The tip of the red giant branch distance to the Large Magellanic Cloud

Citation
S. Sakai et al., The tip of the red giant branch distance to the Large Magellanic Cloud, ASTRONOM J, 119(3), 2000, pp. 1197-1204
Citations number
44
Categorie Soggetti
Space Sciences
Journal title
ASTRONOMICAL JOURNAL
ISSN journal
00046256 → ACNP
Volume
119
Issue
3
Year of publication
2000
Pages
1197 - 1204
Database
ISI
SICI code
0004-6256(200003)119:3<1197:TTOTRG>2.0.ZU;2-O
Abstract
We present the I-band luminosity function of the red giant branch stars in the Large Magellanic Cloud (LMC) using the data from the Magellanic Clouds Photometric Survey (MCPS). By selecting stars in uncrowded, low-extinction regions, we observe a discontinuity in the luminosity function at I-0 = 14. 54 mag. Identifying this feature with the tip of the red giant branch (TRGB ) and adopting an absolute TRGB magnitude of -4.05 +/- 0.04 based on the ca libration of Lee, Freedman, & Madore, we obtain a distance modulus of 18.59 +/- 0.09 (random) +/- 0.16 (systematic) mag. If the theoretical TRGB calib ration provided by Cassisi & Salaris is adopted instead, the derived distan ce would be 4% greater. The LMC distance modulus reported here, 18.59 It 0. 09, is larger by 0.09 mag (1 sigma) than the value that is most commonly us ed in the extragalactic distance scale calibrated by the period-luminosity relation of the Cepheid variable stars. Our TRGB distance modulus agrees wi th several RR Lyrae distances to the LMC based on Hipparcos parallaxes. Fin ally, we note that, by using the same MCPS data, we obtain a distance modul us of 18.29 +/- 0.03 mag using the red clump method, which yields a distanc e shorter by 0.3 mag compared with the TRGB estimate.