{"corpus_id":55800969,"paper_sha":"6ed4a7d653526730c74a9aa2b3017d93ee348896","doi":"10.1051/0004-6361/201016333","arxiv_id":"1103.0584","pmid":null,"pmcid":null,"mag_id":2137964810,"dblp_id":null,"acl_id":null,"title":"Chromospheric activities and kinematics for solar type dwarfs and subgiants : analysis of the activity distribution and the AVR","year":2011,"publication_date":"2011-03-03","venue":"","journal":{"name":"Astronomy and Astrophysics","pages":null,"volume":"531"},"journal_issn":null,"journal_title":null,"publication_types":[],"pubmed_pub_types":null,"s2_fields_of_study":["Physics"],"reference_count":49,"citation_count":92,"influential_citation_count":16,"is_open_access":true,"arxiv_categories":["astro-ph.SR","astro-ph.EP"],"arxiv_license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","arxiv_journal_ref":null,"mesh_headings":null,"chemicals":null,"comments_corrections":null,"source_flags":1,"s2_open_access_pdf_url":"https://www.aanda.org/articles/aa/pdf/2011/07/aa16333-10.pdf","s2_open_access_landing_url":"https://www.semanticscholar.org/paper/6ed4a7d653526730c74a9aa2b3017d93ee348896","s2_open_access_license":null,"s2_open_access_status":"BRONZE","pmc_open_access_pdf_url":null,"pmc_open_access_landing_url":null,"pmc_open_access_license":null,"pmc_open_access_status":null,"unpaywall_open_access_pdf_url":null,"unpaywall_open_access_landing_url":null,"unpaywall_open_access_license":null,"unpaywall_open_access_status":null,"abstract":"Aims. In this work we present chromospheric activity indices, kinematics, radial-velocities, and rotational velocities for more than 850 FGK-type dwarfs and subgiant stars in the southern hemisphere and test how best to calibrate and measure S-indices from echelle spectra. Methods. We measured our parameters using the high-resolution and high-S /N FEROS echelle spectra acquired for this purpose. Results. We confirm the bimodal distribution of chromospheric activities for such stars and highlight the role that the more active K-dwarfs play in biasing the number of active stars. We show that the age-activity relationship does appear to continue to ages older than the Sun if we simply compare main sequence stars and subgiant stars with an offset of around 2.5 Gyr between the peaks of both distributions. Also we show evidence of an increased spin-down timescale for cool K dwarfs compared with earlier F and G type stars. We highlight that activities drawn from low-resolution spectra (R < 2500) significantly increase the rms scatter when calibrating onto common systems of measurements like the Mt. Wilson system. Also we show that older and widely used catalogues —————‐ ‐ ‐ ‐","claims":[{"public_id":"cl_9007c22e789af8ea6fadd6eca74d3578","status":"active","text":"Chromospheric activity is bimodally distributed in the surveyed FGK-type dwarfs and subgiants, and active K dwarfs bias the active-star counts.","confidence":0.97,"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/claims/cl_9007c22e789af8ea6fadd6eca74d3578"},{"public_id":"cl_68c0fd1a53ce914c0d50594b175d7e4c","status":"active","text":"Cool K dwarfs show a longer spin-down timescale than earlier F and G type stars.","confidence":0.93,"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/claims/cl_68c0fd1a53ce914c0d50594b175d7e4c"},{"public_id":"cl_7add2558599365ff2857dc5725730336","status":"active","text":"High-resolution FEROS echelle spectra were used to measure chromospheric activity indices, kinematics, radial velocities, rotational velocities, and to test calibration and measurement of S-indices for more than 850 southern FGK-type dwarfs and subgiants.","confidence":0.9,"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/claims/cl_7add2558599365ff2857dc5725730336"},{"public_id":"cl_deb3a50545fdb2bb9624c8fea5a00dd5","status":"active","text":"The age-activity relationship appears to extend to ages older than the Sun when main-sequence stars and subgiants are compared with an offset of about 2.5 Gyr between the peaks of the two distributions.","confidence":0.94,"contributors":[{"id":1,"public_id":"12632b8b5f","public_label":"Anonymous (12632b8b5f)","roles":["extraction"],"url":"https://sah.borca.ai/u/12632b8b5f"}],"url":"https://sah.borca.ai/claims/cl_deb3a50545fdb2bb9624c8fea5a00dd5"},{"public_id":"cl_c43aa9ad4b0b98b740fb4ad778046054","status":"active","text":"Using low-resolution spectra with R < 2500 increases the rms scatter when calibrating activity measurements onto the Mt. 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