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The European Union is aiming at reaching greenhouse gas (GHG) emission neutrality in 2050. Austria's current greenhouse gas emissions are 80 million t/year. Renewable Energy (REN) contributes 32 % to Austria's total energy consumption. To decarbonize energy consumption, a substantial increase in energy generation from renewable energy is required. This increase will add to the seasonality of energy supply and amplifies the seasonality in energy demand. In this paper, the seasonality of energy supply and demand in a Net Zero Scenario are analyzed for Austria and requirements for hydrogen storage derived. We looked into the potential usage of hydrogen in Austria and the economics of hydrogen generation and technology and market developments to assess the Levelized Cost of Hydrogen (LCOH). Then, we cover the energy consumption in Austria followed by the REN potential. The results show that incremental potential of up to 140 TWh for hydropower, photovoltaic (PV), and wind exists in Austria. Hydropower generation and PV is higher in summer- than in wintertime while wind energy leads to higher energy generation in wintertime. The largest incremental potential is PV, agrivoltaic is significantly increasing the area amenable for PV compared with PV usage only. Battery Electric Vehicles (BEV) and Fuel Cell Vehicles (FCV) are using energy more efficiently than Internal Combustion Engine (ICE) cars, however, the use of hydrogen for electricity generation is significantly decreasing the efficiency due to electricity — hydrogen — electricity conversion. The increase in REN use and the higher demand for energy in Austria in wintertime require seasonal storage of energy. We developed three scenarios, Externally Dependent Scenario (EDS), Balanced Energy Scenario (BES) or Self-Sustained Scenario (SSS) for Austria. The EDS scenario assumes significant REN import to Austria whereas the SSS scenario relies on REN generation within Austria. The required hydrogen storage would be 10.82 bn ms for EDS, 13.34 bn ms for BES, and 18.69 bn ms for SSS. Gas and oil production in Austria and the presence of aquifers indicates that sufficient storage capacity might be available. Significant technology development is required to be able to implement hydrogen as energy carrier and to balance seasonal energy demand and supply.

We describe the Herschel Virgo Cluster Survey (HeViCS) and the first data that cover the complete survey area (four 4 x 4 deg2 regions). We use these data to measure and compare the global far infrared properties of 78 optically bright galaxies that are selected at 500 \mum and detected in all five far-infrared bands. We show that our measurements and calibration are broadly consistent with previous data obtained by IRAS, ISO, Spitzer and Planck. We use SPIRE and PACS photometry data to produce 100, 160, 250, 350 and 500 \mum cluster luminosity distributions. These luminosity distributions are not power laws, but peaked, with small numbers of both faint and bright galaxies. We measure a cluster 100-500 micron far-infrared luminosity density of 1.6(7.0) \pm 0.2 x 10^9 Lsun/Mpc3. This compares to a cluster 0.4-2.5 \mum optical luminosity density of 5.0(20.0) x 10^9 Lsun/Mpc3, some 3.2(2.9) times larger than the far-infrared. A typical photon originates from an optical depth of 0.4\pm0.1. Most of our sample galaxies are well fitted by a single modified blackbody (beta=2), leading to a mean dust mass of log Mdust = 7.31 Msun and temperature of 20.0 K. We also derive both stellar and atomic hydrogen masses from which we calculate mean values for the stars:gas(atomic) and gas(atomic): dust mass ratios of 15.1 and 58.2 respectively. Using our derived dust, atomic gas and stellar masses we estimate cluster mass densities of 8.6(27.8) x 10^6, 4.6(13.9) x 10^8, 7.8(29.7) x 10^9 Msun/Mpc3, respectively for dust, atomic gas and stars. These values are higher than those derived for field galaxies by factors of 39(126), 6(18) and 34(129) respectively. In the above luminosity/mass densities are given using the whole sample with values in brackets using just those galaxies that lie between 17 and 23 Mpc. We provide a data table of flux densities in all the Herschel bands for all 78 bright Virgo cluster galaxies.

We make use of Spitzer imaging between 4 and 16 μm and near-infrared data at 2.2 μm to investigate the nature and distribution of the mid-infrared emission in a sample of early-type galaxies (ETGs) in the Virgo cluster. These data allow us to conclude, with some confidence, that the emission at 16 μm in passive ETGs is stellar in origin, consistent with previous work concluding that the excess mid-infrared emission comes from the dusty envelopes around evolved asymptotic giant branch (AGB) stars. There is little evidence for the mid-infrared emission of an unresolved central component, as might arise in the presence of a dusty torus associated with a low-luminosity active galactic nucleus. We none the less find that the 16-μm emission is more centrally peaked than the near-infrared emission, implying a radial stellar population gradient. By comparing with independent evidence from studies at optical wavelengths, we conclude that a metallicity that falls with increasing radius is the principal driver of the observed gradient. We also plot the mid-infrared colour–magnitude diagram and combine with similar work on the Coma cluster to define the colour–magnitude relation for absolute K-band magnitudes from −26 to −19. Because a correlation between mass and age would produce a relation with a gradient in the opposite sense to that observed, we conclude that the relation reflects the fact that passive ETGs of lower mass also have a lower average metallicity. The colour–magnitude relation is thus driven by metallicity effects. In contrast to what is found in Coma, we do not find any objects with anomalously bright 16-μm emission relative to the colour–magnitude relation. Although there is little overlap in the mass ranges probed in the two clusters, this may suggest that observable ‘rejuvenation’ episodes are limited to intermediate-mass objects.

We present GALEX far-ultraviolet (FUV, $\lambda_{eff}$=1538 \AA) and near-ultraviolet (NUV, $\lambda_{eff}$=2316 \AA) surface photometry of 40 early-type galaxies (ETGs) selected from a wider sample of 65 nearby ETGs showing emission lines in their optical spectra. We derive FUV and NUV surface brightness profiles, (FUV-NUV) colour profiles and D$_{25}$ integrated magnitudes. We extend the photometric study to the optical {\it r} band from SDSS imaging for 14 of these ETGs. In general, the (FUV-NUV) radial colour profiles become redder with galactocentric distance in both rejuvenated ($\leq 4$ Gyr) and old ETGs. Colour profiles of NGC 1533, NGC 2962, NGC 2974, NGC 3489, and IC 5063 show rings and/or arm-like structures, bluer than the body of the galaxy, suggesting the presence of recent star formation. Although seven of our ETGs show shell systems in their optical image, only NGC 7135 displays shells in the UV bands. We characterize the UV and optical surface brightness profiles, along the major axis, using a Sersic law. The Sersic law exponent, $n$, varies from 1 to 16 in the UV bands. S0 galaxies tend to have lower values of $n$ ($\leq5$). The Sersic law exponent $n=4$ seems to be a watershed: ETGs with $n>4$ tend to have [$\alpha$/Fe] greater than 0.15, implying a short star-formation time scale. We find a significant correlation between the FUV$-$NUV colour and central velocity dispersions $\sigma$, with the UV colours getting bluer at larger $\sigma$. This trend is likely driven by a combined effect of `downsizing' and of the mass-metallicity relation.

We use 16 micron, Spitzer-IRS, blue peakup photometry of 50 early-type galaxies in the Coma cluster to define the mid-infrared colour-magnitude relation. We compare with recent simple stellar population models that include the mid-infrared emission from the extended, dusty envelopes of evolved stars. The Ks-[16] colour in these models is very sensitive to the relative population of dusty Asymptotic Giant Branch (AGB) stars. We find that the passively evolving early-type galaxies define a sequence of approximately constant age (~10 Gyr) with varying metallicity. Several galaxies that lie on the optical/near-infrared colour-magnitude relation do not lie on the mid-infrared relation. This illustrates the sensitivity of the Ks-[16] colour to age. The fact that a colour-magnitude relation is seen in the mid-infrared underlines the extremely passive nature of the majority (68%) of early-type galaxies in the Coma cluster. The corollary of this is that 32% of the early-type galaxies in our sample are not `passive', insofar as they are either significantly younger than 10 Gyr or they have had some rejuvenation episode within the last few Gyr., 11 pages, 8 figures. Accepted for publication in MNRAS. This replacement has mainly cosmetic textual changes but the model in figure 6 has been modified

To assess the effects of the cluster environment on the different components of the interstellar medium, we analyse the FIR-submm properties of a sample of star-forming dwarf (SFD) galaxies detected by the Herschel Virgo Cluster Survey (HeViCS). We determine dust masses and dust temperatures by fitting a modified black body (MBB) function to the spectral energy distributions (SEDs). Stellar and gas masses, star formation rates (SFRs), and metallicities are obtained from the analysis of a set of ancillary data. Dust is detected in 49 out of 140 optically identified dwarfs covered by the HeViCS field; considering only dwarfs brighter than $m_B$ = 18 mag, this gives a detection rate of 43%. After evaluating different emissivity indices, we find that the FIR-submm SEDs are best-fit by $\beta$=1.5, with a median dust temperature $T_d$ = 22.4 K. Assuming $\beta$=1.5, 67% of the 23 galaxies detected in all five Herschel bands show emission at 500 $\mu$m in excess of the MBB model. The excess is inversely correlated with SFR and stellar masses. To study the variations in the global properties of our sample due to environmental effects, we compare the Virgo SFDs to other Herschel surveys, such as KINGFISH, the Dwarf Galaxy Survey (DGS), and the HeViCS bright galaxy catalogue (BGC). We explore the relations between stellar mass and HI fraction, specific SFR, dust fraction, gas-to-dust ratio over a wide range of stellar masses. Highly HI-deficient Virgo dwarf galaxies are mostly characterised by quenched star formation activity and lower dust fractions giving hints for dust stripping in cluster dwarfs. However, we find that the fraction of dust removed has to be less than that of the HI component. Since the Virgo SFDs are likely to be crossing the cluster for the first time, a longer timescale might be necessary to strip the more centrally concentrated dust distribution., Comment: 31 pages, 20 figures, accepted for publication in Astronomy and Astrophysics. V2: minor corrections, updated references

We present high signal to noise ratio Spitzer Infrared Spectrograph observations of 17 Virgo early-type galaxies. The galaxies were selected from those that define the colour-magnitude relation of the cluster, with the aim of detecting the silicate emission of their dusty, mass-losing evolved stars. To flux calibrate these extended sources we have devised a new procedure that allows us to obtain the intrinsic spectral energy distribution and to disentangle resolved and unresolved emission within the same object. We have found that thirteen objects of the sample (76%) are passively evolving galaxies with a pronounced broad silicate feature which is spatially extended and likely of stellar origin, in agreement with model predictions. The other 4 objects (24%) are characterized by different levels of activity. In NGC 4486 (M 87) the line emission and the broad silicate emission are evidently unresolved and, given also the typical shape of the continuum, they likely originate in the nuclear torus. NGC 4636 shows emission lines superimposed on extended (i.e. stellar) silicate emission, thus pushing the percentage of galaxies with silicate emission to 82%. Finally, NGC 4550 and NGC 4435 are characterized by polycyclic aromatic hydrocarbon (PAH) and line emission, arising from a central unresolved region. A more detailed analysis of our sample, with updated models, will be presented in a forthcoming paper., 6 pages; ApJ Letters, accepted

We present 12 CO (J = 1-0) and 12 CO (J = 2-1) observations of eight early-type galaxies, forming part of a sample of interacting galaxies, each consisting of one late- and one early-type system. All of the early-type galaxies observed are undetected in CO to low levels, allowing us to place tight constraints on their molecular gas content. Additionally, we present H I absorption data for one system. The implications for possible gas transfer from the late- to the early-type galaxy during the interaction are discussed.

Both Arp 140 and Arp 104 reveal extended tidal tails in the HI. The Halpha and FIR fluxes of Arp 140 yield similar SFR of ~0.8 solar masses per year. In contrast the Halpha flux of Arp 104 yields a SFR of ~0.05 solar masses per year, ~ 20 times smaller than that obtained from the FIR flux. Spectra were used to examine the changing velocity of atomic and molecular gas in NGC 5218 (Arp 104). The atomic and molecular gas were found to be dynamically similar with comparable velocities and velocity widths across the galaxy; consistent with the two phases responding similarly to the interaction, or enhanced HI to CO conversion in the centre of the galaxy.

arXiv:1501.02170v2.-- et al., We discuss the potential of a next generation space-borne CMB experiment for studies of extragalactic sources with reference to COrE+, a project submitted to ESA in response to the call for a Medium-size mission (M4). We consider three possible options for the telescope size: 1 m, 1.5 m and 2 m (although the last option is probably impractical, given the M4 boundary conditions). The proposed instrument will be far more sensitive than Planck and will have a diffraction-limited angular resolution. These properties imply that even the 1 m telescope option will perform substantially better than Planck for studies of extragalactic sources. The source detection limits as a function of frequency have been estimated by means of realistic simulations taking into account all the relevant foregrounds. Predictions for the various classes of extragalactic sources are based on up-to-date models. The most significant improvements over Planck results are presented for each option. COrE+ will provide much larger samples of truly local star-forming galaxies (by about a factor of 8 for the 1 m telescope, of 17 for 1.5 m, of 30 for 2 m), making possible analyses of the properties of galaxies (luminosity functions, dust mass functions, star formation rate functions, dust temperature distributions, etc.) across the Hubble sequence. Even more interestingly, COrE+ will detect, at |b| > 30°, thousands of strongly gravitationally lensed galaxies (about 2,000, 6,000 and 13,000 for the 1 m, 1.5 m and 2 m options, respectively). Such large samples are of extraordinary astrophysical and cosmological value in many fields. Moreover, COrE+ high frequency maps will be optimally suited to pick up proto-clusters of dusty galaxies, i.e. to investigate the evolution of large scale structure at larger redshifts than can be reached by other means. Thanks to its high sensitivity COrE+ will also yield a spectacular advance in the blind detection of extragalactic sources in polarization: we expect that it will detect up to a factor of 40 (1 m option) or of 160 (1.5 m option) more radio sources than can be detected by Planck and, for the first time, from several tens (1 m option) to a few hundreds (1.5 m option) of star forming galaxies. This will open a new window for studies of the global properties of magnetic fields in star forming galaxies and of their relationships with star formation rates., Work supported in part by ASI/INAF agreement n. 2014-024-R.0. MB acknowledges the financial assistance of the South African National Research Foundation (NRF) and of the Polish National Science Centre under contract #UMO-2012/07/D/ST9/02785.

We present three independent catalogs of point-sources extracted from SPIRE images at 250, 350, and 500 micron as a part of the Herschel Virgo Cluster Survey (HeViCS). The source positions are determined by estimating the likelihood to be a real source for each peak on the maps and the flux densities are estimated using the sourceExtractorTimeline, a timeline-based point source fitter. Afterwards, each source is subtracted from the maps, removing a Gaussian function in every position with the full width half maximum equal to that estimated in sourceExtractorTimeline. This procedure improves the robustness of our algorithm in terms of source identification. The HeViCS catalogs contain about 52000, 42200, and 18700 sources selected at 250, 350, and 500 micron above 3sigma and are ~ 75%, 62%, and 50% complete at flux densities of 20 mJy at 250, 350, 500 micron, respectively. We then measured source number counts at 250, 350, and 500 micron and we also cross-correlated the catalogs with the Sloan Digital Sky Survey to investigate the redshift distribution of the nearby sources. From this cross-correlation, we select ~2000 sources with reliable fluxes and a high signal-to-noise ratio, finding an average redshift z~0.3+/-0.22. The number counts at 250, 350, and 500 micron show an increase in the slope below 200 mJy, indicating a strong evolution in number of density for galaxies at these fluxes. In general, models tend to overpredict the counts at brighter flux densities, underlying the importance of studying the Rayleigh-Jeans part of the spectral energy distribution to refine the theoretical recipes of the models. Our iterative method for source identification allowed the detection of a family of 500 micron sources that are not foreground objects belonging to Virgo and not found in other catalogs., Comment: Accepted for publication in Astronomy and Astrophysics

M. Baes et al., We cross-correlate the Planck Catalogue of Compact Sources (PCCS) with the fully sampled 84 deg2Herschel Virgo Cluster Survey (HeViCS) fields. We search for and identify the 857 and 545 GHz PCCS sources in the HeViCS fields by studying their FIR/submm and optical counterparts. We find 84 and 48 compact Planck sources in the HeViCS fields at 857 and 545 GHz, respectively. Almost all sources correspond to individual bright Virgo Cluster galaxies. The vast majority of the Planck detected galaxies are late-type spirals, with the Sc class dominating the numbers, while early-type galaxies are virtually absent from the sample, especially at 545 GHz. We compare the HeViCS SPIRE flux densities for the detected galaxies with the four different PCCS flux density estimators and find an excellent correlation with the aperture photometry flux densities, even at the highest flux density levels. We find only seven PCCS sources in the HeViCS fields without a nearby galaxy as obvious counterpart, and conclude that all of these are dominated by Galactic cirrus features or are spurious detections. No Planck sources in the HeViCS fields seem to be associated to high-redshift proto-clusters of dusty galaxies or strongly lensed submm sources. Finally, our study is the first empirical confirmation of the simulation-based estimated completeness of the PCCS, and provides a strong support of the internal PCCS validation procedure. © 2014 ESO., M.B., J.F. and T.H. acknowledge financial support from the Belgian Science Policy Office (BELSPO) through the PRODEX project “Herschel-PACS Guaranteed Time and Open Time Programs: Science Exploitation” (C90370). M.C. and G.D.Z. acknowledge financial support from ASI/INAF Agreement I/072/09/0. M.B., F.A., I.D.L., G.G., S.V. and J.V. acknowledge support from the Flemish Fund for Scientific Research (FWO-Vlaanderen). SPIRE has been developed by a consortium of institutes led by Cardiff University (UK) and including Univ. Lethbridge (Canada); NAOC (China); CEA, LAM (France); IFSI, Univ. Padua (Italy); IAC (Spain); Stockholm Observatory (Sweden); Imperial College London, RAL, UCLMSSL, UKATC, Univ. Sussex (UK); and Caltech, JPL, NHSC, Univ. Colorado (USA). This development has been supported by national funding agencies: CSA (Canada); NAOC (China); CEA, CNES, CNRS (France); ASI (Italy); MCINN (Spain); SNSB (Sweden); STFC (UK); and NASA (USA). The development of Planck has been supported by: ESA; CNES and CNRS/INSU-IN2P3-INP (France); ASI, CNR, and INAF (Italy); NASA and DoE (USA); STFC and UKSA (UK); CSIC, MICINN and JA (Spain); Tekes, AoF and CSC (Finland); DLR and MPG (Germany); CSA (Canada); DTU Space (Denmark); SER/SSO (Switzerland); RCN (Norway); SFI (Ireland); FCT/MCTES (Portugal); and PRACE (EU). Funding for the SDSS and SDSS-II has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, the US Department of Energy, the National Aeronautics and Space Administration, the Japanese Monbukagakusho, the Max Planck Society, and the Higher Education Funding Council for England.

The European Space Agency’s Planck satellite, dedicated to studying the early Universe and its subsequent evolution, was launched 14 May 2009 and has been scanning the microwave and submillimetre sky continuously since 12 August 2009. In March 2013, ESA and the Planck Collaboration released the initial cosmology products based on the first 15.5 months of Planck data, along with a set of scientific and technical papers and a web-based explanatory supplement. This paper gives an overview of the mission and its performance, the processing, analysis, and characteristics of the data, the scientific results, and the science data products and papers in the release. The science products include maps of the cosmic microwave background (CMB) and diffuse extragalactic foregrounds, a catalogue of compact Galactic and extragalactic sources, and a list of sources detected through the Sunyaev-Zeldovich effect. The likelihood code used to assess cosmological models against the Planck data and a lensing likelihood are described. Scientific results include robust support for the standard six-parameter ΛCDM model of cosmology and improved measurements of its parameters, including a highly significant deviation from scale invariance of the primordial power spectrum. The Planck values for these parameters and others derived from them are significantly different from those previously determined. Several large-scale anomalies in the temperature distribution of the CMB, first detected by WMAP, are confirmed with higher confidence. Planck sets new limits on the number and mass of neutrinos, and has measured gravitational lensing of CMB anisotropies at greater than 25σ. Planck finds no evidence for non-Gaussianity in the CMB. Planck’s results agree well with results from the measurements of baryon acoustic oscillations. Planck finds a lower Hubble constant than found in some more local measures. Some tension is also present between the amplitude of matter fluctuations (σ8) derived from CMB data and that derived from Sunyaev-Zeldovich data. The Planck and WMAP power spectra are offset from each other by an average level of about 2% around the first acoustic peak. Analysis of Planck polarization data is not yet mature, therefore polarization results are not released, although the robust detection of E-mode polarization around CMB hot and cold spots is shown graphically., Centre National D'etudes Spatiales, CNRS/INSU-IN2P3, Italian Space Agency (ASI), Danish Natural Science Research Council, European Space Agency, CNRS/INSU-IN2P3-INP (France), Italian National Research Council, Istituto Nazionale Astrofisica (INAF), National Aeronautics & Space Administration (NASA), United States Department of Energy (DOE), Science & Technology Facilities Council (STFC), UKSA (UK), Consejo Superior de Investigaciones Cientificas (CSIC), Spanish Government, JA (Spain), Finnish Funding Agency for Technology & Innovation (TEKES), AoF (Finland), CSC (Finland), Helmholtz Association, German Aerospace Centre (DLR), Max Planck Society, CSA (Canada), DTU Space (Denmark), SER/SSO (Switzerland), RCN (Norway), Science Foundation Ireland, Portuguese Foundation for Science and Technology, European Union (EU), Science & Technology Facilities Council (STFC) ST/I002006/1 ST/J000388/1 ST/H001239/1 ST/K000977/1 ST/K002805/1 ST/J001368/1 ST/K00333X/1 ST/I005129/1 ST/J005673/1 ST/K003674/1 ST/L000768/1 ST/G003874/1 ST/H008586/1 ST/L001314/1 ST/K004131/1 ST/M007685/1 ST/K000985/1 ST/K001051/1 ST/K00106X/1 ST/I005765/1 ST/K002899/1 ST/J004812/1

ADP-bildende Acetyl-CoA Synthetasen (ACD) gehören wie die Succinyl-CoA Synthetasen (SCS) zur Proteinfamilie der NDP-bildenden Acyl-CoA Synthetasen. Beide Enzyme sind ubiquitär in allen drei Domänen des Lebens vorhanden und katalysieren die NDP- und Pi-abhängige Umsetzung von Acyl-CoA Estern (Acetyl-CoA bzw. Succinyl-CoA) zu den kor-respondierenden Säuren unter der Bildung von NTP über Substratstufenphosphorylierung. Die ACD-Reaktion wurde erstmals in dem Acetat bildenden Protisten Entamoeba histolytica beschrieben, nicht aber charakterisiert. Erste detaillierte Analysen von ACDs in Prokaryoten wurden in dem hyperthermophilen Archaeon Pyrococcus furiosus durchgeführt und dabei zwei α2β2-heterotetramere ACD-Isoenzyme - ACDI und ACDII - identifiziert, die sich hin-sichtlich ihres Substratspektrums und ihrer kinetischen Konstanten unterscheiden. Ein weite-res ACD-Isoenzym wurde in Thermococcus kodakaraensis charakterisiert, welches mit hoher Effizienz Succinat umsetzt. Es ist bisher nicht bekannt, welche Untereinheit in ACDs die Substratspezifität determiniert. Inzwischen wurde die ACD in allen untersuchten Acetat bildenden Archaea identifiziert und eine Funktion bei der Säurebildung während des Kohlenhydrat- und Peptidabbaus wurde nachgewiesen. Kürzlich wurden auch im Genom des Korarchaeoten Candidatus Korarchaeum cryptophilum, einem sehr ursprünglichen Organismus, vier ACD-Homologe und ein SCS-Homolog identifiziert, deren Funktion bislang unklar ist. Auch in einigen Acetat bildenden Bakterien, wie z.B. Chloroflexus aurantiacus, finden sich Gene für ACDs, deren Funktion aber unbekannt ist. In anderen Bakterien, wie Pseudomonas mendoci-na und Delftia acidovorans, weisen funktionelle Analysen darauf hin, dass ACD-Homologe, anders als in Archaea, an der Aktivierung bestimmter Säuren wie Pimelat und Ferulat beteiligt sind. Je nach Substrat werden diese Enzyme als Pimeloyl-CoA Synthetase (PCS) oder als Feruloyl-CoA Synthetase (FCS) bezeichnet. Zu diesen Enzymen liegen nur wenige biochemi-sche Daten vor. Insbesondere wurde bislang noch keine FCS biochemisch charakterisiert. In der vorliegenden Arbeit wurde die Rolle und Funktion von Acyl-CoA Synthetasen in den drei Domänen des Lebens untersucht. ACD in Archaea. ACD in P. furiosus. Es sollte geprüft werden, ob P. furiosus ein ACD-Isoenzym enthält, das effizient Succinat umsetzt. ORF Pf_0233 und Pf_1837 wurden kloniert und heterolog in E. coli exprimiert. Das gereinigte, rekonstituierte ACD-Isoenzym zeigte eine siebenfach höhe-re Aktivität mit Succinat als mit Acetat, was das Enzym als ACDsucc klassifiziert. Die ACD könnte daher, wie für T. kodakaraensis gezeigt, am Abbau von Glutamat zu Succinat beteiligt sein. Durch Erstellung chimärer ACDs aus den Untereinheiten zweier ACD-Isoenzyme sollte der Einfluss der Untereinheiten auf die Substratspezifität von ACDs untersucht werden. Mit je einer α- und β-Untereinheit von ACDI und ACDsucc wurden vier aktive α2β2-heterotetramere Enzyme rekonstituiert und hinsichtlich ihres Substratspektrums analysiert. Eine Chimäre aus ACDsuccα und ACDIβ ergab ein zur ACDsucc identisches Substratspektrum, während eine Kombination der ACDIα mit der β Untereinheit der ACDsucc ein Substratspektrum wie die ACDI zeigte. Die Ergebnisse der Untersuchungen der ACD-Chimären weisen darauf hin, dass das Substratspektrum der ACDs in P. furiosus durch die α-Untereinheit determiniert wird. ACDs und SCS in Ca. K. cryptophilum. Im Genom des hyperthermophilen Korarchaeoten Ca K. cryptophilum, der zu den ursprünglichsten Organismen zählt, sind Homologe von vier ACDα- und einer ACDβ Untereinheit sowie die Untereinheiten einer SCS annotiert. Die ACD-Untereinheiten wurden getrennt exprimiert, gereinigt und zu vier α2β2-heterotetrameren ACD-Isoenzymen rekonstituiert. Es konnten dabei drei aktive hyperthermophile ACDs (Topt = 85 °C) charakterisiert werden (ckcACD1, ckcACD3 und ckcACD4). Die ckcACD2 zeigte keine Aktivität. Bei ckcACD1 und ckcACD4 handelt es sich um ACDs mit einem neu-artigen Substratspektrum, die Arylsäuren sowie verzweigte und unverzweigte Acylsäuren und deren korrespondierende CoA-Ester als Substrat verwenden. Die ckcACD3 setzte hingegen effektiv Acetyl-CoA bzw. Acetat um und zeigte keine Aktivität mit Arylsäuren. Die α- und die β Untereinheit der SCS wurden getrennt exprimiert, gereinigt und zu einem aktiven 134 kDa α2β2-Heterotetramer rekonstituiert. Die hyperthermophile SCS (Topt ~ 85 °C) zeigte eine hohe Spezifität für Succinyl-CoA und Succinat. Genomanalysen sprechen dafür, dass die ACDs und die SCS eine zentrale Rolle bei der Energiekonservierung im Zuge der Peptid-fermentation spielen. ACD in M. mazei. Die Gene der getrennt vorliegenden ACDα- und ACDβ-Untereinheiten MM_0358 und MM_0493 wurden kloniert, heterolog in E. coli exprimiert, gereinigt und als aktive ACD rekonstituiert. Das 170 kDa-Enzym (α2β2) katalysierte die Umsetzung von Ace-tyl-CoA und Isobutyryl-CoA mit gleicher Effizienz, Phenylacetyl-CoA wurde nicht akzep-tiert. Die ACD katalysierte mit geringerer Aktivität auch die Säureaktivierung. ACD in Eukarya. ACD in E. histolytica. Die ACD aus E. histolytica wurde heterolog exprimiert, gereinigt und als 164 kDa Homodimer charakterisiert. Neben Acetat bzw. Acetyl-CoA setzte die ACD auch die Säuren Propionat und Thioglycolat um. Verzweigte Acylsäuren und Arylsäuren sowie deren CoA-Ester wurden nicht akzeptiert. Das Substratspektrum des Enzyms und Genomana-lysen lassen auf eine physiologische Rolle bei der Glucose- und Peptidfermentation zu Acetat und Propionat schließen. ACD-Homologe in Bacteria. ACD in C. aurantiacus. Im Genom von C. aurantiacus finden sich keine Gene für die typi-schen Enzyme bakterieller Acetatbildung, Phosphotransacetylase (PTA) und Acetatkinase (AK), jedoch ein ACD-Homolog. Durch Wachstumsexperimente und Zellsuspensionen wurde die Acetatbildung aus Glucose in C. aurantiacus analysiert. Pro Mol Glucose wurden bis zu 1.2 Mol Acetat gebildet. In Zellextrakten konnten keine Aktivitäten von AK und PTA nach-gewiesen werden, aber eine durch Glucose induzierte ACD-Aktivität. Das Enzym wurde aus auf Glucose gewachsenen Zellen gereinigt und das kodierende Gen als Caur_3920 identifi-ziert. Mit einem Molekulargewicht von 300 kDa wies das Enzym eine für ACDs ungewöhnliche homotetramere Struktur auf. Die rekombinant exprimierte ACD setzte ähnlich der ACDI aus P. furiosus mit hoher Aktivität Acetyl-CoA und nur mit geringer Effizienz Phenylacetyl-CoA um. Diese Ergebnisse sprechen für eine funktionelle Beteiligung der ACD bei der Ace-tatbildung aus Glucose. Dies ist der erste Nachweis einer funktionellen ACD in der Domäne der Bacteria. Phylogenetische Analysen deuten darauf hin, dass das acd-Gen über lateralen Gentransfer von Archaea aufgenommen wurde, um das Fehlen von AK und PTA zu komple-mentieren. PCS in Ralstonia eutropha. Im Genom von R. eutropha wurden bei Sequenzvergleichen zwei putative PCSs identifiziert, die als RaPCS1 und RaPCS2 gereinigt und charakterisiert wurden. Beide rekombinanten Enzyme bilden Homodimere und setzen mit der höchsten spezifischen Aktivität Pimelat, HSCoA und ATP zu Pimeloyl-CoA, ADP und Phosphat um. Damit konn-ten erstmals ADP-bildende PCSs nachgewiesen werden. Neben Pimelat (9.5 U/mg = 100 %) setzte die RaPCS1 auch Adipat, Phenylacetat, Isobutyrat und Thioglycolat mit über 30 % der Rate um. Die RaPCS2 nutzte neben Pimelat (11.5 U/mg) nur Butyrat effizient. Keine der PCS konnte die CoA-Ester Acetyl-CoA, Isobutyryl-CoA oder Phenylacetyl-CoA umzusetzen, was darauf hindeutet, dass die PCS ausschließlich an der Säureaktivierung beteiligt ist. Alle bis-lang charakterisierten ACDs enthalten zwei katalytisch essentielle Histidine, die auch in PCS hochkonserviert sind. Mittels ortsspezifischer Mutagenese wurden beide Histidine jeweils gegen Alanin ausgetauscht, was in beiden Fällen zum Verlust der PCS-Aktivität führte. Dies lässt auf eine essentielle Beteiligung beider Histidine an der Pimelataktivierung schließen. Phylogenetische Analysen deuten darauf hin, dass PCSs gemeinsam mit FCS eine distinkte phylogenetische Gruppe innerhalb der ACD-homologen Acyl-CoA Synthetasen bilden. FCS in D. acidovorans. Die rekombinante FCS ist ein 170 kDa Homodimer und katalysiert die Umsetzung von Ferulat, HSCoA und ATP zu Feruloyl-CoA, ADP und Pi. Das Enzym ist hoch spezifisch für Ferulat (Km = 4 µM). Neben Ferulat (12 U/mg = 100 %) setzt die FCS nur Adipat (7 %), Butyrat (12 %) und Pimelat (4 %) mit geringer Effizienz um. Damit konnte erstmals eine ADP-bildende FCS charakterisiert werden. The family of NDP-forming acyl-CoA synthetases comprises, amongst other synthetases, succinyl-CoA synthetases (SCS) and acetyl-CoA synthetases (ACD). Both enzymes are ubiq-uitous in the three domains of life, catalysing the NDP- and Pi-dependent conversion of acyl-CoA esters (succinyl-CoA or acetyl-CoA) to the corresponding acids while coupling the reac-tion with the formation of NTP by substrate level-phosphorylation. ACD-activity was first detected in the acetate-forming eukaryote Entamoeba histolytica, but the enzyme has not been characterised so far. The first detailed description of ACDs in pro-karyotes was carried out in the hyperthermophilic archaeon Pyrococcus furiosus, where two α2β2 heterotetrameric isoenzymes (ACDI and ACDII) were distinguished in respect to their substrate specificity and kinetic constants. Another ACD-isoenzyme was characterised in Thermococcus kodakaraensis, which catalyses the conversion of succinate to succinyl-CoA with high efficiency. It has still not been solved which subunit determines the substrate speci-ficity of ACDs. In all acetate-forming archaea studied so far, ACDs have been identified and an acid-forming function during fermentation of carbohydrates and peptides has been shown. Recently four ACD-homologues and an SCS-homologue were identified in the genome of the primordial organism Candidatus Korarchaeum cryptophilum but the function of these homo-logues is still unsolved. Genes for ACDs can also be found in some acetate-forming Bacteria like Chloroflexus aurantiacus, but their function is yet unknown. Functional analyses of ACD-homologues in other bacteria like Pseudomonas mendocina and Delftia acidovorans provide evidence that these ACD-homologues are involved in the activation of certain acids like pimelate and ferulate, in contrast to archaea. According to their substrate these enzymes are referred to as pimeloyl-CoA synthetase (PCS) or feruloyl-CoA synthetase (FCS). Only little data are available for these enzymes. Especially no biochemical characterisation of FCS has been performed so far. This study aimed to investigate the roles and possible functions of acyl-CoA Synthetases in the three domains of life. ACD in Archaea. ACD in P. furiosus. It had to be tested, if P. furiosus contains an ACD-isoenzyme that effi-ciently converts succinate to succinyl-CoA. ORF Pf_0233 and Pf_1837 were cloned and ex-pressed heterologous in E. coli. The purified ACD-isoenzyme showed a seven fold higher activity with succinate than with acetate, classifying the enzyme as an ACDsucc. According to these results it might be possible that the enzyme participates in degradation of glutamate to succinate. In order to study the influence of the subunits on substrate specificity of ACDs, four chimeric ACDs were constructed out of the subunits of two ACD-isoenzymes in P. furiosus. Four active α2β2-heterotetrameric enzymes were reconstituted, each with an α- and a β-subunit of ACDsucc and ACDI respectively, and they were analysed in regard to their substrate specificity. A chimaera of ACDsuccα and ACDIβ showed the same substrate specific-ity as ACDsucc did, whereas a combination of ACDIα and ACDsuccβ exhibited the same sub-strate specificity as ACDI did. The data indicate that substrate specificity of ACDs is determi-nated by the α subunit. ACD and SCS in Ca. K. cryptophilum. In the genome of the hyperthermophilic korarchaeon Ca. K. cryptophilum, one of the most primordial organisms discovered so far, four homo-logues of an ACDα- and a homologue of an ACDβ subunit, as well as both subunits of a SCS, are annotated. All of the ACD-subunits were expressed and purified separately and subse-quently reconstituted to four α2β¬2-heterotetrameric ACD-isoenzymes. Three active hyper-thermophilic ACDs (Topt = 85 °C) could be characterised (ckcACD1, ckcACD3, ckcACD4), while ckcACD2 showed no activity. As the two enzymes ckcACD1 and ckcACD4 catalysed the reaction primarily with arylic acids, as well as with unbranched and branched chain fatty acids and the corresponding CoA-esters, they showed a novel type of substrate specificity for ACDs. In contrast ckcACD3 catalysed predominantly the conversion of acetyl-CoA and ace-tate and showed no activity with arylic acids. The α- and β-subunit of the SCS were separately expressed, purified and subsequently reconstituted to an active 134 kDa α2β2-heterotetramere. The hyperthermophilic SCS exhibited high specificity for succinyl-CoA and succinate. Analy-ses of the genome indicate that these ACDs and the SCS play a central role in energy-conservation during the fermentation of peptides. ACD in Methanosarcina mazei. The genes MM_0358 and MM_0493, encoding the putative α- and β-subunit are situated separately in the genome. The genes were cloned, expressed het-erologous in E. coli, purified and reconstituted as an active ACD. The 170 kDa enzyme (α2β2) catalysed the conversion of acetyl-CoA and isobutyryl-CoA with the same efficiency, whereas phenylacetyl-CoA was not converted. The enzyme converted the activation of the corresponding acids only with low efficiency. There is no evidence in the present data to con-clude a metabolic function. ACD in Eukarya ACD in E. histolytica. After heterologous expression in E. coli the ACD from E. histolytica was purified and characterised as a 164 kDa homodimere. In addition to acetate and acetyl-CoA respectively, the ACD effectively utilizes propionate and thioglycolate as substrate. Branched-chain fatty acids and arylic acids as well as the corresponding CoA-esters were not accepted. The substrate specificities, in accordance with genomic studies, suggest a physio-logical role of the ACD in the fermentation of glucose and peptides to acetate and propionate. ACD-homologues in bacteria. ACD in C. aurantiacus. The genes for acetate kinase (AK) and phosphotransacetylase (PTA), the typical enzymes of acetate formation in bacteria, are missing in C. aurantiacus, yet an ACD-homologue can be found. The formation of acetate from glucose in C. aurantiacus was analysed by growth experiments and cell suspensions. Per mole of glucose 1.2 moles of ace-tate were formed. No activity of AK and PTA could be measured in cell-free extracts, but an inducible activity of an ACD was detected. The enzyme was purified from cells grown on glucose and the gene encoding the ACD was identified as Caur_3920. The molecular mass of the enzyme was determined as 300 kDa, indicating a heterotetrameric structure, which is quite unusual for ACDs. The recombinant ACD showed high activity with acetyl-CoA but only low activity with phenylacetyl-CoA, thus its substrate specificity is similar to that of ACDI from P. furiosus. These results indicate an implication of the ACD in acetate formation from glu-cose. This is the first report ever of a functional ACD in the bacterial domain. Phylogenetic analyses suggest that the acd-gene was adapted from archaea by horizontal gene transfer to complement the absence of AK and PTA. PCS in Ralstonia eutropha. Sequence comparison led to the identification of two putative PCSs in the genome of R. eutropha which were purified and characterised as RaPCS1 and RaPCS2. Both recombinant enzymes are homodimers and catalysed with highest specificity the conversion of pimelate, HSCoA and ATP to pimeloyl-CoA, ADP and Pi. This study is the first report of an ADP-formation by PCSs. In addition to pimelate (9.5 U/mg = 100 %) RaPCS1 converted adipate, phenylacetate, isobutyrate and thioglycolate with more than 30 % of the activity with pimelate. RaPCS2 catalysed the reaction only efficiently with pimelate (11.5 U/mg) and butyrate. Neither RaPCS1 nor RaPCS2 were able to catalyse the reaction with CoA-esters like acetyl-CoA, isobutyryl-CoA or phenylacetyl-CoA, indicating that PCS only participates in acid formation. Two catalytically essential histidine-residues, conserved in all ACDs characterised so far, are also highly conserved in PCSs. Each of the histidine-residues was mutated to alanine by site-directed mutagenesis, causing a complete loss of PCS-activity. The data indicate that both histidine-residues are essential for the activation of pime-late by PCSs. Phylogenetic analyses indicate that PCSs and FCSs form a distinct phylogenetic cluster within the ACD-homologous Acyl-CoA Synthetases. FCS in D. acidovorans. The recombinant FCS formed a 170 kDa homodimere and catalysed the conversion of ferulate, ATP and HSCoA to feruloyl-CoA, ADP and Pi. The enzyme was highly specific for ferulate (Km = 4 µM). In addition to ferulate (12 U/mg = 100 %) the FCS only converted adipate (7 %), butyrate (12 %) and pimelate (4 %) with low efficiency. This is the first report of the characterisation of an ADP-forming FCS so far.

We present the results of a cross-correlation of the Planck Early Release Compact Source catalogue (ERCSC) with the catalogue of Herschel-ATLAS sources detected in the phase 1 fields, covering 134.55 deg2. There are 28ERCSC sources detected by Planck at 857GHz in this area. Asmany as16 of them are probably high Galactic latitude cirrus; 10additional sources can be clearly identified as bright, low-z galaxies; one further source is resolved by Herschel as two relatively bright sources; and the last is resolved into an unusual condensation of low-flux, probably high-redshift point sources, around a strongly lensed Herschel-ATLAS source at z=3.26. Our results demonstrate that the higher sensitivity and higher angular resolution H-ATLAS maps provide essential information for the interpretation of candidate sources extracted from Planck sub-mm maps. © 2012 ESO., D.H. and M.L.C. acknowledge partial financial support from the Spanish Ministerio de Ciencia e Innovación project AYA2010-21766-C03-01 and the Consolider Ingenio- 2010 Programme project CSD2010-00064. D.H. also acknowledges the Spanish Ministerio de Educación for a José Castillejo’ mobility grant with reference JC2010-0096 and the Astronomy Department at the Cavendish Laboratory for their hospitality during the elaboration of this paper. The Italian group has been supported in part by ASI/INAF agreement No. I/009/10/0 and by INAF through the PRIN 2009 “New light on the early Universe with sub-mm spectroscopy”. F.J.C. acknowledges partial financial support from the Spanish Ministerio de Ciencia e Innovación project AYA2010-21490-C02-01.

ADP-bildende Acetyl-CoA Synthetasen (ACD) gehören wie die Succinyl-CoA Synthetasen (SCS) zur Proteinfamilie der NDP-bildenden Acyl-CoA Synthetasen. Beide Enzyme sind ubiquitär in allen drei Domänen des Lebens vorhanden und katalysieren die NDP- und Pi-abhängige Umsetzung von Acyl-CoA Estern (Acetyl-CoA bzw. Succinyl-CoA) zu den kor-respondierenden Säuren unter der Bildung von NTP über Substratstufenphosphorylierung. Die ACD-Reaktion wurde erstmals in dem Acetat bildenden Protisten Entamoeba histolytica beschrieben, nicht aber charakterisiert. Erste detaillierte Analysen von ACDs in Prokaryoten wurden in dem hyperthermophilen Archaeon Pyrococcus furiosus durchgeführt und dabei zwei α2β2-heterotetramere ACD-Isoenzyme - ACDI und ACDII - identifiziert, die sich hin-sichtlich ihres Substratspektrums und ihrer kinetischen Konstanten unterscheiden. Ein weite-res ACD-Isoenzym wurde in Thermococcus kodakaraensis charakterisiert, welches mit hoher Effizienz Succinat umsetzt. Es ist bisher nicht bekannt, welche Untereinheit in ACDs die Substratspezifität determiniert. Inzwischen wurde die ACD in allen untersuchten Acetat bildenden Archaea identifiziert und eine Funktion bei der Säurebildung während des Kohlenhydrat- und Peptidabbaus wurde nachgewiesen. Kürzlich wurden auch im Genom des Korarchaeoten Candidatus Korarchaeum cryptophilum, einem sehr ursprünglichen Organismus, vier ACD-Homologe und ein SCS-Homolog identifiziert, deren Funktion bislang unklar ist. Auch in einigen Acetat bildenden Bakterien, wie z.B. Chloroflexus aurantiacus, finden sich Gene für ACDs, deren Funktion aber unbekannt ist. In anderen Bakterien, wie Pseudomonas mendoci-na und Delftia acidovorans, weisen funktionelle Analysen darauf hin, dass ACD-Homologe, anders als in Archaea, an der Aktivierung bestimmter Säuren wie Pimelat und Ferulat beteiligt sind. Je nach Substrat werden diese Enzyme als Pimeloyl-CoA Synthetase (PCS) oder als Feruloyl-CoA Synthetase (FCS) bezeichnet. Zu diesen Enzymen liegen nur wenige biochemi-sche Daten vor. Insbesondere wurde bislang noch keine FCS biochemisch charakterisiert. In der vorliegenden Arbeit wurde die Rolle und Funktion von Acyl-CoA Synthetasen in den drei Domänen des Lebens untersucht. ACD in Archaea. ACD in P. furiosus. Es sollte geprüft werden, ob P. furiosus ein ACD-Isoenzym enthält, das effizient Succinat umsetzt. ORF Pf_0233 und Pf_1837 wurden kloniert und heterolog in E. coli exprimiert. Das gereinigte, rekonstituierte ACD-Isoenzym zeigte eine siebenfach höhe-re Aktivität mit Succinat als mit Acetat, was das Enzym als ACDsucc klassifiziert. Die ACD könnte daher, wie für T. kodakaraensis gezeigt, am Abbau von Glutamat zu Succinat beteiligt sein. Durch Erstellung chimärer ACDs aus den Untereinheiten zweier ACD-Isoenzyme sollte der Einfluss der Untereinheiten auf die Substratspezifität von ACDs untersucht werden. Mit je einer α- und β-Untereinheit von ACDI und ACDsucc wurden vier aktive α2β2-heterotetramere Enzyme rekonstituiert und hinsichtlich ihres Substratspektrums analysiert. Eine Chimäre aus ACDsuccα und ACDIβ ergab ein zur ACDsucc identisches Substratspektrum, während eine Kombination der ACDIα mit der β Untereinheit der ACDsucc ein Substratspektrum wie die ACDI zeigte. Die Ergebnisse der Untersuchungen der ACD-Chimären weisen darauf hin, dass das Substratspektrum der ACDs in P. furiosus durch die α-Untereinheit determiniert wird. ACDs und SCS in Ca. K. cryptophilum. Im Genom des hyperthermophilen Korarchaeoten Ca K. cryptophilum, der zu den ursprünglichsten Organismen zählt, sind Homologe von vier ACDα- und einer ACDβ Untereinheit sowie die Untereinheiten einer SCS annotiert. Die ACD-Untereinheiten wurden getrennt exprimiert, gereinigt und zu vier α2β2-heterotetrameren ACD-Isoenzymen rekonstituiert. Es konnten dabei drei aktive hyperthermophile ACDs (Topt = 85 °C) charakterisiert werden (ckcACD1, ckcACD3 und ckcACD4). Die ckcACD2 zeigte keine Aktivität. Bei ckcACD1 und ckcACD4 handelt es sich um ACDs mit einem neu-artigen Substratspektrum, die Arylsäuren sowie verzweigte und unverzweigte Acylsäuren und deren korrespondierende CoA-Ester als Substrat verwenden. Die ckcACD3 setzte hingegen effektiv Acetyl-CoA bzw. Acetat um und zeigte keine Aktivität mit Arylsäuren. Die α- und die β Untereinheit der SCS wurden getrennt exprimiert, gereinigt und zu einem aktiven 134 kDa α2β2-Heterotetramer rekonstituiert. Die hyperthermophile SCS (Topt ~ 85 °C) zeigte eine hohe Spezifität für Succinyl-CoA und Succinat. Genomanalysen sprechen dafür, dass die ACDs und die SCS eine zentrale Rolle bei der Energiekonservierung im Zuge der Peptid-fermentation spielen. ACD in M. mazei. Die Gene der getrennt vorliegenden ACDα- und ACDβ-Untereinheiten MM_0358 und MM_0493 wurden kloniert, heterolog in E. coli exprimiert, gereinigt und als aktive ACD rekonstituiert. Das 170 kDa-Enzym (α2β2) katalysierte die Umsetzung von Ace-tyl-CoA und Isobutyryl-CoA mit gleicher Effizienz, Phenylacetyl-CoA wurde nicht akzep-tiert. Die ACD katalysierte mit geringerer Aktivität auch die Säureaktivierung. ACD in Eukarya. ACD in E. histolytica. Die ACD aus E. histolytica wurde heterolog exprimiert, gereinigt und als 164 kDa Homodimer charakterisiert. Neben Acetat bzw. Acetyl-CoA setzte die ACD auch die Säuren Propionat und Thioglycolat um. Verzweigte Acylsäuren und Arylsäuren sowie deren CoA-Ester wurden nicht akzeptiert. Das Substratspektrum des Enzyms und Genomana-lysen lassen auf eine physiologische Rolle bei der Glucose- und Peptidfermentation zu Acetat und Propionat schließen. ACD-Homologe in Bacteria. ACD in C. aurantiacus. Im Genom von C. aurantiacus finden sich keine Gene für die typi-schen Enzyme bakterieller Acetatbildung, Phosphotransacetylase (PTA) und Acetatkinase (AK), jedoch ein ACD-Homolog. Durch Wachstumsexperimente und Zellsuspensionen wurde die Acetatbildung aus Glucose in C. aurantiacus analysiert. Pro Mol Glucose wurden bis zu 1.2 Mol Acetat gebildet. In Zellextrakten konnten keine Aktivitäten von AK und PTA nach-gewiesen werden, aber eine durch Glucose induzierte ACD-Aktivität. Das Enzym wurde aus auf Glucose gewachsenen Zellen gereinigt und das kodierende Gen als Caur_3920 identifi-ziert. Mit einem Molekulargewicht von 300 kDa wies das Enzym eine für ACDs ungewöhnliche homotetramere Struktur auf. Die rekombinant exprimierte ACD setzte ähnlich der ACDI aus P. furiosus mit hoher Aktivität Acetyl-CoA und nur mit geringer Effizienz Phenylacetyl-CoA um. Diese Ergebnisse sprechen für eine funktionelle Beteiligung der ACD bei der Ace-tatbildung aus Glucose. Dies ist der erste Nachweis einer funktionellen ACD in der Domäne der Bacteria. Phylogenetische Analysen deuten darauf hin, dass das acd-Gen über lateralen Gentransfer von Archaea aufgenommen wurde, um das Fehlen von AK und PTA zu komple-mentieren. PCS in Ralstonia eutropha. Im Genom von R. eutropha wurden bei Sequenzvergleichen zwei putative PCSs identifiziert, die als RaPCS1 und RaPCS2 gereinigt und charakterisiert wurden. Beide rekombinanten Enzyme bilden Homodimere und setzen mit der höchsten spezifischen Aktivität Pimelat, HSCoA und ATP zu Pimeloyl-CoA, ADP und Phosphat um. Damit konn-ten erstmals ADP-bildende PCSs nachgewiesen werden. Neben Pimelat (9.5 U/mg = 100 %) setzte die RaPCS1 auch Adipat, Phenylacetat, Isobutyrat und Thioglycolat mit über 30 % der Rate um. Die RaPCS2 nutzte neben Pimelat (11.5 U/mg) nur Butyrat effizient. Keine der PCS konnte die CoA-Ester Acetyl-CoA, Isobutyryl-CoA oder Phenylacetyl-CoA umzusetzen, was darauf hindeutet, dass die PCS ausschließlich an der Säureaktivierung beteiligt ist. Alle bis-lang charakterisierten ACDs enthalten zwei katalytisch essentielle Histidine, die auch in PCS hochkonserviert sind. Mittels ortsspezifischer Mutagenese wurden beide Histidine jeweils gegen Alanin ausgetauscht, was in beiden Fällen zum Verlust der PCS-Aktivität führte. Dies lässt auf eine essentielle Beteiligung beider Histidine an der Pimelataktivierung schließen. Phylogenetische Analysen deuten darauf hin, dass PCSs gemeinsam mit FCS eine distinkte phylogenetische Gruppe innerhalb der ACD-homologen Acyl-CoA Synthetasen bilden. FCS in D. acidovorans. Die rekombinante FCS ist ein 170 kDa Homodimer und katalysiert die Umsetzung von Ferulat, HSCoA und ATP zu Feruloyl-CoA, ADP und Pi. Das Enzym ist hoch spezifisch für Ferulat (Km = 4 µM). Neben Ferulat (12 U/mg = 100 %) setzt die FCS nur Adipat (7 %), Butyrat (12 %) und Pimelat (4 %) mit geringer Effizienz um. Damit konnte erstmals eine ADP-bildende FCS charakterisiert werden. The family of NDP-forming acyl-CoA synthetases comprises, amongst other synthetases, succinyl-CoA synthetases (SCS) and acetyl-CoA synthetases (ACD). Both enzymes are ubiq-uitous in the three domains of life, catalysing the NDP- and Pi-dependent conversion of acyl-CoA esters (succinyl-CoA or acetyl-CoA) to the corresponding acids while coupling the reac-tion with the formation of NTP by substrate level-phosphorylation. ACD-activity was first detected in the acetate-forming eukaryote Entamoeba histolytica, but the enzyme has not been characterised so far. The first detailed description of ACDs in pro-karyotes was carried out in the hyperthermophilic archaeon Pyrococcus furiosus, where two α2β2 heterotetrameric isoenzymes (ACDI and ACDII) were distinguished in respect to their substrate specificity and kinetic constants. Another ACD-isoenzyme was characterised in Thermococcus kodakaraensis, which catalyses the conversion of succinate to succinyl-CoA with high efficiency. It has still not been solved which subunit determines the substrate speci-ficity of ACDs. In all acetate-forming archaea studied so far, ACDs have been identified and an acid-forming function during fermentation of carbohydrates and peptides has been shown. Recently four ACD-homologues and an SCS-homologue were identified in the genome of the primordial organism Candidatus Korarchaeum cryptophilum but the function of these homo-logues is still unsolved. Genes for ACDs can also be found in some acetate-forming Bacteria like Chloroflexus aurantiacus, but their function is yet unknown. Functional analyses of ACD-homologues in other bacteria like Pseudomonas mendocina and Delftia acidovorans provide evidence that these ACD-homologues are involved in the activation of certain acids like pimelate and ferulate, in contrast to archaea. According to their substrate these enzymes are referred to as pimeloyl-CoA synthetase (PCS) or feruloyl-CoA synthetase (FCS). Only little data are available for these enzymes. Especially no biochemical characterisation of FCS has been performed so far. This study aimed to investigate the roles and possible functions of acyl-CoA Synthetases in the three domains of life. ACD in Archaea. ACD in P. furiosus. It had to be tested, if P. furiosus contains an ACD-isoenzyme that effi-ciently converts succinate to succinyl-CoA. ORF Pf_0233 and Pf_1837 were cloned and ex-pressed heterologous in E. coli. The purified ACD-isoenzyme showed a seven fold higher activity with succinate than with acetate, classifying the enzyme as an ACDsucc. According to these results it might be possible that the enzyme participates in degradation of glutamate to succinate. In order to study the influence of the subunits on substrate specificity of ACDs, four chimeric ACDs were constructed out of the subunits of two ACD-isoenzymes in P. furiosus. Four active α2β2-heterotetrameric enzymes were reconstituted, each with an α- and a β-subunit of ACDsucc and ACDI respectively, and they were analysed in regard to their substrate specificity. A chimaera of ACDsuccα and ACDIβ showed the same substrate specific-ity as ACDsucc did, whereas a combination of ACDIα and ACDsuccβ exhibited the same sub-strate specificity as ACDI did. The data indicate that substrate specificity of ACDs is determi-nated by the α subunit. ACD and SCS in Ca. K. cryptophilum. In the genome of the hyperthermophilic korarchaeon Ca. K. cryptophilum, one of the most primordial organisms discovered so far, four homo-logues of an ACDα- and a homologue of an ACDβ subunit, as well as both subunits of a SCS, are annotated. All of the ACD-subunits were expressed and purified separately and subse-quently reconstituted to four α2β¬2-heterotetrameric ACD-isoenzymes. Three active hyper-thermophilic ACDs (Topt = 85 °C) could be characterised (ckcACD1, ckcACD3, ckcACD4), while ckcACD2 showed no activity. As the two enzymes ckcACD1 and ckcACD4 catalysed the reaction primarily with arylic acids, as well as with unbranched and branched chain fatty acids and the corresponding CoA-esters, they showed a novel type of substrate specificity for ACDs. In contrast ckcACD3 catalysed predominantly the conversion of acetyl-CoA and ace-tate and showed no activity with arylic acids. The α- and β-subunit of the SCS were separately expressed, purified and subsequently reconstituted to an active 134 kDa α2β2-heterotetramere. The hyperthermophilic SCS exhibited high specificity for succinyl-CoA and succinate. Analy-ses of the genome indicate that these ACDs and the SCS play a central role in energy-conservation during the fermentation of peptides. ACD in Methanosarcina mazei. The genes MM_0358 and MM_0493, encoding the putative α- and β-subunit are situated separately in the genome. The genes were cloned, expressed het-erologous in E. coli, purified and reconstituted as an active ACD. The 170 kDa enzyme (α2β2) catalysed the conversion of acetyl-CoA and isobutyryl-CoA with the same efficiency, whereas phenylacetyl-CoA was not converted. The enzyme converted the activation of the corresponding acids only with low efficiency. There is no evidence in the present data to con-clude a metabolic function. ACD in Eukarya ACD in E. histolytica. After heterologous expression in E. coli the ACD from E. histolytica was purified and characterised as a 164 kDa homodimere. In addition to acetate and acetyl-CoA respectively, the ACD effectively utilizes propionate and thioglycolate as substrate. Branched-chain fatty acids and arylic acids as well as the corresponding CoA-esters were not accepted. The substrate specificities, in accordance with genomic studies, suggest a physio-logical role of the ACD in the fermentation of glucose and peptides to acetate and propionate. ACD-homologues in bacteria. ACD in C. aurantiacus. The genes for acetate kinase (AK) and phosphotransacetylase (PTA), the typical enzymes of acetate formation in bacteria, are missing in C. aurantiacus, yet an ACD-homologue can be found. The formation of acetate from glucose in C. aurantiacus was analysed by growth experiments and cell suspensions. Per mole of glucose 1.2 moles of ace-tate were formed. No activity of AK and PTA could be measured in cell-free extracts, but an inducible activity of an ACD was detected. The enzyme was purified from cells grown on glucose and the gene encoding the ACD was identified as Caur_3920. The molecular mass of the enzyme was determined as 300 kDa, indicating a heterotetrameric structure, which is quite unusual for ACDs. The recombinant ACD showed high activity with acetyl-CoA but only low activity with phenylacetyl-CoA, thus its substrate specificity is similar to that of ACDI from P. furiosus. These results indicate an implication of the ACD in acetate formation from glu-cose. This is the first report ever of a functional ACD in the bacterial domain. Phylogenetic analyses suggest that the acd-gene was adapted from archaea by horizontal gene transfer to complement the absence of AK and PTA. PCS in Ralstonia eutropha. Sequence comparison led to the identification of two putative PCSs in the genome of R. eutropha which were purified and characterised as RaPCS1 and RaPCS2. Both recombinant enzymes are homodimers and catalysed with highest specificity the conversion of pimelate, HSCoA and ATP to pimeloyl-CoA, ADP and Pi. This study is the first report of an ADP-formation by PCSs. In addition to pimelate (9.5 U/mg = 100 %) RaPCS1 converted adipate, phenylacetate, isobutyrate and thioglycolate with more than 30 % of the activity with pimelate. RaPCS2 catalysed the reaction only efficiently with pimelate (11.5 U/mg) and butyrate. Neither RaPCS1 nor RaPCS2 were able to catalyse the reaction with CoA-esters like acetyl-CoA, isobutyryl-CoA or phenylacetyl-CoA, indicating that PCS only participates in acid formation. Two catalytically essential histidine-residues, conserved in all ACDs characterised so far, are also highly conserved in PCSs. Each of the histidine-residues was mutated to alanine by site-directed mutagenesis, causing a complete loss of PCS-activity. The data indicate that both histidine-residues are essential for the activation of pime-late by PCSs. Phylogenetic analyses indicate that PCSs and FCSs form a distinct phylogenetic cluster within the ACD-homologous Acyl-CoA Synthetases. FCS in D. acidovorans. The recombinant FCS formed a 170 kDa homodimere and catalysed the conversion of ferulate, ATP and HSCoA to feruloyl-CoA, ADP and Pi. The enzyme was highly specific for ferulate (Km = 4 µM). In addition to ferulate (12 U/mg = 100 %) the FCS only converted adipate (7 %), butyrate (12 %) and pimelate (4 %) with low efficiency. This is the first report of the characterisation of an ADP-forming FCS so far.

The GALEX Ultraviolet Virgo Cluster Survey (GUViCS) is a complete blind survey of the Virgo cluster covering about 40 sq. deg. in the far UV (FUV, lambda_eff=1539A, Delta-lambda=442A) and about 120 sq. deg. in the near UV (NUV, lambda_eff=2316A, Delta-lambda=1060A). The goal of the survey is to study the ultraviolet (UV) properties of galaxies in a rich cluster environment, spanning a wide luminosity range from giants to dwarfs, and regardless of prior knowledge of their star formation activity. The UV data will be combined with those in other bands (optical: NGVS; far-infrared - submm: HeViCS; HI: ALFALFA) and with our multizone chemo-spectrophotometric models of galaxy evolution to make a complete and exhaustive study of the effects of the environment on the evolution of galaxies in high density regions. We present here the scientific objectives of the survey, describing the observing strategy and briefly discussing different data reduction techniques. Using UV data already in-hand for the central 12 sq. deg. we determine the FUV and NUV luminosity functions of the Virgo cluster core for all cluster members and separately for early- and late-type galaxies and compare it to the one obtained in the field and other nearby clusters (Coma, A1367). This analysis shows that the FUV and NUV luminosity functions of the core of the Virgo clusters are flatter (alpha about -1.1) than those determined in Coma and A1367. We discuss the possible origin of this difference, 18 pages, 14 figures, accepted in A&A, high resolution version of figure 1 and 2 and other information available at http://galex.oamp.fr/guvics/observations.html

The origin of the far-infrared emission from the nearby radio galaxy M87 remains a matter of debate. Some studies find evidence of a far-infrared excess due to thermal dust emission, whereas others propose that the far-infrared emission can be explained by synchrotron emission without the need for an additional dust emission component. We observed M87 with PACS and SPIRE as part of the Herschel Virgo Cluster Survey (HeViCS). We compare the new Herschel data with a synchrotron model based on infrared, submm and radio data to investigate the origin of the far-infrared emission. We find that both the integrated SED and the Herschel surface brightness maps are adequately explained by synchrotron emission. At odds with previous claims, we find no evidence of a diffuse dust component in M87., 4 pages, 2 figures, proceedings IAU Symposium 275 (Jets at all scales)

We present infrared colours (in the 25-500 mic spectral range) and UV to radio continuum spectral energy distributions of a sample of 51 nearby galaxies observed with SPIRE on Herschel. The observed sample includes all morphological classes, from quiescent ellipticals to active starbursts. Active galaxies have warmer colour temperatures than normal spirals. In ellipticals hosting a radio galaxy, the far-infrared (FIR) emission is dominated bynthe synchrotron nuclear emission. The colour temperature of the cold dust is higher in quiescent E-S0a than in star-forming systems probably because of the different nature of their dust heating sources (evolved stellar populations, X-ray, fast electrons) and dust grain properties. In contrast to the colour temperature of the warm dust, the f350/f500 index sensitive to the cold dust decreases with star formation and increases with metallicity, suggesting an overabundance of cold dust or an emissivity parameter beta, Accepted for publication on A&A, Herschel special issue

We describe radio observations at 244 and 610 MHz of a sample of 20 luminous and ultra-luminous IRAS galaxies. These are a sub-set of a sample of 31 objects that have well-measured radio spectra up to at least 23 GHz. The radio spectra of these objects below 1.4 GHz show a great variety of forms and are rarely a simple power-law extrapolation of the synchrotron spectra at higher frequencies. Most objects of this class have spectral turn-overs or bends in their radio spectra. We interpret these spectra in terms of free-free absorption in the starburst environment. Several objects show radio spectra with two components having free-free turn-overs at different frequencies (including Arp 220 and Arp 299), indicating that synchrotron emission originates from regions with very different emission measures. In these sources, using a simple model for the supernova rate, we estimate the time for which synchrotron emission is subject to strong free-free absorption by ionized gas, and compare this to expected HII region lifetimes. We find that the ionized gas lifetimes are an order of magnitude larger than plausible lifetimes for individual HII regions. We discuss the implications of this result and argue that those sources which have a significant radio component with strong free-free absorption are those in which the star formation rate is still increasing with time. We note that if ionization losses modify the intrinsic synchrotron spectrum so that it steepens toward higher frequencies, the often observed deficit in fluxes higher than ~10 GHz would be much reduced., 13 pages, 5 figures, accepted by MNRAS

We present the analysis of Spitzer-IRS spectra of four early-type galaxies, NGC 1297, NGC 5044, NGC 6868, and NGC 7079, all classified as LINERs in the optical bands. Their IRS spectra present the full series of H2 rotational emission lines in the range 5--38 microns, atomic lines, and prominent PAH features. We investigate the nature and origin of the PAH emission, characterized by unusually low 6 -- 9/11.3 microns inter-band ratios. After the subtraction of a passive early type galaxy template, we find that the 7 -- 9 microns spectral region requires dust features not normally present in star forming galaxies. Each spectrum is then analyzed with the aim of identifying their components and origin. In contrast to normal star forming galaxies, where cationic PAH emission prevails, our 6--14 microns spectra seem to be dominated by large and neutral PAH emission, responsible for the low 6 -- 9/11.3 microns ratios, plus two broad dust emission features peaking at 8.2 microns and 12 microns. Theses broad components, observed until now mainly in evolved carbon stars and usually attributed to pristine material, contribute approximately 30-50% of the total PAH flux in the 6--14 microns region. We propose that the PAH molecules in our ETGs arise from fresh carbonaceous material which is continuously released by a population of carbon stars, formed in a rejuvenation episode which occurred within the last few Gyr. The analysis of the MIR spectra allows us to infer that, in order to maintain the peculiar size and charge distributions biased to large and neutral PAHs, this material must be shocked, and excited by the weak UV interstellar radiation field of our ETG., Comment: ApJ accepted

We present the dust properties of a small sample of Virgo cluster dwarf galaxies drawn from the science demonstration phase data set of the Herschel Virgo Cluster Survey. These galaxies have low metallicities (7.8 < 12 + log(O/H) < 8.3) and star-formation rates < 10^{-1} M_{sun}/yr. We measure the spectral energy distribution (SED) from 100 to 500 um and derive dust temperatures and dust masses. The SEDs are fitted by a cool component of temperature T < 20 K, implying dust masses around 10^{5} M_{sun} and dust-to-gas ratios D within the range 10^{-3}-10^{-2}. The completion of the full survey will yield a larger set of galaxies, which will provide more stringent constraints on the dust content of star-forming dwarf galaxies., Letter accepted for publication in A&A (Herschel special issue)

Several second-generation antipsychotics are characterised by a significant antagonistic effect at serotonin 5-HT(2A) receptors (5-HT(2A)R), a feature that has been associated with lower incidence of extra-pyramidal symptoms and a putative amelioration of positive and negative symptoms experienced by schizophrenic patients. However, the neurofunctional substrate of 5-HT(2A) antagonism and its exact contribution to the complex pharmacological profile of these drugs remain to be elucidated.Here, we used pharmacological magnetic resonance imaging to map the modulatory effects of the selective 5-HT(2A)R antagonist Ml00907 on the spatiotemporal patterns of brain activity elicited by acute phencyclidine (PCP) challenge in the rat. PCP is a non-competitive NMDA receptor antagonist that induces dysregulation of corticolimbic glutamatergic neurotransmission and produces cognitive impairment and psychotic-like symptoms reminiscent of those observed in schizophrenia.Pre-administration of M100907 produced focal and region-dependent attenuation of PCP-induced response in frontoseptohippocampal areas. As early studies highlighted a permissive role of 5-HT(2A)R on frontal dopamine release, the role of post-synaptic dopamine D(1) receptors on PCP-induced response was examined by using the potent antagonist SCH23390. Interestingly, SCH23390 did not affect PCP's response in any of the regions examined. This finding rules out a significant contribution of dopamine in the functional changes mapped and, indirectly, the inhibitory effect of M100907, in favour of a glutamatergic origin.Our data expand recent evidence suggesting a key role of 5-HT(2A)R in modulating glutamate-mediated cognitive performance in the prefrontal cortex and highlight the whole frontoseptohippocampal circuit as a key functional substrate of 5-HT(2A)R antagonism in normal and disease states.

We study in detail the mid-infrared Spitzer-IRS spectrum of M 87 in the range 5 to 20 micron. Thanks to the high sensitivity of our Spitzer-IRS spectra we can disentangle the stellar and nuclear components of this active galaxy. To this end we have properly subtracted from the M 87 spectrum, the contribution of the underlying stellar continuum, derived from passive Virgo galaxies in our sample. The residual is a clear power-law, without any additional thermal component, with a zero point consistent with that obtained by high spatial resolution, ground based observations. The residual is independent of the adopted passive template. This indicates that the 10 micron silicate emission shown in spectra of M 87 can be entirely accounted for by the underlying old stellar population, leaving little room for a possible torus contribution. The MIR power-law has a slope alpha ~ 0.77-0.82 (S$_\nu\propto\nu^{-\alpha}$), consistent with optically thin synchrotron emission., Comment: 5 pages, 4 figures, accepted for publication in ApJ main journal

We define a volume limited sample of over 14,000 early-type galaxies (ETGs) selected from data release six of the Sloan Digital Sky Survey. The density of environment of each galaxy is robustly measured. By comparing narrow band spectral line indices with recent models of simple stellar populations (SSPs) we investigate trends in the star formation history as a function of galaxy mass (velocity dispersion), density of environment and galactic radius. We find that age, metallicity and alpha-enhancement all increase with galaxy mass and that field ETGs are younger than their cluster counterparts by ~2 Gyr. We find negative radial metallicity gradients for all masses and environments, and positive radial age gradients for ETGs with velocity dispersion over 180 km/s. Our results are qualitatively consistent with a relatively simple picture for ETG evolution in which the low-mass halos accreted by a proto-ETG contained not only gas but also a stellar population. This fossil population is preferentially found at large radii in massive ETGs because the stellar accretions were dissipationless. We estimate that the typical, massive ETG should have been assembled at z < 3.5. The process is similar in the cluster and the field but occurred earlier in dense environments., 5 pages, 2 figures. Submitted to MNRAS

As a constraint for new starburst/AGN models of IRAS bright galaxies we determine the radio spectra of 31 luminous and ultraluminous IRAS galaxies (LIRGs/ULIRGs). We construct the radio spectra using both new and archival data. From our sample of radio spectra we find that very few have a straight power-law slope. Although some sources show a flattening of the radio spectral slope at high frequencies the average spectrum shows a steepening of the radio spectrum from 1.4 to 22.5 GHz. This is unexpected because in sources with high rates of star formation we expect flat spectrum, free-free emission to make a significant contribution to the radio flux at higher radio frequencies. Despite this trend the radio spectral indices between 8.4 and 22.5 GHz are flatter for sources with higher values of the FIR-radio flux density ratio q, when this is calculated at 8.4 GHz. Therefore, sources that are deficient in radio emission relative to FIR emission (presumably younger sources) have a larger thermal component to their radio emission. However, we find no correlation between the radio spectral index between 1.4 and 4.8 GHz and q at 8.4 GHz. Because the low frequency spectral index is affected by free-free absorption, and this is a function of source size for a given mass of ionized gas, this is evidence that the ionized gas in ULIRGs shows a range of densities. The youngest LIRGs and ULIRGs are characterized by a larger contribution to their high-frequency radio spectra from free-free emission. However, the youngest sources are not those that have the greatest free-free absorption at low radio frequencies. The sources in which the effects of free-free absorption are strongest are instead the most compact sources. Although these have the warmest FIR colours, they are not necessarily the youngest sources., Comment: 16 pages. Submitted to A&A Re-submitted, with aesthetic improvements to the text and figures

The mid infrared emission of early type galaxies traces the presence of intermediate age stellar populations as well as even tiny amounts of ongoing star formation. Here we discuss high S/N Spitzer IRS spectra of a sample of Virgo early type galaxies, with particular reference to NGC 4435. We show that, by combining mid infrared spectroscopic observations with existing broad band fluxes, it is possible to obtain a very clean picture of the nuclear activity in this galaxy., 4 pages; proceedings of IAU Symposium No. 241, "Stellar Populations as Building Blocks of Galaxies", editors A. Vazdekis and R. Peletier

We investigate the atomic and molecular interstellar medium and star formation of NGC 275, the late-type spiral galaxy in Arp 140, which is interacting with NGC 274, an early-type system. The atomic gas (HI) observations reveal a tidal tail from NGC 275 which extends many optical radii beyond the interacting pair. The HI morphology implies a prograde encounter between the galaxy pair approximately 1.5 x 10**8 years ago. The Halpha emission from NGC 275 indicates clumpy irregular star-formation, clumpiness which is mirrored by the underlying mass distribution as traced by the Ks-band emission. The molecular gas distribution is striking in its anti-correlation with the {HII regions. Despite the evolved nature of NGC 275's interaction and its barred potential, neither the molecular gas nor the star formation are centrally concentrated. We suggest that this structure results from stochastic star formation leading to preferential consumption of the gas in certain regions of the galaxy. In contrast to the often assumed picture of interacting galaxies, NGC 275, which appears to be close to merger, does not display enhanced or centrally concentrated star formation. If the eventual merger is to lead to a significant burst of star formation it must be preceded by a significant conversion of atomic to molecular gas as at the current rate of star formation all the molecular gas will be exhausted by the time the merger is complete., 13 paper, accepted my Monthly Notices of the Royal Astronomical Society

Using the third data release of the Sloan Digital Sky Survey (SDSS) we have rigorously defined a volume limited sample of early-type galaxies in the redshift range z < 0.1. We have defined the density of the local environment for each galaxy using a method which takes account of the redshift bias introduced by survey boundaries if traditional methods are used. At luminosities greater than our absolute r-band magnitude cutoff of -20.45 the mean density of environment shows no trend with redshift. We calculate the Lick indices for the entire sample and correct for aperture effects and velocity dispersion in a model independent way. Although we find no dependence of redshift or luminosity with environment we do find that the mean velocity dispersion, sigma, of early-type galaxies in dense environments tends to be higher than in low density environments. Taking account of this effect we find that several indices show small but very significant trends with environment that are not the result of the correlation between indices and velocity dispersion. The statistical significance of the data is sufficiently high to reveal that models accounting only for alpha-enhancement struggle to produce a consistent picture of age and metallicity of the sample galaxies, whereas a model that also includes carbon enhancement fares much better. We find that early-type galaxies in the field are younger than those in environments typical of clusters but that neither metallicity, alpha-enhancement nor carbon enhancement are influenced by the environment. The youngest early-type galaxies in both field and cluster environments are those with the lowest sigma. However, there is some evidence that the objects with the largest sigma are slightly younger, especially in denser environments., 19 pages, 15 figures. Accepted for publication in MNRAS. Version with full resolution figures at: http://www.gb.nrao.edu/~bnikolic/publications/2006/MF1210rv4.pdf Replaced 17/5/2006 to include 2 impotrant references

We have performed 23 GHz VLA observations of 7 compact, luminous infrared galaxies, selected to have evidence of starburst activity. New and published multi-frequency data are combined to obtain the spectral energy distributions of all 7 galaxies from the near-infrared to the radio (at 1.4 GHz). These SEDs are compared with new models, for dust enshrouded galaxies, which account for both starburst and AGN components. In all 7 galaxies the starburst provides the dominant contribution to the infrared luminosity; in 4 sources no contribution from an AGN is required. Although AGN may contribute up to 50 percent of the total far--infrared emission, the starbursts always dominate in the radio. The SEDs of most of our sources are best fit with a very high optical depth of (>=50) at 1 micron. The scatter in the far-infrared/radio correlation, found among luminous IRAS sources, is due mainly to the different evolutionary status of their starburst components. The short time-scale of the star formation process amplifies the delay between the far-infrared and radio emission. This becomes more evident at low radio frequencies (below about 1 GHz) where synchrotron radiation is the dominant process. In the far-infrared (at wavelengths shorter than 100 micron) an additional source of scatter is provided by AGN, where present. AGN may be detected in the near-infrared by the absence of the knee, typical of stellar photospheres. However, near-infrared data alone cannot constrain the level at which AGN contribute because the interpretation of their observed properties, in this wave-band, depends strongly on model parameters., 14 pages, accepted for publication in Astronomy and Astrophysics

The morphological and velocity structures in the gaseous (Hi and CO) and stellar components of two interacting systems are examined. Both Arp 140 and Arp 104 reveal extended tidal tails in the Hi. The Hα and FIR fluxes of Arp 140 yield similar SFR of ∼ 0.8 M⊙ yr−1. In contrast the Hα flux of Arp 104 yields a SFR of 0.05 ∼ M⊙ yr−1, ∼ 20 times smaller than that obtained from the FIR flux. Spectra were used to examine the changing velocity of atomic and molecular gas in NGC 5218 (Arp 104). The atomic and molecular gas were found to be dynamically similar with comparable velocities and velocity widths across the galaxy; consistent with the two phases responding similarly to the interaction, or enhanced Hi to CO conversion in the centre of the galaxy.

We present preliminary results of recent spatially resolved mid infrared (Mid-IR) spectroscopy with the MICHELLE instrument on UKIRT of NGC 7469, observed as part of a larger programme to study a sample of starburst and AGN in the Mid-IR.

We present Herschel observations of 62 Early-Type Galaxies (ETGs), including 39 galaxies morphologically classified as S0+S0a and 23 galaxies classified as ellipticals using SPIRE at 250, 350 and 500 microns (and PACS 100 and 160 microns for 19 sources) as part of the volume-limited Herschel Reference Survey. We detect dust emission in 24% of the ellipticals and 62% of the S0s. The mean temperature of the dust is 23.9+/-0.8 K, warmer than that found for late-type galaxies in the Virgo Cluster. Including the non-detections, the mean dust mass is log(Mdust) = 5.9+/-0.1 and 5.2+/-0.1 Msun for the S0s and elliptical galaxies respectively. The mean dust-to-stellar mass is log(Mdust/Mstar) = -4.4+/-0.1 (S0s) and -5.8+/-0.1 (ellipticals). Virtually all the galaxies lie close to the red sequence yet the large number of detections of cool dust, the gas-to-dust ratios and the ratios of far-infrared to radio emission all suggest that many ETGs contain a cool interstellar medium similar to that in late-type galaxies. The mean dust-to-stellar mass ratio for S0s is approximatly a factor of ten less than for early-type spirals and the sizes of the dust sources in the S0s are also much smaller. We show that the difference cannot be explained by either the different bulge-to-disk ratios or environmental effects such as ram-pressure stripping. The wide range in the dust-to-stellar mass ratio for ETGs and the lack of a correlation between dust mass and optical luminosity suggest that much of the dust in the ETGs detected by Herschel has been acquired as the result of gravitational interactions; these interactions are unlikely to have had a major effect on the stellar masses of the ETGs. The Herschel observations tentatively suggest that in the most massive ETGs, the mass of the interstellar medium is unconnected to the evolution of the stellar populations., Comment: 28 Pages, 12 Figures. Submitted to ApJ December 2011; accepted January 2012

We use the Science Demonstration Phase data of the Herschel Virgo Cluster Survey to search for dust emission of early-type dwarf galaxies in the central regions of the Virgo Cluster as an alternative way of identifying the interstellar medium.We present the first possible far-infrared detection of cluster early-type dwarf galaxies: VCC781 and VCC951 are detected at the 10 sigma level in the SPIRE 250 micron image. Both detected galaxies have dust masses of the order of 10^5 Msun and average dust temperatures ~20K. The detection rate (less than 1%) is quite high compared to the 1.7% detection rate for Hi emission, considering that dwarfs in the central regions are more Hi deficient. We conclude that the removal of interstellar dust from dwarf galaxies resulting from ram pressure stripping, harassment, or tidal effects must be as efficient as the removal of interstellar gas., Letter accepted for publication in A&A (Herschel special issue)