Description: Several authors have reported that the dynamical masses of massive compact galaxies ( M * 10 11 M , r e  ~ 1 kpc), computed as $M_\mathrm{dyn}= 5.0 \ \sigma _\mathrm{e}^2 r_\mathrm{e}/ G$ , are lower than their stellar masses M * . In a previous study from our group, the discrepancy is interpreted as a breakdown of the assumption of homology that underlie the M dyn determinations. Here, we present new spectroscopy of six redshift z   1.0 massive compact ellipticals from the Extended Groth Strip, obtained with the 10.4 m Gran Telescopio Canarias. We obtain velocity dispersions in the range 161–340 km s –1 . As found by previous studies of massive compact galaxies, our velocity dispersions are lower than the virial expectation, and all of our galaxies show M dyn  〈  M * (assuming a Salpeter initial mass function). Adding data from the literature, we build a sample covering a range of stellar masses and compactness in a narrow redshift range z   1.0 . This allows us to exclude systematic effects on the data and evolutionary effects on the galaxy population, which could have affected previous studies. We confirm that mass discrepancy scales with galaxy compactness. We use the stellar mass plane ( M * , e , r e ) populated by our sample to constrain a generic evolution mechanism. We find that the simulations of the growth of massive ellipticals due to mergers agree with our constraints and discard the assumption of homology.

Description: We report on results from the analysis of a stellar mass-selected (log ( M * /M ) ≥ 9.0) sample of 1644 galaxies at 0.65 〈 z  〈 1.1 with ultradeep (m AB  〈 26.5) optical medium-band ( R ~ 50) photometry from the Survey for High-z Absorption Red and Dead Sources (SHARDS). The spectral resolution of SHARDS allows us to consistently measure the strength of the 4000 Å spectral break [ D n (4000), an excellent age indicator for the stellar populations of quiescent galaxies] for all galaxies at z ~ 0.9 down to log ( M * /M ) ~ 9. The D n (4000) index cannot be resolved from broad-band photometry, and measurements from optical spectroscopic surveys are typically limited to galaxies at least 10 times more massive. When combined with the rest-frame U  – V colour, ( U  – V ) r , D n (4000) provides a powerful diagnostic of the extinction affecting the stellar population that is relatively insensitive to degeneracies with age, metallicity or star formation history. We use this novel approach to estimate de-reddened colours and light-weighted stellar ages for individual sources. We explore the relationships linking stellar mass, ( U  – V ) r , and D n (4000) for the sources in the sample, and compare them to those found in local galaxies. The main results are: (a) both D n (4000) and ( U  – V ) r correlate with M * . The dispersion in D n (4000) values at a given M * increases with M * , while the dispersion for ( U  – V ) r decreases due to the higher average extinction prevalent in massive star-forming galaxies. (b) For massive galaxies, we find a smooth transition between the blue cloud and red sequence in the intrinsic U  – V colour, in contrast with other recent results. (c) At a fixed stellar age, we find a positive correlation between extinction and stellar mass. (d) The fraction of sources with declining or halted star formation increases steeply with the stellar mass, from ~5 per cent at log ( M * /M ) = 9.0–9.5 to ~80 per cent at log ( M * /M ) 〉 11, in agreement with downsizing scenarios.

Description: Harmonized forest area information provides an important basis for environmental modelling and policy-making at both national and international levels. Traditionally, this information has been provided by national forest inventory statistics but is now increasingly complemented with remote sensing tools. Reliability and harmonization of both sources are important aspects to ensure comparability and to enable the development of international forest scenarios. Initiatives with the purpose of harmonization of forest area for both sources are currently ongoing. Nevertheless, all forest area estimates contain uncertainties, which must be quantified and included in the error budget. This is a prerequisite for combining and comparing data. The purpose of this study is to compare, taking into account uncertainties, forest area estimates for year 2000 derived from four different harmonized satellite-based maps, covering Europe with recognized official forest statistics. It was found that the major cause of disagreements between official statistics and map-derived forest area originates from the general issue of accounting for land cover instead of land use. Consequently, CORINE land cover results had the best accordance with official statistics due to its focus on land use. The other maps overestimated the forest area in mountainous countries and showed underestimation in countries with large forest area or open forest formations.

Description: Using a simple model of photodissociated atomic hydrogen on a galactic scale, it is possible to derive total hydrogen volume densities. These densities, obtained through a combination of atomic hydrogen, far-ultraviolet and metallicity data, provide an independent probe of the combined atomic and molecular hydrogen gas in galactic discs. We present a new, flexible and fully automated procedure using this simple model. This automated method will allow us to take full advantage of a host of available data on galaxies in order to calculate the total hydrogen volume densities of the giant molecular clouds surrounding sites of recent star formation. Until now this was only possible on a galaxy-by-galaxy basis using by-eye analysis of candidate photodissociation regions. We test the automated method by adopting various models for the dust-to-gas ratio and comparing the resulting densities for M74, including a new metallicity map of M74 produced by integral field spectroscopy. We test the procedure against previously published M83 volume densities based on the same method and find no significant differences. The range of total hydrogen volume densities obtained for M74 is approximately 5–700 cm –3 . Different dust-to-gas ratio models do not result in measurably different densities. The cloud densities presented here mean that M74 is added to the list of galaxies analysed using the assumption of photodissociated atomic hydrogen occurring near sites of recent star formation, and consolidate the method. For the first time, full metallicity maps are included in the analysis as opposed to metallicity gradients. The results will need to be compared with other tracers of the interstellar medium and photodissociation regions, such as CO and C  ii , in order to test our basic assumptions, specifically our assumption that the H i we detect originates in photodissociation regions.

Description: The 3'X domain of hepatitis C virus is a strongly conserved structure located at the 3' terminus of the viral genomic RNA. This domain modulates the replication and translation processes of the virus in conjunction with an upstream 5BSL3.2 stem–loop, and contains a palindromic sequence that facilitates RNA dimerization. Based on nuclear magnetic resonance spectroscopy and gel electrophoresis, we report here that domain 3'X adopts a structure composed of two stem–loops, and not three hairpins or a mixture of folds, as previously proposed. This structure exposes unpaired terminal nucleotides after a double-helical stem and palindromic bases in an apical loop, favoring genomic RNA replication and self-association. At higher ionic strength the domain forms homodimers comprising an intermolecular duplex of 110 nucleotides. The 3'X sequences can alternatively form heterodimers with 5BSL3.2. This contact, reported to favor translation, likely involves local melting of one of the 3'X stem–loops.

Description: We present a study of the molecular gas properties in a sample of 98 H i  – flux selected spiral galaxies within ~25 Mpc, using the CO J  = 3 – 2 line observed with the James Clerk Maxwell Telescope. We use the technique of survival analysis to incorporate galaxies with CO upper limits into our results. Comparing the group and Virgo samples, we find a larger mean H 2 mass in the Virgo galaxies, despite their lower mean H i  mass. This leads to a significantly higher H 2 to H i  ratio for Virgo galaxies. Combining our data with complementary Hα star formation rate measurements, Virgo galaxies have longer molecular gas depletion times compared to group galaxies, due to their higher H 2 masses and lower star formation rates. We suggest that the longer depletion times may be a result of heating processes in the cluster environment or differences in the turbulent pressure. From the full sample, we find that the molecular gas depletion time has a positive correlation with the stellar mass, indicative of differences in the star formation process between low- and high-mass galaxies, and a negative correlation between the molecular gas depletion time and the specific star formation rate.

Description: We discuss a definition of morphological cellular neural networks (MCNN) where the state change operator are auto-associative morphological memories (AMM). The fast convergence properties of AMM and the shape of its fixed point set make the MCNN dynamics trivial. However, segmentation results are poor. We propose a morphological cellular automata (MCA) with assured convergence to a state characterized by morphological dependences and independences between neighbouring cell states. Cell dynamic rules test morphological dependence among neighbouring cell's states. When neighbouring cell states are morphological dependent in the erosive or dilative sense, the morphologically dominant state colonizes the neighbour with morphological-dependent state. The resulting configuration of cell states is composed of homogeneous regions whose boundaries are defined by the morphological independence relation. Results are given on image segmentation, where MCA cells correspond to image pixels.

Description: We present 12 CO J  = 3-〉2 maps of NGC 2976 and NGC 3351 obtained with the James Clerk Maxwell Telescope (JCMT), both early targets of the JCMT Nearby Galaxy Legacy Survey (NGLS). We combine the present observations with 12 CO J  = 1-〉0 data and find that the computed 12 CO J  = 3-〉2 to 12 CO J  = 1-〉0 line ratio ( R 31 ) agrees with values measured in other NGLS field galaxies. We compute the M H 2 value and find that it is robust against the value of R 31 used. Using H i data from The H i Nearby Galaxy Survey, we find a tight correlation between the surface density of H 2 and star formation rate density for NGC 3351 when 12 CO J  = 3-〉2 data are used. Finally, we compare the 12 CO J  = 3-〉2 intensity with the polycyclic aromatic hydrocarbon (PAH) 8 μm surface brightness and find a good correlation in the high surface brightness regions. We extend this study to include all 25 Spitzer Infrared Nearby Galaxies Survey galaxies within the NGLS sample and find a tight correlation at large spatial scales. We suggest that both PAH 8 μm and 12 CO J  = 3-〉2 are likely to originate in regions of active star formation.

Description: We analyse the stellar populations in the host galaxies of 53 X-ray selected optically dull active galactic nuclei (AGN) at 0.34 〈 z 〈 1.07 with ultradeep ( m AB = 26.5, 3) optical medium-band ( R ~ 50) photometry from the Survey for High-z Absorption Red and Dead Sources (SHARDS). The spectral resolution of SHARDS allows us to consistently measure the strength of the 4000 Å break, D n (4000), a reliable age indicator for stellar populations. We confirm that most X-ray selected moderate-luminosity AGN ( L X 〈 10 44  erg s –1 ) are hosted by massive galaxies (typically M * 〉10 10.5 M ) and that the observed fraction of galaxies hosting an AGN increases with the stellar mass. A careful selection of random control samples of inactive galaxies allows us to remove the stellar mass and redshift dependences of the AGN fraction to explore trends with several stellar age indicators. We find no significant differences in the distribution of the rest-frame U – V colour for AGN hosts and inactive galaxies, in agreement with previous results. However, we find significantly shallower 4000 Å breaks in AGN hosts, indicative of younger stellar populations. With the help of a model-independent determination of the extinction, we obtain extinction-corrected U – V colours and light-weighted average stellar ages. We find that AGN hosts have younger stellar populations and higher extinction compared to inactive galaxies with the same stellar mass and at the same redshift. We find a highly significant excess of AGN hosts with D n (4000) ~ 1.4 and light-weighted average stellar ages of 300–500 Myr, as well as a deficit of AGN in intrinsic red galaxies. We interpret failure in recognizing these trends in previous studies as a consequence of the balancing effect in observed colours of the age–extinction degeneracy.

Description: We are undertaking a search for high-redshift low-luminosity Lyman Alpha sources in the SHARDS (Survey for High-z Absorption Red and Dead Sources) survey. Among the pre-selected Lyman Alpha sources two candidates were spotted, located 3.19 arcsec apart, and tentatively at the same redshift. Here, we report on the spectroscopic confirmation with Gran Telescopio Canarias of the Lyman Alpha emission from this pair of galaxies at a confirmed spectroscopic redshifts of z =5.07. Furthermore, one of the sources is interacting/merging with another close companion that looks distorted. Based on the analysis of the spectroscopy and additional photometric data, we infer that most of the stellar mass of these objects was assembled in a burst of star formation 100 Myr ago. A more recent burst (2 Myr old) is necessary to account for the measured Lyman Alpha flux. We claim that these two galaxies are good examples of Lyman Alpha sources undergoing episodic star formation. Besides, these sources very likely constitute a group of interacting Lyman Alpha emitters (LAEs).