scholarly journals Several evolutionary channels for bright planetary nebulae

2015 ◽  
Vol 11 (S317) ◽  
pp. 344-345 ◽  
Author(s):  
Michael G. Richer ◽  
Marshall L. McCall
Keyword(s):  
Spectral Properties ◽  
Milky Way ◽  
Spiral Galaxies ◽  
Planetary Nebulae

AbstractThe populations of bright planetary nebulae in the discs of spirals appear to differ in their spectral properties from those in ellipticals and the bulges of spirals. The bright planetary nebulae from the bulge of the Milky Way are entirely compatible with those observed in the discs of spiral galaxies. The similarity might be explained if the bulge of the Milky Way evolved secularly from the disc, in which case the bulge should be regarded as a pseudo-bulge.

scholarly journals Globular Cluster and Galaxy Formation: M31, the Milky Way, and Implications for Globular Cluster Systems of Spiral Galaxies

2004 ◽  
Vol 614 (1) ◽  
pp. 158-166 ◽  
Author(s):  
David Burstein ◽  
Yong Li ◽  
Kenneth C. Freeman ◽  
John E. Norris ◽  
Michael S. Bessell ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
Globular Cluster ◽  
Milky Way ◽  
Spiral Galaxies ◽  
Cluster Systems

scholarly journals Vertical distribution and kinematics of planetary nebulae in the milky way

2017 ◽  
Vol 43 (5) ◽  
pp. 304-315 ◽  
Author(s):  
V. V. Bobylev ◽  
A. T. Bajkova
Keyword(s):  
Vertical Distribution ◽  
Milky Way ◽  
Planetary Nebulae

scholarly journals A Kiloparsec-scale Molecular Wave in the Inner Galaxy: Feather of the Milky Way?

2021 ◽  
Vol 921 (2) ◽  
pp. L42
Author(s):  
V. S. Veena ◽  
P. Schilke ◽  
Á. Sánchez-Monge ◽  
M. C. Sormani ◽  
R. S. Klessen ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Aspect Ratio ◽  
Milky Way ◽  
Spiral Galaxies ◽  
Galactic Center ◽  
Velocity Data ◽  
Sinusoidal Wave ◽  
Angular Extent ◽  
The Vertical Distribution ◽  
Spiral Arm

Abstract We report the discovery of a velocity coherent, kiloparsec-scale molecular structure toward the Galactic center region with an angular extent of 30° and an aspect ratio of 60:1. The kinematic distance of the CO structure ranges between 4.4 and 6.5 kpc. Analysis of the velocity data and comparison with the existing spiral arm models support that a major portion of this structure is either a subbranch of the Norma arm or an interarm giant molecular filament, likely to be a kiloparsec-scale feather (or spur) of the Milky Way, similar to those observed in nearby spiral galaxies. The filamentary cloud is at least 2.0 kpc in extent, considering the uncertainties in the kinematic distances, and it could be as long as 4 kpc. The vertical distribution of this highly elongated structure reveals a pattern similar to that of a sinusoidal wave. The exact mechanisms responsible for the origin of such a kiloparsec-scale filament and its wavy morphology remains unclear. The distinct wave-like shape and its peculiar orientation makes this cloud, named as the Gangotri wave, one of the largest and most intriguing structures identified in the Milky Way.

scholarly journals Similarities between Hurricanes and Galaxies: A Short Review

2021 ◽  
Author(s):  
Jim Henry ◽  
Mesut Yurukcu ◽  
George Nnanna
Keyword(s):  
Milky Way ◽  
Spiral Galaxies ◽  
Spiral Structure ◽  
Fibonacci Numbers ◽  
Short Review ◽  
Review Article ◽  
Double Spiral ◽  
Natural Pattern

Universe created with the fundamental laws of science. Nature is lazy and needs to form with the least possible to be perfect. A natural pattern, such as pinecones, sunflowers, pineapples, and cacti, has a double spiral structure. Once we look at these plants' centers, we will see the seeds line up in spirals shape. The number of spirals whirling in each direction will give us the Fibonacci numbers. We can give more examples representing these natural patterns; however, one example is unique and remarkable. The similarities between spiral galaxies- Milky Way and hurricanes. Are they similar in every property or just in shape and rotational movements? What are the similarities between them? This short review article will try to find these questions' answers by reviewing some literature articles. The first part of this article gave some information about hurricanes and galaxies. The second of this article focused on the comparison between hurricanes and galaxies. Finally, we will conclude the article with our remarks.

scholarly journals Planetary nebulae in the inner Milky Way

2009 ◽  
Vol 5 (S265) ◽  
pp. 354-355
Author(s):  
Oscar Cavichia ◽  
Roberto D. D. Costa ◽  
Walter J. Maciel
Keyword(s):  
Statistical Analysis ◽  
Milky Way ◽  
Planetary Nebulae ◽  
Galactic Bulge ◽  
Intermediate Mass ◽  
Disk Interface ◽  
The Galaxy ◽  
Outer Border ◽  
Good Agreement

AbstractNew abundances of planetary nebulae located towards the bulge of the Galaxy are derived based on observations made at LNA (Brazil). We present accurate abundances of the elements He, N, S, O, Ar, and Ne for 56 PNe located towards the galactic bulge. The data shows a good agreement with other results in the literature, in the sense that the distribution of the abundances is similar to those works. From the statistical analysis performed, we can suggest a bulge-disk interface at 2.2 kpc for the intermediate mass population, marking therefore the outer border of the bulge and inner border of the disk.

scholarly journals High reddening patches in Gaia DR2

2020 ◽  
Vol 634 ◽  
pp. A33
Author(s):  
Leire Beitia-Antero ◽  
Ana Inés Gómez de Castro ◽  
Raúl de la Fuente Marcos
Keyword(s):  
Star Formation ◽  
Milky Way ◽  
Spectroscopic Analysis ◽  
Galactic Halo ◽  
Spiral Galaxies ◽  
Monte Carlo Sampling ◽  
The Other ◽  
Host Galaxies ◽  
Galactic Model ◽  
Gaia Dr2

Context. Deep GALEX UV data show that the extreme outskirts of some spiral galaxies are teeming with star formation. Such young stellar populations evolving so far away from the bulk of their host galaxies challenge our overall understanding of how star formation proceeds at galactic scales. It is at present unclear whether our own Milky Way may also exhibit ongoing and recent star formation beyond the conventional edge of the disk (∼15 kpc). Aims. Using Gaia DR2 data, we aim to determine if such a population is present in the Galactic halo, beyond the nominal radius of the Milky Way disk. Methods. We studied the kinematics of Gaia DR2 sources with parallax values between 1/60 and 1/30 milliarcseconds towards two regions that show abnormally high values of extinction and reddening; the results are compared with predictions from GALAXIA Galactic model. We also plotted the color–magnitude (CM) diagrams with heliocentric distances computed inverting the parallaxes, and studied the effects of the large parallax errors by Monte Carlo sampling. Results. The kinematics point towards a Galactic origin for one of the regions, while the provenance of the stars in the other is not clear. A spectroscopic analysis of some of the sources in the first region confirms that they are located in the halo. The CM diagram of the sources suggests that some of them are young.

scholarly journals Abundance gradients from Planetary Nebulae in the galactic disk

1997 ◽  
Vol 180 ◽  
pp. 397-404 ◽  
Author(s):  
W.J. Maciel
Keyword(s):  
Chemical Evolution ◽  
Spiral Galaxies ◽  
Galactic Disk ◽  
Chemical Elements ◽  
Planetary Nebulae ◽  
Hii Regions ◽  
Additional Constraint ◽  
Established Fact ◽  
Metallicity Distribution

Radial abundance gradients in the disks of spiral galaxies are made evident from observations of ionized nebulae (HII regions, planetary nebulae, and SNRs) and stars. They have been observed for several chemical elements, and their presence is an established fact, despite some inconsistencies in the results. Therefore, these gradients can be considered as an additional constraint to the chemical evolution models, as the age-metallicity relation or the metallicity distribution of the G-dwarfs.

Sign in / Sign up

Export Citation Format

Share Document