-
F. Pozzi,
C. Vignali,
C. Gruppioni,
A. Feltre,
J. Fritz,
D. Fadda,
P. Andreani,
S. Berta,
A. Cimatti,
I. Delvecchio,
D. Lutz,
B. Magnelli,
R. Maiolino,
R. Nordon,
P. Popesso,
G. Rodighiero,
D. Rosario,
P. Santini,
M. Vaccari
[show abstract]
[hide abstract]
ABSTRACT: We use Herschel-PACS far-infrared data, combined with previous multi-band
information and mid-IR spectra, to properly account for the presence of an
active nucleus and constrain its energetic contribution in luminous infrared
(IR) sources at z\sim2. The sample is composed of 24 sources in the GOODS-South
field, with typical IR luminosity of 10^{12} Lo. Data from the 4 Ms Chandra
X-ray imaging in this field are also used to identify and characterize AGN
emission. We reproduce the observed spectral energy distribution (SED),
decomposed into a host-galaxy and an AGN component. A smooth-torus model for
circum-nuclear dust is used to account for the direct and re-processed
contribution from the AGN. We confirm that galaxies with typical
L_{8-1000um}\sim10^{12}Lo at z\sim2 are powered predominantly by
star-formation. An AGN component is present in nine objects (\sim35% of the
sample) at the 3sigma confidence level, but its contribution to the 8-1000 um
emission accounts for only \sim5% of the energy budget. The AGN contribution
rises to \sim23% over the 5-30 um range (in agreement with Spitzer IRS results)
and to \sim60% over the narrow 2-6 um range. The presence of an AGN is
confirmed by X-ray data for 3 (out of nine) sources, with X-ray spectral
analysis indicating the presence of significant absorption, i.e.
NH\sim10^{23}-10^{24} cm^{-2}. An additional source shows indications of
obscured AGN emission from X-ray data. The comparison between the
mid-IR--derived X-ray luminosities and those obtained from X-ray data suggests
that obscuration is likely present also in the remaining six sources that
harbour an AGN according to the SED-fitting analysis.
04/2012;
-
I. Oteo,
A. Bongiovanni,
A. M. Pérez García,
J. Cepa,
A. Ederoclite,
M. Sánchez-Portal,
I. Pintos-Castro,
R. Pérez-Martínez,
D. Lutz,
B. Altieri, [......],
E. Le Floc'h,
B. Magnelli,
R. Maiolino,
A. Poglitsch,
P. Popesso, F. Pozzi,
L. Riguccini,
E. Sturm,
L. Tacconi,
I. Valtchanov
[show abstract]
[hide abstract]
ABSTRACT: The analysis of the physical properties of low-redshift Ly$\alpha$ emitters
(LAEs) can provide clues in the study of their high-redshift analogues. At $z
\sim 0.3$, LAEs are bright enough to be detected over almost the entire
electromagnetic spectrum and it is possible to carry out a more precise and
complete study than at higher redshifts. In this study, we examine the UV and
IR emission, dust attenuation, SFR and morphology of a sample of 23
GALEX-discovered star-forming (SF) LAEs at $z \sim 0.3$ with direct UV (GALEX),
optical (ACS) and FIR (PACS and MIPS) data. Using the same UV and IR limiting
luminosities, we find that LAEs at $z\sim 0.3$ tend to be less dusty, have
slightly higher total SFRs, have bluer UV continuum slopes, and are much
smaller than other galaxies that do not exhibit Ly$\alpha$ emission in their
spectrum (non-LAEs). These results suggest that at $z \sim 0.3$ Ly$\alpha$
photons tend to escape from small galaxies with low dust attenuation. Regarding
their morphology, LAEs belong to Irr/merger classes, unlike non-LAEs. Size and
morphology represent the most noticeable difference between LAEs and non-LAEs
at $z \sim 0.3$. Furthermore, the comparison of our results with those obtained
at higher redshifts indicates that either the Ly$\alpha$ technique picks up
different kind of galaxies at different redshifts or that the physical
properties of LAEs are evolving with redshift.
04/2012;
-
[show abstract]
[hide abstract]
ABSTRACT: The aim of this study was to evaluate the effects of a new antipsychotic compound on negative symptoms and cognitive deficit in schizophrenia. Psychiatric symptoms and cognition were assessed in 25 patients with schizophrenia, at baseline and after they had taken risperidone for 4 weeks. The Positive and Negative Symptoms Scale (PANSS), the Wisconsin Card Sorting Test (WCST) and two WAIS sub-tests were used to assess the patients. After the study period, both negative and positive symptoms and also measures of cognitive performance improved significantly. The WCST results correlated with negative symptom scores before and after treatment. This suggests that negative symptoms and cognitive deficit have a common underlying substrate which is the target of the risperidone treatment. Our data show that risperidone may have a substantial effect on complex cognitive functions in schizophrenia, and they suggest that certain cognitive deficits are relatively dependent on the negative symptoms of this disorder.
Acta Psychiatrica Scandinavica 02/1997; 95(1):40-3. · 4.22 Impact Factor
-
G. Baldacchini,
M. Cremona,
M. Casalboni,
D. de Viry,
U. M. Grassano,
A. Luci,
M. Palummo,
L. Casalis,
P. Minguzzi, F. Pozzi,
M. Tonelli,
A. Scacco
[show abstract]
[hide abstract]
ABSTRACT: Data are presented on the optical absorption and emission of F-aggregate centers in NaCl:OH-. In particular, we have studied the properties of the laser-active (F2+)H centers. The formation of the (F2+)H center is temperature dependent. One mechanism operates below and another above ∼50 K. The bleaching of the (F2+)H-center emission observed under intense Nd:YAG or He-Ne laser irradiation, due to reorientation of the emitting centers, is accompanied by a process at low temperatures that is predominant at temperatures below 20 K and involves the ionization of the X or F3 centers always present in the crystal. Thus the laser-active (F2+)H centers are destroyed by electron capture but are reformed by F-band light irradiation, which reverses the bleaching process.
Phys. Rev. B. 11/1991; 44(22).
-
L. Casalis,
P. Minguzzi, F. Pozzi,
M. Tonelli,
A. Scacco,
M. Casalboni,
D. de Viry,
U. M. Grassano,
A. Luci,
M. Palummo,
G. Baldacchini,
M. Cremona
Radiation Effects and Defects in Solids 11/1991; 119-121(2):547-552. · 0.40 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Evaluating the total numbers of people at risk from infectious disease in the world requires not just tabular population data, but data that are spatially explicit and global in extent at a moderate resolution. This review describes the basic methods for constructing estimates of global population distribution with attention to recent advances in improving both spatial and temporal resolution. To evaluate the optimal resolution for the study of disease, the native resolution of the data inputs as well as that of the resulting outputs are discussed. Assumptions used to produce different population data sets are also described, with their implications for the study of infectious disease. Lastly, the application of these population data sets in studies to assess disease distribution and health impacts is reviewed. The data described in this review are distributed in the accompanying DVD.
Advances in Parasitology.
-
[show abstract]
[hide abstract]
ABSTRACT: The effect of an electric field on the emission from FA(II) centres in KCl:Li has been detected in a colour centre laser. A clear evidence has been obtained by comparing the visible absorption and infrared emission signals in two different experimental configurations, either by applying a sinusoidal field to the crystal or by modulating the pump beam intensity. We found that the Stark effect on the emission depends on the polarization angle of the pump light.
Optics Communications.
-
C Tosello,
F Rossi,
S Ronchin,
R Rolli,
G.C Righini, F Pozzi,
S Pelli,
M Fossi,
E Moser,
M Montagna,
M Ferrari,
C Duverger,
A Chiappini,
C De Bernardi
[show abstract]
[hide abstract]
ABSTRACT: Erbium-activated silica–titania planar waveguides were prepared by radio-frequency (rf) sputtering technique. Silica-on-silicon substrates obtained by plasma-enhanced chemical vapor deposition (PECVD) and rf sputtering (RFS) were employed. The refractive indices, the thickness and the propagation losses of the waveguides were measured. The refractive index and the roughness of the silica substrates produced by RFS appear to be dependent on the thickness. Thermal annealing, which is a necessary condition to obtain light propagation, induces a decrease of the refractive index in the silica substrates. The waveguide deposited on PECVD substrate exhibits several propagating modes with an attenuation coefficient 1.7 dB/cm compared with 12.2 dB/cm measured for the waveguide deposited on silica substrate produced by RFS technique. Emission of the transition with a 53 nm bandwidth was observed.
Journal of Non-Crystalline Solids.
