Skip navigation
Skip navigation

Absolute Magnitudes of Seismic Red Clumps in the Kepler Field and SAGA: The Age Dependency of the Distance Scale

Chen, Y. H.; Casagrande, Luca; Zhao, G; Bovy, Jo; Aguirre, V Silva; Zhao, Jingkun; Jia, Yunpeng

Description

Red clump stars are fundamental distance indicators in astrophysics, although theoretical stellar models predict a dependence of absolute magnitudes with age. This effect is particularly strong below ∼2 Gyr, but even above this limit a mild age dependence is still expected. We use seismically identified red clump stars in the Kepler field for which we have reliable distances, masses, and ages from the SAGA survey, to first explore this effect. By excluding red clump stars with masses larger...[Show more]

dc.contributor.authorChen, Y. H.
dc.contributor.authorCasagrande, Luca
dc.contributor.authorZhao, G
dc.contributor.authorBovy, Jo
dc.contributor.authorAguirre, V Silva
dc.contributor.authorZhao, Jingkun
dc.contributor.authorJia, Yunpeng
dc.date.accessioned2020-12-20T20:51:35Z
dc.date.available2020-12-20T20:51:35Z
dc.identifier.issn0004-637X
dc.identifier.urihttp://hdl.handle.net/1885/217821
dc.description.abstractRed clump stars are fundamental distance indicators in astrophysics, although theoretical stellar models predict a dependence of absolute magnitudes with age. This effect is particularly strong below ∼2 Gyr, but even above this limit a mild age dependence is still expected. We use seismically identified red clump stars in the Kepler field for which we have reliable distances, masses, and ages from the SAGA survey, to first explore this effect. By excluding red clump stars with masses larger than (corresponding to ages younger than 2 Gyr), we derive robust calibrations linking intrinsic colors to absolute magnitudes in the following photometric systems: Strömgren by, Johnson BV, Sloan griz, 2MASS JHK s, and WISE . With the precision achieved we also detect a slope of absolute magnitudes ∼ 0.020 ± l0.003 mag Gyr-1 in the infrared, implying that distance calibrations of clump stars can be off by up to ∼0.2 mag in the infrared (over the range from 2 to 12 Gyr) if their ages are unknown. Even larger uncertainties affect optical bands, because of the stronger interdependency of absolute magnitudes on colors and age. Our distance calibrations are ultimately based on asteroseismology, and we show how the distance scale can be used to test the accuracy of seismic scaling relations. Within the uncertainties our calibrations are in agreement with those built upon local red clumps with Hipparcos parallaxes, although we find a tension, which, if confirmed, would imply that scaling relations overestimate the radii of red clump stars by 2 ± 2%. Data releases post Gaia DR1 will provide an important testbed for our results
dc.format.mimetypeapplication/pdf
dc.language.isoen_AU
dc.publisherIOP Publishing
dc.sourceThe Astrophysical Journal
dc.titleAbsolute Magnitudes of Seismic Red Clumps in the Kepler Field and SAGA: The Age Dependency of the Distance Scale
dc.typeJournal article
local.description.notesImported from ARIES
local.identifier.citationvolume840
dc.date.issued2017
local.identifier.absfor020110 - Stellar Astronomy and Planetary Systems
local.identifier.ariespublicationa383154xPUB6533
local.type.statusPublished Version
local.contributor.affiliationChen, Y. H., Chinese Academy of Sciences
local.contributor.affiliationCasagrande, Luca, College of Science, ANU
local.contributor.affiliationZhao, G, Chinese Academy of Sciences
local.contributor.affiliationBovy, Jo, New York University
local.contributor.affiliationAguirre, V Silva, Aarhus University
local.contributor.affiliationZhao, Jingkun, Chinese Academy of Sciences
local.contributor.affiliationJia, Yunpeng, Chinese Academy of Sciences
local.bibliographicCitation.issue2
local.identifier.doi10.3847/1538-4357/aa6d0f
dc.date.updated2020-11-23T10:09:13Z
local.identifier.scopusID2-s2.0-85019831509
local.identifier.thomsonID000403228100006
CollectionsANU Research Publications

Download

There are no files associated with this item.


Items in Open Research are protected by copyright, with all rights reserved, unless otherwise indicated.

Updated:  19 May 2020/ Responsible Officer:  University Librarian/ Page Contact:  Library Systems & Web Coordinator