| Authors | Macri, L. M.; Huchra, J. P.; Stetson, P. B.; Silbermann, N. A.; Freedman, W. L.; Kennicutt, R. C.; Mould, J. R.; Madore, B. F.; Bresolin, F.; Ferrarese, L.; Ford, H. C.; Graham, J. A.; Gibson, B. K.; Han, M.; Harding, P.; Hill, R. J.; Hoessel, J. G.; Hughes, S. M. G.; Kelson, D. D.; Illingworth, G. D.; Phelps, R. L.; Prosser, C. F.; Rawson, D. M.; Saha, A.; Sakai, S.; Turner, A. |
| Abstract | We report on the discovery of Cepheids in the Virgo spiral galaxy NGC 4535, based on observations made with the Wide Field and Planetary Camera 2 on board the Hubble Space Telescope (HST). NGC 4535 is one of 18 galaxies observed as a part of The HST Key Project on the Extragalactic Distance Scale, which aims to measure the Hubble constant to 10% accuracy. NGC 4535 was observed over 13 epochs using the F555W filter, and over 9 epochs using the F814W filter. The HST F555W and F814W data were transformed to the Johnson V and Kron-Cousins I magnitude systems, respectively. Photometry was performed using two independent programs, DoPHOT and DAOPHOT II/ALLFRAME. Period-luminosity relations in the V and I bands were constructed using 39 high-quality Cepheids present in our set of 50 variable candidates. We obtain a distance modulus of 31.02+/-0.26 mag, corresponding to a distance of 16.0+/-1.9 Mpc. Our distance estimate is based on values of μ0=18.50+/-0.10 mag and E(V-I)=0.13 mag for the distance modulus and reddening of the LMC, respectively. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, operated by AURA, Inc., under NASA contract NAS 5-26555. |
