Spectroscopic follow-up of a subset of the Gaia/IPHAS catalogue of Hα-excess sources

Fratta, M; Scaringi, S; Monguió, M; Pala, AF; Drew, JE; Knigge, C; Iłkiewicz, KA; Gandhi, P

Abstract

State-of-the-art techniques to identify Hα emission-line sources in narrow-band photometric surveys consist of searching for  Hα excess with reference to nearby objects in the sky (position-based selection). However, while this approach usually yields very few spurious detections, it may fail to select intrinsically faint and/or rare Hα-excess sources. In order to obtain a more complete representation of the heterogeneous emission-line populations, we recently developed a technique to find outliers relative to nearby objects in the colour–magnitude diagram (CMD-based selection). By combining position-based and CMD-based selections, we built an updated catalogue of Hα-excess candidates in the Northern Galactic Plane. Here, we present spectroscopic follow-up observations and classification of 114 objects from this catalogue that enables us to test our novel selection method. Out of the 70 spectroscopically confirmed Hα-emitters in our sample, 15 were identified only by the CMD-based selection, and would have been thus missed by the classic position-based technique. In addition, we explore the distribution of our spectroscopically confirmed emitters in the Gaia CMD. This information can support the classification of emission-line sources in large surveys such as the upcoming WEAVE and 4-m Multi-Object Spectroscopic Telescope, especially if augmented with the introduction of other colours.

Citation

Fratta, M., Scaringi, S., Monguió, M., Pala, A., Drew, J., Knigge, C., Iłkiewicz, K., & Gandhi, P. (2022). Spectroscopic follow-up of a subset of the Gaia/IPHAS catalogue of Hα-excess sources. Monthly Notices of the Royal Astronomical Society, 518(3), 3301-3311. https://doi.org/10.1093/mnras/stac3216

• Journal Article Type: Article
• Acceptance Date: Nov 2, 2022
• Online Publication Date: Nov 30, 2022
• Publication Date: 2022
• Deposit Date: Jan 6, 2023
• Publicly Available Date: Jan 6, 2023
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 518
• Issue: 3
• Pages: 3301-3311
• DOI: https://doi.org/10.1093/mnras/stac3216
• Public URL: https://durham-repository.worktribe.com/output/1182283