Extreme galactic wind and Wolf--Rayet features in infrared mergers and infrared quasi-stellar objects

Abstract

We report, as a part of a long-term study of infrared (IR) mergers and IR quasi-stellar objects (QSOs), detailed spectroscopic evidence for outflow (OF) and Wolf-Rayet (WR) features in the nearby mergers NGC 4038/39 and IRAS 23128−5919 (with low-velocity OF); and the nearby QSOs IRAS 01003−2238 and 13218+0552 (with extreme velocity OF, EVOF). We also study the presence of EVOF in a complete sample of ultraluminous IR galaxies and QSOs ('The IRAS 1-Jy Survey', 118 objects). We found EVOF in IRAS 11119+3257, 14394+5332, 15130−1958 and 15462−0450.The low-velocity OF components were detected mainly in objects with starburst processes, i.e. OF associated with galactic winds generated in multiple type II supernova (SN) explosions and massive stars. Meanwhile the EVOF were detected mainly in objects with strong starburst plus obscured IR QSOs; which suggests that the coexistence of both processes could generate EVOF.Hubble Space Telescope (HST) images of IR+BAL+Fe II QSOs show in practically all of these objects 'arc or shell' features probably associated with galactic winds [i.e. with multiple type II SN explosions or with starburst+active galactic nuclei (AGN)] or merger processes.In addition, we analyse the presence of Wolf-Rayet features in part of the large sample of bright PG-QSOs. We found possible WR features in the Fe II PG-QSOs PG 1244+026, 1444+407, 1448+273 and 1535+547.The results are discussed mainly within the framework of the composite scenario: starburst+AGN. We analyse the presence of extreme starburst and galactic winds as a possible link between IR mergers and IR QSOs. Finally, we discuss the probable role of mergers, extreme starburst and galactic winds processes in BAL-QSOs and galaxies in formation.

A 0.8–2.4μm spectral atlas of active galactic nuclei

“…They both show a spectrum dominated by molecular H 2 and weak Brγ emission. Our composite JHK spectroscopy reveals a poor emis- Lipari et al (2003). The continuum emission is steep and featureless of a powerlaw type.…”

Quantifying the AGN-driven outflows in ULIRGs (QUADROS) – I: VLT/Xshooter observations of nine nearby objects

“…Indeed, outflows have been observed in all gas phases in merging galaxies: ionized (e.g. [OIII]; Wilman et al 1999;Lipari et al 2003;Holt et al 2003;Holt et al 2006; Cicone et al 2012;Veilleux et al 2013;Cicone et al 2014).…”

Obscured Activity: AGN, Quasars, Starbursts and ULIGs Observed by the Infrared Space Observatory

“…Alternatively they may be a young phase in quasar evolution. The latter together with the high occurrence of BALQSO in IRAS selected samples suggests that they may be a transition stage between ULIGs and QSOs (Voit et al, 1993;Lípari, 1994;Egami et al, 1996;Canalizo and Stockton, 2001;Lípari et al, 2003). In this scenario very young QSOs are ejecting their gaseous envelopes at very high velocity close to the initiation of the active phase of the black hole (Hazard et al, 1984).…”

“…Recently, Lípari et al (2003) identified possible Wolf-Rayet features in the spectra of some PG quasars. The identifying Wolf-Rayet signatures are in the visible and thus are only representative of the unobscured components.…”

“…(1) merger -giant shocks -super-starbursts + galactic winds -elliptical galaxies (Joseph, 1999) (2) merger -H 2 inflow (starbursts) -cold ULIRGs -warm ULIRGs+QSOs -optical QSOs (Sanders, 1999) (3) merger/s -extreme starburst + galactic wind (inflow + outflow) -FeII/BAL composite IR-QSOs -standard QSOs and ellipticals (Lípari et al, 2003) 6.9.1. Merger Stage and Luminosity Merging activity that initiates associated starbursts leading to the ultraluminous behaviour in the early stages is common to all of the scenarios above.…”