An optical spectroscopic survey of the 3CR sample of radio galaxies with z<0.3. III. Completing the sample

We present optical nuclear spectra for nine 3CR radio sources obtained with the Telescopio Nazionale Galileo, that complete our spectroscopic observations of the sample up to redshifts $<$ 0.3. We measure emission line luminosities and ratios, and derive a spectroscopic classification for these sources.Comment: Accepted for publication in A&A. We provide as additional material two tables presenting the main data for the whole sample, combining the results presented here with those of Paper I and Paper I

An optical spectroscopic survey of the 3CR sample of radio galaxies with z<0.3. IV. Discovery of the new spectroscopic class of relic radio galaxies

From an optical spectroscopic survey of 3CR radio galaxies with z<0.3, we discovered a new spectroscopic class of powerful radio-loud AGN. The defining characteristics of these galaxies are that compared with radio galaxies of similar radio luminosity they have: a [O III]\Hb ratio of ~0.5, indicative of an extremely low level of gas excitation; a large deficit of [O III] emission and radio core power. We interpret these objects as relic AGN, i.e. sources that experienced a large drop in their level of nuclear activity, causing a decrease in their nuclear and line luminosity. This class opens a novel approach to investigating lifetimes and duty cycles of AGN.Comment: Accepted for publication in A&

Does Seifert's Personalism Hold Water?

Does Seifert's personalism hold water? (1) The question is rather provocative but my answer will be clear: yes, it does. Not only it holds water but can be continued and stands in need of being continued. This paper will put Seifert within the phenomenological tradition and in particular within the tradition of realistic phenomenology. Then we will describe Seifert's discovery and its meaning for contemporary philosophy. In the end, we will defend why we think it can be continued and stands in need of being continued and in which direction it should be continued

Exploring the spectroscopic properties of relic radiogalaxies

From an optical spectroscopic survey of 3CR radiogalaxies (RGs) with z < 0.3, we discovered three objects characterized by an extremely low level of gas excitation and a large deficit of line emission with respect to RGs of similar radio luminosity. We interpreted these objects as relic active galactic nuclei (AGN), i.e., sources observed after a large drop in their nuclear activity. We here present new spectroscopic observations for these three galaxies and for a group of "candidate" relics. None of the candidates can be convincingly confirmed. From the new data for the three relics, we estimate the density of the line-emitting gas. This enables us to explore the temporal evolution of the line ratios after the AGN "death". The characteristic timescale is the light-crossing time of the emission-line region, a few ~103 years, too short to correspond to a substantial population of relic RGs. Additional mechanisms of gas ionization, such as "relic shocks" from their past high power phase or stellar sources, should also be considered to account for the spectroscopic properties of the relic RGs. Relic RGs appear to be a mixed bag of sources in different phases of evolution, including AGN recently (~104 years ago) quenched, galaxies that have been inactive for at least ~106 years, and objects caught during the transition from a powerful RG to a low power FR I source

A survey of Low Luminosity Compact sources and its implication for evolution of radio-loud AGNs. II. Optical analysis

This is the second in a series of papers concerning a new sample of low luminosity compact (LLC) objects. Here we discuss the optical properties of the sample based on Sloan Digital Sky Survey (SDSS) images and spectra. We have generated different diagnostic diagrams and classified the sources as high and low excitation galaxies (HEG and LEG, respectively). We have studied the jet-host interactions, relation between radio and optical line emission and evolution of the radio source within a larger sample that included also the published samples of compact steep spectrum (CSS), gigahertz peaked spectrum (GPS) sources and FRII and FRI objects. The optical and radio properties of the LLC sample are in general consistent with brighter CSS and large-scale radio sources, although the LLC objects have lower values of [OIII] luminosity than the more powerful CSS sources (L_1.4GHz>10^25 W/Hz). However, when LLC are added to the other samples, HEG and LEG seem to follow independent, parallel evolutionary tracks. Regarding ionization mechanisms, LLC and luminous CSS objects behave like FRII sources, while FRI seem to belong to a different group of objects. Based on our results, we propose the independent, parallel evolutionary tracks for HEG and LEG sources, evolving from GPS - CSS - FR.Comment: 12 pages, 2 figures, 2 tables, MNRAS in pres

THE ROLE OF MIR-340 IN POST-TRANSCRIPTIONAL REGULATION OF THE UPA-SYSTEM IN BREAST CANCER

The urokinase-type plasminogen activator system (uPA-system), whose main components are the serine protease uPA (PLAU), the cell surface receptor uPAR (PLAUR) and the uPA inhibitor PAI-1 (SERPINE1), has been extensively studied for its involvement in cancer pathogenesis. Specifically, nowadays the components of the uPA-system are well-characterised determinants for the prognosis of breast cancer. The regulation of the gene expression of the uPA-system components is very complex and depends on a plethora of stimuli acting both at transcriptional and post-transcriptional level. The uPA-system components are often over expressed in breast cancer but the detailed molecular mechanisms regulating the expression are still to uncover. In an expression analysis conducted on a cohort of unselected breast cancer patients, we found that the expression of PLAU and PLAUR is highly correlated. Meta-analyses of published experimental data and in silico studies pointed out the possibility that PLAU, PLAUR and also SERPINE1 might be negatively regulated at post-transcriptional level by a microRNA, the miR-340. We experimentally validated the role of miR-340 as negative regulator of the expression of the three uPA-system components using MDA-MB-231, a triple negative breast cancer cell line. Microarray experiments, performed to characterise the global transcriptome changes induced by miR-340 in MDA-MB-231 cells, showed that miR-340 down regulates also the expression of desmoplastic reaction-related genes underlining a possible role of miR-340 in regulating tumour-associated genes. Notably, most of the identified miR-340 target genes were found indeed to be associated with poor clinical outcome in breast cancer. Functional studies carried out in MDA-MB-231 cells suggested that miR-340 might modulate cell proliferation, even if this effect was not confirmed in vivo. In order to better define the functional role of miR-340, we generated a miR-340 deficient mouse model, taken advantage of the zinc finger nuclease technology. Overall these data identify, for the first time, a single microRNA that is able to down regulate the expression of the three main components of the uPA-system together with desmoplastic reaction and breast cancer prognosis-related genes, thus representing a new potential player in the pathogenesis of breast cancer

On the spectro-photometric properties of the bulk of the radio-loud AGN population

In a previous paper we showed that the radio sources selected by combining large areas radio and optical surveys, present a strong deficit of radio emission with respect to 3CR radio-galaxies matched in line emission luminosity. We argued that the prevalence of sources with luminous extended radio structures in high flux limited samples is due to a selection bias. Sources with low radio power form the bulk of the radio-loud AGN population but are still virtually unexplored. We here analyze their photometric and spectroscopic properties. From the point of view of their emission lines, the majority of the sample are Low Excitation Galaxies (LEG), similar to the 3CR objects at the same level of line luminosity. The hosts of LEG are red, massive Early-Type Galaxies (ETG) with large black holes masses , statistically indistinguishable from the hosts of low redshift 3CR/LEG sources. No genuine radio-loud LEG could be found associated with black holes with a mass substantially lower than 10^8 M(sun) or with a late type host. The fraction of galaxies with signs of star formation (5%) is similar to what is found in both the quiescent ETG and 3CR/LEG hosts. We conclude that the deficit in radio emission cannot be ascribed to differences in the properties of their hosts. We argue that instead this could be due to a temporal evolution of the radio luminosity. A minority (10%) of the sample show rather different properties, being associated with low black hole masses, with spiral galaxies, or showing a high excitation spectrum. In general these outliers are the result of the contamination from Seyfert and from galaxies where the radio emission is powered by star formation. For the objects with high excitation spectra there is no a clear discontinuity in either the host or nuclear properties as they span from radio-quiet and radio-loud AGN.Comment: Accepted for publication in A&

The fast matched filter for gravitational-wave data analysis: Characteristics and applications

We report on the application of a matched filter to the data of two-mode resonant gravitational-wave antennas for the detection of burst signals, with reference to data obtained by direct acquisition, i.e. without going through lock-in amplifiers, sampled at relatively high speed. After a review of the basic model of resonant detectors, that includes a discussion of the signal and of the noise, we present a detailed mathematical derivation of the optimum filter matched to an input burst. We then analyze and discuss the performance of the matched filter as regards both the improvement of the signal-to-noise ratio and the observation bandwidth, also considering the adaptive realization of the filter, based on the actual spectrum of the noise as estimated from the data. The discussion that follows is centered on various aspects concerning the practical application of the matched filter as well as the loss of performance due both to uncertainties on the parameters used for building the filter and to various discretization effects, both in the time and frequency domains. Finally, we consider some experimental results obtained by applying the matched filter to the data of the Explorer detector, also providing a comparison with what we obtained by applying an optimum filter to data processed by lock-in amplifiers, sampled at lower speed