Outer Regions of the Milky Way

Abstract

With the start of the Gaia era, the time has come to address the major challenge of deriving the star formation history and evolution of the disk of our MilkyWay. Here we review our present knowledge of the outer regions of the Milky Way disk population. Its stellar content, its structure and its dynamical and chemical evolution are summarized, focussing on our lack of understanding both from an observational and a theoretical viewpoint. We describe the unprecedented data that Gaia and the upcoming ground-based spectroscopic surveys will provide in the next decade. More in detail, we quantify the expect accuracy in position, velocity and astrophysical parameters of some of the key tracers of the stellar populations in the outer Galactic disk. Some insights on the future capability of these surveys to answer crucial and fundamental issues are discussed, such as the mechanisms driving the spiral arms and the warp formation. Our Galaxy, theMilkyWay, is our cosmological laboratory for understanding the process of formation and evolution of disk galaxies. What we learn in the next decades will be naturally transferred to the extragalactic domain.

22 pages, 10 figures, Invited review, Book chapter in "Outskirts of Galaxies", Eds. J. H. Knapen, J. C. Lee and A. Gil de Paz, Astrophysics and Space Science Library, Springer, in press

References in corpus (33)

• The Galaxy in Context: Structural, Kinematic and Integrated Properties
• New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey
• The Geneva-Copenhagen Survey of the Solar neighbourhood II. New uvby calibrations and rediscussion of stellar ages, the G dwarf problem, age-metallicity diagram, and heating mechanisms of the disk
• Outer structure of the Galactic warp and flare: explaining the Canis Major over-density
• The Gaia-ESO Survey: the Galactic Thick to Thin Disc transition
• Rings and Radial Waves in the Disk of the Milky Way
• The Vertical Structure of the Outer Milky Way HI Disk
• A First Constraint on the Thick Disk Scale Length: Differential Radial Abundances in K Giants at Galactocentric Radii 4, 8, and 12 kpc
• Tracing chemical evolution over the extent of the Milky Way's Disk with APOGEE Red Clump Stars
• On the fine structure of the Cepheid metallicity gradient in the Galactic thin disk
• Dark matter in the Milky Way, II. the HI gas distribution as a tracer of the gravitational potential
• The Tycho-Gaia astrometric solution. How to get 2.5 million parallaxes with less than one year of Gaia data
• Constraining the thick disc formation scenario of the Milky Way
• On the origin of rR_1 ring structures in barred galaxies
• Bending and Breathing Modes of the Galactic Disk
• Abundance gradients in the Milky Way for alpha elements, Iron peak elements, Barium, Lanthanum and Europium
• The Gaia-ESO Survey: the chemical structure of the Galactic discs from the first internal data release
• Re-visiting the relations: Galactic thin disc age-velocity dispersion relation
• Revisiting two local constraints of the Galactic chemical evolution
• Flare in the Galactic stellar outer disc detected in SDSS-SEGUE data
• On the galaxy spiral arms' nature as revealed by rotation frequencies
• The Gaia-ESO Survey: Probes of the inner disk abundance gradient
• Cepheid Variables in the Flared Outer Disk of our Galaxy
• The Complex Structure of Stars in the Outer Galactic Disk as revealed by Pan-STARRS1
• The Edge of the Milky Way Stellar Disk Revealed Using Clump Giant Stars as Distance Indicators
• Impacts of a Flaring Star-forming Disc and Stellar Radial Mixing on the Vertical Metallicity Gradient
• Vertical velocities from proper motions of red clump giants
• An Introduction to Galactic Chemical Evolution
• The analysis of realistic Stellar Gaia mock catalogues. I. Red Clump Stars as tracers of the central bar
• Does the stellar distribution flare? A comparison of stellar scale heights with LAB HI data
• First detection of the field star overdensity in the Perseus arm
• Characterizing the Galactic warp with Gaia: I. The tilted ring model with a twist
• Kinematics of symmetric Galactic longitudes to probe the spiral arms of the Milky Way with Gaia

Cited by in corpus (1)

• Resolved Stellar Populations as Tracers of Outskirts