TY - JOUR
T1 - The Complexity of the Cetus Stream Unveiled from the Fusion of STREAMFINDER and StarGO
AU - Yuan, Zhen
AU - Malhan, Khyati
AU - Sestito, Federico
AU - Ibata, Rodrigo A.
AU - Martin, Nicolas F.
AU - Chang, Jiang
AU - Li, Ting S.
AU - Caffau, Elisabetta
AU - Bonifacio, Piercarlo
AU - Bellazzini, Michele
AU - Huang, Yang
AU - Voggel, Karina
AU - Longeard, Nicolas
AU - Arentsen, Anke
AU - Doliva-Dolinsky, Amandine
AU - Navarro, Julio
AU - Famaey, Benoit
AU - Starkenburg, Else
AU - Aguado, David S.
N1 - Funding Information:
Z.Y. wishes to thank Guillaume F. Thomas for helpful comments when drafting the paper. Z.Y., R.A.I., N.F.M., A.A., and B.F. acknowledge the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation program (grant agreement No. 834148). Z.Y., R.A..I, N.F.M., E.C., and P.B. also acknowledge funding from the Agence Nationale de la Recherche (ANR project ANR-18-CE31-0017). K.M. acknowledges support from the Alexander von Humboldt Foundation at Max-Planck-Institut für Astronomie, Heidelberg. K.M. is also grateful to the IAU’s Gruber Foundation Fellowship Program for financial support. E.C. and P.B. to the list of people supported by ANR-18-CE31-0017. M.B. acknowledges the support to this research by the PRIN INAF 2019 grant ObFu 1.05.01.85.14 (“Building up the halo: chemo-dynamical tagging in the age of large surveys,” PI. S. Lucatello). Y.H. is supported by National Key R&D Program of China No. 2019YFA0405500 and National Natural Science Foundation of China grant Nos. 11903027, 11833006, and 11973001. E.S. acknowledges funding through VIDI grant “Pushing Galactic Archaeology to its limits” (with project No. VI.Vidi.193.093), which is funded by the Dutch Research Council (NWO). D.A. acknowledges support from the ERC Starting Grant NEFERTITI H2020/808240.
Publisher Copyright:
© 2022. The Author(s). Published by the American Astronomical Society.
PY - 2022/5/10
Y1 - 2022/5/10
N2 - We combine the power of two stream-searching tools, STREAMFINDER and StarGO applied to the Gaia EDR3 data, to detect stellar debris belonging to the Cetus stream system that forms a complex, nearly polar structure around the Milky Way. In this work, we find the southern extensions of the northern Cetus stream as the Palca stream and a new southern stream, which overlap on the sky but have different distances. These two stream wraps extend over more than 1/4100° on the sky (-60° < δ < +40°). The current N-body model of the system reproduces both as two wraps in the trailing arm. We also show that the Cetus system is confidently associated with the Triangulum/Pisces, Willka Yaku, and the recently discovered C-20 streams. The association with the ATLAS-Aliqa Uma stream is much weaker. All of these stellar debris are very metal-poor, comparable to the average metallicity of the southern Cetus stream with [Fe/H] = -2.17 ± 0.20. The estimated stellar mass of the Cetus progenitor is at least 105.6 M ⊙, compatible with Ursa Minor or Draco dwarf galaxies. The associated globular cluster with similar stellar mass, NGC 5824 very possibly was accreted in the same group infall. The multi-wrap Cetus stream is a perfect example of a dwarf galaxy that has undergone several periods of stripping, leaving behind debris at multiple locations in the halo. The full characterization of such systems is crucial to unravel the history of the assembly of the Milky Way, and importantly, to provide nearby fossils to study ancient low-mass dwarf galaxies.
AB - We combine the power of two stream-searching tools, STREAMFINDER and StarGO applied to the Gaia EDR3 data, to detect stellar debris belonging to the Cetus stream system that forms a complex, nearly polar structure around the Milky Way. In this work, we find the southern extensions of the northern Cetus stream as the Palca stream and a new southern stream, which overlap on the sky but have different distances. These two stream wraps extend over more than 1/4100° on the sky (-60° < δ < +40°). The current N-body model of the system reproduces both as two wraps in the trailing arm. We also show that the Cetus system is confidently associated with the Triangulum/Pisces, Willka Yaku, and the recently discovered C-20 streams. The association with the ATLAS-Aliqa Uma stream is much weaker. All of these stellar debris are very metal-poor, comparable to the average metallicity of the southern Cetus stream with [Fe/H] = -2.17 ± 0.20. The estimated stellar mass of the Cetus progenitor is at least 105.6 M ⊙, compatible with Ursa Minor or Draco dwarf galaxies. The associated globular cluster with similar stellar mass, NGC 5824 very possibly was accreted in the same group infall. The multi-wrap Cetus stream is a perfect example of a dwarf galaxy that has undergone several periods of stripping, leaving behind debris at multiple locations in the halo. The full characterization of such systems is crucial to unravel the history of the assembly of the Milky Way, and importantly, to provide nearby fossils to study ancient low-mass dwarf galaxies.
UR - https://www.scopus.com/pages/publications/85130475693
U2 - 10.3847/1538-4357/ac616f
DO - 10.3847/1538-4357/ac616f
M3 - Article
AN - SCOPUS:85130475693
SN - 0004-637X
VL - 930
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 103
ER -