distance, the enclosed Galactic mass is $\sim 3 \meleven$. We comment on the barionic mass fraction of the galaxies in the Local Group.'
author:
- 'Yoshiaki [Sofue]{}'
title: 'Pseudo Rotation Curve connecting the Galaxy, Dark Halo, and Local Group'
---

Introduction
============

The Milky Way Galaxy and M31 are the major constituents of the Local Group, around which many satellites and dwarf galaxies are orbiting(Mateo 1998; Sawa and Fujimoto 2005). Masses and extents of dark halos around these two giant galaxies are crucial for understanding the dynamics and structure of the Local Group. Outer rotation curve of the Galaxy is a key to put constraints on the dark halo structure. In this paper, we consider the dark halo of our Galaxy based on a recent accurate rotation curve (Sofue et al. 2008), and try to link it to the dynamics of the Local Group and M31.

Rotation curve of the Galaxy has been extensively used to derive the mass structure (Fich and Tremaine 1991; Sofue and Rubin 2001). The inner rotation curve was obtained by the terminal velocity method applied to radio line observations (Burton, Gordon 1978; Clemens 1985; Fich et al. 1989). The outer rotation curve has been obtained 