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Population gradients in dwarf spheroidal galaxies KKs 3 and ESO 269-66

Published online by Cambridge University Press:  30 October 2019

M. E. Sharina
Affiliation:
Special Astrophysical Observatory, Russian Academy of Sciences, N. Arkhyz, KChR 369167, Russia emails: [email protected], [email protected], [email protected]
L. N. Makarova
Affiliation:
Special Astrophysical Observatory, Russian Academy of Sciences, N. Arkhyz, KChR 369167, Russia emails: [email protected], [email protected], [email protected]
D. I. Makarov
Affiliation:
Special Astrophysical Observatory, Russian Academy of Sciences, N. Arkhyz, KChR 369167, Russia emails: [email protected], [email protected], [email protected]
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Abstract

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We compare the properties of stellar populations for globular clusters (GCs) and field stars in two dwarf spheroidal galaxies (dSphs): ESO269-66, a close neighbour of NGC5128, and KKs3, one of the few isolated dSphs within 10 Mpc. We analyse the surface density profiles of low and high metallicity (blue and red) stars in two galaxies using the Sersic law. We argue that 1) the density profiles of red stars are steeper than those of blue stars, which evidences in favour of the metallicity and age gradients in dSphs; 2) globular clusters in KKs3 and ESO 269-66 contain 4 and 40 percent of all stars with [Fe / H] ~ 1.6 dex and the age of 12 Gyr, correspondingly. Therefore, GCs are relics of the first powerful star-forming bursts in the central regions of the galaxies. KKs 3 has lost a smaller percentage of old low-metallicity stars than ESO269-66, probably, thanks to its isolation.

Type
Contributed Papers
Copyright
© International Astronomical Union 2019 

References

Bertelli, G., Girardi, L., Marigo, P., & Nasi, E. 2008, A&A, 484, 815 Google Scholar
Ciotti, L. & Bertin, G., 1999 A&A, 352, 447 Google Scholar
Crnojevic, D., Rejkuba, M., Grebel, E. K., da Costa, G. & Jerjen, H., 2011, A&A, 530, 58 Google Scholar
Davidge, T. J., 2005 AJ, 130, 2087 10.1086/491706CrossRefGoogle Scholar
Djorgovski, S. & Meylan, G., 1993, in: Djorgovski, S. G. & Meylan, G. (eds.), Structure and Dynamics of Globular Clusters, ASP-CS 50 (San Francisco: ASP), p. 325 Google Scholar
Dolphin, A. E. et al., 2003, AJ 126, 187 10.1086/375761CrossRefGoogle Scholar
Harbeck, D. et al., 2001, AJ, 122, 3092 CrossRefGoogle Scholar
Karachentsev, I. D., Makarova, L. N., Makarov, D. I., Tully, R. B., & Rizzi, L., 2015, MNRAS, 447, L85 10.1093/mnrasl/slu181CrossRefGoogle Scholar
Karachentsev, I. D., Kniazev, A. Yu. & Sharina, M. E., 2015, AN, 336, 707 Google Scholar
Karachentsev, I. D., Makarov, D. I. & Kaisina, E. I., 2013, AJ, 145, 101 10.1088/0004-6256/145/4/101CrossRefGoogle Scholar
Karachentsev, I. D. et al., 2007, AJ, 133, 504 10.1086/510125CrossRefGoogle Scholar
Makarova, L., et al., 2007, in: Eds. Combes, F. and Palous, J. (eds.), Galaxy Evolution across the Hubble Time, Proc. IAU Symposium No. 235 (Cambridge: Cambridge Univ. Press), p. 320 Google Scholar
McConnachie, A. W., 2012, AJ, 144, 4 10.1088/0004-6256/144/1/4CrossRefGoogle Scholar
Sersic, J. L., 1968, Atlas de Galaxias Australes (Cordoba, Argentina: Observatorio Astronomico)Google Scholar
Sharina, M. E., Shimansky, V. V. & Kniazev, A. Y., 2017, MNRAS, 471, 1955 10.1093/mnras/stx1605CrossRefGoogle Scholar
Sharina, M. E. et al., 2008, MNRAS, 384, 1544 CrossRefGoogle Scholar