The Next Generation Virgo Cluster Survey. XIX. Tomography of Milky Way Substructures in the NGVS Footprint

Abstract

The Next Generation Virgo Cluster Survey (NGVS) is a deep $u^{\ast }giz$ survey targeting the Virgo cluster of galaxies at 16.5~Mpc. This survey provides high-quality photometry over an $\sim$ 100 deg${}^2$ region straddling the constellations of Virgo and Coma Berenices. This sightline through the Milky Way is noteworthy in that it intersects two of the most prominent substructures in the Galactic halo: the Virgo Over-Density (VOD) and Sagittarius stellar stream (close to its bifurcation point). In this paper, we use deep $u^{\ast }gi$ imaging from the NGVS to perform tomography of the VOD and Sagittarius stream using main-sequence turnoff (MSTO) stars as a halo tracer population. The VOD, whose centroid is known to lie at somewhat lower declinations ($\alpha \sim 190^{\circ }$, $\delta \sim -5^{\circ }$) than is covered by the NGVS, is nevertheless clearly detected in the NGVS footprint at distances between $\sim$ 8 and 25~kpc. By contrast, the Sagittarius stream is found to slice directly across the NGVS field at distances between 25 and 40~kpc, with a density maximum at $\simeq$~35~kpc. No evidence is found for new substructures beyond the Sagittarius stream, at least out to a distance of $\sim$~90 kpc --- the largest distance to which we can reliably trace the halo using MSTO stars. We find clear evidence for a distance gradient in the Sagittarius stream across the $\sim 30$~deg of sky covered by the NGVS and its flanking fields. We compare our distance measurements along the stream to those predicted by leading stream models.

14 pages, 10 figures, accepted for publication in ApJ

References in corpus (24)

• "Skinny Milky Way, Please", says Sagittarius
• The Origin of the Bifurcation in the Sagittarius Stream
• Detection of a 60 Degree-Long Dwarf Galaxy Debris Stream
• MegaPipe: the MegaCam image stacking pipeline at the Canadian Astronomical Data Centre
• The QUEST RR Lyrae Survey II: The Halo Overdensities in the First Catalog
• A 2MASS All-Sky View of the Sagittarius Dwarf Galaxy: Variation of the Metallicity Distribution Function Along the Sagittarius Stream
• Tracing Sagittarius Structure with SDSS and SEGUE Imaging and Spectroscopy
• The Overdensity in Virgo, Sagittarius Debris, and the Asymmetric Spheroid
• The Next Generation Virgo Cluster Survey. VI. The Kinematics of Ultra-compact Dwarfs and Globular Clusters in M87
• The PAndAS Field of Streams: stellar structures in the Milky Way halo toward Andromeda and Triangulum
• Revealing Substructure in the Galactic Halo - The SEKBO RR Lyrae Survey
• The Next Generation Virgo Cluster Survey. X. Properties of Ultra-Compact Dwarfs in the M87, M49 and M60 Regions
• The Next Generation Virgo Cluster Survey. XII. Stellar Populations and Kinematics of Compact, Low-Mass Early-Type Galaxies from Gemini GMOS-IFU Spectroscopy
• The Next Generation Virgo cluster Survey. V. modelling the dynamics of M87 with the Made-to-Measure method
• Tracing the tidal streams of the Sagittarius dSph, and halo Milky Way features, with carbon-rich long-period variables
• A comprehensive view of the Virgo Stellar Stream
• Sagittarius stream 3-d kinematics from SDSS Stripe 82
• The Next Generation Virgo Cluster Survey. XV. The photometric redshift estimation for background sources
• Exposing Sgr tidal debris behind the Galactic disk with M giants selected in WISE$\cap$2MASS
• Stellar over-densities in the halo: the extent of the Virgo over-density
• The Next Generation Virgo Cluster Survey. IX. Estimating the Efficiency of Galaxy Formation on the Lowest-Mass Scales
• A Deep Proper-Motion Survey in Kapteyn Selected Areas: I. Survey Description and First Results for Stars in the Tidal Tail of Sagittarius and in the Monoceros Ring
• The GALEX Ultraviolet Virgo Cluster Survey (GUViCS). V. Ultraviolet diffuse emission and cirrus properties in the Virgo cluster direction
• Selecting Sagittarius: Identification and Chemical Characterization of the Sagittarius Stream

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• The Pristine survey III: Spectroscopic confirmation of an efficient search for extremely metal-poor stars
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• Disentangling the Virgo Overdensity with RR Lyrae stars
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