Multifrequency study of the ring nebula SG 13

We investigate the morphology and kinematics of the interstellar medium in the environs of the open cluster Mrk 50, which includes the Wolf-Rayet star WR 157 and a number of early B-type stars. The analysis was performed using radio continuum images at 408 and 1420 MHz, and H i 21-cm line data taken from the Canadian Galactic Plane Survey, molecular observations of the 12CO (J = 1 → 0) line at 115 GHz from the Five College Radio Astronomy Observatory and available mid- and far-infrared (FIR) observations obtained with the Midcourse Space Experiment and IRAS satellites, respectively. This study allowed the identification of the radio continuum and molecular counterpart of the ring nebula SG 13, while no neutral atomic structure was found to be associated. The nebula is also detected in the images in the mid- and FIR, showing the existence of dust well mixed with the ionized gas. We estimate the main physical parameters of the material linked to the nebula. The interstellar gas distribution in the environs of Mrk 50 is compatible with a stellar wind bubble created by the mass loss from WR 157. The distribution of young stellar object candidates in the region shows that the stellar formation activity may be present in the molecular shell that encircles the ring nebula.Facultad de Ciencias Astronómicas y Geofísica

Ciborgues, clones e remotos controles: narrativas curtas tecnológicas

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão. Programa de Pós-Graduação em Literatura.A televisão, o vídeo e o cinema são hoje a cultura global, e há bastante tempo eles utilizam a matéria-prima literária para o seu fazer. Outrossim, resta indagar se essas mídias, tão presentes nas relações sociais contemporâneas, assim como as novas tecnologias da comunicação, como o computador e o ciberespaço, podem constituir intertextos para a literatura. As relações entre tecnologia - notadamente a eletrônica - e literatura podem ser verificadas tanto na questão temática, de que é exemplo a literatura cyberpunk, como na estrutura (hipertexto) e na forma dos textos, que às vezes faz lembrar o pulsar tecnológico. Neste trabalho, apresento relações entre literatura e tecnologia a partir da análise de cinco contos de autores contemporâneos da literatura brasileira, incluindo, ao final, comentários sobre blogs, a partir da obra impressa Wunderblogs.com

Scaling laws of quiet-Sun coronal loops

We study a series of relations between physical parameters in coronal loops of the quiet Sun reconstructed by combining tomographic techniques and modeling of the coronal magnetic field. We use differential emission measure tomography (DEMT) to determine the three-dimensional distribution of the electron density and temperature in the corona, and we model the magnetic field with a potential-field source-surface (PFSS) extrapolation of a synoptic magnetogram. By tracing the DEMT products along the extrapolated magnetic field lines, we obtain loop-averaged electron density and temperature. Also, loop-integrated energy-related quantities are computed for each closed magnetic field line. We apply the procedure to Carrington rotation 2082, during the activity minimum between Solar Cycles 23 and 24, using data from the Extreme Ultraviolet Imager on board the Solar Terrestrial Relations Observatory (STEREO) spacecraft. We find a scaling law between the loop-average density N and loop length L,Nm∼L-0.35, but we do not find a significant relation between loop-average temperature and loop length. We confirm though the previously found result that loop-average temperatures at the equatorial latitudes are lower than at higher latitudes. We associate this behavior with the presence at the equatorial latitudes of loops with decreasing temperatures along their length (“down” loops), which are in general colder than loops with increasing temperatures (“up” loops). We also discuss the role of “down” loops in the obtained scaling laws of heating flux versus loop length for different heliographic latitudes. We find that the obtained scalings for quiet-Sun loops do not generally agree with those found in the case of AR loops from previous observational and theoretical studies. We suggest that to better understand the relations found, it is necessary to forward model the reconstructed loops using hydrodynamic codes working under the physical conditions of the quiet-Sun corona.Fil: Mac Cormack, Cecilia. Universidad Nacional de Tres de Febrero; Argentina. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Lopez Fuentes, Marcelo Claudio. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Mandrini, Cristina Hemilse. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Lloveras, Diego Gustavo. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Poisson, Mariano. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina. Universidad Nacional de Tres de Febrero; ArgentinaFil: Vasquez, Alberto Marcos. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina. Universidad Nacional de Tres de Febrero; Argentin

The radio and infrared counterparts of the ring nebula around HD 211564

We report the detection of the radio and infrared (IR) counterparts of the ring nebula around the WN3(h) star HD 211564 (WR 152), located to the south-west of the H II region Sh2 132. Using radio continuum data from the Canadian Galactic Plane Survey, we identified the radio counterparts of the two concentric rings, of about 9 and 16 arcmin in radius, related to the star. After applying a filling factor f = 0.05-0.12, electron densities and ionized masses are in the range 10-16 cm-3 and 450-700 M⊙ respectively. The analysis of the H I gas emission distribution allowed the identification of 5900 M⊙ of neutral atomic gas with velocities between -52 and -43 km s-1 probably linked to the nebula. The region of the nebula is almost free of molecular gas. Only four small clumps were detected, with a total molecular mass of 790 M⊙. About 310 M⊙ are related to a small IR shell-like source linked to the inner ring, which is also detected in the MSX band A.AnIRAS young stellar object candidate is detected in coincidence with the shell-like IR source. We suggest that the optical nebula and its neutral counterparts originated from the stellar winds from the Wolf-Rayet star and its massive progenitor, and are evolving in the envelope of a slowly expanding shell centred at (l,b) = (102.30, -0°.50) of about 31 pc in radius. The bubble's energy conversion efficiency is in agreement with recent numerical analysis and with observational results.Facultad de Ciencias Astronómicas y Geofísica

An H I interstellar bubble surrounding WR 85 and RCW 118

We analyse the distribution of the interstellar matter in the environs of the Wolf-Rayet star LSS 3982 (= WR 85, WN6+OB?) linked to the optical ring nebula RCW118. Our study is based on neutral hydrogen 21-cm line data belonging to the Southern Galactic Plane Survey (SGPS). The analysis of the H I data allowed the identification of a neutral hydrogen interstellar bubble related to WR85 and the 25-arcmin-diameter ring nebula RCW 118. The H I bubble was detected at a systemic velocity of -21.5 km s-1, corresponding to a kinematical distance of 2.8 ± 1.1 kpc, compatible with the stellar distance. The neutral structure is about 25 arcmin in radius or 21 ± 8 pc, and is expanding at 9 ± 2 km s-1. The associated ionized and neutral masses amount to 3000 M⊙ . The carbon monoxide (CO) emission distribution depicts a region lacking CO coincident in position and velocity with the H I structure. The 9.3-arcmin-diameter inner optical nebula appears to be related to the approaching part of the neutral atomic shell. The H I void and shell are the neutral gas counterparts of the optical bubble and have very probably originated in the action of the strong stellar wind of the central star during the O-type and WR phases on the surrounding interstellar medium. The H I bubble appears to be in the momentum conserving stage.Facultad de Ciencias Astronómicas y GeofísicasInstituto Argentino de Radioastronomí

The radio and infrared counterparts of the ring nebula around HD 211564

We report the detection of the radio and infrared (IR) counterparts of the ring nebula around the WN3(h) star HD 211564 (WR 152), located to the south-west of the H II region Sh2 132. Using radio continuum data from the Canadian Galactic Plane Survey, we identified the radio counterparts of the two concentric rings, of about 9 and 16 arcmin in radius, related to the star. After applying a filling factor f = 0.05-0.12, electron densities and ionized masses are in the range 10-16 cm-3 and 450-700 M⊙ respectively. The analysis of the H I gas emission distribution allowed the identification of 5900 M⊙ of neutral atomic gas with velocities between -52 and -43 km s-1 probably linked to the nebula. The region of the nebula is almost free of molecular gas. Only four small clumps were detected, with a total molecular mass of 790 M⊙. About 310 M⊙ are related to a small IR shell-like source linked to the inner ring, which is also detected in the MSX band A.AnIRAS young stellar object candidate is detected in coincidence with the shell-like IR source. We suggest that the optical nebula and its neutral counterparts originated from the stellar winds from the Wolf-Rayet star and its massive progenitor, and are evolving in the envelope of a slowly expanding shell centred at (l,b) = (102.30, -0°.50) of about 31 pc in radius. The bubble's energy conversion efficiency is in agreement with recent numerical analysis and with observational results.Facultad de Ciencias Astronómicas y Geofísica

Evaluación de la concentración de sapino (Musa balbisiana) en la reducción de la turbidez del agua del río Huallaga, Picota, región San Martín – 2022

El tratamiento de aguas superficiales es una tecnología que ayuda a mejorar la calidad del agua, es por ello que el presente proyecto se utilizó la técnica de fitorremediación utilizando el sapino (Musa balbisiana) en la reducción de los parámetros de Turbidez, Color, Solidos Disueltos Totales, pH y Temperatura, con el objetivo de, determinar la eficiencia de remoción del sapino (Musa balbisiana) de las concentraciones de parámetros fisicoquímicos presentes en el agua del rio Huallaga, la investigación fue aplicada con diseño experimental, se realizó los análisis mediante test de jarras en mezcla rápida (300 rpm/30 seg) y mezcla lenta ( 60 rpm/15 min) utilizando diferentes presentaciones de sapino (harina, solución y extracto) en 3 proporciones (10, 20 y 30), obteniendo como resultado que la muestra testigo de los parámetros sobrepasaban el el estándar de calidad del agua según el DS. N° 004-2017-MINAM- Categoría 1Subcategoria A1, después del tratamiento las concentraciones bajaron de nivel y el más óptimo fue en mezcla lenta con velocidad de 60 rpm/15 min en el T3 con 30 ml de extracto, concluyendo que el sapino fue eficiente en la remoción de turbidez y otros parámetros del agua del rio Huallaga

Ionized gas, molecules and dust in Sh2-132

We analyse the various interstellar components of the H II region Sh2-132. The main stellar source is the double binary system that includes the Wolf–Rayet star WR 153ab. We use radio continuum images at 408 and 1420 MHz, and H I 21-cm line data taken from the Canadian Galactic Plane Survey, molecular observations of the 12CO(1–0) line at 115 GHz from the Five College Radio Astronomy Observatory, and available mid- and far-infrared observations obtained with the MSX and IRAS satellites, respectively. Sh2-132 is composed of two shells showing radio continuum counterparts at both frequencies. The emission is thermal in nature. The estimated rms electron density and ionized mass of the nebula are ne≃ 20 cm−3 and MH II ≃ 1500 M⊙. The distribution of the CO emission shows molecular gas bordering the ionized nebula and interacting with it. The velocities of the molecular gas is in the range −38 to −53 km s−1, similar to the velocity of the ionized gas. The emission at 8.3 μm reveals a ring-like feature of about 15 arcmin that encircles the bright optical regions. This emission is due to the polycyclic aromatic hydrocarbons and marks the location of photodissociation regions. The gas distribution in the environs of Sh2-132 can be explained in a scenario where the massive stars in the region photodissociated, ionized and swept up the dense molecular material from the parental cloud through their strong stellar winds and intense ultraviolet (UV) photon flux.Facultad de Ciencias Astronómicas y Geofísica

Ionized gas, molecules and dust in Sh2-132

We analyse the various interstellar components of the H II region Sh2-132. The main stellar source is the double binary system that includes the Wolf–Rayet star WR 153ab. We use radio continuum images at 408 and 1420 MHz, and H I 21-cm line data taken from the Canadian Galactic Plane Survey, molecular observations of the 12CO(1–0) line at 115 GHz from the Five College Radio Astronomy Observatory, and available mid- and far-infrared observations obtained with the MSX and IRAS satellites, respectively. Sh2-132 is composed of two shells showing radio continuum counterparts at both frequencies. The emission is thermal in nature. The estimated rms electron density and ionized mass of the nebula are ne≃ 20 cm−3 and MH II ≃ 1500 M⊙. The distribution of the CO emission shows molecular gas bordering the ionized nebula and interacting with it. The velocities of the molecular gas is in the range −38 to −53 km s−1, similar to the velocity of the ionized gas. The emission at 8.3 μm reveals a ring-like feature of about 15 arcmin that encircles the bright optical regions. This emission is due to the polycyclic aromatic hydrocarbons and marks the location of photodissociation regions. The gas distribution in the environs of Sh2-132 can be explained in a scenario where the massive stars in the region photodissociated, ionized and swept up the dense molecular material from the parental cloud through their strong stellar winds and intense ultraviolet (UV) photon flux.Facultad de Ciencias Astronómicas y Geofísica

Molecular gas toward G18.8+1.8

Aims. This work aims at investigating the characteristics of the molecular gas associated with the nebula G18.8+1.8, which is linked to the Wolf-Rayet star HD 168206 (WR 113), and its relation to other components of its local interstellar medium. Methods. We carried out molecular observations of the 12CO(J = 1-0) and (J = 2-1) lines with an angular resolution of 44′′ and 22′′ using the SEST telescope. Complementary NANTEN data of the 12CO(1-0) line were also used. The dust emission was analyzed using Spitzer-IRAC images at 8.0 μm, and WISE data at 3.4 μm, 4.6 μm, and 12.0 μm. Results. The SEST data allowed us to identify a molecular component (Cloud 3) that has velocities in the interval from ~+30 to +36 km s -1 and is most probably linked to the nebula. Morphological and kinematical properties suggest that Cloud 3 consists of a wind-blown molecular half-shell, which expands around WR 113. The ratio R2-1/1-0 and excitation temperatures indicate that the molecular gas is being irradiated by strong UV radiation. The location of the inner optical ring in the outer edge of Cloud 3 suggests that the stars SerOB2-1,-2,-3,-63, and-64 are responsables for the ionization of Cloud 3 and the inner ring nebula. A comparison between the spatial distribution of the molecular gas and the PAH emission at 8 μm indicates the existence of a photodissociation region between the ionized and the molecular gas. A search for candidate young stellar objects (YSOs) in the region around G18.8+1.8 based on available 2MASS, MSX, IRAS, and Spitzer-IRAC catalogs resulted in the detection of about sixty sources, some of them projected onto Cloud 3. Two small spots of clustered candidate YSOs are projected near the outer border of Cloud 3, although a triggered stellar formation scenario is doubtful.Facultad de Ciencias Astronómicas y GeofísicasInstituto Argentino de Radioastronomí