J/A+A/315/40 Photometry of the Tuc dwarf galaxy (Saviane, 1996)
CCD photometry of the Tucana dwarf galaxy
Saviane I., Held E.V., Piotto G
<Astron. Astrophys. 315, 40 (1996)>
=1996A&A...315...40S 1996A&A...315...40S (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, photometry ; Photometry, CCD
Keywords: Galaxies: fundamental parameters - Galaxies: individual: Tucana -
Local Group - Galaxies: stellar content - Galaxies: structure
Abstract:
We present V and I CCD photometry for ∼360 stars in the recently
discovered dwarf galaxy Tucana. The large field investigated and the
accurate photometric calibration make our data complementary to the
deeper HST photometry. From the I magnitude of the tip of the red
giant branch we estimate a distance modulus (m-M)0=24.69±0.16,
corresponding to 870±60Kpc, confirming that Tucana is an isolated
dwarf spheroidal located almost at the border of the Local Group. From
the color of the red giant branch tip and by direct comparison with
the giant branches of galactic globular clusters we estimate a
metallicity [Fe/H]=-1.8±0.2, with no clear indication for a
metallicity spread. The color-magnitude diagram indicates that Tucana
has had a single star formation burst at the epoch of the Galactic
globular cluster star formation. There is no evidence for an
intermediate or young stellar population. We derive the V luminosity
profile, the surface density profile of resolved stars, and the
structural parameters of Tucana, from which we confirm that Tucana
participates to the general metallicity-surface brightness-absolute
magnitude relations defined by the Galaxy and M31 dwarf spheroidal and
dwarf elliptical companions.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tuc 45 363 Coordinates and photometry of the stars
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Byte-by-byte Description of file: tuc
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Bytes Format Units Label Explanations
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1- 9 I9 --- No Number of star
10- 18 F9.3 pix Xpos X-coordinate of star
19- 27 F9.3 pix Ypos Y-coordinate of star
28- 36 F9.3 mag Imag Landolt I magnitude
37- 45 F9.3 mag (V-I) Landolt (V-I) color
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Acknowledgements: I. Saviane,
(End) Patricia Bauer [CDS] 15-Apr-1996