scholarly journals Spatial orientation of galaxies in supercluster S[227+006+0078]

BIBECHANA ◽  
2020 ◽  
Vol 17 ◽  
pp. 117-122
Author(s):  
Janak Ratna Malla ◽  
Walter Saurer ◽  
Binil Aryal
Keyword(s):  
Galaxy Formation ◽  
Spatial Orientation ◽  
Three Dimensional ◽  
Position Angle ◽  
Sloan Digital Sky Survey ◽  
Spin Vector ◽  
Sky Survey ◽  
Hierarchy Model ◽  
Vector Orientation ◽  
Angle Method

We present a study of spin vector orientation of 1218 SDSS (Sloan Digital Sky Survey) galaxies in Supercluster S [227+006+0078] having redshift 0.07 to 0.09. The database of these galaxies is taken from SDSS (Sloan Digital Sky Survey) 7th and 9th data release. We have converted two dimensional data to three dimensional by Godlowskian Transformation using position angle-inclination angle method. We intend to find non-random effects in the spatial orientation of galaxies in the Supercluster.  No preferred alignment of angular momentum vectors is noticed, supporting Hierarchy model of galaxy formation. BIBECHANA 17 (2020) 117-122

scholarly journals Spatial Orientation of Galaxies in Supercluster S[195+027+0022]

2019 ◽  
Vol 5 (1) ◽  
pp. 14-18
Author(s):  
J. R. Malla ◽  
B. Aryal ◽  
W. Saurer
Keyword(s):  
Galaxy Formation ◽  
Spatial Orientation ◽  
Three Dimensional ◽  
Position Angle ◽  
Sloan Digital Sky Survey ◽  
Spin Vector ◽  
Sky Survey ◽  
Hierarchy Model ◽  
Vector Orientation ◽  
Angle Method

We present a study of spin vector orientation of 1198 SDSS (Sloan Digital Sky Survey) galaxies in Super cluster S[195+027+0022] having red shift 0.07 to 0.09. The databases of these galaxies are taken from SDSS (Sloan Digital Sky Survey) 7th and 9th data release. We have converted two dimensional data to three-dimensional by Godlowskian Transformation using position angle-inclination angle method. We intend to find non-random effects in the spatial orientation of galaxies in Super cluster. No preferred alignment of angular momentum vectors (spin vector) is noticed, supporting Hierarchy model of galaxy formation.

scholarly journals Preferred Alignments of Angular Momentum Vectors of Galaxies in the SDSS Supercluster S[202-001+0084]

NUTA Journal ◽  
2019 ◽  
Vol 6 (1-2) ◽  
pp. 12-17
Author(s):  
Janak Ratna Malla ◽  
Binil Aryal ◽  
Walter Saurer
Keyword(s):  
Angular Momentum ◽  
Galaxy Formation ◽  
Particle Physics ◽  
Statistical Tests ◽  
Three Dimensional ◽  
Sloan Digital Sky Survey ◽  
Sky Survey ◽  
Hierarchy Model ◽  
Vector Orientation ◽  
Almost All

We present a study of spin vector orientation of 1331 SDSS (Sloan Digital Sky Survey) galaxies in SDSS Supercluster S[202-001+0084] having redshift 0.02 to 0.03. The data are provided by our collaborator, Institute of Astro-particle Physics, Innsbruck University, Austria. We have converted two dimensional data to three dimensional by Godlowskian Transformation. Our aim is to find out non-random effects in the preferred alignments of angular momentum vectors of galaxies. In general, no preferred alignments angular momentum vectors of galaxies are noticed, supporting Hierarchy model of galaxy formation. In almost all sub samples the 1st order Fourier coefficient suggests that the angular momentum vectors are randomly oriented but other statistical tests suggest anisotropic distribution probably due to the binning effect and gravitational shearing effect.

scholarly journals A Study of R-Magnitude Dependence in Spatial Orientation of Spin Vectors of SDSS DR-7 Galaxies of Redshift 0.10 < Z < 0.11

2020 ◽  
Vol 13 (13) ◽  
pp. 42-45
Author(s):  
Shiv Narayan Yadav
Keyword(s):  
Galaxy Formation ◽  
Spatial Orientation ◽  
Three Dimensional ◽  
Simulation Method ◽  
Sloan Digital Sky Survey ◽  
Spin Vector ◽  
Local Anisotropy ◽  
Charge Coupled Device ◽  
Rotation Axes ◽  
Sky Survey

We present a study of spin vector orientations of 44749 r-magnitude SDSS (Sloan Digital Sky Survey) galaxies having redshift 0.10 to 0.11. The r -magnitudes are observed through 616.5 nm CCD (charge coupled device) filter attached to SDSS telescope located at New Mexico, USA. We have converted two dimensional data to three dimensional galaxy rotation axes. Our aim is to find out non-random effects in the spatial orientation of galaxies. In addition, we wanted to check r-magnitude dependence in the spatial orientation. The expected isotropy distribution curves are obtained by removing the selection effects and performing a random simulation method. In general, spin vector orientations of galaxies is found to be random, supporting Hierarchy model of galaxy formation. A local anisotropy is observed in few samples suggesting a gravitational tidal interaction between neighbor galaxies.

scholarly journals A Study of r- and u-Magnitude Dependence in the Spatial Orientation of Spin Vectors of SDSS Galaxies having redshift 0.10 < z < 0.11

2015 ◽  
Vol 5 ◽  
pp. 1-11
Author(s):  
Shiv Narayan Yadav ◽  
Binil Aryal
Keyword(s):  
Galaxy Formation ◽  
Spatial Orientation ◽  
Three Dimensional ◽  
Simulation Method ◽  
Sloan Digital Sky Survey ◽  
Angular Momentum Vector ◽  
Spin Vector ◽  
Local Anisotropy ◽  
Rotation Axes ◽  
Merging Process

We present a study of spin vector orientations of 44749 r and u-magnitude SDSS (Sloan Digital Sky Survey) galaxies having redshift 0.10 to 0.11. The r and u-magnitudes are observed through 616.5 nm and 354.3 nm CCD (charge coupled device) filter attached to SDSS telescope located at New Mexico, USA. We have converted two dimensional data to three dimensional galaxy rotation axes. Our aim is to find out non-random effects in the spatial orientation of galaxies. In addition, we wanted to check r and u-magnitude dependence in the spatial orientation. The expected isotropy distribution curves are obtained by removing the selection effects and performing a random simulation method. In general, spin vector orientations of galaxies is found to be random, supporting Hierarchy model of galaxy formation. A local anisotropy is observed in few samples suggesting a gravitational tidal interaction between neighbor galaxies, a merging process in which the angular momentum vector distort the original alignment of evolution of rotational supported system to the randomized system.The Himalayan Physics Year 5, Vol. 5, Kartik 2071 (Nov 2014)Page: 1-11

scholarly journals Spatial Orientations of Angular Momentum Vectors of Galaxies in Supercluster S [195+027+0022] and Substructure

2021 ◽  
Vol 7 (2) ◽  
pp. 81-88
Author(s):  
J. R. Malla ◽  
W. Saurer ◽  
B. Aryal
Keyword(s):  
Galaxy Evolution ◽  
Azimuthal Angle ◽  
Three Dimensional ◽  
Simulation Method ◽  
Position Angle ◽  
Sloan Digital Sky Survey ◽  
Chi Square ◽  
Rotation Axes ◽  
Sky Survey ◽  
The Galaxy

This paper presents an analysis of the spin vector orientations of SDSS (Sloan Digital Sky Survey) galaxies in the Supercluster S [195+027+0022] using the seventh data release (2008 October). By using the spectroscopic database of galaxies, identified number density map in the region of Superclusters. Several density enhancements are observed, suggesting the possibility of substructure in the Supercluster. Two-dimensional observed parameters that we received from the database are used to compute three-dimensional galaxy rotation axes by applying `position angle-inclination' method. Apply the selection effects by performing the random simulation method. The expected distribution curves are obtained from the simulation. Chi-square, auto-correlation, and Fourier tests are used to examine non-random effects in the polar and azimuthal angle distributions of the galaxy rotation axes. To check these results with the different galaxy evolution models namely Hierarchy, Primordial, and Pancake model. The result supports the Hierarchy model.

scholarly journals Spatial orientations of angular momentum vectors of galaxies in Supercluster S [173+014+0082]

BIBECHANA ◽  
2021 ◽  
Vol 18 (1) ◽  
pp. 26-32
Author(s):  
Janak Ratna Malla ◽  
Walter Saurer ◽  
B Aryal
Keyword(s):  
Angular Momentum ◽  
Galaxy Formation ◽  
Three Dimensional ◽  
Position Angle ◽  
Sloan Digital Sky Survey ◽  
Chi Square ◽  
Isotropic Distribution ◽  
The Galaxy ◽  
Inclination Angles ◽  
Chi Square Test

The spin vector orientation of 1302 SDSS (Sloan Digital Sky Survey) galaxies in Supercluster S[173+014+0082] having redshift 0.076 to 0.091 has been analysed. The positions, position angles and inclination angles of galaxies are used to convert two-dimensional observed parameters into three-dimensional angular momentum vectors of the galaxy using the `position angle-inclination' method. The expected isotropic distribution curves are determined performing numerical simulation by generating 107 virtual galaxies. The observed distribution is compared with the expected isotropic distribution curves using three statistical tools namely Chi-square test, auto-correlation test and Fourier test. Redshift map is studied and found that the distributions fit with the Gaussian. No preferred alignment of angular momentum vectors is noticed, supporting Hierarchy model of galaxy formation. BIBECHANA 18 (2021) 26-32  

scholarly journals A Study of z-Magnitude Dependence in the Spatial Orientation of Angular Momentum Vectors of Galaxies having Redshift < 30,000 km s-1

2016 ◽  
Vol 30 (2) ◽  
pp. 195-210
Author(s):  
Shiv Narayan Yadav
Keyword(s):  
Galaxy Formation ◽  
Gravitational Lensing ◽  
Spatial Orientation ◽  
Azimuthal Angle ◽  
Three Dimensional ◽  
Polar Angle ◽  
Simulation Method ◽  
Sloan Digital Sky Survey ◽  
Angle Distribution ◽  
Local Anisotropy

I present a study of spin vector orientations of 229,675 z-magnitude SDSS (Sloan Digital Sky Survey) galaxies having red shift of 0.05 to 0.10. The z-magnitudes are observed through 913.3 nm CCD (charge coupled device) filter attached to SDSS telescope located at New Mexico, USA. We have converted two dimensional data to three-dimensional by Godlowskian Transformation. Our aim is to find out non-random effects in the spatial orientation of galaxies. The expected isotropy distribution curves are obtained by removing the selection effects and performing a random simulation method. In general, spinvector orientations of galaxies are found to be random, supporting Hierarchy model of galaxy formation. In some samples (z12 and z13) of polar angle distribution is observed anisotropy supporting Primordial Vorticity Theory. For azimuthal angle distribution in more sample we observed anisotropy result. A local anisotropy is observed in few samples suggesting a gravitational tidal interaction, merging process and gravitational lensing effect.

scholarly journals A New Catalog of Isolated Galaxies

2009 ◽  
Vol 5 (S267) ◽  
pp. 464-464
Author(s):  
J. A. Vázquez-Mata ◽  
H. M. Hernández-Toledo ◽  
Changbom Park ◽  
Yun-Young Choi
Keyword(s):  
Galaxy Formation ◽  
Environmental Effects ◽  
Comparative Studies ◽  
Sloan Digital Sky Survey ◽  
Selection Algorithm ◽  
Isolated Galaxies ◽  
Galaxy Formation And Evolution ◽  
Sky Survey ◽  
Data Release ◽  
Formation And Evolution

We present a new catalog of isolated galaxies (coined as UNAM–KIAS) obtained through an automated systematic search. The 1520 isolated galaxies were found in ~ 1.4 steradians of the sky in the Sloan Digital Sky Survey Data Release 5 (SDSS DR5) photometry. The selection algorithm was implemented from a variation of the criteria developed by Karachentseva (1973), with full redshift information. This new catalog is aimed to carry out comparative studies of environmental effects and constraining the currently competing scenarios of galaxy formation and evolution.

scholarly journals Surface Photometry of Spiral Galaxy NGC 5005 and Elliptical Galaxy NGC 4278

2018 ◽  
Vol 15 (3) ◽  
pp. 314-323
Author(s):  
Baghdad Science Journal
Keyword(s):  
Spiral Galaxy ◽  
Surface Brightness ◽  
Elliptical Galaxy ◽  
Position Angle ◽  
Sloan Digital Sky Survey ◽  
Surface Photometry ◽  
Contour Maps ◽  
Sky Survey ◽  
Flat Field ◽  
The Galaxy

Two galaxies have been chosen, spiral galaxy NGC 5005 and elliptical galaxy NGC 4278 to study their photometric properties by using surface photometric techniques with griz-Filters. Observations are obtained from the Sloan Digital Sky Survey (SDSS). The data reduction of all images have done, like bias and flat field, by SDSS pipeline. The overall structure of the two galaxies (a bulge, a disk), together with isophotal contour maps, surface brightness profiles and a bulge/disk decomposition of the galaxy images were performed, although the disk position angle, ellipticity and inclination of the galaxies have been estimated.

scholarly journals GALAXY CLUSTERING TOPOLOGY IN THE SLOAN DIGITAL SKY SURVEY MAIN GALAXY SAMPLE: A TEST FOR GALAXY FORMATION MODELS

2010 ◽  
Vol 190 (1) ◽  
pp. 181-202 ◽  
Author(s):  
Yun-Young Choi ◽  
Changbom Park ◽  
Juhan Kim ◽  
J. Richard Gott ◽  
David H. Weinberg ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
Sloan Digital Sky Survey ◽  
Galaxy Clustering ◽  
Main Galaxy ◽  
Sky Survey ◽  
Galaxy Sample
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