2008/01/31 by Padeli P. Papadopoulos, Ilana J. Feain, Ilana Feain +2 · 1 citation
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Galaxy #Line (geometry) #Luminous infrared galaxy #Physics #QSOS #Quasar #Spiral galaxy #Star formation #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/590233
25 pages, 5 figures, accepted for publication by The Astrophysical Journal
arxiv created 2008/05/21 · openalex publication_date 2008/09/04 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We report on interferometric imaging of the CO J = 1–0 and J = 3–2 line emission from the controversial QSO/galaxy pair HE 0450–2958. The detected CO J = 1–0 line emission is found associated with the disturbed companion galaxy, not the luminous QSO , and implies M gal (H 2 ) ∼ (1–2) × 10 10 M ☉ , which is ≳30% of the dynamical mass in its CO-luminous region. Fueled by this large gas reservoir, this galaxy is the site of an intense starburst with SFR ∼ 370 M ☉ yr −1 , placing it firmly on the upper gas-rich/star-forming end of ultra luminous infrared galaxies (ULIRGs, L IR > 10 12 L ☉ ). This makes HE 0450–2958 the first case of extreme starburst and powerful QSO activity, intimately linked (triggered by a strong interaction) but not coincident. The lack of CO emission toward the QSO itself renews the controversy regarding its host galaxy by making a gas-rich spiral (the typical host of narrow-line Seyfert 1 AGNs) less likely. Finally, given that HE 0450–2958 and similar IR-warm QSOs are considered typical ULIRG → optically bright QSO transition candidates, our results raise the possibility that some may simply be gas-rich/gas-poor (e.g., spiral/elliptical) galaxy interactions which "activate" an optically bright unobscured QSO in the gas-poor galaxy, and a starburst in the gas-rich one. We argue that such interactions may have gone largely unnoticed even in the local universe because the combination of tools necessary to disentangle the progenitors (high-resolution and S/N optical and CO imaging) became available only recently.