Clusters have a wide range of richness

Clusters have a wide range of richness - Clusters have a...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Clusters have a wide range of richness, size, and internal structure in the distribution of galaxies. It is hard to draw a line between groups and clusters. We are located in a rather distinct subgroup on the outskirts of the Virgo Cluster, viz. the Local Group. It is now recognized to contain the following members; possibly bound satellites of the Milky Way and Andromeda are placed with their putative central galaxies. The edges of the Local Group are not as well-defined as one might like; not only distance but kinematics enter, through the zero-velocity surface at which the Hubble expansion would overcome the binding potential of the group. An up-to-date list of members is maintained by Mike Irwin. My tabulation follows Courteau and van den Bergh (1999 AJ 118, 337) and adding Cetus from Whiting, Hau, and Irwin (1999 AJ 118, 2767). Local Group Members Galaxy Type M B RA/Dec l, b D (kpc) v r (km/s) Milky Way Sbc I-II -20.0 1830-30 0 0 8.5 0 LMC SBm -18.4 0524-60 280 -33 50 270 SMC Im -17.0 0051-73 303 -44 63
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/10/2011 for the course AST AST1002 taught by Professor Emilyhoward during the Fall '10 term at Broward College.

Page1 / 2

Clusters have a wide range of richness - Clusters have a...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online