A Dwarf Galaxy Debris Stream Associated with Palomar 1 and the Anticenter Stream

Abstract

We report the discovery of a new stream (dubbed as Yangtze) detected in Gaia Data Release 3. The stream is at a heliocentric distance of ∼9.12 kpc and spans nearly 27° by 1.°9 on the sky. The color–magnitude diagram of Yangtze indicates a stellar population of age ∼11 Gyr and [M/H] ∼ −0.7 dex. It has a number density of about 5.5 stars deg−2 along with a surface brightness of Σ G ≃ 34.9 mag arcsec−2. The dynamics and metallicity estimate suggest that Yangtze may be closely related to Palomar 1 and the Anticenter Stream.