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arXiv · 2209.13221

Emission line star catalogues post-Gaia DR3: A validation of Gaia DR3 data using LAMOST OBA emission catalogue

B. Shridharan·Blesson Mathew·Suman Bhattacharyya·T. Robin·R. Arun·Sreeja S Kartha·P. Manoj·S. Nidhi·G. Maheshwar·K. T. Paul·Mayank Narang·T. Himanshu
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Abstract

Gaia DR3 and further releases have the potential to identify and categorise new emission-line stars in the Galaxy. We perform a comprehensive validation of astrophysical parameters from Gaia DR3 with the spectroscopically estimated emission-line star parameters from LAMOST OBA emission catalogue. We compare different astrophysical parameters provided by Gaia DR3 with those estimated using LAMOST spectra. By using a larger sample of emission-line stars, we perform a global polynomial and piece-wise linear fit to update the empirical relation to convert Gaia DR3 pseudo-equivalent width to observed equivalent width, after removing the weak emitters from the analysis. We find that the emission-line source classifications given by DR3 is in reasonable agreement with the classification from LAMOST OBA emission catalogue. The astrophysical parameters estimated by esphs module from Gaia DR3 provides a better estimate when compared to gspphot and gspspec. A second-degree polynomial relation is provided along with piece-wise linear fit parameters for the equivalent width conversion. We notice that the LAMOST stars with weak Hα emission are not identified to be in emission from BP/RP spectra. This suggests that emission-line sources identified by Gaia DR3 is incomplete. In addition, Gaia DR3 provides valuable information about the binary and variable nature of a sample of emission-line stars.

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B. Shridharan, Blesson Mathew, Suman Bhattacharyya, T. Robin, R. Arun, Sreeja S Kartha, P. Manoj, S. Nidhi, G. Maheshwar, K. T. Paul, Mayank Narang, T. Himanshu. 2022-09-27. Emission line star catalogues post-Gaia DR3: A validation of Gaia DR3 data using LAMOST OBA emission catalogue. https://doi.org/10.1051/0004-6361%2F202244353

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