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| Paper: |
Identification of Artifacts and Interesting Celestial Objects in the LAMOST Spectral Survey |
| Volume: |
521, Astronomical Data Analysis Software and Systems XXVI |
| Page: |
402 |
| Authors: |
Škoda, P.; Shakurova, K.; Koza, J.; Palička, A. |
| Abstract: |
The LAMOST DR1 survey contains about two million spectra labelled by its
pipeline as stellar objects of common spectral classes. There are, however, a
lot of spectra corrupted in some way by both instrumental and processing
artifacts, which may mimic spectral properties of interesting celestial
objects, namely emission lines of Be stars and quasars.
We have tested several clustering methods as well as outlier
analysis on a sample of one hundred thousand spectra using Spark scripts
running on a Hadoop cluster consisting of twenty-four sixteen-core nodes. This
experiment was motivated by an attempt to find rare objects with interesting
spectra as outliers most dissimilar from all common spectra.
The result of this time-consuming procedure is a list of several
hundred candidates where different artifacts are prominent, but also tens of
very interesting emission-line spectra requiring further detailed examination.
Many of them may be quasars or even blazars as well as yet unknown Be-stars.
It deserves mentioning that most of the work benefitted considerably from
technologies of the Virtual Observatory. |
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