scholarly journals A Survey of Planetary Nebulae in the SMC and M31

1989 ◽  
Vol 131 ◽  
pp. 351-351
Author(s):  
N. Meyssonnier ◽  
M. Azzopardi ◽  
J. Lequeux ◽  
R. Gathier
Keyword(s):  
Emission Line ◽  
Planetary Nebulae ◽  
Wide Field ◽  
Objective Prism ◽  
Low Dispersion ◽  
Selection Of ◽  
General Method

Our general method for finding planetary nebulae (PN) is to make wide field objective-prism or objective-grating low-dispersion spectra on photographic plates, PN stand up amongst other emission-line objects either as Hα + [N II] 6548-6583 A emitters or as [O III] 50007 A emitters with faint or no continuum, higher-resolution spectroscopy is used for confirming a selection of candidates.

scholarly journals The Absolute Spectrophotometry of 170 Planetary Nebulae

1968 ◽  
Vol 34 ◽  
pp. 55-58 ◽  
Author(s):  
B.A. Vorontsov-Velyaminov ◽  
E.B. Kostjakova ◽  
O.D. Dokuchaeva ◽  
V.P. Arhipova
Keyword(s):  
Emission Line ◽  
Planetary Nebulae ◽  
Homogeneous System ◽  
Astronomical Institute ◽  
Line Intensities ◽  
Objective Prism ◽  
The Absolute

An investigation of planetary nebulae has been underway at the Sternberg State Astronomical Institute in Moscow for several years. It was begun with the measurement of the emission-line intensities of planetary nebulae in an homogeneous system in absolute units. More than 300 long-exposure objective prism spectrograms were obtained with the 50-cm Maksutov telescope at the Crimean Station of the Institute and with the 70-cm meniscus telescope of the Abastumani Observatory. The dispersion of the spectrograms was 190 and 160 Å/mm at Hγ respectively.

scholarly journals Lists of Confirmed Planetary Nebulae in the Magellanic Clouds

1978 ◽  
Vol 76 ◽  
pp. 64-64
Author(s):  
N. Sanduleak ◽  
D.J. MacConnell ◽  
A.G. Davis Philip
Keyword(s):  
Emission Line ◽  
Total Mass ◽  
Planetary Nebulae ◽  
High Sensitivity ◽  
Hii Regions ◽  
Magellanic Clouds ◽  
Schmidt Telescope ◽  
Deep Blue ◽  
Two Systems ◽  
Objective Prism

Very deep, blue and red-sensitive objective-prism plates, taken with the Curtis Schmidt telescope at the Cerro Tololo Inter-American Observatory, were used to survey both Magellanic Clouds for unresolved objects which could be classified as highly probable planetary nebulae. The high sensitivity of the baked Kodak IIIa-J emulsion at 5000 Å made it possible to detect the N1 and N2 lines of [OIII] in fainter objects than previously observed. A number of emission-line stars, compact HII regions, and very-low-excitation objects, formerly considered to be probable or possible planetaries, were recognized and excluded. The final lists contain 27 confirmed planetaries in the SMC and 100 in the LMC, a ratio equivalent to the estimated ratio of total mass in the two systems. As would be expected, most of these objects had been detected in previous objective-prism surveys but some apparently new planetaries were found.

scholarly journals Orientation of galactic bulge planetary nebulae toward the Galactic center

2014 ◽  
Vol 10 (S312) ◽  
pp. 128-130
Author(s):  
Ashkbiz Danehkar ◽  
Quentin A. Parker
Keyword(s):  
Emission Line ◽  
Galactic Center ◽  
Planetary Nebulae ◽  
Wide Field ◽  
Spatially Resolved ◽  
Integral Field Spectroscopy ◽  
Field Spectroscopy ◽  
National University ◽  
Hα Emission ◽  
Integral Field

AbstractWe have used the Wide Field Spectrograph on the Australian National University 2.3-m telescope to perform the integral field spectroscopy for a sample of the Galactic planetary nebulae. The spatially resolved velocity distributions of the Hα emission line were used to determine the kinematic features and nebular orientations. Our findings show that some bulge planetary nebulae toward the Galactic center have a particular orientation.

scholarly journals Hamburg Observatory Northern Milky Way Spectral Survey For Emission Objects

1984 ◽  
Vol 78 ◽  
pp. 311-314
Author(s):  
L. Kohoutek
Keyword(s):  
Emission Line ◽  
Milky Way ◽  
Planetary Nebulae ◽  
H Ii Region ◽  
Objective Prism ◽  
Protoplanetary Nebula ◽  
Spectral Survey ◽  
Individual Objects

Objective-prism spectral surveys open the possibility to search for faint emission-line objects with the aim to complete their statistics and to pick out most interesting individual objects for further study. In the years 1964 - 1970 the Hamburg Hα Spectral Survey of the Northern Milky Way was accomplished using the Schmidt camera (80/120 cm, f= 240 cm) in Bergedorf with the following parameters: area 1 32° - 214°, -10°<b<+10°, 160 fields. Kodak 103aE + RG1, exp. 60min, widen. 10", 4° prism (580 Å/mm at Hγ ). As a main result the list of about 140 faint objects classified as planetary nebulae or possible planetary nebulae (Kohoutek,1965, 1969a,1972), and the identification of about 1500 new stars having Hα in emission (Kohoutek, Wehmeyer, in preparation) can be reported. The best known examples of this survey are K 3-50, a prototype of a compact H II region, and the symbiotic variable HBV 475 = V 1329 Cyg (Kohoutek, 1969b), which is also classified as a protoplanetary nebula.

scholarly journals Surveys for Hα Emission-Line Stars using the Bosscha Schmidt Telescope

1995 ◽  
Vol 148 ◽  
pp. 388-394
Author(s):  
Bambang Hidayat ◽  
Katsuo Ogura ◽  
Masao Shinohara
Keyword(s):  
Emission Line ◽  
Planetary Nebulae ◽  
T Tauri Stars ◽  
Schmidt Telescope ◽  
Dark Clouds ◽  
T Tauri ◽  
Hα Emission ◽  
Objective Prism ◽  
Emission Stars

According to McCarthy (1984) the objects detected in objective prism surveys for Hα emission line are a ”most unnatural“ group. Of course they consist of many natural groupings whose identities or other peculiarities could become apparent after observing them with higher dispersion and resolution spectroscopy. In some cases, however, their galactic locations and associations with other known populations, can provide a clue to their population types.The aims of the objective prism surveys using the Bosscha Schmidt telescope can be broadly categorised as follows: 1.Searches for galactic planetary nebulae in the region 240° < l < 360 °; |b| ≤ 10°, initiated by The (1968).2.Searches for T-Tauri stars in some southern dark clouds (Shinohara, Ogura & Hidayat 1989).3.Searches for variations in Hα intensities and luminous emission stars in some selected galactic regions, such as in the Puppis and Carina regions.

Novae in the Magellanic Clouds

1979 ◽  
Vol 46 ◽  
pp. 96-101
Author(s):  
J.A. Graham
Keyword(s):  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
University Of Michigan ◽  
The Past ◽  
Spectroscopic Information ◽  
Objective Prism ◽  
The University ◽  
Small Cloud ◽  
Low Dispersion

During the past several years, a systematic search for novae in the Magellanic Clouds has been carried out at Cerro Tololo Inter-American Observatory. The Curtis Schmidt telescope, on loan to CTIO from the University of Michigan is used to obtain plates every two weeks during the observing season. An objective prism is used on the telescope. This provides additional low-dispersion spectroscopic information when a nova is discovered. The plates cover an area of 5°x5°. One plate is sufficient to cover the Small Magellanic Cloud and four are taken of the Large Magellanic Cloud with an overlap so that the central bar is included on each plate. The methods used in the search have been described by Graham and Araya (1971). In the CTIO survey, 8 novae have been discovered in the Large Cloud but none in the Small Cloud. The survey was not carried out in 1974 or 1976. During 1974, one nova was discovered in the Small Cloud by MacConnell and Sanduleak (1974).

General Method for Optimizing Composite Patch Repairs

2015 ◽  
Vol 1120-1121 ◽  
pp. 670-674
Author(s):  
Abdelmadjid Ait Yala ◽  
Abderrahmanne Akkouche
Keyword(s):  
Mechanical Properties ◽  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Optimization Problem ◽  
Composite Patch ◽  
Matlab Program ◽  
Patch Repairs ◽  
Selection Of ◽  
General Method

The aim of this work is to define a general method for the optimization of composite patch repairing. Fracture mechanics theory shows that the stress intensity factor tends towards an asymptotic limit K∞.This limit is given by Rose’s formula and is a function of the thicknesses and mechanical properties of the cracked plate, the composite patch and the adhesive. The proposed approach consists in considering this limit as an objective function that needs to be minimized. In deed lowering this asymptote will reduce the values of the stress intensity factor hence optimize the repair. However to be effective this robust design must satisfy the stiffness ratio criteria. The resolution of this double objective optimization problem with Matlab program allowed us determine the appropriate geometric and mechanical properties that allow the optimum design; that is the selection of the adhesive, the patch and their respective thicknesses.

scholarly journals Substellar and low-mass dwarf identification with near-infrared imaging space observatories

2018 ◽  
Vol 620 ◽  
pp. A132 ◽  
Author(s):  
B. W. Holwerda ◽  
J. S. Bridge ◽  
R. Ryan ◽  
M. A. Kenworthy ◽  
N. Pirzkal ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Imaging ◽  
High Redshift ◽  
Brown Dwarfs ◽  
Wide Field ◽  
Space Telescope ◽  
Low Mass ◽  
Space Observatories ◽  
Broad Type ◽  
Selection Of

Aims. We aim to evaluate the near-infrared colors of brown dwarfs as observed with four major infrared imaging space observatories: the Hubble Space Telescope (HST), the James Webb Space Telescope (JWST), the Euclid mission, and the WFIRST telescope. Methods. We used the SPLAT SPEX/ISPEX spectroscopic library to map out the colors of the M-, L-, and T-type dwarfs. We have identified which color–color combination is optimal for identifying broad type and which single color is optimal to then identify the subtype (e.g., T0-9). We evaluated each observatory separately as well as the narrow-field (HST and JWST) and wide-field (Euclid and WFIRST) combinations. Results. The Euclid filters perform equally well as HST wide filters in discriminating between broad types of brown dwarfs. WFIRST performs similarly well, despite a wider selection of filters. However, subtyping with any combination of Euclid and WFIRST observations remains uncertain due to the lack of medium, or narrow-band filters. We argue that a medium band added to the WFIRST filter selection would greatly improve its ability to preselect brown dwarfs its imaging surveys. Conclusions. The HST filters used in high-redshift searches are close to optimal to identify broad stellar type. However, the addition of F127M to the commonly used broad filter sets would allow for unambiguous subtyping. An improvement over HST is one of two broad and medium filter combinations on JWST: pairing F140M with either F150W or F162M discriminates very well between subtypes.

scholarly journals Hybrid 3-D Spectrophotometry of Emission-Line Nebulae at Ohio State

1995 ◽  
Vol 149 ◽  
pp. 167-171
Author(s):  
Richard W. Pogge ◽  
Nancy Joanne Lame
Keyword(s):  
Emission Line ◽  
Planetary Nebulae ◽  
Hii Regions ◽  
Ohio State University ◽  
State University ◽  
Considerable Success ◽  
Fabry Perot ◽  
The Ohio State University ◽  
Scientific Results ◽  
Narrowband Filter

AbstractA program of 3-D spectrophotometry of emission nebulae being carried out at the Ohio State University will be described. We have had considerable success combining Fabry-Perot imaging, long-slit spectroscopy, and narrowband filter imaging into a hybrid 3-D spectroscopic approach that we have used to obtain detailed spectrophotometric maps of the density, temperature, extinction, and ionization in HII regions and Planetary Nebulae. The centerpiece instrument of this effort, the OSU Imaging Fabry-Perot Spectrograph (IFPS), will be described, and scientific results illustrative of our work will be presented.

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