59 citations · 128 across the 8 of their papers we have counts for
8 papers
A principal component analysis approach to the morphology of Planetary Nebulae
Stavros Akras, Panayotis Boumis
Principal Component Analysis (PCA) is a well-known technique used to decorrelate a set of vectors. It has been applied to explore the star formation history of galaxies or to deter…
Boxy/peanut "bulges": comparing the structure of galaxies with the underlying families of periodic orbits
P. A. Patsis, E. M. Xilouris
The vertical profiles of disc galaxies are built by the material trapped around stable periodic orbits, which form their "skeletons". According to this, the knowledge of the stabil…
The creation of the Helix planetary nebula (NGC 7293) by multiple events
J. Meaburn, P. Boumis, J. A. Lopez +4
A deep, continuum-subtracted, image of NGC 7293 has been obtained in the light of the Halpha+[N II] emission lines. New images of two filamentary halo stuctures have been obtained…
The global kinematics of the Dumbbell planetary nebula (NGC 6853, M27, PN G060.8-03.6)
J. Meaburn, P. Boumis, P. E. Christopoulou +3
Spatially resolved profiles of the HeII 6560 A, Halpha and [N II] 6548 & 6584 A nebular emission lines have been obtained in two orthogonal long cuts over the Dumbbell planetary ne…
Multi-band optical micro-variability observations of the BL Lac object S4 0954+658
I. E. Papadakis, V. Samaritakis, P. Boumis +1
We have observed S4 0954+658 in the BVRI bands in 2001, and in the BI bands in 2002. The observations resulted in almost evenly sampled light curves, 3-8 hours long, with an averag…
The Cluster M/L and the Value of Omega_m
H. Andernach, M. Plionis, O. L'opez-Cruz +2
From an up-to-date compilation of ACO cluster redshifts and velocity dispersions we extract a homogeneous sample of 459 clusters with robust velocity dispersion. Using the virial t…