A new twist to an old story: HE 0450-2958 and the ULIRG -> optically bright QSO transition hypothesis

作者：Papadopoulos Padeli P^*; Feain Ilana J; Wagg Jeff; Wilner David J

来源：Astrophysical Journal, 2008, 684(2): 845-852.

DOI：10.1086/590233

• galaxies : active
• galaxies : ISM
• galaxies : starburst
• ISM : molecules quasars : individual (HE 0450-2958)

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)) similar to (1-2); 10(10) M(circle dot), which is greater than or similar to 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 similar to 370 M(circle dot) yr(-1), placing it firmly on the upper gas-rich/star-forming end of ultra luminous infrared galaxies (ULIRGs, L(IR) > 10(12) L(circle dot)). 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.

• 出版日期2008-9-10
• 单位CSIRO