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http://hdl.handle.net/20.500.12386/27807
Campo DC | Valore | Lingua |
---|---|---|
dc.contributor.author | Robrade, J. | en_US |
dc.contributor.author | Oskinova, L. M. | en_US |
dc.contributor.author | Schmitt, J. H. M. M. | en_US |
dc.contributor.author | LETO, PAOLO | en_US |
dc.contributor.author | TRIGILIO, CORRADO | en_US |
dc.date.accessioned | 2020-10-14T13:56:32Z | - |
dc.date.available | 2020-10-14T13:56:32Z | - |
dc.date.issued | 2018 | en_US |
dc.identifier.issn | 0004-6361 | en_US |
dc.identifier.uri | http://hdl.handle.net/20.500.12386/27807 | - |
dc.description.abstract | Context. Among the intermediate-mass magnetic chemically peculiar (MCP) stars, CU Vir is one of the most intriguing objects. Its 100% circularly polarized beams of radio emission sweep the Earth as the star rotates, thereby making this strongly magnetic star the prototype of a class of nondegenerate stellar radio pulsars. While CU Vir is well studied in radio, its high-energy properties are not known. Yet, X-ray emission is expected from stellar magnetospheres and confined stellar winds. <BR /> Aims: Using X-ray data we aim to test CU Vir for intrinsic X-ray emission and investigate mechanisms responsible for its generation. <BR /> Methods: We present X-ray observations performed with XMM-Newton and Chandra and study obtained X-ray images, light curves, and spectra. Basic X-ray properties are derived from spectral modelling and are compared with model predictions. In this context we investigate potential thermal and nonthermal X-ray emission scenarios. <BR /> Results: We detect an X-ray source at the position of CU Vir. With L<SUB>X</SUB> ≍ 3×10<SUP>28</SUP> erg s<SUP>-1</SUP> it is moderately X-ray bright, but the spectrum is extremely hard compared to other Ap stars. Spectral modelling requires multi-component models with predominant hot plasma at temperatures of about T<SUB>X</SUB> = 25 MK or, alternatively, a nonthermal spectral component. Both types of model provide a virtually equivalent description of the X-ray spectra. The Chandra observation was performed six years later than those by XMM-Newton, yet the source has similar X-ray flux and spectrum, suggesting a steady and persistent X-ray emission. This is further confirmed by the X-ray light curves that show only mild X-ray variability. <BR /> Conclusions: CU Vir is also an exceptional star at X-ray energies. To explain its full X-ray properties, a generating mechanism beyond standard explanations, like the presence of a low-mass companion or magnetically confined wind-shocks, is required. Magnetospheric activity might be present or, as proposed for fast-rotating strongly magnetic Bp stars, the X-ray emission of CU Vir is predominantly auroral in nature. | en_US |
dc.language.iso | eng | en_US |
dc.title | Outstanding X-ray emission from the stellar radio pulsar CU Virginis | en_US |
dc.type | Article | - |
dc.identifier.doi | 10.1051/0004-6361/201833492 | en_US |
dc.identifier.scopus | 2-s2.0-85056500043 | en_US |
dc.identifier.isi | 000449277500001 | en_US |
dc.identifier.url | https://www.aanda.org/articles/aa/abs/2018/11/aa33492-18/aa33492-18.html | en_US |
dc.identifier.url | https://arxiv.org/pdf/1808.02367.pdf | en_US |
dc.relation.medium | STAMPA | en_US |
dc.relation.volume | 619 | en_US |
dc.relation.issue | A33 | en_US |
dc.relation.firstpage | 1 | en_US |
dc.relation.lastpage | 6 | en_US |
dc.relation.numberofpages | 6 | en_US |
dc.type.referee | REF_1 | en_US |
dc.description.numberofauthors | 5 | en_US |
dc.description.international | sì | en_US |
dc.contributor.country | DEU | en_US |
dc.relation.scientificsector | FIS/05 - ASTRONOMIA E ASTROFISICA | en_US |
dc.relation.journal | ASTRONOMY & ASTROPHYSICS | en_US |
dc.type.miur | 262 Articolo in rivista | - |
dc.identifier.adsbibcode | 2018A&A...619A..33R | en_US |
dc.description.apc | no | en_US |
dc.description.oa | 1 – prodotto con file in versione Open Access (allegare il file al passo 5-Carica) | en_US |
item.openairecristype | http://purl.org/coar/resource_type/c_18cf | - |
item.openairetype | Article | - |
item.languageiso639-1 | en | - |
item.cerifentitytype | Publications | - |
item.grantfulltext | open | - |
item.fulltext | With Fulltext | - |
crisitem.author.dept | O.A. Catania | - |
crisitem.author.dept | O.A. Catania | - |
crisitem.author.orcid | 0000-0003-4864-2806 | - |
crisitem.author.orcid | 0000-0002-1216-7831 | - |
crisitem.journal.journalissn | 0004-6361 | - |
crisitem.journal.ance | E016240 | - |
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