{"doi":"10.3847/2041-8213/ada02b","title":"The GD-1 Stellar Stream Perturber as a Core-collapsed Self-interacting Dark Matter Halo","abstract":"Abstract The GD-1 stellar stream exhibits spur and gap structures that may result from a close encounter with a dense substructure. When interpreted as a dark matter subhalo, the perturber is denser than predicted in the standard cold dark matter (CDM) model. In self-interacting dark matter (SIDM), however, a halo could evolve into a phase of gravothermal collapse, resulting in a higher central density than its CDM counterpart. We conduct high-resolution controlled N -body simulations to show that a collapsed SIDM halo could account for the GD-1 perturber's high density. We model a progenitor halo with a mass of 3 × 10 8 M ⊙ , motivated by a cosmological simulation of a Milky Way analog, and evolve it in the Milky Way's tidal field. For a cross section per mass of σ / m ≈ 30–100 cm 2 g −1 at <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:msub> <mml:mrow> <mml:mi>V</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant=\"normal\">max</mml:mi> </mml:mrow> </mml:msub> <mml:mo>~</mml:mo> <mml:mn>10</mml:mn> <mml:mspace width=\"1em\"/> <mml:mi mathvariant=\"normal\">km</mml:mi> <mml:mspace width=\"1em\"/> <mml:msup> <mml:mrow> <mml:mi mathvariant=\"normal\">s</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:math> , the enclosed mass of the SIDM halo within the inner 10 pc can be increased by more than 1 order of magnitude compared to its CDM counterpart, leading to a good agreement with the properties of the GD-1 perturber. Our findings indicate that stellar streams provide a novel probe into the self-interacting nature of dark matter.","journal":"The Astrophysical Journal Letters","year":2025,"id":510370,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":20,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9579,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1366679,"name":"Hai-Bo Yu","orcid":"0000-0002-8421-8597","position":1,"is_corresponding":false},{"id":1356360,"name":"Daneng Yang","orcid":"0000-0002-5421-3138","position":2,"is_corresponding":false},{"id":1356361,"name":"Ethan O. Nadler","orcid":"0000-0002-1182-3825","position":3,"is_corresponding":false},{"id":1366678,"name":"X. Zhang","orcid":"0009-0009-2791-1684","position":0,"is_corresponding":true}],"reference_count":98,"raw_metadata":null,"created_at":"2026-07-19T02:47:36.538276Z","pmid":"39759172","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}