BeppoSAX observations of low power radio galaxies: possible detection of obscured nuclei

We present the first results of BeppoSAX observations of a small sample of low brightness FRI radio galaxies. The flux of all the targets is consistent with a thermal spectrum, as due to the presence of hot intracluster gas or galactic corona. Moreover in three sources a non thermal absorbed spectrum can be present in the MECS spectrum at energies larger than 7 keV, while for a fourth object a high energy flux has been detected in the PDS instrument at energies larger than 15 keV. This component could be related to the inner AGN surrounded by an obscuring torus.Comment: 4 pages, LateX, 3 figures (included). Uses espcrc2.sty (included). To appear in: "The Active X-ray Sky: Results from BeppoSAX and Rossi-XTE", Rome, Italy, 21-24 October, 1997, Eds.: L. Scarsi, H. Bradt, P. Giommi and F. Fior

Influence of harvest method on the quality and storage of highbush blueberry

Blueberry quality is one of the most important elements that needs to be evaluated when automatisation processes, such as harvest automation, occur along the supply chain. The aim of this work was to evaluate the suitability of two blueberry cultivars, of new introduction for the area of study, to the mechanical harvest. Particularly the influence of harvest method was evaluated on the quality of cv. Cargo® and Top Shelf® for a short storage time (max. 28 days) in normal atmosphere assuming so an immediate sale of blueberries. Samples mechanically harvested were compared in terms of qualitative performance with samples manually picked throught two activity carried on two years. In the activity 1 a preliminary laboratory test simulation of mechanical harvest was carried on to evaluate the attitude of both cultivars to the automatisation process and the berries were evaluated immediately after the harvest time. The activity 2 was aimed to evaluate the quality of berries mechanically harvested in field and after the storage process at 2 ± 1 °C and 90% RH in a cold room for 28 days under normal atmospheric conditions (NA). The higher percentage of shrivelled berries for the simulation of mechanical harvest samples (SEH) (activity 1) and berries harvested with the Easy Harvester machine® (EH samples) (activity 2) in the post-harvest period was probably due to the low % of pruin on berries skin content at the harvest time (0 days). All samples although achieved a quality assessment equivalent to still marketable berries after 28 days of storage. TSSC were significantly higher in the EH group for both years. TSSC and TA were higher in Cargo® than in Top Shelf®. In general the automatisation of the harvesting process did not significantly affect blueberry quality after storage

Internal velocity factors

Computer program analyzes the entries and planetary trajectories of space vehicles. It obtains the equivalence of altitude and flight path angle, respectively, to acceleration load factor with respect to velocity for a given inertial velocity

Wine industry’s attitude towards oenological yeasts : Italy as a case study

Yeast inoculation is a widespread practice in winemaking in order to control the must fermentation. However, the use of indigenous wine yeasts can enrich wine quality and differentiate wine styles. Yeast cream preparation (CRY), recently accepted by the International Organization of Vine and Wine, could allow an easier usage of autochthonous yeasts. This work aimed at investigating the actual Italian wine industry\u2019s attitude towards the available formulations of commercial wine yeasts with attention to CRY. Moreover, this study evaluated the perception of wineries toward indigenous yeasts in both winemaking and marketing viewpoints. Data show different levels of knowledge and use about the available yeast formulations. In general, there is not a predominantly positive or negative participants\u2019 opinion regarding the use of indigenous yeasts. Wineries using CRY (4% of the sample) mainly adopt them as a part of the production in order to compare the wines with the ones traditionally obtained with commercial yeasts. CRY is perceived by some interviewees as a potential tool to increase communication and product differentiation. This survey could have anticipated future trends in the use of yeast formulations, determined by the market demands for diversified, unique, and environmentally sustainable products, that can allow an accessible application of precision enology

X-ray-emitting Atmospheres of B2 Radio Galaxies

We report ROSAT PSPC spatial and spectral analysis of the eight B2 radio galaxies NGC 315, NGC 326, 4C 35.03, B2 0326+39, NGC 2484, B2 1040+31, B2 1855+37, and 3C 449, expected to be representative of the class of low-power radio galaxies. Multiple X-ray components are present in each, and the gas components have a wide range of linear sizes and follow an extrapolation of the cluster X-ray luminosity/temperature correlation, implying that there is no relationship between the presence of a radio galaxy and the gas fraction of the environment. No large-scale cooling flows are found. There is no correlation of radio-galaxy size with the scale or density of the X-ray atmosphere. This suggests that it is processes on scales less than those of the overall gaseous environments which are the major influence on radio-source dynamics. The intergalactic medium is usually sufficient to confine the outer parts of the radio structures, in some cases even to within 5 kpc of the core. In the case of NGC 315, an extrapolation suggests that the pressure of the atmosphere may match the minimum pressure in the radio source over a factor of about 40 in linear size (a factor of about 1600 in pressure).Comment: 34 pages, including 10 figures, using aasms4.sty To appear in the Ap

Relativistic MHD Simulations of Jets with Toroidal Magnetic Fields

This paper presents an application of the recent relativistic HLLC approximate Riemann solver by Mignone & Bodo to magnetized flows with vanishing normal component of the magnetic field. The numerical scheme is validated in two dimensions by investigating the propagation of axisymmetric jets with toroidal magnetic fields. The selected jet models show that the HLLC solver yields sharper resolution of contact and shear waves and better convergence properties over the traditional HLL approach.Comment: 12 pages, 5 figure

The core fundamental plane of B2 radio galaxies

The photometric, structural and kinematical properties of the centers of elliptical galaxies, harbor important information of the formation history of the galaxies. In the case of non active elliptical galaxies these properties are linked in a way that surface brightness, break radius and velocity dispersion of the core lie on a fundamental plane similar to that found for their global properties. We construct the Core Fundamental Plane (CFP) for a sizeable sample of low redshift radio galaxies and compare it with that of non radio ellipticals. To pursue this aim we combine data obtained from high resolution HST images with medium resolution optical spectroscopy to derive the photometric and kinematic properties of ~40 low redshift radio galaxies. We find that the CFPs of radio galaxies is indistinguishable from that defined by non radio elliptical galaxies of similar luminosity. The characteristics of the CFP of radio galaxies are also consistent (same slope) with those of the Fundamental Plane (FP) derived from the global properties of radio (and non radio) elliptical galaxies. The similarity of CFP and FP for radio and non radio ellipticals suggests that the active phase of these galaxies has minimal effects for the structure of the galaxies.Comment: 8 pages, 4 figures, accepted for publication in Astronomy and Astrophysic

MHD simulations of jet acceleration from Keplerian accretion disks: the effects of disk resistivity

Accretion disks and astrophysical jets are used to model many active astrophysical objects, viz., young stars, relativistic stars, and active galactic nuclei. In this paper we present self-consistent time-dependent simulations of supersonic jets launched from magnetized accretion disks, using high resolution numerical techniques. In particular we study the effects of the disk magnetic resistivity, parametrized through an alpha-prescription, in determining the properties of the inflow-outflow system. Moreover we analyze under which conditions steady state solutions of the type proposed in the self similar models of Blandford and Payne can be reached and maintained in a self consistent nonlinear stage. We use the resistive MHD FLASH code with adaptive mesh refinement, allowing us to follow the evolution of the structure for a time scale long enough to reach steady state. A detailed analysis of the initial configuration state is given. We obtain the expected solutions in the axisymmetric (2.5D) limit. Assuming a magnetic field around equipartition with the thermal pressure of the disk, we show how the characteristics of the disk jet system, as the ejection efficiency and the energetics, are affected by the anomalous resistivity acting inside the disk.Comment: 20 pages, 18 figures, accepted for publication in Astronomy and Astrophysic

EVN Observations of GRS1915+105

We obtained EVN observations of the X-ray transient source GRS1915+105 in its radio-loud state. In 2 images obtained before a major flare, the source is resolved, showing two opposite asymmetric jets. This indicates that steady jets exist also before a major flare, with an estimated velocity of 0.2-0.6c.Comment: Proceedings of the 5th EVN Symposium, Eds. J. Conway, A. Polatidis, R. Booth, Onsala Observatory, Sweden (June 2000