{"paper":{"title":"Population Synthesis Studies of Close Binary Systems Using a Variable Common Envelope Efficiency Parameter: I. Dependence upon Secondary Mass","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"Kevin P. Weiler, Michael Politano","submitted_at":"2007-02-25T01:11:00Z","abstract_excerpt":"We perform population synthesis calculations of present-day post common envelope binaries (PCEBs) and zero-age cataclysmic variables (ZACVs) using a common envelope efficiency parameter, alphaCE, that is a function of secondary mass, Ms. We investigate three basic possibilities: (1) a standard constant alphaCE prescription, with alphaCE = 1.0, 0.6, 0.3, 0.2, 0.1 and 0.05, to provide a baseline for comparison, (2) a power law dependence, alphaCE = (Ms)^n, with n = 0.5, 1.0 and 2.0, and (3) a dependence in which alphaCE approaches1 for large secondary masses and alphaCE = 0 below some assumed cu"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0702662","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}