Search Publications
Mapping lunar surface chemistry: New prospects with the Chandrayaan-2 Large Area Soft X-ray Spectrometer (CLASS)
Kellett, B. J.; Narendranath, S.; Sreekumar, P. +4 more
Surface chemistry of airless bodies in the solar system can be derived from remote X-ray spectral measurements from an orbiting spacecraft. X-rays from planetary surfaces are excited primarily by solar X-rays. Several experiments in the past have used this technique of X-ray fluorescence for deriving abundances of the major rock forming elements. …
The optical emission lines of type 1 X-ray bright Active Galactic Nuclei
La Mura, G.; Ciroi, S.; Cracco, V. +3 more
A strong X-ray emission is one of the defining signatures of nuclear activity in galaxies. According to the Unified Model for Active Galactic Nuclei (AGN), both the X-ray radiation and the prominent broad emission lines, characterizing the optical and UV spectra of Type 1 AGNs, are originated in the innermost regions of the sources, close to the S…
Characterization of lunar soils through spectral features extraction in the NIR
Mall, U.; Wöhler, C.; Grumpe, A. +2 more
Recently launched hyper-spectral instrumentation with ever-increasing data return capabilities deliver the remote-sensing data to characterize planetary soils with increased precision, thus generating the need to classify the returned data in an efficient way for further specialized analysis and detection of features of interest. This paper invest…
A statistical study of C IV regions in 20 Oe-stars
Popović, L. Č.; Antoniou, A.; Stathopoulos, D. +3 more
In this paper, using the Gauss-Rotation model (GR model), we analyse the UV C IV resonance lines in the spectra of 20 Oe-stars of different spectral subtypes, in order to detect the structure of C IV region. We study the presence and behavior of absorption clouds and analyse their characteristics. From this analysis we can calculate the values of …
Are Boltzmann plots of hydrogen Balmer lines a tool for identifying a subclass of S1 AGN?
Popović, L. Č.; La Mura, G.; Ciroi, S. +4 more
It is becoming clear that we can define two different types of nearby AGN belonging to the Seyfert 1 class (S1), on the basis of the match of the intensities of their Broad Balmer Lines (BBL) with the Boltzmann Plots (BP). These two types of S1 galaxies, that we call BP-S1 and NoBP-S1, are characterized, in first approximation, by Broad Line Regio…