scholarly journals Calculation and comparison of certain physical properties of sample irregular galaxies with the Milky Way galaxy

2021 ◽  
Vol 7 (4) ◽  
Author(s):  
Hasanain Hassan AL-Dahlaki
Keyword(s):  
Physical Properties ◽  
Milky Way ◽  
Milky Way Galaxy ◽  
Irregular Galaxies

scholarly journals The Galaxy and its stellar halo - insights from a hybrid cosmological approach

2008 ◽  
Vol 4 (S254) ◽  
pp. 423-428
Author(s):  
Gabriella De Lucia ◽  
Amina Helmi
Keyword(s):  
High Resolution ◽  
Physical Properties ◽  
Milky Way ◽  
Dynamical Friction ◽  
Milky Way Galaxy ◽  
The Galaxy ◽  
Stellar Halo ◽  
Good Agreement ◽  
Milky Way Halo

AbstractWe use a series of high-resolution N-body simulations of a ‘Milky-Way’ halo, coupled to semi-analytic techniques, to study the formation of our own Galaxy and of its stellar halo. Our model Milky Way galaxy is a relatively young system whose physical properties are in quite good agreement with observational determinations. In our model, the stellar halo is mainly formed from a few massive satellites accreted early on during the galaxy's lifetime. The stars in the halo do not exhibit any metallicity gradient, but higher metallicity stars are more centrally concentrated than stars with lower abundances. This is due to the fact that the most massive satellites contributing to the stellar halo are also more metal rich, and dynamical friction drags them closer to the inner regions of the host halo.

The Long View of Planetary Systems

2018 ◽  
Author(s):  
Karel Schrijver
Keyword(s):  
Solar System ◽  
Milky Way ◽  
Planetary Systems ◽  
Giant Planets ◽  
Milky Way Galaxy ◽  
Population Statistics ◽  
The Past ◽  
General Terms ◽  
The Galaxy ◽  
The Universe

How many planetary systems formed before our’s did, and how many will form after? How old is the average exoplanet in the Galaxy? When did the earliest planets start forming? How different are the ages of terrestrial and giant planets? And, ultimately, what will the fate be of our Solar System, of the Milky Way Galaxy, and of the Universe around us? We cannot know the fate of individual exoplanets with great certainty, but based on population statistics this chapter sketches the past, present, and future of exoworlds and of our Earth in general terms.

scholarly journals A Statistical Estimation of the Occurrence of Extraterrestrial Intelligence in the Milky Way Galaxy

Galaxies ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 5
Author(s):  
Xiang Cai ◽  
Jonathan H. Jiang ◽  
Kristen A. Fahy ◽  
Yuk L. Yung
Keyword(s):  
Statistical Estimation ◽  
Milky Way ◽  
Galactic Center ◽  
Model Simulation ◽  
Temporal Variations ◽  
Extraterrestrial Intelligence ◽  
Milky Way Galaxy ◽  
The Galaxy ◽  
Peak Location ◽  
Intelligent Life

In the field of astrobiology, the precise location, prevalence, and age of potential extraterrestrial intelligence (ETI) have not been explicitly explored. Here, we address these inquiries using an empirical galactic simulation model to analyze the spatial–temporal variations and the prevalence of potential ETI within the Galaxy. This model estimates the occurrence of ETI, providing guidance on where to look for intelligent life in the Search for ETI (SETI) with a set of criteria, including well-established astrophysical properties of the Milky Way. Further, typically overlooked factors such as the process of abiogenesis, different evolutionary timescales, and potential self-annihilation are incorporated to explore the growth propensity of ETI. We examine three major parameters: (1) the likelihood rate of abiogenesis (λA); (2) evolutionary timescales (Tevo); and (3) probability of self-annihilation of complex life (Pann). We found Pann to be the most influential parameter determining the quantity and age of galactic intelligent life. Our model simulation also identified a peak location for ETI at an annular region approximately 4 kpc from the galactic center around 8 billion years (Gyrs), with complex life decreasing temporally and spatially from the peak point, asserting a high likelihood of intelligent life in the galactic inner disk. The simulated age distributions also suggest that most of the intelligent life in our galaxy are young, thus making observation or detection difficult.

Milky Way galaxy is fluttering like a flag

2013 ◽  
Vol 220 (2941) ◽  
pp. 18
Author(s):  
Michael Slezak
Keyword(s):  
Milky Way ◽  
Milky Way Galaxy

Computer Information Library Clusters

2019 ◽  
pp. 142-147
Author(s):  
Fu Yuhua
Keyword(s):  
Solar System ◽  
Social Science ◽  
Natural Science ◽  
Milky Way ◽  
Variation Principle ◽  
Unified Theory ◽  
Milky Way Galaxy ◽  
System Information ◽  
Set Up

Based on creating generalized and hybrid set and library with neutrosophy and quad-stage method, this chapter presents the concept of computer information library clusters (CILC). There are various ways and means to form CILC. For example, CILC can be considered as the “total-library” and consists of several “sub-libraries.” As another example, in CILC, a total-library can be set up, and a number of sub-libraries are side by side with the total-library. Specially, for CILC, the operation functions can be added; for example, according to natural science computer information library clusters (natural science CILC), and applying variation principle of library (or sub-library), partial and temporary unified theory of natural science so far with different degrees can be established. Referring to the concept of natural science CILC, the concepts of social science CILC, natural science and social science CILC, and the like can be presented. While referring to the concept of computer information library clusters, the concepts of computer and non-computer information library clusters, earth information library clusters, solar system information library clusters, Milky Way galaxy information library clusters, universe information library clusters, and the like can be presented.

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