32 research outputs found
A massive nebula around the Luminous Blue Variable star RMC143 revealed by ALMA
The luminous blue variable (LBV) RMC143 is located in the outskirts of the
30~Doradus complex, a region rich with interstellar material and hot luminous
stars. We report the sub-millimetre detection of its circumstellar
nebula with ALMA. The observed morphology in the sub-millimetre is different
than previously observed with HST and ATCA in the optical and centimetre
wavelength regimes. The spectral energy distribution (SED) of RMC143 suggests
that two emission mechanisms contribute to the sub-mm emission: optically thin
bremsstrahlung and dust. Both the extinction map and the SED are consistent
with a dusty massive nebula with a dust mass of
(assuming ). To date, RMC143 has the most
dusty LBV nebula observed in the Magellanic Clouds. We have also re-examined
the LBV classification of RMC143 based on VLT/X-shooter spectra obtained in
2015/16 and a review of the publication record. The radiative transfer code
CMFGEN is used to derive its fundamental stellar parameters. We find an
effective temperature of ~K, luminosity of log, and a relatively high mass-loss rate of ~yr. The luminosity is much lower than previously
thought, which implies that the current stellar mass of is
comparable to its nebular mass of (from an assumed
gas-to-dust ratio of 100), suggesting that the star has lost a large fraction
of its initial mass in past LBV eruptions or binary interactions. While the
star may have been hotter in the past, it is currently not hot enough to ionize
its circumstellar nebula. We propose that the nebula is ionized externally by
the hot stars in the 30~Doradus star-forming region.Comment: Paper accepted by A&A on 09/05/2019 and in proof stage. Second
comments by referee are included in this versio
Digital reconstruction and scientific analysis prior the restoration of two paintings by Mattia Preti in the Church of the Immaculate Conception of Sarria (Floriana, Malta)
The paper presents the results of scientific investigations carried out in support of a professionally executed restoration on two paintings by Mattia Preti, located in the Church of the Immaculate Conception of Sarria in Floriana, Malta. In particular, the attention was mainly paid on a combined approach, using 2D/3D survey in order to formulate hypothetic reconstruction, and XRF spectroscopy in order to get more information on how the master prepared the various types of materials, with particular regard to the painting preparation, the pigments palette and the formulation of shades and highlights.peer-reviewe
Valorizing underground cultural heritage through the use of virtual reality
This paper presents the results of scientific investigations carried out at the Batia Church which is located in the small village of Tortorici (Messina, Sicily, Italy). We performed several geophysical surveys, as well as geomatics approaches, were used in order to reconstruct 2D and 3D digital models of the monument mainly using digital photogrammetry. Previous geophysical investigations have shown the presence of a crypt which was ultimately surveyed and digitally reconstructed. Here, we present the potential of valorizing the site and its underground structures by the means of advanced technologies and digital reconstructions.peer-reviewe
Additional file 2: Figure S1. of Efficacy and safety of bevacizumab plus chemotherapy compared to chemotherapy alone in previously untreated advanced or metastatic colorectal cancer: a systematic review and meta-analysis
Comparative effect in hematologic toxicities of chemotherapy with bevacizumab versus chemotherapy alone. (PDF 503 kb