A skewer survey of the Galactic halo from deep CFHT and INT images

Abstract

We study the density profile and shape of the Galactic halo using deep multicolour images from the MENeaCS and CCCP projects, over 33 fields selected to avoid overlap with the Galactic plane. Using multicolour selection and PSF homogenization techniques we obtain catalogues of F stars (near-main sequence turnoff stars) out to Galactocentric distances up to 60kpc. Grouping nearby lines of sight, we construct the stellar density profiles through the halo in eight different directions by means of photometric parallaxes. Smooth halo models are then fitted to these profiles. We find clear evidence for a steepening of the density profile power law index around R=20 kpc, from -2.50 +- 0.04 to -4.85 +- 0.04, and for a flattening of the halo towards the poles with best-fit axis ratio 0.63 +- 0.02. Furthermore, we cannot rule out a mild triaxiality (w>=0.8). We recover the signatures of well-known substructure and streams that intersect our lines of sight. These results are consistent with those derived from wider but shallower surveys, and augur well for upcoming, wide-field surveys of comparable depth to our pencil beam surveys.

14 pages, 8 figures, 6 tables

References in corpus (8)

• The Milky Way Tomography with SDSS: II. Stellar Metallicity
• The accretion origin of the Milky Way's stellar halo
• Stellar SEDs from 0.3-2.5 Microns: Tracing the Stellar Locus and Searching for Color Outliers in SDSS and 2MASS
• An Orphan in the "Field of Streams"
• CARS: the CFHTLS-Archive-Research Survey; I. Five-band multi-colour data from 37 sq. deg. CFHTLS-Wide observations
• Substructure in Tidal Streams; Tributaries in the Anticenter Ring
• Galactic halo stellar structures in the Triangulum-Andromeda region
• RR Lyrae in XSTPS: The halo density profile in the North Galactic Cap

Cited by in corpus (16)

• The total stellar halo mass of the Milky Way
• The local high velocity tail and the Galactic escape speed
• The first all-sky view of the Milky Way stellar halo with Gaia+2MASS RR Lyrae
• The Stellar Halo of the Galaxy is Tilted & Doubly Broken
• Stellar halo substructure generated by bar resonances
• Mapping the Milky Way with LAMOST II: the stellar halo
• Radial halo substructure in harmony with the Galactic bar
• Mapping the anisotropic Galactic stellar halo with Blue Horizontal Branch stars
• The Stellar Density Profile of the Distant Galactic Halo
• Contribution of Gaia Sausage to the Galactic Stellar Halo Revealed by K Giants and Blue Horizontal Branch Stars from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope, Sloan Digital Sky Survey, and Gaia
• Modelling the stellar halo with RR-Lyrae stars
• Constructing the Milky Way Stellar Halo in the Galactic Center by Direct Orbit Integration
• Influence of the Gaia-Sausage-Enceladus on the density shape of the Galactic stellar halo revealed by halo K giants from the LAMOST survey
• Mapping the Milky Way's stellar halo with 2D data
• Deciphering the Kinematic Substructure of Local Dark Matter with LAMOST K Giants
• photoD with Rubin's Data Preview 1: first stellar photometric distances and deficit of faint blue stars. Stellar distances with Rubin's DP1