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

TL;DR

This paper reports the discovery of a new stellar stream named Yangtze in Gaia DR3 data, with properties suggesting a connection to Palomar 1 and the Anticenter stream, providing insights into galactic structure and stellar populations.

Contribution

The paper introduces the newly identified Yangtze stream, detailing its properties and potential association with known galactic features, advancing understanding of stellar streams.

Findings

Yangtze stream spans nearly 27° by 1.9° on sky.

Stellar population is approximately 11 Gyr old with [M/H] ~ -0.7.

Yangtze may be related to 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 $\sim$ 9.12 kpc and spans nearly 27$\deg$ by 1.9$\deg$ on sky. The colour-magnitude diagram of Yangtze indicates a stellar population of Age $\sim$ 11 Gyr and [M/H] $\sim$ -0.7 dex. It has a number density of about 5.5 stars degree$^{-2}$ along with a surface brightness of $\Sigma_G \simeq$ 34.9 mag arcsec$^{-2}$. The dynamics and metallicity estimate suggest that Yangtze may be closely related to Palomar 1 and the Anticenter stream.