Exploring Scalability in Pattern Finding in Galactic Structure Using MapReduce

2016 ◽  
Author(s):  
Anca Vulpe ◽  
Marc Frincu
Keyword(s):  
Galactic Structure ◽  
Pattern Finding

Calibration problems in hydrogen luminosities

1966 ◽  
Vol 24 ◽  
pp. 322-330
Author(s):  
A. Beer
Keyword(s):  
Galactic Structure ◽  
B Stars ◽  
Insight Into

The investigations which I should like to summarize in this paper concern recent photo-electric luminosity determinations of O and B stars. Their final aim has been the derivation of new stellar distances, and some insight into certain patterns of galactic structure.

scholarly journals Relaxation Times in Strictly Disk Systems

1971 ◽  
Vol 10 ◽  
pp. 15-19
Author(s):  
George B. Rybicki
Keyword(s):  
Numerical Experiments ◽  
Relaxation Times ◽  
Galactic Structure ◽  
Large Numbers ◽  
Order Of Magnitude ◽  
Vlasov Limit ◽  
The Mean ◽  
Gravitating Systems

AbstractIt is shown that the time of relaxation by particle encounters of self-gravitating systems in the plane interacting by 1/r2 forces is of the same order of magnitude as the mean orbit time. Therefore such a system does not have a Vlasov limit for large numbers of particles, unless appeal is made to some non-zero thickness of the disk. The relevance of this result to numerical experiments on galactic structure is discussed.

scholarly journals Towards an Improved Model of the Galaxy

1998 ◽  
Vol 11 (1) ◽  
pp. 570-570
Author(s):  
Johan Holmberg ◽  
Lennart Lindegren ◽  
Chris Flynn
Keyword(s):  
Three Dimensional ◽  
Direct Determination ◽  
Galactic Structure ◽  
Open Clusters ◽  
Selection Effects ◽  
Observational Errors ◽  
Red Giant ◽  
Improved Model ◽  
First Time ◽  
Hr Diagram

We use the Hipparcos survey to derive an improved model of the local galactic structure. The availability of parallaxes for all the stars permits direct determination of stellar distributions, eliminating the basic indeterminacy of classical methods based on star counts. Hipparcos gives for the first time a truly three-dimensional view of the solar vicinity, and a complete, homogeneous and highly accurate set of magnitudes and colours. This means that new techniques can be applied in the treatment of the data which place strong constraints on a model that tries to describe the local Galactic structure. Here we investigate how well a static model of low complexitycan describe the Hipparcos observations. The interpretation of the Hipparcos data is complicated by various observational errors and selection effects that are hard to treat correctly. We do not try to correct the data, but instead use a model and subject this model to the same observational errors and selection effects. A model catalogue is created that can be compared with the observed catalogue directly in the observational domain, thereby eliminating the effects from various biases. Many features in the HR diagram are for the first time seen in field stars thanks to Hipparcos, such as the slanted red giant clump, previously seen in rich old open clusters such as Berkeley 18. This and other features ofthe observed HR diagram are well reproduced by the model thanks to the rather detailed modelling of the joint Mv/B — V distribution. Actually, separate distributions were derived for the three different components, disk, thick disk and halo, using the kinematic characteristics of the components to discriminate between them.

scholarly journals Galactic structure from the Calar Alto Deep Imaging Survey (CADIS)

2005 ◽  
Vol 443 (3) ◽  
pp. 929-943 ◽  
Author(s):  
S. Phleps ◽  
S. Drepper ◽  
K. Meisenheimer ◽  
B. Fuchs
Keyword(s):  
Galactic Structure ◽  
Deep Imaging ◽  
Calar Alto

scholarly journals A new dynamical model for the study of galactic structure

New Astronomy ◽  
2011 ◽  
Vol 16 (6) ◽  
pp. 391-401 ◽  
Author(s):  
Euaggelos E. Zotos
Keyword(s):  
Galactic Structure ◽  
Dynamical Model

scholarly journals Extinction in the Star Cluster SAI 113 and Galactic Structure in Carina

2017 ◽  
Vol 153 (4) ◽  
pp. 156 ◽  
Author(s):  
Giovanni Carraro ◽  
David G. Turner ◽  
Daniel J. Majaess ◽  
Gustavo L. Baume ◽  
Roberto Gamen ◽  
...  
Keyword(s):  
Galactic Structure ◽  
Star Cluster
Sign in / Sign up

Export Citation Format

Share Document