Population-based identification of H α-excess sources in the Gaia DR2 and IPHAS catalogues

We present a catalogue of point-like H α-excess sources in the Northern Galactic Plane. Our catalogue is created using a new technique that leverages astrometric and photomeric information from Gaia to select H α-bright outliers in the INT Photometric H α Survey of the Northern Galactic Plane (IPHAS...

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Detalles Bibliográficos
Autores: Fratta, M., Scaringi, Simone, Drew, J.E., Monguió-Tortajada, Marta, Knigge, C., Maccarone, T. J., Court, J. M. C., Iłkiewicz, K. A., Pala, A. F., Gandhi, Poshak, Gänsicke, Boris T.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2021
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/261078
Acceso en línea:http://hdl.handle.net/10261/261078
Access Level:acceso abierto
Palabra clave:Techniques: photometric
Catalogues
Stars: emission-line
Be
Hertzsprung-Russell and colour-magnitude
Novae
Cataclysmic variables
Descripción
Sumario:We present a catalogue of point-like H α-excess sources in the Northern Galactic Plane. Our catalogue is created using a new technique that leverages astrometric and photomeric information from Gaia to select H α-bright outliers in the INT Photometric H α Survey of the Northern Galactic Plane (IPHAS), across the colour-absolute magnitude diagram. To mitigate the selection biases due to stellar population mixing and to extinction, the investigated objects are first partitioned with respect to their positions in the Gaia colour-absolute magnitude space, and Galactic coordinates space, respectively. The selection is then performed on both partition types independently. Two significance parameters are assigned to each target, one for each partition type. These represent a quantitative degree of confidence that the given source is a reliable H α-excess candidate, with reference to the other objects in the corresponding partition. Our catalogue provides two flags for each source, both indicating the significance level of the H α-excess. By analysing their intensity in the H α narrow band, 28 496 objects out of 7474 835 are identified as H α-excess candidates with a significance higher than 3. The completeness fraction of the H α outliers selection is between 3 and 5 per cent. The suggested 5σ conservative cut yields a purity fraction of 81.9 per cent.