Mass function of dormant black holes and the evolution of the Active Galactic Nuclei

We derive the mass function of the relic black holes and compared with that of the Massive Dark Objects in galaxies. Under the assumption that accretion onto massive BH's powers the Active Galactic Nuclei, the mass function of the BH responsibile for the past activity of QSO/AGN is computed. Our results support the scenario in which the QSO phase has exclusively occurred in every proto-elliptical.Comment: 10 pages, 8 Figures. Version improved with referee comments. J. Accepted on MNRA

Nucleon transfer in heavy ion reactions

An analytical formula is derived for the amplitude for transfer of a nucleon in quasi-elastic reactions between heavy ions. The derivation takes advantage of the semiclassical conditions found in peripheral collisions between heavy ions. The relative motion of the two nuclei is treated classically and the transfer amplitude is calculated by a perturbation method. Under the approximation of small overlap between the nuclear potentials, the semiclassical amplitude is reduced to a surface integral. This can be calculated analytically by using Hankel function forms for the bound-state wavefunctions and by approximating the actual orbit by a constant velocity orbit tangential to it at the distance of closest approach. These approximations seem reasonable in strong absorption conditions. Corrections to the formula of the amplitude are evaluated. The analytical form of the amplitude exhibits an exponential behaviour as a function of the distance of closest approach. The decay constant of the exponential is given explicitly and it is found to be an important parameter of the reaction. Kinematical conditions for maximum transfer are derived which relate the incident energy to the reaction Q-value. The physical interpretation of the amplitude is discussed. In the case of proton transfer, the effect of Coulomb potential results in a shift of the binding energy of the proton. With this prescription we still obtain the same form of the transfer amplitude for both neutrons and protons. The formula for the semiclassical tranfer amplitude is used to calculate angular distributions within a simplified formalism derived from the distorted wave Born approximation (DWBA). The reactions considered are 208 pb(16O,15O)209pb , 26mg(11B,10B)27mg and 34S(32S, 33S) 33S for neutron transfer and 208pb(16O,15N)209 Bi for proton transfer. It is found that the shapes of the present angular distributions agree with full DWBA calculations but the magnitude of the former depends on whether the distance of closest approach is that of the initial channel, the final channel or some average of the two. Conditions for the selective population of definite states are discussed in relation to the reaction Q-value, energy and initial and final states involved. It is found that an inversion of the selectivity with respect to the spins of the initial and final state occurs when the energy of relative motion at distance of closest apprach equals the reaction Q-value. An approximate formula for the angle-integrated cross section has also been derived

Brief assessment of negative dysmorphic signs

Body dysmorphic disorder is a body image dysperception, characterized either by an excessive preoccupation with a presumed or minimal flaw in appearance, or by unrecognition, denial, or even neglect regarding an obvious defect. These features are evaluated by a novel questionnaire, the Brief Assessment of Negative Dysmorphic Signs (BANDS). Moreover, the temperament and character background is examined. The relationship with addictive mentality/behavior and schizoaffectivity is also highlighted. Lastly, the potential shift toward cognitive impairment and dementia is considered

Kinetic AGN Feedback Effects on Cluster Cool Cores Simulated using SPH

We implement novel numerical models of AGN feedback in the SPH code GADGET-3, where the energy from a supermassive black hole (BH) is coupled to the surrounding gas in the kinetic form. Gas particles lying inside a bi-conical volume around the BH are imparted a one-time velocity (10,000 km/s) increment. We perform hydrodynamical simulations of isolated cluster (total mass 10^14 /h M_sun), which is initially evolved to form a dense cool core, having central T<10^6 K. A BH resides at the cluster center, and ejects energy. The feedback-driven fast wind undergoes shock with the slower-moving gas, which causes the imparted kinetic energy to be thermalized. Bipolar bubble-like outflows form propagating radially outward to a distance of a few 100 kpc. The radial profiles of median gas properties are influenced by BH feedback in the inner regions (r<20-50 kpc). BH kinetic feedback, with a large value of the feedback efficiency, depletes the inner cool gas and reduces the hot gas content, such that the initial cool core of the cluster is heated up within a time 1.9 Gyr, whereby the core median temperature rises to above 10^7 K, and the central entropy flattens. Our implementation of BH thermal feedback (using the same efficiency as kinetic), within the star-formation model, cannot do this heating, where the cool core remains. The inclusion of cold gas accretion in the simulations produces naturally a duty cycle of the AGN with a periodicity of 100 Myr.Comment: 22 pages, 11 figures, version accepted for publication in MNRAS, references and minor revisions adde

Gaze direction influences grasping actions towards unseen, haptically explored, objects

Haptic exploration produces mental object representations that can be memorized for subsequent object-directed behaviour. Storage of haptically-acquired object images (HOIs), engages, besides canonical somatosensory areas, the early visual cortex (EVC). Clear evidence for a causal contribution of EVC to HOI representation is still lacking. The use of visual information by the grasping system undergoes necessarily a frame of reference shift by integrating eye-position. We hypothesize that if the motor system uses HOIs stored in a retinotopic coding in the visual cortex, then its use is likely to depend at least in part on eye position. We measured the kinematics of 4 fingers in the right hand of 15 healthy participants during the task of grasping different unseen objects behind an opaque panel, that had been previously explored haptically. The participants never saw the object and operated exclusively based on haptic information. The position&nbsp;of the object was fixed, in front of the participant, but the subject's gaze varied from trial to trial between 3 possible positions, towards the unseen object or away from it, on either side. Results showed that the middle and little fingers' kinematics during reaching for the unseen object changed significantly according to gaze position. In a control experiment we showed that intransitive hand movements were not modulated by gaze direction. Manipulating eye-position produces small but significant configuration errors, (behavioural errors due to shifts in frame of reference) possibly related to an eye-centered frame of reference, despite the absence of visual information, indicating sharing of resources between the haptic and the visual/oculomotor system to delayed haptic grasping

EFFECTS OF EARTHQUAKES ON THE MINOAN «ROYAL VILLA» AT HAGHIA TRIADA (CRETE)

Examination of damages affecting the buildings of the archaeological site of Haghia Triada (southern Crete), suggests that this Minoan settlement was probably destroyed by a major seismic event characterized by MKS intensities of IX-X and occurred in the Neo-palatial (1450 B.C.) periods. Geological and morphological studies carried out in the neighbouring areas show the occurrence of E-W trending Quaternary normal fault segments (Spili and Haghia Galini faults) that control the present topography and morphology, and exhibit steep young scarps mostly Holocene in age. These fault segments are related to a NW-SE extension direction which is consistent with that indicated by the available focal mechanisms of the earthquakes occurring in this area in the last 50 years. Combining structural and seismic data we can infer that the Spili and Haghia Galini fault segments could represent good candidates to be considered active faults generating large earthquakes (M~6.5) that were responsible for the damages of Haghia Triada. This hypothesis suggests that the Minoan palatial centres were destroyed by several large earthquakes related to ruptures along distinct fault segments rather than by a single catastrophic event that caused the abrupt destruction of the Minoan civilisation in the eastern Mediterranean