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Mapeamento "tridimensional" do entorno dos buracos negros supermassivos em galáxias Seyfert

Riffel, Rogemar André
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Tese de Doutorado Formato: application/pdf
Português
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18.05%
Apresentamos mapas bidimensionais (2D) para os fluxos e razões de linhas de emissão, cinemática do gás e das estrelas na região central (≈ 100 − 300 pc de raio em torno do núcleo) das galáxias Seyfert ESO428-G14, NGC7582, NGC4051 e NGC4258 a partir de dados espectroscópicos obtidos com a Unidade de Campo Integral (IFU) do instrumento GNIRS (Gemini Near-Infrared Spectrograph) e com o instrumento NIFS (Near-infrared Integral Field Spectrograph) instaladas nos telescópios Gemini. Obtivemos medidas da cinemática estelar a partir de ajustes das bandas de absorção do CO em λ ≈ 2, 3 μm por templates estelares e mapas para as distribuições e cinemática do gás a partir de ajustes de curvas gaussianas aos perfis das linhas de emissão. A alta resolução espectral dos dados ainda nos permitiu obter a “tomografia” do gás a partir de cortes ao longo dos perfis das linhas, fornecendo um mapeamento “tridimensional”. Os campos de velocidades das estrelas são dominados por rotação no disco da galáxia. Modelamos estes campos através de rotação num potencial de Plummer. O campo de velocidades de NGC4051 é bem representado pelo modelo e apresenta um potencial gravitacional bastante concentrado, atribu´ıdo ao bojo. NGC7582 apresenta algumas distorções no campo de velocidades que não são bem representadas pelo modelo...

Gemini near-infrared integral field spectroscopy of the narrow-line region of ESO428-G14 : kinematics, escitation and the role of the radio jet

Riffel, Rogemar André; Storchi-Bergmann, Thaisa; Winge, Claudia; Barbosa, Fausto Kuhn Berenguer
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
Português
Relevância na Pesquisa
27.13%
We present two-dimensional (2D) gas kinematics and excitation of the inner 300 pc of the Seyfert galaxy ESO 428−G14 at a sampling of 14 pc², from near-infrared spectroscopic observations at R≈6000 obtained with the Integral Field Unit (IFU) of the Gemini Near-Infrared Spectrograph. From measurements of fluxes and profiles of the emission lines [Fe II]λ1.257 μm, Paβ, H2λ 2.121 μm and Brγ , we construct 2D maps of line intensities and ratios, radial velocities and velocity dispersions. Emission line ‘tomography’ is provided by velocity slices obtained across the line profiles, a unique capability of IFUs, which allows the mapping of not only the peak velocities but including also the wings. We compare these maps with a previously published high spatial resolution radio map and find a tight relation between the radio structure and the emission-line flux distributions and kinematics, revealing that the radio jet plays a fundamental role not only in shaping the narrow-line region but also in the imprint of its kinematics. Blueshifts of up to 400 km s-ˡ and velocity dispersions of up to 150 km s-ˡ are observed in association with the radio jet at a position angle (PA) = 129◦, which is also the PA of the photometric major axis of the galaxy. We conclude that the radio jet is launched at a small angle relative to the galactic plane...

Clareamento dental com perôxido de hidrogênio contendo nano partículas de óxido de titânio como semicondutor: efeito de concentrações, tempos e formas de ativação

Caldonazzo, Marilia
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Dissertação de Mestrado Formato: 90 f.: il. color.
Português
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17.63%
Pós-graduação em Ciências Odontológicas - FOAR; Este trabalho teve como objetivo estudar a efetividade de dois agentes clareadores compostos por peróxido de hidrogênio 38 % e a 15% contendo dióxido de titânio como semicondutor. Foram utilizadas 170 fatias de incisivos bovinos, distribuídas em 17 grupos (n=10), previamente manchadas por infusão de chá preto, por 7 dias. Os grupos de G1 a G4 receberam gel clareador à 15% e foto-catalisação, os grupos de G5 a G8 receberam apenas gel clareador. O grupo 9 (controle) não recebeu tratamento. Os grupos G10 ao G13 foram clareados com gel à 38% e fotocatalização, enquanto os grupos G14 ao G17 receberam apenas o tratamento clareador. Foram realizadas 3 aplicações, nos tempos experimentais de 4 (G1, G5, G10 e G14), 8 (G2, G6, G11 e G15), 12 (G3, G7, G12 e G16) e 16 (G4, G8, G13 e G17) minutos em 3 simulações com intervalos de 7dias. A efetividade do clareamento foi analisada por espectrofotometria (Color Guide) e processamento de imagens digitais (ScanWhite). Realizaram-se registros de cor antes do manchamento (M1) e após cada sessão (M2-M4). A longevidade do clareamento foi avaliada no período de 7 (M5) dias após o tratamento. Conclui-se que protocolos de tempo completo foram mais efetivos nas sessões iniciais (T1 e T2). A fotocatalização melhorou significativamente a eficácia do clareamento. Não houve diferença em relação à concentração utilizada (15% e 38%) nem ao tempo em que o agente clareador permaneceu em contato com o dente. Conclui-se que protocolos de tempo reduzido deveriam ser adotados para evitar exposição desnecessária.; This work aimed to study the effectiveness of two bleaching agents composed of 38% hydrogen peroxide and 15% containing titanium dioxide as a semiconductor. 170 slices were used bovine incisors divided into 17 groups (n = 10)...

Incidência, controle de doenças de feijão-vagem e anatomia e histoquímica de Phaseolus vulgaris e Vigna unguiculata resistentes e suscetíveis ao oídio (Erysiphe polygoni)

Pedroso, Caroline
Fonte: Universidade de Brasília Publicador: Universidade de Brasília
Tipo: Tese
Português
Relevância na Pesquisa
17.63%
Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Fitopatologia, 2012.; A cultura do feijão-vagem é constituída principalmente por variedades da espécie botânica Phaseolus vulgaris, mas também inclui cultivos de P. lunatus e de Vigna unguiculata. Diferencia-se do feijão comum pelas características das vagens, que são consumidas verdes, normalmente maiores e apresentam reduzidos teores de fibras. No Brasil, o feijão-vagem é cultivado principalmente por pequenos produtores, em cultura tutorada, com alta demanda de mão-de-obra e baseado em métodos tradicionais de plantio e uso intensivo de insumos químicos. Apesar do amplo consumo, são poucas as cultivares de feijão-vagem disponíveis no mercado brasileiro, assim como estudos de incidência de doenças e avaliação de resistência de variedades. Estudos de métodos alternativos de controle de doenças nesta cultura são raros. Entretanto, alguns trabalhos revelaram que o nim (Azadiractha indica) tem ação fungicida, inclusive sobre o oídio (Erysiphe polygoni) em feijoeiro, mas em casa-de-vegetação. Dada a relativa carência de informações sobre as doenças incidentes no feijão vagem e seu controle, este trabalho objetivou: avaliar...

Análise molecular e filogenética de Echinococcus granulosus isolados de hospedeiros das áreas endêmicas do PERU

Romani, Elizabeth Luz Sánchez
Fonte: Instituto Oswaldo Cruz Publicador: Instituto Oswaldo Cruz
Tipo: Dissertação
Português
Relevância na Pesquisa
17.44%
Echinococcus granulosus, o menor cestóide, é distribuído por todo o mundo. Este parasito, sob a forma de larva, é responsável pela equinococose cística (EC) ou hidatidose, uma das zoonoses de maior importância médica e veterinária que ocasiona grandes perdas econômicas nas regiões pecuárias e agrícolas. E. granulosus é caracterizado por apresentar uma alta variabilidade intra-específica que é associada com hospedeiros intermediários diferentes. Dez variantes intra-específicas ou genótipos distintos (G1-G10) foram definidos com base na diversidade genética. A identificação de variantes ou genótipos circulantes em diferentes hospedeiros das regiões endêmicas da EC é epidemiologicamente importante, porque diferentes características biológicas entre as variantes individuais podem influenciar no padrão de ciclo de vida, especificidade do hospedeiro, o tempo de desenvolvimento, antigenicidade, dinâmica de transmissão, sensibilidade a agentes quimioterápicos e patogênese, com implicações importantes para a epidemiologia, diagnóstico, tratamento e controle de endemia. A região andina do Peru, que inclui as áreas de Puno, Junín, Arequipa, Cusco, Huanacavelica e Ayacucho, tem uma alta prevalência de EC. Para determinar as variantes ou genótipos de E. granulosus circulantes em hospedeiros intermediários das regiões endêmicas do Peru...

Cereus jamacaru seed germination and initial seedling establishment as a function of light and temperature conditions

Alencar,Nara Lídia Mendes; Gomes-Filho,Enéas; Innecco,Renato
Fonte: São Paulo - Escola Superior de Agricultura "Luiz de Queiroz" Publicador: São Paulo - Escola Superior de Agricultura "Luiz de Queiroz"
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2012 Português
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Cereus jamacaru is a widespread Cactaceae of northeast Brazil, largely used as cattle food, and as ornamental and medicinal plant. Despite its distinguished importance, until now, there has been little information about the physiological aspects involved on its germination. The objective of this study was to evaluate the effect of light and temperature interaction on the seed germination and seedling establishment of this plant. The evaluated variables were germination percentage at 7 (% G7) and at 14 days after imbibition (% G14), germination average time index (GSI), germination average time (GAT), germination accumulated frequency (GAF), seedling dry mass and height. The highest % G14 and GSI were at 25 ºC in white light, whereas the highest GAT values were in darkness for all evaluated temperatures. On the other hand, % G14, GSI and GAF had the lowest values in darkness. Seeds germinated even in darkness, being however stimulated by the presence of light. The combination of white light and temperature of 25 or 30 °C is the most appropriate condition for seed germination tests.

Nucleotide sequences at the phi X gene A protein cleavage site in replicative form I DNAs of bacteriophages U3, G14, and alpha 3.

Heidekamp, F; Baas, P D; Jansz, H S
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /04/1982 Português
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27.76%
Gene A protein, a bacteriophage phi X174-encoded endonuclease involved in phi X replicative form (RF) DNA replication, nicks not only phi X RFI DNA but also RFI DNAs of several other spherical single-stranded DNA bacteriophages. The position of the phi X gene A protein nick and the nucleotide sequence surrounding this site in RF DNAs of the bacteriophages U3, G14, and alpha 3 were determined. Comparison of the nucleotide sequences which surround the nick site of the gene A protein in RF DNAs of phi X174, G4, St-1, U3, G14, and alpha 3 revealed that a strongly conserved 30-nucleotide stretch occurred in RF DNAs of all six phages. However, perfect DNA sequence homology around this site was only 10 nucleotides, the decamer sequence CAACTTGATA. The present results support the hypothesis that, for nicking of double-stranded supercoiled DNA by the phi X gene A protein, the presence of the recognition sequence CAACTTGATA and a specific gene A protein binding sequence upstream from the recognition sequence are required. The sequence data obtained so far from phages U3, G14, St-1, and alpha 3 have been compared with the nucleotide sequences and amino acid sequences of both phi X and G4. According to this comparison, the evolutionary relationship between phages G4...

Equine rotaviruses with G14 serotype specificity circulate among venezuelan horses.

Ciarlet, M; Reggeti, F; Piña, C I; Liprandi, F
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/1994 Português
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Two group A rotavirus strains isolated from diarrheic foals in Venezuela were classified as belonging to G14 serotype by cross-neutralization tests and on the basis of the homology of the sequenced VP7 gene. This report confirms that rotavirus strains of G14 serotype specificity circulate among equine populations.

Protective and Nonprotective Human Immunoglobulin M Monoclonal Antibodies to Cryptococcus neoformans Glucuronoxylomannan Manifest Different Specificities and Gene Use Profiles

Maitta, Robert W.; Datta, Kausik; Chang, Qing; Luo, Robin X.; Witover, Bradley; Subramaniam, Krishanthi; Pirofski, Liise-anne
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /08/2004 Português
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The features of protective murine antibodies to the Cryptococcus neoformans capsular polysaccharide glucuronoxylomannan (GXM) have been rigorously investigated; however, the characteristics of protective human antibodies to GXM have not been defined. We produced monoclonal antibodies (MAbs) from XenoMouse mice (transgenic mice that express human immunoglobulin M [IgM], IgG2, and κ) which were immunized with a C. neoformans serotype D strain 24067 GXM-diphtheria toxoid conjugate. This study reports the specificity and efficacy of three human IgM MAbs, G14, G15, and G19, generated from these mice. Each MAb was specific for GXM, but G14 and G19 had different specificity based on their binding to serotype A strain H99 and SB4 GXMs, to which G15 did not bind. Nucleic acid sequence analysis revealed that G15 uses VH3-64 in the germ line configuration. G14 and G19 use VH6-1, which has somatic mutations. All of the MAbs use Vκ DPK22/A27. Studies of MAb efficacy in BALB/c mice showed that administration of 0.1 mg, but not 1 or 0.01 mg, of G15 prolonged survival against lethal C. neoformans strain 24067 challenge, whereas G14 and G19 were not protective at any dose. This panel of MAbs illustrates that serotype D GXM has epitopes that elicit human antibodies that can be either protective or nonprotective. Our findings suggest that VH gene use may influence GXM specificity and efficacy...

Giardia Duodenalis 14-3-3 Protein Is Polyglycylated by a Tubulin Tyrosine Ligase-like Member and Deglycylated by Two Metallocarboxypeptidases*

Lalle, Marco; Camerini, Serena; Cecchetti, Serena; Fantauzzi, Claudia Blasetti; Crescenzi, Marco; Pozio, Edoardo
Fonte: American Society for Biochemistry and Molecular Biology Publicador: American Society for Biochemistry and Molecular Biology
Tipo: Artigo de Revista Científica
Português
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17.63%
The flagellated protozoan Giardia duodenalis is a parasite of the upper part of the small intestine of mammals, including humans, and an interesting biological model. Giardia harbors a single 14-3-3 isoform, a multifunctional protein family, that is modified at the C terminus by polyglycylation, an unusual post-translational modification consisting of the covalent addition of one or multiple glycines on the γ-carboxyl groups of specific glutamic acids. Polyglycylation affects the intracellular localization of g14-3-3, as the shortening of the polyglycine chain is correlated with a partial relocalization of 14-3-3 inside the nuclei during encystation. In this work we demonstrate that the gTTLL3, a member of the tubulin tyrosine ligase-like family, is the enzyme responsible for the 14-3-3 polyglycylation. We also identify two metallopeptidases of the M20 family, here termed gDIP1 (giardial dipeptidase 1) and gDIP2, as enzymes able to shorten the g14-3-3 polyglycine tail both in vivo and in vitro. Finally, we show that the ectopic expression of gDIP2 alters the g14-3-3 localization and strongly hampers the cyst formation. In conclusion, we have identified a polyglycylase and two deglycylases that act in concert to modulate the stage-dependent glycylation status of the multifunctional regulatory g14-3-3 protein in G. duodenalis.

Interkingdom Complementation Reveals Structural Conservation and Functional Divergence of 14-3-3 Proteins

Lalle, Marco; Leptourgidou, Flora; Camerini, Serena; Pozio, Edoardo; Skoulakis, Efthimios M. C.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 11/10/2013 Português
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17.63%
The 14-3-3s are small acidic cytosolic proteins that interact with multiple clients and participate in essential cellular functions in all eukaryotes. Available structural and functional information about 14-3-3s is largely derived from higher eukaryotes, which contain multiple members of this protein family suggesting functional specialization. The exceptional sequence conservation among 14-3-3 family members from diverse species suggests a common ancestor for 14-3-3s, proposed to have been similar to modern 14-3-3ε isoforms. Structural features of the sole family member from the protozoan Giardia duodenalis (g14-3-3), are consistent with this hypothesis, but whether g14-3-3 is functionally homologous to the epsilon isoforms is unknown. We use inter-kingdom reciprocal functional complementation and biochemical methods to determine whether g14-3-3 is structurally and functionally homologous with members of the two 14-3-3 conservation groups of the metazoan Drosophila melanogaster. Our results indicate that although g14-3-3 is structurally homologous to D14-3-3ε, functionally it diverges presenting characteristics of other 14-3-3s. Given the basal position of Giardia in eukaryotic evolution, this finding is consistent with the hypothesis that 14-3-3ε isoforms are ancestral to other family members.

The Crystal Structure of Giardia duodenalis 14-3-3 in the Apo Form: When Protein Post-Translational Modifications Make the Difference

Fiorillo, Annarita; di Marino, Daniele; Bertuccini, Lucia; Via, Allegra; Pozio, Edoardo; Camerini, Serena; Ilari, Andrea; Lalle, Marco
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 21/03/2014 Português
Relevância na Pesquisa
17.76%
The 14-3-3s are a family of dimeric evolutionary conserved pSer/pThr binding proteins that play a key role in multiple biological processes by interacting with a plethora of client proteins. Giardia duodenalis is a flagellated protozoan that affects millions of people worldwide causing an acute and chronic diarrheal disease. The single giardial 14-3-3 isoform (g14-3-3), unique in the 14-3-3 family, needs the constitutive phosphorylation of Thr214 and the polyglycylation of its C-terminus to be fully functional in vivo. Alteration of the phosphorylation and polyglycylation status affects the parasite differentiation into the cyst stage. To further investigate the role of these post-translational modifications, the crystal structure of the g14-3-3 was solved in the unmodified apo form. Oligomers of g14-3-3 were observed due to domain swapping events at the protein C-terminus. The formation of filaments was supported by TEM. Mutational analysis, in combination with native PAGE and chemical cross-linking, proved that polyglycylation prevents oligomerization. In silico phosphorylation and molecular dynamics simulations supported a structural role for the phosphorylation of Thr214 in promoting target binding. Our findings highlight unique structural features of g14-3-3 opening novel perspectives on the evolutionary history of this protein family and envisaging the possibility to develop anti-giardial drugs targeting g14-3-3.

Markets for Information: Of Inefficient Firewalls and Efficient Monopolies

CABRALES, Antonio; GOTTARDI, Piero
Fonte: European University Institute Publicador: European University Institute
Tipo: Trabalho em Andamento Formato: application/pdf; digital
Português
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27.13%
In this paper we study, within a formal model, market environments where information is costly to acquire and is of use also to potential competitors. Agents may then sell, or buy, reports over the information acquired and choose the trades in the market on the basis of what they learnt. Reports are unverifiable - cheap talk messages – hence the quality of the information transmitted depends on the conflicts of interest faced by the senders. We find that, in equilibrium, information is acquired when its costs are not too high and in that case it is also sold, though reports are typically noisy. Also, the market for information tends to be a monopoly, and there is inefficiency given by underinvestment in information acquisition. Regulatory interventions in the form of firewalls, limiting the access to the sale of information to agents uninterested in trading the underlying object, only make the inefficiency worse. Efficiency can be attained with a monopolist selling differentiated information, provided entry is blocked. The above findings hold when information has a prevalent horizontal differentiation component. When the vertical differentiation element is more important firewalls can in fact be beneficial. JEL Classification: D83...

Characterization of a human MHC class III region gene product with S-thioesterase activity.

Aguado, B; Campbell, R D
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 01/08/1999 Português
Relevância na Pesquisa
17.97%
Palmitoylated proteins contain a 16-carbon saturated fatty acyl group that is post-translationally attached by a labile thioester bond. These modified proteins are mainly membrane-bound; the lability of the thioester bond allows the process to be reversible, a unique property of this modification. We report here that the gene for G14, located in the class III region of the human MHC, encodes a polypeptide with significant sequence similarity to mammalian palmitoyl protein thioesterase (PPT1), an enzyme that removes palmitate from palmitoylated proteins. The gene for G14, also known as PPT2, is transcribed as at least five different transcripts, which are expressed in different cell lines of the immune system. Immunoprecipitation of these mammalian cells, with an anti-G14 antiserum, showed a specific band of approx. 42 kDa in cell extracts and supernatants. Expression of the G14 cDNA in the baculovirus system revealed that it encoded a secreted glycosylated polypeptide with S-thioesterase activity. The enzymic activity of the recombinant G14 protein was further characterized in quantitative spectrophotometric assays, which revealed that it had the highest S-thioesterase activity for the acyl groups palmitic and myristic acid followed by other long-chain acyl substrates. The S-thioesterase activity of the G14 protein was found to be considerably higher in supernatants than in cell extracts...

Molecular Characterization of Equine Rotavirus in Ireland▿

Collins, P. J.; Cullinane, A.; Martella, V.; O'Shea, H.
Fonte: American Society for Microbiology (ASM) Publicador: American Society for Microbiology (ASM)
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
17.63%
Group A rotaviruses are important causative agents of severe, acute dehydrating diarrhea in foals. A total of 86 rotavirus-positive fecal samples, collected from diarrheic foals from 11 counties in three of the four provinces of Ireland, were obtained from the Irish Equine Centre in Kildare during a 7-year (1999 to 2005) passive surveillance study and were characterized molecularly to establish the VP7 (G type) and VP4 (P type) antigenic specificities. Fifty-eight samples (67.5%) were found to contain G3 viruses, while in 26 samples (30.2%) the rotaviruses were typed as G14 and in 2 samples (2.3%) there was a mixed infection, G3 plus G14. All samples except for two, which were untypeable, were characterized as P[12]. Fifty-eight percent of the samples were obtained from County Kildare, the center of the Irish horse industry, where an apparent shift from G3P[12] to G14P[12] was observed in 2003. By sequence analysis of the VP7 protein, the G3 Irish strains were shown to resemble viruses of the G3A subtype (H2-like) (97.1 to 100% amino acid [aa] identity), while the G14 Irish strains displayed 93.9 to 97.1% aa identity to other G14 viruses. In the VP8* fragment of the VP4 protein, the P[12] Irish viruses displayed high conservation (92.3 to 100% aa) with other equine P[12] viruses. Worldwide...

Unveiling a network of parallel filaments in the Infrared Dark Cloud G14.225-0.506

Busquet, Gemma; Zhang, Qizhou; Palau, Aina; Liu, Hauyu Baobab; Sánchez-Monge, Álvaro; Estalella, Robert; Ho, Paul T. P.; de Gregorio-Monsalvo, Itziar; Pillai, Thushara; Wyrowski, Friedrich; Girart, Josep M.; Santos, Fábio P.; Franco, Gabriel A. P.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 24/12/2012 Português
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27.44%
We present the results of combined NH3(1,1) and (2,2) line emission observed with the Very Large Array and the Effelsberg 100m telescope of the Infrared Dark Cloud G14.225-0.506. The NH3 emission reveals a network of filaments constituting two hub-filament systems. Hubs are associated with gas of rotational temperature Trot \sim 25 K, non-thermal velocity dispersion ~1.1 km/s, and exhibit signs of star formation, while filaments appear to be more quiescent (Trot \sim 11 K, non-thermal velocity dispersion ~0.6 km/s). Filaments are parallel in projection and distributed mainly along two directions, at PA \sim 10 deg and 60 deg, and appear to be coherent in velocity. The averaged projected separation between adjacent filaments is between 0.5 pc and 1pc, and the mean width of filaments is 0.12 pc. Cores within filaments are separated by ~0.33 pc, which is consistent with the predicted fragmentation of an isothermal gas cylinder due to the 'sausage'-type instability. The network of parallel filaments observed in G14.225-0.506 is consistent with the gravitational instability of a thin gas layer threaded by magnetic fields. Overall, our data suggest that magnetic fields might play an important role in the alignment of filaments, and polarization measurements in the entire cloud would lend further support to this scenario.; Comment: 6 pages...

Helical Strands in the Jet-like Narrow Line Region of ESO 428-G14

Falcke, Heino; Wilson, Andrew S.; Simpson, Chris; Bower, Gary A.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 08/08/1996 Português
Relevância na Pesquisa
27.13%
We present HST/WFPC2 images of the narrow line region (NLR) of the Seyfert 2 galaxy ESO 428-G14 (0714-2914, M4-1). The NLR consists of many individual, thin strands, which are very closely related to the radio jet and produce a highly complex yet ordered structure. We find that the jet is two-sided with a double-helix of emission-line gas apparently wrapped around the NW side. To the SE, the jet seems to be deflected at a ridge of highly excited gas. The strands to the SE may also wrap around the radio jet, but here complete helices are not seen. The overall structure is reminiscent of the jet seen in NGC 4258. Faint symmetric features aligned with the nucleus could indicate the presence of a highly collimated beam of photons or plasma from the center.; Comment: ApJ Letters, accepted for publication, 10 pages, 2 PS Figures, AASTeX, also available at http://www.astro.umd.edu/~hfalcke/publications.html#eso428

Gemini Near Infrared Integral Field Spectroscopy of the Narrow-Line Region of ESO428-G14: kinematics, excitation and the role of the radio jet

Riffel, Rogemar A.; Storchi-Bergmann, Thaisa; Winge, Claudia; Barbosa, Fausto K. B.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 12/09/2006 Português
Relevância na Pesquisa
27.13%
We present 2D gas kinematics and excitation of the inner 300 pc of the Seyfert galaxy ESO428-G14 at a sampling of 14 pc^2, from near-IR spectroscopic observations at R~6000 obtained with the IFU of the Gemini Near-Infrared Spectrograph. From measurements of fluxes and profiles of the emission lines [FeII]lambda1.257, Pa_beta, H_2lambda2.121 and Br_gamma, we construct 2D maps of line intensities and ratios, radial velocities and velocity dispersions. Emission lines "tomography" is provided by velocity slices obtained across the line profiles, which allows the mapping of not only of peak velocities but including also the wings. We compare these maps with a previously published high spatial resolution radio map and find a tight relation between the radio structure and the emission-line flux distributions and kinematics, revealing that the radio-jet plays a fundamental role not only in shaping the NLR but also in the imprint of its kinematics. Blueshifts of up to 400 km/s and velocity dispersions of up to 150 km/s are observed in association with the radio jet at position angle PA=129, which is also the PA of the photometric major axis of the galaxy. The [FeII] shows the largest blueshifts and velocity dispersions and its flux distribution is concentrated along the jet...

Distance to G14.33-0.64 in the Sagittarius Spiral Arm: H2O Maser Trigonometric Parallax with VERA

Sato, Mayumi; Hirota, Tomoya; Reid, Mark J.; Honma, Mareki; Kobayashi, Hideyuki; Iwadate, Kenzaburo; Miyaji, Takeshi; Shibata, Katsunori M.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 14/01/2010 Português
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27.85%
We report on trigonometric parallax measurements for the Galactic star forming region G14.33-0.64 toward the Sagittarius spiral arm. We conducted multi-epoch phase-referencing observations of an H2O maser source in G14.33-0.64 with the Japanese VLBI array VERA. We successfully detected a parallax of 0.893+/-0.101 mas, corresponding to a source distance of 1.12+/-0.13 kpc, which is less than half of the kinematic distance for G14.33-0.64. Our new distance measurement demonstrates that the Sagittarius arm lies at a closer distance of ~1 kpc, instead of previously assumed ~2-3 kpc from kinematic distances. The previously suggested deviation of the Sagittarius arm toward the Galactic center from the symmetrically fitted model (Taylor & Cordes 1993) is likely due to large errors of kinematic distances at low galactic longitudes. G14.33-0.64 most likely traces the near side of the Sagittarius arm. We attempted fitting the pitch angle of the arm with other parallax measurements along the arm, which yielded two possible pitch angles of i=34.7+/-2.7 degrees and i=11.2+/-10.5 degrees. Our proper motion measurements suggest G14.33-0.64 has no significant peculiar motion relative to the differential rotation of the Galaxy (assumed to be in a circular orbit)...

Unveiling a Network of Parallel Filaments in the Infrared Dark Cloud G14.225–0.506

Busquet, Gemma; Zhang, Qizhou; Palau, Aina; Liu, Hauyu Baobab; Sánchez-Monge, Álvaro; Estalella, Robert; Ho, Paul T. P.; de Gregorio-Monsalvo, Itziar; Pillai, Thushara; Wyrowski, Friedrich; Girart, Josep M.; Santos, Fábio P.; Franco, Gabriel A. P.
Fonte: American Astronomical Society Publicador: American Astronomical Society
Tipo: Article; PeerReviewed Formato: application/pdf
Publicado em 20/02/2013 Português
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We present the results of combined NH_3 (1,1) and (2,2) line emission observed with the Very Large Array and the Effelsberg 100 m telescope of the infrared dark cloud G14.225–0.506. The NH3 emission reveals a network of filaments constituting two hub-filament systems. Hubs are associated with gas of rotational temperature T_(rot) ~ 15 K, non-thermal velocity dispersion σ_(NT) ~ 1 km s^(–1), and exhibit signs of star formation, while filaments appear to be more quiescent (T_(rot) ~ 11 K and σ_(NT) ~ 0.6 km s^(–1)). Filaments are parallel in projection and distributed mainly along two directions, at P.A. ~ 10° and 60°, and appear to be coherent in velocity. The averaged projected separation between adjacent filaments is between 0.5 pc and 1 pc, and the mean width of filaments is 0.12 pc. Cores within filaments are separated by ~0.33 ± 0.09 pc, which is consistent with the predicted fragmentation of an isothermal gas cylinder due to the "sausage"-type instability. The network of parallel filaments observed in G14.225–0.506 is consistent with the gravitational instability of a thin gas layer threaded by magnetic fields. Overall, our data suggest that magnetic fields might play an important role in the alignment of filaments...