The Census of Planetary Nebulae in the Local Group

2006 ◽  
pp. 36-45 ◽  
Author(s):  
Romano L.M. Corradi ◽  
Laura Magrini
Keyword(s):  
Local Group ◽  
Planetary Nebulae

scholarly journals Planetary Nebulae in Local Group Galaxies

1983 ◽  
Vol 103 ◽  
pp. 443-460
Author(s):  
Holland C. Ford
Keyword(s):  
Local Group ◽  
Planetary Nebulae ◽  
Stellar Populations ◽  
Chemical Compositions ◽  
H Ii Regions ◽  
Helium Abundance ◽  
Abundance Gradient ◽  
Star Forming ◽  
Ic 10 ◽  
Ngc 6822

Recent surveys for planetary nebulae have given the first identifications in Fornax, NGC 6822, M33, IC 10, Leo A, Sextans A, Pegasus, WLM, NGC 404, and M81, and extended the identifications in the SMC, the LMC, and M31. Observations of planetaries have established chemical compositions in old or intermediate age populations in 8 Local Group galaxies. The chemical compositions show that i) the helium abundance is higher in planetary nebulae than in H II regions in the same galaxy, and ii) nitrogen is overabundant relative to H II regions by factors of 4 to 100. Planetary nebulae are not a major source of helium in star-forming galaxies, and are a major source of nitrogen. The planetary in Fornax has a relatively high O abundance, and, together with Fornax's carbon stars, establishes the presence of at least 2 stellar populations. The abundance gradient derived from 3 planetaries in M31 is very shallow, and gives high abundances at ~ 20 kpc. By using planetary nebulae as standard candles, upper and lower distance limits have been set for 10 Local Group candidates, and a new distance estimated for M81.

scholarly journals What do planetary nebulae and H II regions reveal about the chemical evolution of nearby dwarf galaxies?

2018 ◽  
Vol 14 (S344) ◽  
pp. 161-177 ◽  
Author(s):  
Denise R. Gonçalves
Keyword(s):  
Chemical Evolution ◽  
Local Group ◽  
Planetary Nebulae ◽  
H Ii Regions ◽  
Chemical Abundances ◽  
Local Universe ◽  
Time Line ◽  
Nearby Galaxies ◽  
H Ii Region ◽  
Age Range

AbstractThe Local Group contains a great number of dwarf irregulars and spheroidals, for which the spectroscopy of individual stars can be obtained. Thus, the chemical evolution of these galaxies can be traced, with the only need of finding populations spanning a large age range and such that we can accurately derive the composition. Planetary nebulae (PNe) are old- and intermediate-age star remnants and their chemical abundances can be obtained up to 3-4 Mpc. H ii regions, which are brighter and much easily detected, represent galaxies young content. PNe and H ii regions share similar spectroscopic features and are analysed in the same way. Both are among the best tracers of the chemical evolution allowing to draw the chemical time line of nearby galaxies. The focus in this review are the PN and H ii region populations as constraints to the chemical evolution models and the mass-metallicity relation of the local universe.

Planetary Nebulae in Local-Group Galaxies. I. Identifications in NGC 185, NGC 205, and NGC 221

1973 ◽  
Vol 183 ◽  
pp. L73 ◽  
Author(s):  
Holland C. Ford ◽  
David C. Jenner ◽  
Harland W. Epps
Keyword(s):  
Local Group ◽  
Planetary Nebulae

scholarly journals A deep narrowband survey for planetary nebulae at the outskirts of M 33

2018 ◽  
Vol 612 ◽  
pp. A35 ◽  
Author(s):  
R. Galera-Rosillo ◽  
R. L. M. Corradi ◽  
A. Mampaso
Keyword(s):  
Local Group ◽  
Planetary Nebulae ◽  
Wide Field ◽  
Low Surface Brightness ◽  
The Galaxy ◽  
Northern Side ◽  
The Rich ◽  
Red Giant ◽  
Field Imaging ◽  
Projected Distance

Context. Planetary nebulae (PNe) are excellent tracers of stellar populations with low surface brightness, and therefore provide a powerful method to detect and explore the rich system of substructures discovered around the main spiral galaxies of the local group. Aim. We searched the outskirts of the local group spiral galaxy M 33 (the Triangulum) for PNe to gain new insights into the extended stellar substructure on the northern side of the disc and to study the existence of a faint classical halo. Methods. The search is based on wide field imaging covering a 4.5 square degree area out to a maximum projected distance of about 40 kpc from the centre of the galaxy. The PN candidates are detected by the combination of images obtained in narrowband filters selecting the [OIII]λ5007 Å and Hα + [NII] nebular lines and in the continuum g′ and r′ broadband filters. Results. Inside the bright optical disc of M 33, eight new PN candidates were identified, three of which were spectroscopically confirmed. No PN candidates were found outside the limits of the disc. Fourteen additional sources showing [OIII] excess were also discovered. Conclusions. The absence of bright PN candidates in the area outside the galaxy disc covered by this survey sets an upper limit to the luminosity of the underlying population of ~1.6 × 107 L⊙, suggesting the lack of a massive classical halo, which is in agreement with the results obtained using the red giant branch population.

scholarly journals Planetary Nebulae as a Probe of the Local Group Galaxies Evolution

2006 ◽  
Vol 2 (S235) ◽  
pp. 215-215
Author(s):  
A. Y. Kniazev ◽  
S. A. Pustilnik ◽  
E. K. Grebel ◽  
D. B. Zucker ◽  
P. Vaisanen
Keyword(s):  
Local Group ◽  
Planetary Nebulae ◽  
Ic 10 ◽  
Irregular Galaxies ◽  
Ngc 6822 ◽  
Dwarf Irregular Galaxies

AbstractWe present the latest results from our study of PNe and HII regions in two Local Group dwarf irregular galaxies IC 10 and NGC 6822.

scholarly journals Dust and molecules in extra-galactic planetary nebulae

2015 ◽  
Vol 11 (A29B) ◽  
Author(s):  
D. A. García-Hernández
Keyword(s):  
Solid State ◽  
Gas Phase ◽  
Organic Molecules ◽  
Local Group ◽  
Planetary Nebulae ◽  
Circumstellar Envelopes ◽  
The Galaxy ◽  
Models Comparison ◽  
Polycyclic Aromatic ◽  
Complex Organic

AbstractExtra-galactic planetary nebulae (PNe) permit the study of dust and molecules in metallicity environments other than the Galaxy. Their known distances lower the number of free parameters in the observations vs. models comparison, providing strong constraints on the gas-phase and solid-state astrochemistry models. Observations of PNe in the Galaxy and other Local Group galaxies such as the Magellanic Clouds (MC) provide evidence that metallicity affects the production of dust as well as the formation of complex organic molecules and inorganic solid-state compounds in their circumstellar envelopes. In particular, the lower metallicity MC environments seem to be less favorable to dust production and the frequency of carbonaceous dust features and complex fullerene molecules is generally higher with decreasing metallicity. Here, I present an observational review of the dust and molecular content in extra-galactic PNe as compared to their higher metallicity Galactic counterparts. A special attention is given to the level of dust processing and the formation of complex organic molecules (e.g., polycyclic aromatic hydrocarbons, fullerenes, and graphene precursors) depending on metallicity.

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