Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-17T15:13:33.717Z Has data issue: false hasContentIssue false
  • English
  • Français

Stellar Content of Local Group Galaxies - An Introduction

Published online by Cambridge University Press:  25 May 2016

Sidney van den Bergh
Sidney van den Bergh*
Affiliation:
Dominion Astrophysical Observatory, Herzberg Institute of Astrophysics, National Research Council of Canada, 5071 West Saanich Road, Victoria, British Columbia, V8X 4M6, Canada E-mail: [email protected]

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

In The Realm of the Nebulae, Hubble (1936) first drew attention to the fact that the Milky Way system and the Andromeda galaxy belong to a small cluster that also contains M32, M33, the Magellanic Clouds, NGC 205, NGC 6822 and IC 1613. Hubble also listed IC 10 as a possible member of what he referred to as “the Local Group”. Inspection of the prints of the Palomar Sky Survey shows (van den Bergh 1962) that a large fraction of all field galaxies are located in such small groups or clusters. Our Milky Way system therefore appears to be situated in a rather typical region of space. All of the well-established Local Group members that are listed above are at distances D ≤ 1.0 Mpc. A conservative limit D < 1.5 Mpc may therefore be used to search for new Local Group members. An additional criterion for physical membership in the Local Group is that a candidate member with solar apex distance θ and radial velocity Vr should lie close to the Vr versus cos θ relation for well-established Local Group members (Courteau & van den Bergh 1999). Finally candidates may be disqualified from membership if they appear projected on nearby groups of galaxies that are centered at distances greater than 1.5 Mpc. In particular the Local Group candidates NGC 1560, NGC 1569, UGC-A86 and Cassiopeia 1 were excluded because they appear projected on (or near) the IC 342/Maffei group. Furthermore NGC 55 and UKS 2323-326 were excluded because they appear projected on (or near) the Sculptor (= South Polar) group. Observational data on 35 probable Local Group members are given in Table 1.

Type
Part 1: Setting the Scene
Information
Symposium - International Astronomical Union , Volume 192: The Stellar Content of Local Group Galaxies , 1999 , pp. 3 - 16
Copyright
Copyright © Astronomical Society of the Pacific 1999 

References

Baade, W. 1944a, ApJ, 100, 137 CrossRefGoogle Scholar
Baade, W. 1944b, ApJ, 100, 147 Google Scholar
Babul, A., Ferguson, H.C. 1996, ApJ, 458, 100 CrossRefGoogle Scholar
Blitz, L., Spergel, D.N. 1991, ApJ, 379, 631 CrossRefGoogle Scholar
Butcher, H. 1977, ApJ, 216, 372 Google Scholar
Courteau, S., van den Bergh, S. 1999, in preparation Google Scholar
Einasto, J., Saar, E., Kaasik, A. 1974, Nature, 252, 111 Google Scholar
Feast, M.W., Catchpole, R.M. 1997, MNRAS, 186, L1 Google Scholar
Harris, W.E. 1991, ARA&A, 29, 543 Google Scholar
Hubble, E. 1936, The Realm of the Nebulae , Yale University Press, New Haven Google Scholar
Irwin, M.J. 1994 in: Dwarf Galaxies , (eds.) Meylan, G. & Pugniel, P., ESO, Garching, p. 27 Google Scholar
Kahn, F.D., Woltjer, L. 1959, ApJ, 130, 705 CrossRefGoogle Scholar
Lauer, T. et al. 1993, AJ, 106, 1436 Google Scholar
Madore, B.F., van den Bergh, S., Rogstad, D.H. 1974, ApJ, 191, 317 Google Scholar
Mathewson, D.S., Ford, V.L., Visvanathan, N. 1986, ApJ, 301, 664 CrossRefGoogle Scholar
McLean, I.S., Liu, T. 1996, ApJ, 456, 499 CrossRefGoogle Scholar
Morgan, W.W. 1959, AJ, 64, 432 CrossRefGoogle Scholar
Morgan, W.W., Whitford, A.E., Code, A.D. 1953, ApJ, 118, 318 Google Scholar
Morrison, H.L. 1993, AJ, 106, 578 CrossRefGoogle Scholar
Olsen, K.A.G., et al. 1998, MNRAS, in press Google Scholar
Pritchet, C.J., van den Bergh, S. 1994, AJ, 107, 1730 CrossRefGoogle Scholar
Roberts, M.S. 1972, in: External Galaxies and Quasi-stellar Objects , (ed.) Evans, D.S., Reidel, Dordrecht, p. 12 Google Scholar
Roberts, M.S., Whitehurst, R.N. 1975, ApJ, 201, 327 Google Scholar
Sage, L.J., Welch, G.A., Mitchell, G.F. 1998, ApJ, in press Google Scholar
Sarajedini, A., Geisler, D., Harding, P., Schommer, R. 1998, ApJ, in press Google Scholar
Schommer, R.A., Christian, C.A., Caldwell, N., Bothun, G.D., Huchra, J. 1991, AJ, 101, 873 Google Scholar
Schommer, R.A., Olszewski, E.W., Suntzeff, N.B., Harris, H.C. 1992, AJ, 103, 447 Google Scholar
Searle, L., Zinn, R. 1978, ApJ, 225, 357 Google Scholar
Udalski, A. et al. 1998, astro-ph/9803035 Google Scholar
van den Bergh, S. 1962, Zs.f.Astrophyik, 55, 21 Google Scholar
van den Bergh, S. 1969, ApJS, 19, 145 Google Scholar
van den Bergh, S. 1972, ApJ, 171, L31 CrossRefGoogle Scholar
van den Bergh, S. 1998a, ApJ, 495, L79 Google Scholar
van den Bergh, S. 1998b, AJ, 116, 1688 CrossRefGoogle Scholar
van den Bergh, S. 2000, The Galaxies of the Local Group, Cambridge: Cambridge Univ. Press, in press CrossRefGoogle Scholar
Walker, A.R. 1992, ApJ, 390, L81 Google Scholar
Westerlund, B.E. 1997, The Magellanic Clouds, Cambridge: Cambridge Univ. Press CrossRefGoogle Scholar
Zwicky, F. 1933, Helv. Phys. Acta, 6, 11 Google Scholar