The Absolute Magnitudes of Red Horizontal Branch Stars in the ugriz System

Abstract

Based on photometric data of the central parts of eight globular clusters and one open cluster presented by An and his collaborators, we select red horizontal branch (RHB) stars in the (g-r)0-g0 diagram and make a statistical study of the distributions of their colors and absolute magnitudes in the SDSS ugriz system. Meanwhile, absolute magnitudes in the Johnson VRI system are calculated through the translation formulae between gri and VRI in the literature. The calibrations of absolute magnitude as functions of metallicity and age are established by linear regressions of the data. It is found that metallicity coefficients in these calibrations decrease, while age coefficients increase, from the blue $u$ filter to the red $z$ filter. The calibration of Mi= 0.06[Fe/H]+0.040t+0.03 has the smallest scatter of 0.04 mag, and thus i is the best filter in the $ugriz$ system when RHB stars are used for distance indicators. The comparison of the MI calibration from our data with that from red clump stars indicates that the previous suggestion that the $I$ filter is better than the V filter in distance determination may not be true because of its significant dependence on age.

19 pages, 7 figures, accepted by ApJ

References in corpus (5)

• Setting UBVRI Photometric Zero-Points Using Sloan Digital Sky Survey ugriz Magnitudes
• Reaching the End of the White Dwarf Cooling Sequence in NGC 6791
• Galactic Globular and Open Clusters in the Sloan Digital Sky Survey. II. Test of Theoretical Stellar Isochrones
• The red clump absolute magnitude based on revised Hipparcos parallaxes
• vbyCaHbeta CCD Photometry of Clusters. VIII. The Super-Metal Rich, Old Open Cluster NGC 6791

Cited by in corpus (9)

• The feeble giant. Discovery of a large and diffuse Milky Way dwarf galaxy in the constellation of Crater
• A kinematic study of the Andromeda dwarf spheroidal system
• PAndAS' progeny: extending the M31 dwarf galaxy cabal
• A Keck/DEIMOS spectroscopic survey of the faint M31 satellites And IX, And XI, And XII, and And XIII
• The Star Formation History in The Far Outer Disc of M33
• The kinematic identification of a thick stellar disc in M31
• The Metallicity Gradient of the Thick Disk Based on Red Horizontal Branch Stars From SDSS DR8
• Absolute Magnitudes of Seismic Red Clumps in the Kepler Field and SAGA: the age dependency of the distance scale
• Metallicity and Kinematic distributions of Red Horizontal-Branch Stars from the SDSS Survey