Age of submarine debris avalanches and tephrostratigraphy offshore Ischia Island, Tyrrhenian Sea, Italy

We present an "event stratigraphy" framework built for the last 23 cal ka marine record in the southern offshore of Ischia Island based on AMS (14)C dating and tephrostratigraphic analysis of 11 gravity cores. Two collapse events have been recovered in the record: a) the Ischia submarine debris avalanche/debris flow (DA/DF), dated between similar to 3 ka B.P. and 2.4 ka B.P. and possibly between 2.7 ka B.P. and 2.4 ka B.P. (event DF1); b) a former, pre-Holocene, DA/DF older than 23 cal ka B.P. (event DF2). The Ischia DA, with an estimated volume of 1.5 km(3), incorporates thousands of blocks that are still detectable on the sea-floor until 45-50 km far from the island. Our results indicate an age of emplacement younger than previously thought and support the hypothesis that a major catastrophic event occurred when the island was already inhabited by Greek settlers (i.e. after the 7th century BC). Three ash layers have been recognised in the post-DF1 avalanche sequence and correlated with Ischian eruptions occurred between Middle Ages and Roman times. Two tephras recovered in the pre-DF1 succession have been correlated with explosive activity occurred on Ischia and Procida islands from similar to 23 ka to similar to 17.5 ka B.P. The results presented here improve the chronostratigraphic reconstruction of the main eruptive and collapse events that affected Ischia volcano during Late Pleistocene-Holocene and their dispersal at sea The occurrence of at least two major collapsing events in the past 23 kyr confirms the close genetic relationship between gravity failures and Mt. Epomeo uplift. (C) 2010 Elsevier B.V. All rights reserved

DISCOVERY OF CARBON RADIO RECOMBINATION LINES IN M82

Carbon radio recombination lines (RRLs) at low frequencies (<=500 MHz) trace the cold, diffuse phase of the interstellar medium, which is otherwise difficult to observe. We present the detection of carbon RRLs in absorption in M82 with LOFAR in the frequency range of 48-64 MHz. This is the first extragalactic detection of RRLs from a species other than hydrogen, and below 1 GHz. Since the carbon RRLs are not detected individually, we cross-correlated the observed spectrum with a template spectrum of carbon RRLs to determine a radial velocity of 219 +- 9 km/s . Using this radial velocity, we stack 22 carbon-{\alpha} transitions from quantum levels n = 468-508 to achieve an 8.5 sigma detection. The absorption line profile exhibits a narrow feature with peak optical depth of 0.003 and FWHM of 31 km/s. Closer inspection suggests that the narrow feature is superimposed on a broad, shallow component. The total line profile appears to be correlated with the 21 cm H I line profile reconstructed from H I absorption in the direction of supernova remnants in the nucleus. The narrow width and centroid velocity of the feature suggests that it is associated with the nuclear starburst region. It is therefore likely that the carbon RRLs are associated with cold atomic gas in the direction of the nucleus of M82.Comment: 6 pages, 5 figures, accepted for publication in ApJ

LOFAR MSSS: Discovery of a 2.56 Mpc giant radio galaxy associated with a disturbed galaxy group

We report on the discovery in the LOFAR Multifrequency Snapshot Sky Survey (MSSS) of a giant radio galaxy (GRG) with a projected size of $2.56 \pm 0.07$ Mpc projected on the sky. It is associated with the galaxy triplet UGC 9555, within which one is identified as a broad-line galaxy in the Sloan Digital Sky Survey (SDSS) at a redshift of $0.05453 \pm 1 \times 10^{-5}$, and with a velocity dispersion of $215.86 \pm 6.34$ km/s. From archival radio observations we see that this galaxy hosts a compact flat-spectrum radio source, and we conclude that it is the active galactic nucleus (AGN) responsible for generating the radio lobes. The radio luminosity distribution of the jets, and the broad-line classification of the host AGN, indicate this GRG is orientated well out of the plane of the sky, making its physical size one of the largest known for any GRG. Analysis of the infrared data suggests that the host is a lenticular type galaxy with a large stellar mass ($\log~\mathrm{M}/\mathrm{M}_\odot = 11.56 \pm 0.12$), and a moderate star formation rate ($1.2 \pm 0.3~\mathrm{M}_\odot/\mathrm{year}$). Spatially smoothing the SDSS images shows the system around UGC 9555 to be significantly disturbed, with a prominent extension to the south-east. Overall, the evidence suggests this host galaxy has undergone one or more recent moderate merger events and is also experiencing tidal interactions with surrounding galaxies, which have caused the star formation and provided the supply of gas to trigger and fuel the Mpc-scale radio lobes.Comment: Compressed for arXiv, see journal for full resolution image

Definition and management of colorectal polyposis not associated with APC/MUTYH germline pathogenic variants: AIFEG consensus statement

An expert consensus panel convened by the Italian Association for Inherited and Familial Gastrointestinal Tumors (Associazione Italiana per lo Studio della Familiarit\ue0 ed Ereditariet\ue0 dei Tumori Gastrointestinali, AIFEG) reviewed the literature and agreed on a number of position statements regarding the definition and management of polyposis coli without an identified pathogenic mutation on the APC or MUTYH genes, defined in the document as NAMP (non-APC/MUTYH polyposis)