Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/215468

Title

The spectral energy distributions of white dwarfs in 47 Tucanae: the distance to the cluster

Author(s)

Woodley, K. A.;  Goldsbury, R.;  Kalirai, J. S.;  Richer, H. B.;  Tremblay, P. E.;  Anderson, J.;  Bergeron, P.;  Dotter, A.;  Esteves, L.;  Fahlman, G. G.;  Hansen, B. M. S.;  Heyl, J.;  Hurley, J.;  Rich, R. M.;  Shara, M. M.;  Stetson, P. B.

Abstract

We present a new distance determination to the Galactic globular cluster 47 Tucanae by fitting the spectral energy distributions of its white dwarfs (WDs) to pure hydrogen atmosphere WD models. Our photometric data set is obtained from a 121-orbit Hubble Space Telescope program using the Wide Field Camera 3 UVIS/IR channels, capturing F390W, F606W, F110W, and F160W images. These images cover more than 60 arcmin2 and extend over a radial range of 5-13.7 arcmin (6.5-17.9 pc) within the globular cluster. Using a likelihood analysis, we obtain a best-fitting unreddened distance modulus of (m – M)o = 13.36 ± 0.02 ± 0.06 corresponding to a distance of 4.69 ± 0.04 ± 0.13 kpc, where the first error is random and the second is systematic. We also search the WD photometry for infrared excess in the F160W filter, indicative of low-mass companions, and find no convincing cases within our sample.

Publication type

Journal article

Research centre

Swinburne University of Technology. Faculty of Information and Communication Technologies. Centre for Astrophysics and Supercomputing

Source

Astronomical Journal, Vol. 143, no. 2 (Feb 2012), article no. 50

Publication year

2012

FOR Code(s)

0201 Astronomical and Space Sciences

Keyword(s)

47 Tucanae;  Distances;  Globular clusters;  Spectral energy;  Stars;  White dwarfs

Publisher

Institute of Physics Publishing

ISSN

0004-6256

Publisher URL

http://dx.doi.org/10.1088/0004-6256/143/2/50

Copyright

Copyright © 2012 The American Astronomical Society. All rights reserved. The American Astronomical Society does not allow institutions to archive either the accepted manuscript or the published version of the article. However, you can find an earlier version of the full text here: http://arxiv.org/abs/1112.1425.

Peer reviewed