A stellar census in globular clusters with MUSE: A spectral catalogue of emission-line sources
- Aims. Globular clusters produce many exotic stars due to a much higher frequency of dynamical interactions in their dense stellar environments. Some of these objects were observed together with several hundred thousand other stars in our MUSE survey of 26 Galactic globular clusters. Assuming that at least a few exotic stars have exotic spectra (i.e. spectra that contain emission lines), we can use this large spectroscopic data set of over a million stellar spectra as a blind survey to detect stellar exotica in globular clusters. Methods. To detect emission lines in each spectrum, we modelled the expected shape of an emission line as a Gaussian curve. This template was used for matched filtering on the di fferences between each observed 1D spectrum and its fitted spectral model. The spectra with the most significant detections of H alpha emission are checked visually and cross-matched with published catalogues. Results. We find 156 stars with H alpha emission, including several known cataclysmic variables (CV) and two new CVs,Aims. Globular clusters produce many exotic stars due to a much higher frequency of dynamical interactions in their dense stellar environments. Some of these objects were observed together with several hundred thousand other stars in our MUSE survey of 26 Galactic globular clusters. Assuming that at least a few exotic stars have exotic spectra (i.e. spectra that contain emission lines), we can use this large spectroscopic data set of over a million stellar spectra as a blind survey to detect stellar exotica in globular clusters. Methods. To detect emission lines in each spectrum, we modelled the expected shape of an emission line as a Gaussian curve. This template was used for matched filtering on the di fferences between each observed 1D spectrum and its fitted spectral model. The spectra with the most significant detections of H alpha emission are checked visually and cross-matched with published catalogues. Results. We find 156 stars with H alpha emission, including several known cataclysmic variables (CV) and two new CVs, pulsating variable stars, eclipsing binary stars, the optical counterpart of a known black hole, several probable sub-subgiants and red stragglers, and 21 background emission-line galaxies. We find possible optical counterparts to 39 X-ray sources, as we detected H alpha emission in several spectra of stars that are close to known positions of Chandra X-ray sources. This spectral catalogue can be used to supplement existing or future X-ray or radio observations with spectra of potential optical counterparts to classify the sources.…
Author details: | Fabian Göttgens, Tim-Oliver HusserORCiDGND, Sebastian KamannORCiD, Stefan DreizlerORCiDGND, Benjamin GiesersGND, Wolfram KollatschnyORCiDGND, Peter Michael WeilbacherORCiDGND, Martin M. RothORCiDGND, Martin WendtORCiDGND |
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DOI: | https://doi.org/10.1051/0004-6361/201936485 |
ISSN: | 0004-6361 |
ISSN: | 1432-0746 |
Title of parent work (English): | Astronomy and astrophysics : an international weekly journal |
Publisher: | EDP Sciences |
Place of publishing: | Les Ulis |
Publication type: | Article |
Language: | English |
Year of first publication: | 2019 |
Publication year: | 2019 |
Release date: | 2020/10/06 |
Tag: | cataclysmic variables; catalogs; globular clusters: general; novae; stars: emission-line, Be; techniques: imaging spectroscopy |
Volume: | 631 |
Number of pages: | 16 |
Funding institution: | German Research Foundation (DFG)German Research Foundation (DFG) [KA 4537/21, DR 281/35-1]; European Research Council consolidator grantEuropean Research Council (ERC) [ERC-CoG-646928-Multi-Pop]; German Ministry for Education and Science (BMBF Verbundforschung)Federal Ministry of Education & Research (BMBF) [05A14BAC, 05A14MGA, 05A17MGA, 05A17BAA]; ESO Telescopes at the La Silla Paranal Observatory [094.D-0142, 095.D-0629, 096.D-0175, 097.D-0295, 098.D-0148, 099.D-0019, 0100.D-0161, 0101.D-0268, 0102.D-0270]; NASANational Aeronautics & Space Administration (NASA) [NAS 5-26555] |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
DDC classification: | 5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik |
Peer review: | Referiert |
Publishing method: | Open Access |
Open Access / Bronze Open-Access |