{"id":"W3207354965","doi":"10.3847/1538-4357/ac1675","title":"Stellar streams produced from dwarf galaxies provide direct evidence of the hierarchical formation of the Milky Way. Here, we present the first comprehensive study of the LMS-1 stellar stream, that we detect by searching for wide streams in the Gaia EDR3 data set using the STREAMFINDER algorithm. This stream was recently discovered by Yuan et al. We detect LMS-1 as a 60° long stream to the north of the galactic bulge, at a distance of ~20 kpc from the Sun, together with additional components that suggest that the overall stream is completely wrapped around the inner Galaxy. Using spectroscopic measurements from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope, the Sloan Digital Sky Survey, and the Apache Point Observatory Galactic Evolution Experiment, we infer that the stream is very metal-poor (⟨[Fe/H]⟩ = -2.1) with a significant metallicity dispersion (σ[Fe/H] = 0.4), and it possesses a large radial velocity dispersion (σv = 20 ± 4 km s-1). These estimates together imply that LMS-1 is a dwarf galaxy stream. The orbit of LMS-1 is close to polar, with an inclination of 75° to the galactic plane. Both the orbit and metallicity of LMS-1 are remarkably similar to the globular clusters NGC 5053, NGC 5024, and the stellar stream Indus. These findings make LMS-1 an important contributor to the stellar population of the inner Milky Way halo.","year":2021,"lang":"en","type":"article","venue":"HAL (Le Centre pour la Communication Scientifique Directe)","topic":"Stellar, planetary, and galactic studies","field":"Physics and Astronomy","cited_by":59,"is_retracted":false,"has_abstract":true,"ca_institutions":"","funders":"Institut sur la Nutrition et les Aliments Fonctionnels; Agence Nationale de la Recherche","keywords":"Physics; Milky Way; Astrophysics; Dwarf galaxy; Globular cluster; Astronomy; Galactic halo; Galaxy; Dwarf spheroidal galaxy; Metallicity; Stellar population; Galactic plane; Population; Halo; Star formation; Interacting galaxy","routes":{"ca_aff":false,"ca_fund":true,"ca_venue":false,"about_ca":false,"invisible_to_affiliation_only":true},"retraction":null,"screen":null,"direct_labels":[],"prediction":{"model_version":"codex-gemma-dda1882f352a","candidate_categories":["metaepi_narrow","sts"],"consensus_categories":[],"category_scores_codex":[0.006852297,0.001196891,0.001373515,0.00008557963,0.003151083,0.0007866937,0.004615749,0.000177067,0.00005266184],"category_scores_gemma":[0.001244392,0.0003487868,0.0004712037,0.001409834,0.002685109,0.0007014376,0.002470194,0.001310864,4.156263e-7],"about_ca_system_candidate":false,"about_ca_system_consensus":false,"about_ca_system_score_codex":0.0002650202,"about_ca_system_score_gemma":0.0004542468,"about_ca_topic_candidate":true,"about_ca_topic_consensus":true,"about_ca_topic_score_codex":0.04204787,"about_ca_topic_score_gemma":0.08817142,"domain_scores_codex":[0.981334,0.01175446,0.001538771,0.001307934,0.003160303,0.0009044854],"domain_scores_gemma":[0.9718851,0.01865829,0.003010732,0.00527785,0.001024219,0.0001437627],"domain_codex":null,"domain_gemma":null,"domain_candidate":null,"domain_consensus":null,"study_design_codex":"observational","study_design_gemma":"observational","study_design_scores_codex":[0.003582252,0.001235527,0.8900429,0.0001532634,0.002836017,0.000001171444,0.09693734,0.001417148,0.001907289,0.0000506724,0.0009867764,0.00084966],"study_design_scores_gemma":[0.003861995,0.0002920933,0.843953,0.002488413,0.002585473,0.00002081342,0.08161654,0.01491726,0.04876429,0.0002443051,0.0006307723,0.0006250118],"study_design_candidate":"observational","study_design_consensus":"observational","genre_codex":"empirical","genre_gemma":"empirical","genre_scores_codex":[0.9395809,0.003908427,0.0004124723,0.03379397,0.0001099764,0.01080788,0.01135146,0.0000147516,0.00002021789],"genre_scores_gemma":[0.9974228,0.0007874003,0.0001316524,0.0007531189,0.00005389026,0.0002906778,0.0004244452,0.00009846537,0.00003757156],"genre_candidate":"empirical","genre_consensus":"empirical","teacher_disagreement_score":0.05784193,"threshold_uncertainty_score":0.9998964,"prediction_status":"machine_predicted_unvalidated"},"machine_scores":{"provisional":true,"baseline":true,"maturity_gate_passed":false,"score_opus":0.04926241096777441,"score_gpt":0.2680682574165961,"score_spread":0.2188058464488217,"validation_status":"score_only:v0-immature-baseline","note":"Baseline scores from an immature model (maturity gate not passed). Scores rank; they never assert a category."}}