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|Title:||The Gaia-ESO Survey: Catalogue of Hα emission stars||Authors:||Traven, G.
Van Eck, S.
Lanzafame, Alessandro Carmelo
Alfaro, E. J.
Costado, M. T.
SACCO, GIUSEPPE GERMANO
Worley, C. C.
|Issue Date:||2015||Journal:||ASTRONOMY & ASTROPHYSICS||Number:||581||First Page:||A52||Abstract:||We discuss the properties of Hα emission stars across the sample of 22035 spectra from the Gaia-ESO Survey internal data release, observed with the GIRAFFE instrument and largely belonging to stars in young open clusters. Automated fits using two independent Gaussian profiles and a third component that accounts for the nebular emission allow us to discern distinct morphological types of Hα line profiles with the introduction of a simplified classification scheme. All in all, we find 3765 stars with intrinsic emission and sort their spectra into eight distinct morphological categories: single-component emission, emission blend, sharp emission peaks, double emission, P-Cygni, inverted P-Cygni, self-absorption, and emission in absorption. We have more than one observation for 1430 stars in our sample, thus allowing a quantitative discussion of the degree of variability of Hα emission profiles, which is expected for young, active objects. We present a catalogue of stars with properties of their Hα emission line profiles, morphological classification, analysis of variability with time and the supplementary information from the SIMBAD, VizieR, and ADS databases. The records in SIMBAD indicate the presence of Hα emission for roughly 25% of all stars in our catalogue, while at least 305 of them have already been more thoroughly investigated according to the references in ADS. The most frequently identified morphological categories in our sample of spectra are emission blend (23%), emission in absorption (22%), and self-absorption (16%). Objects with repeated observations demonstrate that our classification into discrete categories is generally stable through time, but categories P-Cygni and self-absorption seem less stable, which is the consequence of discrete classification rules, as well as of the fundamental change in profile shape. Such records of emission stars can be valuable for automatic pipelines in large surveys, where it may prove very useful for pinpointing outliers when calculating general stellar properties and elemental abundances. They can be used in studies of star formation processes, interacting binaries, and other fields of stellar physics. <P />Based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 188.B-3002.Full Tables D.1-D.3 are only available at the CDS via anonymous ftp to <A href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A> (ftp://126.96.36.199) or via <A href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/581/A52">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/581/A52</A>||Acknowledgments:||These data products have been processed by the Cambridge Astronomy Survey Unit (CASU) at the Institute of Astronomy, University of Cambridge, and by the FLAMES/UVES reduction team at INAF/Osservatorio Astrofisico di Arcetri. These data have been obtained from the Gaia -ESO Survey Data Archive, prepared and hosted by the Wide Field Astronomy Unit, Institute for Astronomy, University of Edinburgh, which is funded by the UK Science and Technology Facilities Council. This work was partly supported by the European Union FP7 programme through ERC grant number 320360 and by the Leverhulme Trust through grant RPG-2012-541. We acknowledge the support from INAF and Ministero dell’ Istruzione, dell’ Università’ e della Ricerca (MIUR) in the form of the grant “Premiale VLT 2012”. The results presented here benefit from discussions held during the Gaia -ESO workshops and conferences supported by the ESF (European Science Foundation) through the GREAT Research Network Programme. A. Bayo Acknowledges financial support from the Proyecto Fondecyt Iniciación 11140572. F. Jimenez-Esteban acknowledges financial support from the ARCHES project (7th Framework of the European Union, n 313146). This research has made use of the SIMBAD database and VizieR catalogue access tool, CDS, Strasbourg, France. The original description of the VizieR service was published in AAS, 143, 23.||URI:||http://hdl.handle.net/20.500.12386/23065||URL:||https://www.aanda.org/articles/aa/full_html/2015/09/aa25857-15/aa25857-15.html||ISSN:||0004-6361||DOI:||10.1051/0004-6361/201525857||Bibcode ADS:||2015A&A...581A..52T||Fulltext:||open|
|Appears in Collections:||1.01 Articoli in rivista|
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