Determination of the relative inclination and the viewing angle of an
interacting pair of galaxies using convolutional neural networks
- URL: http://arxiv.org/abs/2002.01238v2
- Date: Thu, 30 Jul 2020 06:42:42 GMT
- Title: Determination of the relative inclination and the viewing angle of an
interacting pair of galaxies using convolutional neural networks
- Authors: Prem Prakash, Arunima Banerjee, Pavan Kumar Perepu
- Abstract summary: We construct Deep Convolutional Neural Network (DCNN) models to determine the relative inclination ($i$) and the viewing angle ($theta$) of interacting galaxy pairs.
For a classification based on both $i$ and $theta$ values, we develop a DCNN model for a 9-class classification ($(i,theta) sim (0circ,15circ),(0circ,45circ), (0circ,90circ), (45circ, 45circ), (90circ,
- Score: 0.0
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: Constructing dynamical models for interacting pair of galaxies as constrained
by their observed structure and kinematics crucially depends on the correct
choice of the values of the relative inclination ($i$) between their galactic
planes as well as the viewing angle ($\theta$), the angle between the line of
sight and the normal to the plane of their orbital motion. We construct Deep
Convolutional Neural Network (DCNN) models to determine the relative
inclination ($i$) and the viewing angle ($\theta$) of interacting galaxy pairs,
using N-body $+$ Smoothed Particle Hydrodynamics (SPH) simulation data from the
GALMER database for training the same. In order to classify galaxy pairs based
on their $i$ values only, we first construct DCNN models for a (a) 2-class (
$i$ = 0 $^{\circ}$, 45$^{\circ}$ ) and (b) 3-class ($i = 0^{\circ}, 45^{\circ}
\text{ and } 90^{\circ}$) classification, obtaining $F_1$ scores of 99% and 98%
respectively. Further, for a classification based on both $i$ and $\theta$
values, we develop a DCNN model for a 9-class classification ($(i,\theta) \sim
(0^{\circ},15^{\circ}) ,(0^{\circ},45^{\circ}), (0^{\circ},90^{\circ}),
(45^{\circ},15^{\circ}), (45^{\circ}, 45^{\circ}), (45^{\circ}, 90^{\circ}),
(90^{\circ}, 15^{\circ}), (90^{\circ}, 45^{\circ}), (90^{\circ},90^{\circ})$),
and the $F_1$ score was 97$\%$. Finally, we tested our 2-class model on real
data of interacting galaxy pairs from the Sloan Digital Sky Survey (SDSS) DR15,
and achieve an $F_1$ score of 78%. Our DCNN models could be further extended to
determine additional parameters needed to model dynamics of interacting galaxy
pairs, which is currently accomplished by trial and error method.
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