Finding halo streams with a pencil-beam survey: new wraps in the Sagittarius stream

Abstract

We use data from two CFHT-MegaCam photometric pencil-beam surveys in the g' and the r' bands to measure distances to the Sagittarius, the Palomar 5 and the Orphan stream. We show that, using a cross-correlation algorithm to detect the turnoff point of the main sequence, it is possible to overcome the main limitation of a two-bands pencil-beam survey, namely the lack of adjacent control-fields that can be used to subtract the foreground and background stars to enhance the signal on the colour-magnitude diagrams (CMDs). We describe the cross-correlation algorithm and its implementation. We combine the resulting main sequence turnoff points with theoretical isochrones to derive photometric distances to the streams. Our results (31 detections on the Sagittarius stream and one each for the Palomar 5 and the Orphan streams) confirm the findings by previous studies, expand the distance trend for the Sagittarius faint southern branch and, for the first time, trace the Sagittarius faint branch of the northern-leading arm out to 56 kpc. In addition, they show evidence for new substructure: we argue that these detections trace the continuation of the Sagittarius northern-leading arm into the southern hemisphere, and find a nearby branch of the Sagittarius trailing wrap in the northern hemisphere.

16 pages, 15 figures, 2 tables

References in corpus (21)

• Cats and Dogs, Hair and A Hero: A Quintet of New Milky Way Companions
• The accretion origin of the Milky Way's stellar halo
• The ACS Nearby Galaxy Survey Treasury IX. Constraining asymptotic giant branch evolution with old metal-poor galaxies
• Detection of a 63 Degree Cold Stellar Stream in the Sloan Digital Sky Survey
• An Orphan in the "Field of Streams"
• Is the SMC Bound to the LMC? The HST Proper Motion of the SMC
• The Origin of the Bifurcation in the Sagittarius Stream
• Detection of a 60 Degree-Long Dwarf Galaxy Debris Stream
• Precession of the Sagittarius stream
• 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
• Substructure in Tidal Streams; Tributaries in the Anticenter Ring
• A 22 Degree Tidal Tail for Palomar 5
• The environmental dependence of the stellar mass function at z~1: Comparing cluster and field between the GCLASS and UltraVISTA surveys
• Evidence for a Milky Way Tidal Stream Reaching Beyond 100 kpc
• Is Ursa Major II the Progenitor of the Orphan Stream?
• Identifying Contributions to the Stellar Halo from Accreted, Kicked-Out, and In Situ Populations
• A Pan-STARRS1 View of the Bifurcated Sagittarius Stream
• Proper Motions in Kapteyn Selected Area 103: A Preliminary Orbit for the Virgo Stellar Stream
• The Tidal Tails of NGC 5466
• Hunting the Parent of the Orphan Stream: Identifying Stream Members from Low-Resolution Spectroscopy

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