Matches in SemOpenAlex for { <https://semopenalex.org/work/W2080692017> ?p ?o ?g. }
Showing items 1 to 78 of
78
with 100 items per page.
- W2080692017 endingPage "2147" @default.
- W2080692017 startingPage "2133" @default.
- W2080692017 abstract "We aim to constrain the Hα, Ca ii H and Ca ii K profiles from quiescent and active regions on active dM1e stars. A preliminary analysis of all the data available for dM1e stars shows that the Hα/Ca ii equivalent width (EW) ratio varies by up to a factor of 7 for different stars in our sample. We find that spectroscopic binaries have a significantly smaller ratio than single dM1e stars. We also find that the pre-main-sequence stars Gl 616.2, GJ 1264 and Gl 803 have a ratio lower than main-sequence single dM1e stars. These differences imply that different chromospheric structures are present on different stars, notably the temperature minimum must decrease with an increasing Hα/Ca ii EW ratio. For these reasons, it is impossible to reproduce all observations with only one grid of model chromospheres. We show that the grid of model chromospheres of Paper VI is adequate to describe the physical conditions that prevail in the chromospheres of spectroscopic binaries and pre-main-sequence M1e stars, but not for the conditions in single dM1e stars. One or more additional grids of model chromospheres will be necessary to reproduce all observations. We use the method developed in Paper XI in this series, in order to build two-component model chromospheres for five M1e field stars: FF And A, FF And B, GJ 1264, AU Mic and Gl 815A. Our solutions provide an exact match of the Hα and the mean Ca ii H & K EWs within measurement uncertainties. We compare the theoretical profiles and the observed profiles of Hα and the Ca ii H & K resonance lines. On the one hand, our fits to the Ca ii lines are reasonably good. On the other hand, our models tend to produce Hα profiles with a central absorption that is too deep. This suggests that the column mass at the transition region for plages is underestimated, but this would imply that the contrast factor between quiescent and active regions in the Ca ii lines is larger than 5. We find that, except in the cases of FF And A and AU Mic, the total Hα profile is dominated by the contributions from plage regions. The Hα profiles in quiescent regions are typically filled in or slightly in emission. We also find that, as in the case of the less active dM1 stars, Ca ii emission in dM1e stars is generally dominated by the contribution from plage regions. We find plage filling factors typically in the range 10 to 60 per cent. These are on average (40 per cent) slightly larger than those derived for the less active dM1 stars (30 per cent). Our modelling shows that the grid of model chromospheres of Paper VI is adequate for only a subset of dM1e stars. Physical conditions that prevail in the chromospheres of dM1e stars are very different from one star to another. For this reason, this study demonstrates the critical need for several improved grids of model chromospheres as well as higher signal-to-noise ratio data." @default.
- W2080692017 created "2016-06-24" @default.
- W2080692017 creator A5057347452 @default.
- W2080692017 date "2009-08-21" @default.
- W2080692017 modified "2023-09-24" @default.
- W2080692017 title "Observation and modelling of main-sequence star chromospheres - XII. Two-component model chromospheres for five active dM1e stars" @default.
- W2080692017 cites W1801713239 @default.
- W2080692017 cites W1970363217 @default.
- W2080692017 cites W1979484202 @default.
- W2080692017 cites W1981448013 @default.
- W2080692017 cites W1983662170 @default.
- W2080692017 cites W2019785737 @default.
- W2080692017 cites W2026052621 @default.
- W2080692017 cites W2034767302 @default.
- W2080692017 cites W2040572091 @default.
- W2080692017 cites W2054268826 @default.
- W2080692017 cites W2055488747 @default.
- W2080692017 cites W2094642149 @default.
- W2080692017 cites W2101459704 @default.
- W2080692017 cites W2106611718 @default.
- W2080692017 cites W2146266573 @default.
- W2080692017 cites W2153495170 @default.
- W2080692017 cites W2166469770 @default.
- W2080692017 cites W3100560895 @default.
- W2080692017 cites W3101433845 @default.
- W2080692017 cites W3104494537 @default.
- W2080692017 doi "https://doi.org/10.1111/j.1365-2966.2009.15112.x" @default.
- W2080692017 hasPublicationYear "2009" @default.
- W2080692017 type Work @default.
- W2080692017 sameAs 2080692017 @default.
- W2080692017 citedByCount "16" @default.
- W2080692017 countsByYear W20806920172012 @default.
- W2080692017 countsByYear W20806920172013 @default.
- W2080692017 countsByYear W20806920172015 @default.
- W2080692017 countsByYear W20806920172016 @default.
- W2080692017 countsByYear W20806920172017 @default.
- W2080692017 countsByYear W20806920172019 @default.
- W2080692017 countsByYear W20806920172021 @default.
- W2080692017 countsByYear W20806920172022 @default.
- W2080692017 countsByYear W20806920172023 @default.
- W2080692017 crossrefType "journal-article" @default.
- W2080692017 hasAuthorship W2080692017A5057347452 @default.
- W2080692017 hasBestOaLocation W20806920171 @default.
- W2080692017 hasConcept C101638190 @default.
- W2080692017 hasConcept C121332964 @default.
- W2080692017 hasConcept C1276947 @default.
- W2080692017 hasConcept C150846664 @default.
- W2080692017 hasConcept C2777371749 @default.
- W2080692017 hasConcept C44870925 @default.
- W2080692017 hasConcept C56956389 @default.
- W2080692017 hasConceptScore W2080692017C101638190 @default.
- W2080692017 hasConceptScore W2080692017C121332964 @default.
- W2080692017 hasConceptScore W2080692017C1276947 @default.
- W2080692017 hasConceptScore W2080692017C150846664 @default.
- W2080692017 hasConceptScore W2080692017C2777371749 @default.
- W2080692017 hasConceptScore W2080692017C44870925 @default.
- W2080692017 hasConceptScore W2080692017C56956389 @default.
- W2080692017 hasIssue "4" @default.
- W2080692017 hasLocation W20806920171 @default.
- W2080692017 hasOpenAccess W2080692017 @default.
- W2080692017 hasPrimaryLocation W20806920171 @default.
- W2080692017 hasRelatedWork W1635979223 @default.
- W2080692017 hasRelatedWork W1972018787 @default.
- W2080692017 hasRelatedWork W1986109513 @default.
- W2080692017 hasRelatedWork W1994702306 @default.
- W2080692017 hasRelatedWork W2017391605 @default.
- W2080692017 hasRelatedWork W2029125027 @default.
- W2080692017 hasRelatedWork W2072052661 @default.
- W2080692017 hasRelatedWork W2073679003 @default.
- W2080692017 hasRelatedWork W3105654201 @default.
- W2080692017 hasRelatedWork W3106428885 @default.
- W2080692017 hasVolume "397" @default.
- W2080692017 isParatext "false" @default.
- W2080692017 isRetracted "false" @default.
- W2080692017 magId "2080692017" @default.
- W2080692017 workType "article" @default.