Deep Learning–driven Atmospheric Parameter Prediction for Hot Subdwarf Stars with Synthetic and Observed Spectra

We design a convolutional neural network incorporating channel attention and spatial attention mechanisms to predict atmospheric parameters of hot subdwarfs. The experimental dataset comprises spectra at nine distinct signal-to-noise ratio (SNR) levels, with each SNR level containing 11,396 synthetic spectra and 945 observed spectra. The trained deep learning models achieves mean absolute errors in predicting hot subdwarf atmospheric parameters of 730 K for effective temperature (Teff), 0.09 dex for surface gravity ( logg ), and 0.03 dex for helium abundance ( log(nHe/nH) ), respectively, which reaches the accuracy of traditional spectral fitting methods. Utilizing the trained deep learning models and low-resolution spectra from Large Sky Area Multi-Object Fiber Spectroscopic Telescope DR12, we confirm 1512 hot subdwarfs from the catalog of hot subdwarf candidates, of which 291 are newly identified. Our results demonstrate that the deep learning model not only achieves accuracy comparable to traditional methods in obtaining hot subdwarf atmospheric parameters but also far exceeds them in speed and efficiency, making it particularly suitable for the analysis of large datasets of hot subdwarf spectra.