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Register a new userA new twist to an old story: HE 0450-2958, and the ULIRG$to $(optically bright QSO) transition hypothesis
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Padelis Papadopoulos Dr
Publication date
2008
fields
Physics
and research's language is
English
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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. {it The detected CO J=1--0 line emission is found associated with the disturbed companion galaxy not the luminous QSO,} and implies $rm M_{gal}(H_2)sim (1-2)times 10^{10} M_{odot}$, which is $ga 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 $rm SFRsim 370 M_{odot} yr^{-1}$, placing it firmly on the upper gas-rich/star-forming end of Ultra Luminous Infrared Galaxies (ULIRGs, $rm L_{IR}>10^{12} L_{odot}$). 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 towards 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$to $(optically bright QSO) transition candidates, our results raise the possibility that some may simply be {it 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 disentagle the progenitors (high resolution and S/N optical {it and} CO imaging) became available only recently.
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We report new K-band, radio continuum, and CO (1-0) imaging observations and 850 micron photometric observations of PDS 456, the most luminous QSO in the local universe (z<0.3). The 0.6 resolution K-band image obtained using the Keck telescope shows three compact K~16.5 (M(K)~ -21) sources at a projected distance of ~10 kpc to the southwest, and the host galaxy of PDS 456 may be interacting or merging with one or more companions. The observations using the OVRO millimeter array has revealed a narrow CO (1-0) line (FWHM = 181 km/s) centered at z=0.1849, and 9 x 10^9 solar mass of molecular gas mass is inferred. Radio continuum luminosity is nearly an order of magnitude larger than expected from its FIR luminosity, and the radio source, unresolved by the 2 beam of the VLA, is dominated by the AGN activity. Our 850 micron photometric observations suggest that the cold dust content of the host galaxy is less than one half of the amount in Arp 220. Its SED has both a QSO-like and a ULIRG-like nature, and the observed IR, X-ray, and gas properties suggest that the AGN activity dominates its luminosity. ULIRGs and IR QSOs form a broad continuous track in the ``star formation efficiency plot in the manner consistent with the ULIRG-QSO transition scenario, relating the evolution in the dust processed luminosity with the available fuel (gas and dust) supply. However, the location of PDS 456 is clearly offset from the apparent track traced by the ULIRGs and IR QSOs on this plot, and PDS 456 appears to be a rare, exceptional object, and the duration of the physical process governing its present properties must be short compared with the length of the luminous QSO phase.
Metric perturbations typically strengthen field resonances during preheating. In contrast we present a model in which the super-Hubble field resonances are completely {em suppressed} when metric perturbations are included. The model is the nonminimal Fakir-Unruh scenario which is exactly solvable in the long-wavelength limit when metric perturbations are included, but exhibits exponential growth of super-Hubble modes in their absence. This gravitationally enhanced integrability is exceptional, both for its rarity and for the power with which it illustrates the importance of including metric perturbations in consistent studies of preheating. We conjecture a no-go result - there exists no {em single-field} model with growth of cosmologically-relevant metric perturbations during preheating.
New results of a Programme of study of BAL + IR + Fe II QSOs (at low and high redshift) are presented. Which are based mainly on deep Gemini GMOS integral field unit (IFU/3D) spectroscopy. We have performed a detailed study of the kinematics, morphological, and physical conditions, in the BAL + IR + Fe II QSO: IRAS 04505-2958. From this study, some selected results are presented, mainly for the 3 expanding giant shells (observed with Gemini). In particular, the GMOS data suggest that the outflow (OF) process -in this IR QSO- generated multiple expanding hypergiant shells (from 10, to 100 kpc), in several extreme explosive events. These new Gemini GMOS data are in good agreement with our evolutionary, explosive and composite Model: where part of the ISM of the host galaxy is ejected in the form of multiple giant shells, mainly by HyN explosions. This process could generate satellite/companion galaxies, and even could expel a high fraction -or all- the host galaxy. In addition, this Model for AGN could give important clue about the physical processes that could explain the origin -in AGNs- of very energetic cosmic rays, detected by the P. Auger Observatory.
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