Differential damage in the semi-confined Munazio Ireneo cubicle in Cagliari (Sardinia): a correlation between damage and microclimate

The Early Christian Munazio Ireneo cubicle in Cagliari (Sardinia) is carved into the rock and is one of the rare monuments of Sardinia belonging to Early Christian Age. It is 166 cm under the planking level and is a semi-confined chamber in which a gate allows exchange with the outside. In 1888, when it was discovered, it was completely painted, but over the years, it suffered a serious damage and all the paintings are nearly disappeared. Now the site shows a high moisture and a differential damage characterised by delamination, powdering, salt crystallisation and biological colonisation. The research offers a multidisciplinary approach to study the salt crystallisation damage, which is a phenomenon still not completely understood today. Studies and analyses highlight that different kinds of damage can be recognised. The cement mortar and the air pollution cause crystallisation of the sulphates. Constant capillary rising and the presence of water infiltration due to the rains, which travelled into the site from the vault, were detected during qualitative inspection. Although the microclimate did not change much in the site and the humidity was almost constant during the monitoring period, the variations in temperature allowed the phase transitions of sodium sulphate, especially in summer. The greatest damage of the porous stone is associated with the phase transitions and crystallisation inside the stone of sodium sulphate, one of the most harmful salts for porous materials because of its high crystallisation pressure.     

The Planck On-the-Flight Forecaster (POFF)

The Planck On-the-Flight Forecaster (POFF) is a tool to predict when a position in the sky will be within a selected angular distance from any instrument receiver direction in the Planck satellite taking into consideration its programmed observational plan. The tool has been developed in the framework of the Planck LFI Core Team activities, but it is now used by the whole Planck collaboration.In this paper we describe the tool and its applications to plan observations of point sources with other instruments which are expected to increase the scientific importance of Planck data, once they are publicly available. Collecting simultaneous multi-frequency data, like those that can be planned with the POFF, will aid the investigation of variability in point sources and also allow the reconstruction of point source spectral energy distributions over wide frequency range, thus minimizing the effect of variability itself.POFF is a combination of IDL routines which combine the publicly available information about the Planck scanning strategy with the focal plane shape to identify if a given (list of) position(s) could be observed by the satellite at a given frequency and/or by selected receivers in a given time range. The output can be displayed with any reasonable desired time resolution and with various sorting options.The code is not a Planck product, but has been validated with the Planck LFI pipeline, by searching for sources in the first satellite datasets. It has been implemented as one of the general tools of the LFI Data Processing Center. The code format and its large number of options make the program flexible and suitable for many applications, facilitating fast results.POFF is currently successfully used to plan activities within the Planck collaboration, including observations with several ground-based facilities, and is also available to the larger scientific community.     

Water vapor in Venus determined by airborne observations of the 8200 Å band

The region of the 8200 Å Band of H₂O was studied in spectra of Venus obtained with an echelle grating spectrograph operated at an altitude of 14.6 km in the NASA Learjet research aircraft. Taking advantage of low foreground absorption, observing at a time of velocity quadrature, differential spectroscopy with respect to lunar spectra, and spectrum averaging, we establish a value of H₂O of 3 ± 20 μ for the total path over the entire disk. This value differs from earlier studies of the integrated disk but supports the low values recently derived from infrared bands and by very high spectral resolution groundbased studies.     

An analysis of infrared emission spectra from the regions near the Galactic Centre

We present consistent modelling of line and continuum infrared (IR) spectra in the region close to the Galactic Centre. The models account for the coupled effect of shocks and photoionization from an external source. The results show that the shock velocities range between ∼65 and 80 km s⁻¹ and the pre-shock densities between 1 cm⁻³ in the interstellar medium (ISM) to 200 cm⁻³ in the filamentary structures. The pre-shock magnetic field increases from 5 × 10⁻⁶ G in the surrounding ISM to ∼8 × 10⁻⁵ G in the arched filaments. The stellar temperatures are ∼38 000 K in the Quintuplet cluster and ∼27 000 K in the Arches Cluster. The ionization parameter is relatively low (<0.01) with the highest values near the clusters, reaching a maximum >0.01 near the Arches Cluster. Depletion from the gaseous phase of Si is found throughout the whole observed region, indicating the presence of silicate dust. Grains including iron are concentrated throughout the arched filaments. The modelling of the continuum spectral energy distribution in the IR range indicates that a component of dust at temperatures of ∼100–200 K is present in the central region of the Galaxy. Radio emission appears to be thermal bremsstrahlung in the E2–W1 filaments crossing strip; however, a synchrotron component is not excluded. More data are necessary to resolve these questions.     

Tephra fallout hazard assessment at the Campi Flegrei caldera (Italy)

Tephra fallout associated with renewal of volcanism at the Campi Flegrei caldera is a serious threat to the Neapolitan area. In order to assess the hazards related with tephra loading, we have considered three different eruption scenarios representative of past activity: a high-magnitude event similar to the 4.1 ka Agnano-Monte Spina eruption, a medium-magnitude event, similar to the ∼3.8 ka Astroni 6 eruption, and a low-magnitude event similar to the Averno 2 eruption. The fallout deposits were reconstructed using the HAZMAP computational model, which is based on a semi-analytical solution of the two-dimensional advection–diffusion–sedimentation equation for volcanic tephra. The input parameters into the model, such as total erupted mass, eruption column height, and bulk grain-size and components distribution, were obtained by best-fitting field data. We carried out tens of thousands simulations using a statistical set of wind profiles, obtained from NOAA re-analysis. Probability maps, relative to the considered scenarios, were constructed for several tephra loads, such as 200, 300 and 400 kg/m². These provide a hazard assessment for roof collapses due to tephra loading that can be used for risk mitigation plans in the area.     

COMPASS: an instrument for measuring the polarization of the CMB on intermediate angular scales

COMPASS is an on-axis 2.6-m telescope coupled to a correlation polarimeter. The entire instrument was built specifically for CMB polarization studies. Careful attention was given to receiver and optics design, stability of the pointing platform, avoidance of systematic offsets, and development of data analysis techniques. Here we describe the experiment, its strengths and weaknesses, and the various things we have learned that may benefit future efforts to measure the polarization of the CMB.