Accurate Stellar Kinematics at Faint Magnitudes: application to the Bootes~I dwarf spheroidal galaxy

Abstract

We develop, implement and characterise an enhanced data reduction approach which delivers precise, accurate, radial velocities from moderate resolution spectroscopy with the fibre-fed VLT/FLAMES+GIRAFFE facility. This facility, with appropriate care, delivers radial velocities adequate to resolve the intrinsic velocity dispersions of the very faint dSph dwarf galaxies. Importantly, repeated measurements let us reliably calibrate our individual velocity errors ($0.2\le {\delta }_V\le 5$ km s${}^{-1}$) and directly detect stars with variable radial velocities. We show, by application to the Bootes-1 dwarf spheroidal, that the intrinsic velocity dispersion of this system is significantly below 6.5\,km/s reported by previous studies. Our data favor a two-population model of Bootes-1, consisting of a majority `cold' stellar component, with velocity dispersion $2.4_{-0.5}^{+0.9}$\,km/s, and a minority `hot' stellar component, with velocity dispersion $\sim 9$\,km/s, although we can not completely rule out a single component distribution with velocity dispersion $4.6_{-0.6}^{0.8}$\,km/s. We speculate this complex velocity distribution actually reflects the distribution of velocity anisotropy in Bootes-1, which is a measure of its formation processes.

ApJ in press. Anticipated publication July 1, 2011

References in corpus (21)

• The Kinematics of the Ultra-Faint Milky Way Satellites: Solving the Missing Satellite Problem
• Cats and Dogs, Hair and A Hero: A Quintet of New Milky Way Companions
• The Observed properties of Dark Matter on small spatial scales
• Hundreds of Milky Way Satellites? Luminosity Bias in the Satellite Luminosity Function
• The Luminosity Function of the Milky Way Satellites
• Velocity Dispersion Profiles of Seven Dwarf Spheroidal Galaxies
• The Cold Dark Matter Halos of Local Group Dwarf Spheroidals
• The Invisibles: A Detection Algorithm to Trace the Faintest Milky Way Satellites
• Chemical Enrichment in the Faintest Galaxies: the Carbon and Iron Abundance Spreads in the Boötes I Dwarf Spheroidal Galaxy and the Segue 1 System
• Leo V: A Companion of a Companion of the Milky Way Galaxy
• Metallicity and Alpha-Element Abundance Measurement in Red Giant Stars from Medium Resolution Spectra
• Stellar kinematics and metallicities in the Leo I dwarf spheroidal galaxy -- wide field implications for galactic evolution
• Exploring Halo Substructure with Giant Stars: The Dynamics and Metallicity of the Dwarf Spheroidal in Bootes
• A spectroscopic confirmation of the Bootes II dwarf spheroidal
• Revision of VLT/UVES constraints on a varying fine-structure constant
• Variable stars in the newly discovered Milky Way satellite in Bootes
• Revisiting the influence of unidentified binaries on velocity dispersion measurements in ultra-faint stellar systems
• Fiducial Stellar Population Sequences for the u'g'r'i'z' System
• Numerical Color-Magnitude Diagram Analysis of SDSS Data and Application to the New Milky Way satellites
• Absence of HI in the Bootes Dwarf Spheroidal Galaxy
• The Age and Metallicity of the Bootes I System

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