Open AccessThe Cepheid distance to M96 and the Hubble constant
Author(s) -
Tanvir N. R.,
Ferguson H. C.,
Shanks T.
Publication year - 1999
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1999.02954.x
Subject(s) - cepheid variable , physics , hubble's law , astrophysics , fundamental plane (elliptical galaxies) , galaxy , cosmic distance ladder , metallicity , luminosity , surface brightness , surface brightness fluctuation , large magellanic cloud , supernova , length scale , astronomy , redshift , elliptical galaxy , galaxy group , stars , disc galaxy , quantum mechanics
HST WFPC2 observations of Cepheids in M96 (NGC 3368) are used to find a distance to that galaxy of 11.2±1.0 Mpc. This estimate is based on a calibration of the Cepheid period–luminosity relation in the Large Magellanic Cloud, and includes a correction for the difference in metallicity between the two systems. There are good reasons for believing M96 is at the same distance as four E/S0 galaxies in the Leo‐I group, and hence we calibrate secondary distance indicators based on the early‐type galaxies, namely the fundamental plane and surface‐brightness‐fluctuation method. Also the Type Ia supernova 1998bu occurred in M96 itself and is used to calibrate the SN Ia distance scale. These methods reach to recession velocities of greater than 5000 km s −1 and can therefore allow us to evaluate the Hubble constant without reference to the peculiar velocity of M96 itself. In fact, these indicators agree well between themselves and hence we find H 0 =67±7 km s −1 Mpc −1 where the quoted error includes estimates of potential systematic effects.