English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/212042
Share/Impact:
Statistics
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:

Title

The CARMENES search for exoplanets around m dwarfs: Wing asymmetries of Hα, Na I D, and He I lines

AuthorsFuhrmeister, B.; Czesla, S.; Schmitt, J. H. M. M.; Jeffers, S. V.; Caballero, J. A.; Zechmeister, M.; Reiners, A.; Ribas, Ignasi ; Amado, Pedro J. ; Quirrenbach, A.; Bejar, V. J. S.; Galadí-Enríquez, D.; Guenther, E. W.; Kurster, M.; Montes, D.; Seifert, W.
KeywordsStars: activity
Stars: chromospheres
Stars: late-type
Issue Date2018
PublisherEDP Sciences
CitationAstronomy and Astrophysics 615: A14 (2018)
AbstractStellar activity is ubiquitously encountered in M dwarfs and often characterised by the Hα line. In the most active M dwarfs, Hα is found in emission, sometimes with a complex line profile. Previous studies have reported extended wings and asymmetries in the Hα line during flares. We used a total of 473 high-resolution spectra of 28 active M dwarfs obtained by the CARMENES (Calar Alto high-Resolution search for M dwarfs with Exo-Earths with Near-infrared and optical Echelle Spectrographs) spectrograph to study the occurrence of broadened and asymmetric Hα line profiles and their association with flares, and examine possible physical explanations. We detected a total of 41 flares and 67 broad, potentially asymmetric, wings in Hα. The broadened Hα lines display a variety of profiles with symmetric cases and both red and blue asymmetries. Although some of these line profiles are found during flares, the majority are at Least not obviously associated with flaring. We propose a mechanism similar to coronal rain or chromospheric downward condensations as a cause for the observed red asymmetries; the symmetric cases May also be caused by Stark broadening. We suggest that blue asymmetries are associated with rising material, and our results are consistent with a prevalence of blue asymmetries during the flare onset. Besides the Hα asymmetries, we find some cases of additional line asymmetries in He i D, Na i D lines, and the He i line at 10 830 taken all simultaneously thanks to the large wavelength coverage of CARMENES. Our study shows that asymmetric Hα lines are a rather common phenomenon in M dwarfs and need to be studied in more detail to obtain a better understanding of the atmospheric dynamics in these objects.© ESO 2018.
Publisher version (URL)http://dx.doi.org/10.1051/0004-6361/201732204
URIhttp://hdl.handle.net/10261/212042
Identifiersdoi: 10.1051/0004-6361/201732204
issn: 1432-0746
Appears in Collections:(ICE) Artículos
(CAB) Artículos
(IAA) Artículos
Files in This Item:
File Description SizeFormat 
IAA_2018aa32204-17.pdf3,01 MBAdobe PDFThumbnail
View/Open
Show full item record
Review this work
 

Related articles:


WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.