scholarly journals Inferring the three-dimensional distribution of dust in the Galaxy with a non-parametric method

2017 ◽  
Vol 598 ◽  
pp. A125 ◽  
Author(s):  
S. Rezaei Kh. ◽  
C. A. L. Bailer-Jones ◽  
R. J. Hanson ◽  
M. Fouesneau
2013 ◽  
Vol 9 (S298) ◽  
pp. 213-220
Author(s):  
Jayant Murthy

AbstractA knowledge of the three dimensional distribution of interstellar dust is critical in interpreting all observations of the sky, particularly in the understanding of the structure and morphology of our Galaxy. It has been much easier to map the integrated dust extinction through the Galaxy, which is needed in modeling extragalactic sources, but this yields an overestimate of reddening to Galactic objects. Massive surveys, such as Gaia, present both a problem in that the distribution of interstellar dust must be known in order to model the internal structure of the Galaxy and an opportunity in that multi-color data may be used to deconvolve the dust distribution. I will present the current state of the modeling, which is yet in its early stages.


1996 ◽  
Vol 168 ◽  
pp. 473-475
Author(s):  
I.B. Vavilova

The well- grounded polemics about the fractal structure of the Universe and a new cosmological picture which appears in connection with this, in first instance the absence of any evidence for homogenization up to present observational limits 200h−1Mpc, have been detailed at the work by Coleman, Pietronero (1992). Two versions on nature of fractal pattern of the galaxy distribution in the observed universe also are now: it behaves like a simple homogeneous fractal (Pietronero 1987; Coleman et al. 1988) and as a multifractal - fractal having more than one scaling index (Jones et al. 1988; Martinez, Jones 1990; Martinez et al. 1990; Borgani et al. 1993 (with the good review for matter of above)).This work does not play decisively into hands of these versions so the fractal concepts, exactly a selfsimilarity and multifractal, were applied here for the analysis oftwo - dimensionaldistribution of thebrightgalaxies and dwarf galaxies of the low surface brightness (LSBD) belonging to the Local Supercluster (LS). But if the observed universe holds the fractal structure, so it is useful to trace over the lower fractal pattern on the small scales of clustering of galaxies within the framework of the known superclusters and, in the first instance, within the local overdensity of galaxies. This work is a preliminary before preparing one with the same analysis of three- dimensional distribution of galaxies of LS.


1978 ◽  
Vol 77 ◽  
pp. 175-181
Author(s):  
Robert N. Whitehurst ◽  
Morton S. Roberts ◽  
Thomas R. Cram

Given the wealth of data, the rotation curve, and the necessity for out-of-plane hydrogen demonstrated in the preceding paper, it seems desirable to attempt to establish a systematic procedure for determining the three-dimensional distribution of hydrogen. Under the assumption of cylindrical rotation this is, in principle, possible for most of the galaxy.


1991 ◽  
Vol 9 (1) ◽  
pp. 49-51
Author(s):  
R. J. Dodd ◽  
H. T. MacGillivray

AbstractObservations of the large-scale organisation of matter in the Universe are of great importance in present day astronomy. In the visible part of the spectrum such observations are mainly of the distribution of galaxies on the plane of the sky.Direct and objective prism plates obtained using large Schmidt telescopes form the bulk of the material used. The direct plates provide the observations from which the surface distribution of galaxies may be determined and the prism plates and FLAIR, via redshifts, yield extragalactic distances and hence the three dimensional distribution of galaxies.For large-scale surveys the measuring machines used need to be multi-purpose and fast such as COSMOS and SUPER-COSMOS at the Royal Observatory Edinburgh. More specific programs can make use of smaller, slower machines such as iris photometers and microdensitometers.The method of analysing the data produced rely on seeking density enhancements in the general field of galaxies for cluster detection or using correlation techniques for analysis of the galaxy distribution.A description is given of a southern sky catalogue containing 109 objects recently completed and an outline of some of the extragalactic projects underway using this large body of data.


PLoS ONE ◽  
2018 ◽  
Vol 13 (11) ◽  
pp. e0207710 ◽  
Author(s):  
Ahmed Abass ◽  
Bernardo T. Lopes ◽  
Ashkan Eliasy ◽  
Richard Wu ◽  
Steve Jones ◽  
...  

Author(s):  
Tomoko Ehara ◽  
Shuji Sumida ◽  
Tetsuaki Osafune ◽  
Eiji Hase

As shown previously, Euglena cells grown in Hutner’s medium in the dark without agitation accumulate wax as well as paramylum, and contain proplastids showing no internal structure except for a single prothylakoid existing close to the envelope. When the cells are transferred to an inorganic medium containing ammonium salt and the cell suspension is aerated in the dark, the wax was oxidatively metabolized, providing carbon materials and energy 23 for some dark processes of plastid development. Under these conditions, pyrenoid-like structures (called “pro-pyrenoids”) are formed at the sites adjacent to the prolamel larbodies (PLB) localized in the peripheral region of the proplastid. The single prothylakoid becomes paired with a newly formed prothylakoid, and a part of the paired prothylakoids is extended, with foldings, in to the “propyrenoid”. In this study, we observed a concentration of RuBisCO in the “propyrenoid” of Euglena gracilis strain Z using immunoelectron microscopy.


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