A 3D Automated Classification Scheme for the TAUVEX data pipeline

TL;DR

This paper presents an artificial neural network-based automated classification scheme for stars observed by the TAUVEX ultraviolet space telescope, capable of classifying spectral types and estimating interstellar reddening using synthetic and real UV spectra.

Contribution

It introduces a novel ANN-based method for star classification and reddening estimation tailored for the TAUVEX UV data pipeline, validated with synthetic and real spectra.

Findings

Successfully classified 229 stars within 3-4 spectral subclasses.

Achieved reddening estimates with better than 0.1 magnitude accuracy.

Demonstrated applicability of ANN technique for UV data validation and extinction mapping.

Abstract

In order to develop a pipeline for automated classification of stars to be observed by the TAUVEX ultraviolet space Telescope, we employ an artificial neural network (ANN) technique for classifying stars by using synthetic spectra in the UV region from 1250\AA to 3220\AA as the training set and International Ultraviolet Explorer (IUE) low resolution spectra as the test set. Both the data sets have been pre-processed to mimic the observations of the TAUVEX ultraviolet imager. We have successfully classified 229 stars from the IUE low resolution catalog to within 3-4 spectral sub-class using two different simulated training spectra, the TAUVEX spectra of 286 spectral types and UVBLUE spectra of 277 spectral types. Further, we have also been able to obtain the colour excess (i.e. E(B-V) in magnitude units) or the interstellar reddening for those IUE spectra which have known reddening to an accuracy of better than 0.1 magnitudes. It has been shown that even with the limitation of data from just photometric bands, ANNs have not only classified the stars, but also provided satisfactory estimates for interstellar extinction. The ANN based classification scheme has been successfully tested on the simulated TAUVEX data pipeline. It is expected that the same technique can be employed for data validation in the ultraviolet from the virtual observatories. Finally, the interstellar extinction estimated by applying the ANNs on the TAUVEX data base would provide an extensive extinction map for our galaxy and which could in turn be modeled for the dust distribution in the galaxy.