate distances to the spherical planetary nebula Abell 39 and the bipolar planetary nebula NGC 7027 by interpolating from a wide grid of photoionization models using the 3-D code, MOCASSIN. We find preliminary distances of 1.5 kpc and 0.9 kpc respectively, with uncertainties of about 30%.

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