Characteristic ideals and Iwasawa theory

Let \L be a non-noetherian Krull domain which is the inverse limit of noetherian Krull domains \L_d and let $M$ be a finitely generated \L-module which is the inverse limit of \L_d-modules $M_d\,$. Under certain hypotheses on the rings \L_d and on the modules $M_d\,$, we define a pro-characteristic ideal for $M$ in \L, which should play the role of the usual characteristic ideals for finitely generated modules over noetherian Krull domains. We apply this to the study of Iwasawa modules (in particular of class groups) in a non-noetherian Iwasawa algebra \Z_p[[\Gal(\calf/F)]], where $F$ is a function field of characteristic $p$ and \Gal(\calf/F)\simeq\Z_p^\infty.Comment: 15 pages, substantial chenges in exposition, new section 2.

Characterizing precursors to stellar clusters with Herschel

Context. Despite their profound effect on the universe, the formation of massive stars and stellar clusters remains elusive. Recent advances in observing facilities and computing power have brought us closer to understanding this formation process. In the past decade, compelling evidence has emerged that suggests infrared dark clouds (IRDCs) may be precursors to stellar clusters. However, the usual method for identifying IRDCs is biased by the requirement that they are seen in absorption against background mid-IR emission, whereas dust continuum observations allow cold, dense pre-stellar-clusters to be identified anywhere. Aims: We aim to understand what dust temperatures and column densities characterize and distinguish IRDCs, to explore the population of dust continuum sources that are not IRDCs, and to roughly characterize the level of star formation activity in these dust continuum sources. Methods: We use Hi-GAL 70 to 500 $m data to identify dust continuum sources in the ell = 30deg and ell = 59deg Hi-GAL science demonstration phase (SDP) fields, to characterize and subtract the Galactic cirrus emission, and perform pixel-by-pixel modified blackbody fits on cirrus-subtracted Hi-GAL sources. We utilize archival Spitzer data to indicate the level of star-forming activity in each pixel, from mid-IR-dark to mid-IR-bright. Results: We present temperature and column density maps in the Hi-GAL ell = 30deg and ell = 59deg SDP fields, as well as a robust algorithm for cirrus subtraction and source identification using Hi-GAL data. We report on the fraction of Hi-GAL source pixels which are mid-IR-dark, mid-IR-neutral, or mid-IR-bright in both fields. We find significant trends in column density and temperature between mid-IR-dark and mid-IR-bright pixels; mid-IR-dark pixels are about 10 K colder and have a factor of 2 higher column density on average than mid-IR-bright pixels. We find that Hi-GAL dust continuum sources span a range of evolutionary states from pre- to star-forming, and that warmer sources are associated with more star formation tracers. Additionally, there is a trend of increasing temperature with tracer type from mid-IR-dark at the coldest, to outflow/maser sources in the middle, and finally to 8 and 24$m bright sources at the warmest. Finally, we identify five candidate IRDC-like sources on the far-side of the Galaxy. These are cold (20 K), high column density (N(H$_2$) gt 10$^22$ cm$^-2$) clouds identified with Hi-GAL which, despite bright surrounding mid-IR emission, show little to no absorption at 8 $m. These are the first inner Galaxy far-side candidate IRDCs of which the authors are aware. Herschel in an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation by NASA.The FITS files discussed in the paper would be released publicly WITH the Hi-GAL data (on the Hi-GAL website) when the Hi-GAL data is released publicly.Peer reviewe

A Targeted Search For Point Sources Of Eeev Photons With The Pierre Auger Observatory

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Simultaneous measurements of air showers with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for EeV photon point sources. Several Galactic and extragalactic candidate objects are grouped in classes to reduce the statistical penalty of many trials from that of a blind search and are analyzed for a significant excess above the background expectation. The presented search does not find any evidence for photon emission at candidate sources, and combined p-values for every class are reported. Particle and energy flux upper limits are given for selected candidate sources. These limits significantly constrain predictions of EeV proton emission models from non-transient Galactic and nearby extragalactic sources, as illustrated for the particular case of the Galactic center region.8372Argentina-Comision Nacional de Energia AtomicaAgencia Nacional de Promocion Cientifica y Tecnologica (ANPCyT)Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET)Gobierno de la Provincia de MendozaMunicipalidad de MalargueNDM Holdings and Valle Las Lenas, in gratitude for their continuing cooperation over land accessAustralia-the Australian Research CouncilBrazilConselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Financiadora de Estudos e Projetos (FINEP)Fundacao de Amparo a Pesquisa do Estado de Rio de Janeiro (FAPERJ)Sao Paulo Research Foundation (FAPESP) [2010/07359-6, 1999/05404-3]Ministerio de Ciencia e Tecnologia (MCT)Czech Republic-Grant [MSMT CR LG15014, LO1305, LM2015038]Czech Science Foundation [14-17501S]FranceCentre de Calcul [IN2P3/CNRS]Centre National de la Recherche Scientifique (CNRS)Conseil Regional Ile-deFranceDepartement Physique Nucleaire et Corpusculaire [PNC-IN2P3/CNRS]Departement Sciences de l'Univers [SDU-INSU/CNRS]Institut Lagrange de Paris (ILP), Investissements d'Avenir Programme Grant [LABEX ANR-10-LABX-63, ANR-11-IDEX-0004-02]Germany-Bundesministerium fur Bildung und Forschung (BMBF)Deutsche Forschungsgemeinschaft (DFG)Finanzministerium Baden-WurttembergHelmholtz Alliance for Astroparticle Physics (HAP)Helmholtz-Gemeinschaft Deutscher Forschungszentren (HGF)Ministerium fur Innovation, Wissenschaft und Forschung des Landes NordrheinWestfalenMinisterium fur Wissenschaft, Forschung und Kunst des Landes Baden-WurttembergItaly-Istituto Nazionale di Fisica Nucleare (INFN)Istituto Nazionale di Astrofisica (INAF)Ministero dell'Istruzione, dell'Universita e della Ricerca (MIUR)CETEMPS Center of ExcellenceMinistero degli Affari Esteri (MAE)Mexico-Consejo Nacional de Ciencia y Tecnologia (CONACYT) [167733]Universidad Nacional Autonoma de Mexico (UNAM)PAPIIT DGAPAUNAMNetherlands-Ministerie van Onderwijs, Cultuur en WetenschapNederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)Stichting voor Fundamenteel Onderzoek der Materie (FOM)Poland-National Centre for Research and Development [ERA-NETASPERA/01/11, ERA-NET-ASPERA/02/11]National Science Centre [2013/08/M/ST9/00322, 2013/08/M/ST9/00728, HARMONIA 5-2013/10/M/ST9/00062]Portugal-Portuguese national fundsFEDER funds within Programa Operacional Factores de Competitividade through Fundacao para a Ciencia e a Tecnologia (COMPETE)Romania-Romanian Authority for Scientific Research ANCSCNDI-UEFISCDI [20/2012, 194/2012, PN 16 42 01 02]Slovenia-Slovenian Research AgencySpainComunidad de MadridFondo Europeo de Desarrollo Regional (FEDER) fundsMinisterio de Economia y CompetitividadXunta de GaliciaEuropean Community 7th Framework Program [FP7-PEOPLE-2012-IEF-328826]USA Department of Energy [DE-AC02-07CH11359, DE-FR02-04ER41300, DE-FG02-99ER41107, DE-SC0011689]National Science Foundation [0450696]Grainger FoundationMarie Curie-IRSES/EPLANETEuropean Particle Physics Latin American NetworkEuropean Union 7th Framework Program [PIRSES-2009-GA-246806]UNESCOConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Cytomegalovirus prevents antigen presentation by blocking the transport of peptide-loaded major histocompatibility complex class I molecules into the medial-Golgi compartment

Selective expression of murine cytomegalovirus (MCMV) immediate-early (IE) genes leads to the presentation by the major histocompatibility complex (MHC) class I molecule L a of a peptide derived from MCMV IE protein pp89 (Reddehase, M. J., J. B. Rothbard, and U. H. Koszinowski. 1989. Nature (Lond.). 337:651). Characterization of endogenous antigenic peptides identified the pp89 peptide as the nonapeptide msYPHFMFFNLt76 (del Val, M., H.-J. Schlicht, T. Ruppert, M. J. Reddehase, and U. H. Koszinowski. 1991. Cell. 66:1145). Subsequent expression of MCMV early genes prevents presentation of pp89 (del Val, M., K. Mfinch, M. J. Reddehase, and U. H. Koszinowski. 1989. Cell. 58:305). We report on the mechanism by which MCMV early genes interfere with antigen presentation. Expression of the IE promoter-driven bacterial gene lacZ by recombinant MCMV subjected antigen presentation of B-galactosidase to the same control and excluded antigen specificity. The La-dependent presence of naturally processed antigenic peptides also in nonpresenting cells located the inhibitory function subsequent to the step of antigen processing. The finding that during the E phase of MCMV gene expression the MHC class I heavy chain glycosylation remained in an Endo H-sensitive form suggested a block within the endoplasmic reticulum/c/s-Golgi compartment. The failure to present antigenic peptides was explained by a general retention of nascent assembled trimolecular MHC class I complexes. Accordingly, at later stages of infection a significant decrease of surface MHC class I expression was seen, whereas other membrane glycoproteins remained unaffected. Thus, MCMV E genes endow this virus with an effective immune evasion potential. These results also indicate that the formation of the trimolecular complex of MHC dass I heavy chain, ~2-microglobulin, and the finally trimmed peptide is completed before entering the medial-Golgi compartment