The Arizona Radio Observatory CO Mapping Survey of Galactic Molecular Clouds: III. The Serpens Cloud in CO J=2-1 and 13CO J=2-1 Emission

We mapped 12CO and 13CO J = 2-1 emission over 1.04 square deg of the Serpens molecular cloud with 38 arcsec spatial and 0.3 km/s spectral resolution using the Arizona Radio Observatory Heinrich Hertz Submillimeter telescope. Our maps resolve kinematic properties for the entire Serpens cloud. We also compare our velocity moment maps with known positions of Young Stellar Objects (YSOs) and 1.1 mm continuum emission. We find that 12CO is self-absorbed and 13CO is optically thick in the Serpens core. Outside of the Serpens core, gas appears in filamentary structures having LSR velocities which are blue-shifted by up to 2 km/s relative to the 8 km/s systemic velocity of the Serpens cloud. We show that the known Class I, Flat, and Class II YSOs in the Serpens core most likely formed at the same spatial location and have since drifted apart. The spatial and velocity structure of the 12CO line ratios implies that a detailed 3-dimensional radiative transfer model of the cloud will be necessary for full interpretation of our spectral data. The starless cores region of the cloud is likely to be the next site of star formation in Serpens.Comment: 41 pages, 15 figure

Discovery of Broad Molecular lines and of Shocked Molecular Hydrogen from the Supernova Remnant G357.7+0.3: HHSMT, APEX, Spitzer and SOFIA Observations

We report a discovery of shocked gas from the supernova remnant (SNR) G357.7+0.3. Our millimeter and submillimeter observations reveal broad molecular lines of CO(2-1), CO(3-2), CO(4-3), 13CO (2-1) and 13CO (3-2), HCO^+ and HCN using HHSMT, Arizona 12-Meter Telescope, APEX and MOPRA Telescope. The widths of the broad lines are 15-30 kms, and the detection of such broad lines is unambiguous, dynamic evidence showing that the SNR G357.7+0.3 is interacting with molecular clouds. The broad lines appear in extended regions (>4.5'x5'). We also present detection of shocked H2 emission in mid-infrared but lacking ionic lines using the Spitzer IRS observations to map a few arcmin area. The H2 excitation diagram shows a best-fit with a two-temperature LTE model with the temperatures of ~200 and 660 K. We observed [C II] at 158um and high-J CO(11-10) with the GREAT on SOFIA. The GREAT spectrum of [C II], a 3 sigma detection, shows a broad line profile with a width of 15.7 km/s that is similar to those of broad CO molecular lines. The line width of [C~II] implies that ionic lines can come from a low-velocity C-shock. Comparison of H2 emission with shock models shows that a combination of two C-shock models is favored over a combination of C- and J-shocks or a single shock. We estimate the CO density, column density, and temperature using a RADEX model. The best-fit model with n(H2) = 1.7x10^{4} cm^{-3}, N(CO) = 5.6x10^{16} cm^{-2}, and T = 75 K can reproduce the observed millimeter CO brightnesses.Comment: 19 pages, 22 figure

The abundance of HCN in circumstellar envelopes of AGB stars of different chemical types

A multi-transition survey of HCN (sub-) millimeter line emission from a large sample of AGB stars of different chemical type is presented. The data are analysed and circumstellar HCN abundances are estimated. The sample stars span a large range of properties such as mass-loss rate and photospheric C/O-ratio. The analysis of the new data allows for more accurate estimates of the circumstellar HCN abundances and puts new constraints on chemical models. In order to constrain the circumstellar HCN abundance distribution a detailed non-LTE excitation analysis, based on the Monte Carlo method, is performed. Effects of line overlaps and radiative excitation from dust grains are included. The median values for the derived abundances of HCN (with respect to H2) are 3x10-5, 7x10-7 and 10-7 for carbon stars (25 stars), S-type AGB stars (19 stars) and M-type AGB stars (25 stars), respectively. The estimated sizes of the HCN envelopes are similar to those obtained in the case of SiO for the same sample of sources and agree well with previous results from interferometric observations, when these are available. We find that there is a clear dependence of the derived circumstellar HCN abundance on the C/O-ratio of the star, in that carbon stars have about two orders of magnitude higher abundances than M-type AGB stars, on average. The derived HCN abundances of the S-type AGB stars have a larger spread and typically fall in between those of the two other types, however, slightly closer to the values for the M-type AGB stars. For the M-type stars, the estimated abundances are much higher than what would be expected if HCN is formed in thermal equilibrium. However, the results are also in contrast to predictions from recent non-LTE chemical models, where very little difference is expected in the HCN abundances between the various types of AGB stars.Comment: Accepted for publication in A&

Star formation in the S233 region

The main objective of this paper is to study the possibility of triggered star formation on the border of the HII region S233, which is formed by a B-star. Using high-resolution spectra we determine the spectral class of the ionizing star as B0.5 V and the radial velocity of the star to be -17.5(1.4) km/s. This value is consistent with the velocity of gas in a wide field across the S233 region, suggesting that the ionizing star was formed from a parent cloud belonging to the S233 region. By studying spatial-kinematic structure of the molecular cloud in the S233 region, we detected an isolated clump of gas producing CO emission red-shifted relative to the parent cloud. In the UKIDSS and WISE images, the clump of gas coincides with the infrared source containing a compact object and bright-rimmed structure. The bright-rimmed structure is perpendicular to the direction of the ionizing star. The compact source coincides in position with IRAS source 05351+3549. All these features indicate a possibility of triggering formation of a next-generation star in the S233 region. Within the framework of a theoretical one-dimensional model we conclude that the "collect-and-collapse" process is not likely to take place in the S233 region. The presence of the bright-rimmed structure and the compact infrared source suggest that the "collapse of the pre-existing clump" process is taking place.Comment: 12 pages, 10 figure

X Marks the Spot: Nexus of Filaments, Cores, and Outflows in a Young Star-Forming Region

We present a multiwavelength investigation of a region of a nearby giant molecular cloud that is distinguished by a minimal level of star formation activity. With our new 12CO(J=2-1) and 13CO(J=2-1) observations of a remote region within the middle of the California molecular cloud, we aim to investigate the relationship between filaments, cores, and a molecular outflow in a relatively pristine environment. An extinction map of the region from Herschel Space Observatory observations reveals the presence of two 2-pc-long filaments radiating from a high-extinction clump. Using the 13CO observations, we show that the filaments have coherent velocity gradients and that their mass-per-unit-lengths may exceed the critical value above which filaments are gravitationally unstable. The region exhibits structure with eight cores, at least one of which is a starless, prestellar core. We identify a low-velocity, low-mass molecular outflow that may be driven by a flat spectrum protostar. The outflow does not appear to be responsible for driving the turbulence in the core with which it is associated, nor does it provide significant support against gravitational collapse.Comment: Accepted for publication in the Astrophysical Journa

Niños e Internet: navegar por el mundo virtual

Este artigo aborda especialmente as práticas de consumo da rede www por crianças. Sabe-se que as crianças interagem com os textos da mídia a partir da sua cultura e seus costumes e que elas também são produtoras das mensagens, atribuindo novos significados e empregando-os de formas diferentes. Com isso, este artigo evidencia as práticas de consumo das crianças com relação à rede www e mostra como elas participam deste espaço.This article specifically addresses the practices of consumption of www by children. It is known that children interact with media texts from their culture and their customs and they are also producers of messages, assigning new meanings and using them in different ways. Therefore, this article highlights the consumption practices of children with respect to www and shows how they participate in this space.En este artículo se refiere específicamente a las prácticas de consumo de red www por los niños. Se sabe que los niños interactúan con los textos de los medios de su cultura y sus costumbres y que son también productores de mensajes, asignando nuevos significados y los utilizando en diferentes maneras. Por lo tanto, este artículo pone de relieve las prácticas de consumo de los niños con respecto a la red www y muestra cómo participar en este espacio

Transmidiação como Ferramenta Estratégica: Cheias de Charme Explora uma Nova Forma de Fazer Telenovela

Este artigo tem como objetivo analisar as estratégias transmidiáticas utilizadas pelos produtores da telenovela Cheias de Charme, da Rede Globo, para atingir grande sucesso com o grupo musical ficcional As Empreguetes. Alcançando mais de 12 milhões de visualizações, o videoclipe Vida de Empreguete entra para a história da teledramaturgia como o produto que melhor utilizou as narrativas transmidiáticas. Além disso, possibilitando a participação, o compartilhamento dos conteúdos, a interação e a imersão do público durante o desenvolvimento da trama, a telenovela quebrou as barreiras entre o mundo real e ficcional. This article aims to analyze the strategies of transmedia storytelling used in the telenovela Cheias de Charme, from Rede Globo television, to achieve great success with the fictional musical group As Empreguetes. Reaching more than 12 million views, the video Vida de Empreguete made history in television as the product that has best used transmedia storytelling strategies. In addition, by enabling participation, sharing of content, interaction and immersion of the public during the development of the plot, the telenovela has broken the barriers between the real and fictional words

Da busca de popularidade às práticas de bullying: crianças e produção de sentidos a partir de artefatos midiáticos

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Educação, Programa de Pós-Graduação em Educação, Florianópolis, 2011Este trabalho tem como objetivo entender como as crianças se relacionam com as representações identitárias produzidas pelas mídias, e como tais representações são eventualmente efetivadas nas práticas culturais cotidianas das crianças. O foco é verificar o que as crianças dizem sobre estas diferentes identidades em que o sistema das mídias parece desejar enquadrá-las e como se sentem em relação a elas. Levamos em consideração que a cultura da mídia colabora muito, e de forma complexa, com a constituição de modos de pensar e agir, tanto no sentido da massificação e padronização do cotidiano, como eventualmente abrindo espaços para processos alternativos de formação de identidade. Este trabalho fundamenta-se principalmente nos Estudos Culturais, buscando inspirações e respostas em situações de recepção envolvendo crianças de 9 a 12 anos, meninos e meninas. Em síntese, foi mostrado às crianças um episódio do seriado Hannah Montana, do Disney Channel, e o desenho animado Zica e os Camaleões, ganhador do prêmio de melhor animação na 9ª Mostra de Cinema Infantil de Florianópolis, em 2010 - produzido em São Paulo, entendidos como textos geradores de análise e discussões em grupos focais e entrevistas semiestruturadas. A pesquisa evidenciou que apesar da qualidade e da quantidade de equipamentos de mídias serem diferentes, as crianças possuem acesso semelhante a eles, com exceção da TV por assinatura. As categorias estereotipadas apresentadas nas produções midiáticas - como, por exemplo, "populares", "perdedores", "fracassados", "nerds", "normais", entre outras -, também se mostraram presentes no cotidiano escolar das crianças participantes. Apesar de as crianças naturalmente se dividirem em grupos, com ou sem a televisão, pois isso é próprio da vida social, foi possível perceber como isso acontece hoje a partir da televisão. Mesmo que o bullying não tenha sido o tema inicial desta pesquisa, ele surgiu nas falas das crianças participantes, que relataram que a violência está diretamente ligada à classificação dos grupos no espaço escolar. Ficou evidente que a causa desta divisão entre as crianças está muito mais ligada à intolerância e a desigualdade social, do que unicamente no que as mídias podem sugerir. Esta pesquisa tem como base teórica, entre outros: Ana Carolina Escosteguy, David Buckingham, Douglas Kellner, Edgar Morin, Edmir Perrotti, Gilka Girardello, Jesús Martín-Barbero, Joseph Tobin, Rosa M. B. Fischer e Stuart Hall