A Multi-Cloud Warm-Absorber Model for NGC 4051

A multi-cloud model is presented which explains the soft X-ray excess in NGC 4051 and, consistently, the optical line spectrum and the SED of the continuum. The clouds are heated and ionized by the photoionizing flux from the active center and by shocks. Diffuse radiation, partly absorbed throughout the clouds, nicely fits the bump in the soft X-ray domain, while bremsstrahlung radiation from the gaseous clouds contribute to the fit of the continuum SED. Debris of high density fragmented clouds are necessary to explain the absorption oxygen throats observed at 0.87 keV and 0.74 keV. The debris are heated by shocks of about 200-300 km/s. Low velocity (100 km/s)-density (100 cm-3) clouds contribute to the line and continuum spectra, as well as high velocity (1000 km/s)-density (8000 cm-3) clouds which are revealed by the FWHM of the line profiles. The SED in the IR is explained by reradiation of dust, however, the dust-to-gas ratio is not particularly high. Radio emission is well fitted by synchrotron radiation created at the shock front by Fermi mechanism.Comment: 19 pages + 3 figures PostScrip

Evolution of the mass, size, and star formation rate in high-redshift merging galaxies MIRAGE - A new sample of simulations with detailed stellar feedback

We aim at addressing the questions related to galaxy mass assembly through major and minor wet merging processes in the redshift range 1<z<2. A consequent fraction of Milky Way like galaxies are thought to have undergone an unstable clumpy phase at this early stage. Using the adaptive mesh refinement code RAMSES, with a recent physically-motivated implementation of stellar feedback, we build the Merging and Isolated high-Redshift Adaptive mesh refinement Galaxies (MIRAGE) sample. It is composed of 20 mergers and 3 isolated idealized disks simulations with global physical properties in accordance with the 1<z<2 mass complete sample MASSIV. The numerical hydrodynamical resolution reaches 7 parsecs in the smallest Eulerian cells. Our simulations include: star formation, metal line cooling, metallicity advection, and a recent implementation of stellar feedback which encompasses OB-type stars radiative pressure, photo-ionization heating, and supernovae. The initial conditions are set to match the z~2 observations, thanks to a new public code DICE. The numerical resolution allows us to follow the formation and evolution of giant clumps formed in-situ from Jeans instabilities triggered by high initial gas fraction. The star formation history of isolated disks shows stochastic star formation rate, which proceeds from the complex behavior of the giant clumps. Our minor and major gas-rich merger simulations do not trigger starbursts, suggesting a saturation of the star formation in a turbulent and clumpy interstellar medium fed by substantial accretion from the circum-galactic medium. Our simulations are close to the normal regime of the disk-like star formation on a Schmidt-Kennicutt diagram. The mass-size relation and its rate of evolution matches observations, suggesting that the inside-out growth mechanisms of the stellar disk do not necessarily require to be achieved through a cold accretion.Comment: 18 pages, 12 figures. Accepted in A&

Measurements of atmospheric aerosol in the Salentum Peninsula and its correlation with local meteorology

In this paper the results of measurements of Total Suspended Particles (TSP), PM10 and PM2.5 and their correlation with meteorological parameters are presented. The samplings were carried out with a mobile laboratory in seven locations in the Salentum Peninsula located in the southeastern part of Italy in Puglia. Measurements were taken discontinuously during the period 2002-2005. Up to now no systematic analyses of aerosol concentrations in the Salentum Peninsula have been presented in the scientific literature. This study is therefore a useful basis for assessing the local situation and for planning future monitoring. Measurements have been performed, on a daily basis, using standard European inlet (CEN-EN12341, 1998) and successive gravimetric detection of aerosol deposited on filters. The measurement sites can be considered representative of urban background for all the cases investigated. An analysis of the random uncertainties (LOQ and LOD) for the different types of filters used is reported. Results show concentrations in good agreement with lognormal distributions, indicating that the PM10 fraction is about 66% of TSP and PM2.5 is about 67% of PM10, which allows us to evaluate that the fraction of PM2.5 is about 44% of TSP. Concentration levels were correlated with local meteorological parameters, especially with wind velocity and precipitations. Results indicate that during rainy days the average concentration is reduced of about 70% and the reduction is larger for TSP and PM10 with respect to PM2.5. There is, on average, a substantial decrease of concentration levels in high wind conditions. Results also suggest the possibility of a significant contribution of African dust to PM10 and TSP, especially in the spring and summer season, which could be responsible for some days with concentrations above the threshold imposed by the European legislation on PM10

Gas and Dust Emission from the Nuclear Region of the Circinus Galaxy

Simultaneous modeling of the line and continuum emission from the nuclear region of the Circinus galaxy is presented. Composite models which include the combined effect of shocks and photoionization from the active center and from the circumnuclear star forming region are considered. The effects of dust reradiation, bremsstrahlung from the gas and synchrotron radiation are treated consistently. The proposed model accounts for two important observational features. First, the high obscuration of Circinus central source is produced by high velocity and dense clouds with characteristic high dust-to-gas ratios. Their large velocities, up to 1500 km\s, place them very close to the active center. Second, the derived size of the line emitting region is well in agreement with the observed limits for the coronal and narrow line region of Circinus.Comment: 36 pages, LaTex (including 4 Tables and 9 figures), $$ removed from Abstract To appear in "The Astrophysical Journal

Measurements of atmospheric aerosol in the Salentum Peninsula and its correlation with local meteorology

In this paper the results of measurements of Total Suspended Particles (TSP) and PM10 are presented. The samplings were carried out with a mobile laboratory in five locations on the Salentum peninsula situated in the southeastern part of Italy in Puglia. Measurements were taken discontinuously during the period 2002?2004. Some results of PM2.5 measurements taken only in 2004 are also presented. Up to now no systematic analyses of aerosol concentration in the Salentum peninsula have been presented in the scientific literature. This study is therefore a useful basis for assessing the local situation and for planning future monitoring and investigations. Measurements were performed using a standard European PM10 inlet (CEN?EN12341, 1998) and successive gravimetric detection of aerosol deposited over 24 hours periods on filters. The measurement sites can be considered representative of urban background for all the cases investigated. Results show concentrations in good agreement with lognormal distributions, indicating that the PM10 fraction is about 69% of TSP and PM2.5 is about 81% of PM10, which allows us to evaluate that the fraction of PM2.5 is about 56% of TSP. Concentration levels were correlated with local meteorological parameters, such as wind velocity, wind direction and precipitations. Results indicate that there is, on average, a substantial decrease of concentration levels in high wind conditions and on rainy days. They also suggest the possibility of a significant contribution 1 of African Dust to PM10 and TSP, especially in the summer season, which could be responsible for some periods of concentrations above the threshold imposed by the European legislation on PM10

Alocação de recursos e rentabilidade das pesquisas originadas do Centro Nacional de Pesquisa de Soja.

Desenvolvimento da soja no Brasil; Beneficios gerados pela pesquisa no CNPSo; Propriedades da pesquisa e principais tecnologias geradas.bitstream/item/23241/1/Doc26.pd

High resolution spectroscopy of the extended narrow-line region of IC 5063 and NGC 7212

We studied the properties of the gas of the extended narrow line region (ENLR) of two Seyfert 2 galaxies: IC 5063 and NGC 7212. We analysed high resolution spectra to investigate how the main properties of this region depend on the gas velocity. We divided the emission lines in velocity bins and we calculated several line ratios. Diagnostic diagrams and SUMA composite models (photo-ionization + shocks), show that in both galaxies there might be evidence of shocks significantly contributing in the gas ionization at high |V|, even though photo-ionization from the active nucleus remains the main ionization mechanism. In IC 5063 the ionization parameter depends on V and its trend might be explained assuming an hollow bi-conical shape for the ENLR, with one of the edges aligned with the galaxy disk. On the other hand, NGC 7212 does not show any kind of dependence. The models show that solar O/H relative abundances reproduce the observed spectra in all the analysed regions. They also revealed an high fragmentation of the gas clouds, suggesting that the complex kinematics observed in these two objects might be caused by interaction between the ISM and high velocity components, such as jets.Comment: 29 pages, 32 figures, accepted for publication in MNRA