{"paper":{"title":"A deep Chandra, VLA and Spitzer IRAC study of the very low luminosity nucleus of the elliptical NGC821","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"3), A. Baldi (2), A. Siemiginowska (2), Bologna University, Cambridge, D.W. Kim (2) ((1) Astronomy Dept., G. Fabbiano (2), Italy; (2) Harvard-Smithsonian Center for Astrophysics, L. Greenhill (2), MA (USA); (3) Mullard Space Science Laboratory, M. Elvis (2), R. Soria (2, S. Pellegrini (1), UK), University College London","submitted_at":"2007-01-23T10:54:12Z","abstract_excerpt":"The relatively nearby (distance=24.1 Mpc) elliptical galaxy NGC821 hosts an extreme example of a quiescent central massive black hole, for which deep Chandra observations revealed a nuclear source for the first time (with L(2-10 keV)/L_Edd ~ 3.6X10^{-8}). We present here a multiwavelength study of this nucleus, including VLA observations that detect a radio counterpart to the Chandra nuclear source at 1.4 GHz, with a flux density of 127 $\\mu$m and possibly a flat spectral shape; we also consider new Spitzer IRAC observations and archival HST images. With these data we discuss possible scenario"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0701642","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"}