A vast, thin plane of corotating dwarf galaxies orbiting the Andromeda galaxy
نویسندگان
چکیده
منابع مشابه
Pulsating red giant and supergiant stars in the Local Group dwarf galaxy Andromeda I
We have conducted an optical long-term monitoring survey of the majority of dwarf galaxies in the Local Group, with the Isaac Newton Telescope (INT), to identify the long period variable (LPV) stars. LPV stars vary on timescales of months to years, and reach the largest amplitudes of their brightness variations at optical wavelengths, due to the changing temperature. They trace stellar populati...
متن کاملInternal Kinematics of the Andromeda Ii Dwarf Spheroidal Galaxy
The High Resolution Echelle Spectrometer on the Keck I telescope has been used to measure nine radial velocities having a median precision of ' 2 km s−1 for seven red giants belonging to the isolated dwarf spheroidal galaxy Andromeda II (And II). We find a weighted mean radial velocity of vr = –188±3 km s−1 and a central velocity dispersion of σ0 = 9.3 −2.6 km s −1. There may be evidence for a ...
متن کاملOn the Accretion Origin of a Vast Extended Stellar Disk around the Andromeda Galaxy
We present the discovery of an inhomogenous, low-surface brightness, extended disk-like structure around the Andromeda galaxy (M31) based on a large kinematic survey of more than 2800 stars with the Keck/DEIMOS multi-object spectrograph. The stellar structure spans radii from 15 kpc out to ∼ 40 kpc, with detections out to R ∼ 70 kpc. The constituent stars lag the expected velocity of circular o...
متن کاملDwarf Spheroidal Galaxies : Keystones of Galaxy Evolution
Dwarf spheroidal galaxies are the most insignificant extragalactic stellar systems in terms of their visibility, but potentially very significant in terms of their role in the formation and evolution of much more luminous galaxies. We discuss the present observational data and their implications for theories of the formation and evolution of both dwarf and giant galaxies. The putative dark matt...
متن کاملDwarf Galaxies: Important Clues to Galaxy Formation
The smallest dwarf galaxies are the most straight forward objects in which to study star formation processes on a galactic scale. They are typically single cell star forming entities, and as small potentials in orbit around a much larger one they are unlikely to accrete much (if any) extraneous matter during their lifetime (either intergalactic gas, or galaxies) because they will typically lose...
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ژورنال
عنوان ژورنال: Nature
سال: 2013
ISSN: 0028-0836,1476-4687
DOI: 10.1038/nature11717