Workplans: workshop on planetary nebula observations

This workshop is the second of the WORKPLANS series, which we started in 2016. The main goal of WORKPLANS is to build up a network of planetary nebulae (PNe) experts to address the main open questions in the field of PNe research. The specific aims of the WORKPLANS workshop series are (i) to discuss and prioritize the most important topics to be investigated by the PN community in the following years; (ii) to establish a network of excellent researchers with complementary expertise; (iii) to formulate ambitious observing proposals for the most advanced telescopes and instrumentation presently available (ALMA, SOFIA, VLT, GTC, HST, etc.), addressing those topics; and (iv) to develop strategies for major proposals to future observatories (JWST, ELT, SPICA, Athena, etc.). To achieve these goals, WORKPLANS II brought together experts in all key sub-areas of the PNe research field, namely: analysis and interpretation of PNe observational data; theoretical modeling of gas and dust emission; evolution from Asymptotic Giant Branch stars (PNe progenitors) to PNe; and the instrumentation and technical characteristics of the relevant observatoriesI.A. acknowledges the support of Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES)—Finance Code 001. This research is supported by Space Telescope Science Institute grant HST-GO-15953.001-A to RIT (J.K.). T.U. was supported by NASA under grant NNX15AF24G issued through the Science Mission Directorate. E.V. acknowledges support from the “On the rocks II project” funded by the Spanish Ministerio de Ciencia, Innovación y Universidades under grant PGC2018-101950-B-I00. The Workshop was organized with the financial support of the Lorentz Center, which was provided by the Netherlands Organization for Scientific Research (NWO) and the Leiden Universit

The Herschel Planetary Nebula Survey (HerPlaNS) - a comprehensive dusty photoionization model of NGC6781

We perform a comprehensive analysis of the planetary nebula (PN) NGC6781 to investigate the physical conditions of each of its ionized, atomic, and molecular gas and dust components and the object's evolution, based on panchromatic observational data ranging from UV to radio. Empirical nebular elemental abundances, compared with theoretical predictions via nucleosynthesis models of asymptotic giant branch (AGB) stars, indicate that the progenitor is a solar-metallicity, 2.25-3.0 Msun initial-mass star. We derive the best-fit distance of 0.46 kpc by fitting the stellar luminosity (as a function of the distance and effective temperature of the central star) with the adopted post-AGB evolutionary tracks. Our excitation energy diagram analysis indicate high excitation temperatures in the photodissociation region (PDR) beyond the ionized part of the nebula, suggesting extra heating by shock interactions between the slow AGB wind and the fast PN wind. Through iterative fitting using the Cloudy code with empirically-derived constraints, we find the best-fit dusty photoionization model of the object that would inclusively reproduce all of the adopted panchromatic observational data. The estimated total gas mass (0.41 Msun) corresponds to the mass ejected during the last AGB thermal pulse event predicted for a 2.5 Msun initial-mass star. A significant fraction of the total mass (about 70 percent) is found to exist in the PDR, demonstrating the critical importance of the PDR in PNe that are generally recognized as the hallmark of ionized/H+ regions.Comment: 34 pages, 13 Figures and 16 Tables, accepted for publication in the Astrophysical Journal Supplement Serie

Capacitación tributaria y su efecto en la determinación del impuesto a la renta de cuarta categoría a las directoras de la Empresa Representaciones CARYSUN E.I.R.L., Sullana 2020

La presente investigación tuvo como objetivo determinar el efecto de la capacitación tributaria en la determinación del Impuesto a la Renta de cuarta categoría de las directoras de la empresa Representaciones Carysun E.I.R.L. La metodología desarrollada es aplicativa correlacional, teniendo como muestra a 20 personas, se empleó para la recolección de datos como instrumento a la encuesta. Se planteó como hipótesis que la capacitación tributaria genera un efecto positivo en la determinación del impuesto a la renta de cuarta categoría en las directoras de la empresa Representaciones Carysun E.I.R.L. Los resultados obtenidos a través de la Prueba U de Mann-Whitney, revelaron que antes de la aplicación de la capacitación tributaria a las directoras, en la tabla 15, el nivel de probabilidad fue de 0,912 siendo superior al nivel de probabilidad de 0.05, por ende se determina que la capacitación tributaria no genera un efecto positivo en la determinación del impuesto a la renta de cuarta categoría, mientras que el post test se obtuvo una probabilidad de 0.007 siendo menor a la probabilidad de 0.05 por lo tanto se determina que las directoras obtuvieron un alto nivel de aprendizaje. Por ello se concluye que es importante que toda persona, que comience a realizar una actividad económica, entre a un proceso de capacitación tributaria continua que vaya de acuerdo a sus necesidades.The objective of this research was to determine the effect of tax training in the determination of the fourth category income tax of the directors of the company Representaciones Carysun E.I.R.L. The methodology developed is correlational applicative, having as a sample 20 people, it was used for data collection as a survey instrument. It was hypothesized that tax training generates a positive effect in the determination of the fourth category income tax in the directors of the company Representaciones Carysun E.I.R.L. The results obtained through the Mann-Whitney U Test, revealed that before the application of the tax training to the directors, in table 15, the probability level was 0.912, being higher than the probability level of 0.05, by Thus, it is determined that the tax training does not generate a positive effect in the determination of the fourth category income tax, while the post-test obtained a probability of 0.007 being less than the probability of 0.05, therefore it is determined that the directors they obtained a high level of learning. Therefore, it is concluded that it is important that every person, who begins to carry out an economic activity, enters a process of continuous tax training that is according to their needs.Tesi

Análisis de la Sección 28 de las NIIF para las PYMES “Beneficios a Empleados” en la contabilidad de la Empresa ARCONSA S.A. en el año 2020

La presente investigación “Análisis de la sección 28 de NIIF para las PYMES, beneficios a empleados” se enfoca en analizar la importancia de dicha norma y conocer los beneficios a empleados que la empresa ARCONSA S. A ofrece a su personal de trabajo y el impacto que tienen estos en la contabilidad así mismo presentar dichos beneficios, es por ello que el objetivo principal es Analizar la sección 28 “Beneficios a empleados” de NIIF para las PYMES en la contabilidad de la empresa ARCONSA S.A en el año 2020. Para poder desarrollarla nos hemos basado en información contenida en las Normas de Información Financiera para Pequeñas y Medianas Empresas (NIIF para las PYMES), realizando un estudio más profundo en lo relacionado con los beneficios a los empleados, además de la información contable que se fue revisando, analizando y poniendo en práctica las disposiciones legales que rigen al sector laboral de nuestro país. Se realizo un análisis a la entidad ARCONSA S. A entidad dedicada al ramo de la construcción de obras, diseño, consultoría e interventoría; teniendo una excelente referencia en el mercado por la diversidad y calidad de sus servicios. Con este trabajo se cumple el objetivo de analizar la aplicación la sección 28 de NIIF para las PYMES, se verifica el registro de los beneficios. En el caso se expone la manera que la empresa objeto de estudio presenta los estados financieros y precisamente los beneficios a los empleados. Al final se presentan las conclusiones a las que llegamos luego de terminar nuestro trabajo, las cuales pretenden ayudar a la empresa a obtener otra visión sobre la NIIF para pyme para una mejor toma de decisiones, y de igual forma se presenta una serie de citas bibliográficas a las cuales hemos recurrido para obtener más información. Palabras claves: Beneficios a los empleados, Pequeñas y medianas empresas, NII

Mapping NGC 7027 in New Light: CO+^+ and HCO+^+ Emission Reveal Its Photon- and X-ray-Dominated Regions

The young and well-studied planetary nebula NGC 7027 harbors significant molecular gas that is irradiated by luminous, point-like UV (central star) and diffuse (shocked nebular) X-ray emission. This nebula represents an excellent subject to investigate the molecular chemistry and physical conditions within photon- and X-ray-dominated regions (PDRs and XDRs). As yet, the exact formation routes of CO$^+$ and HCO$^+$ in PN environments remain uncertain. Here, we present $\sim$2$"$ resolution maps of NGC 7027 in the irradiation tracers CO$^+$ and HCO$^+$, obtained with the IRAM NOEMA interferometer, along with SMA CO and HST 2.12~$\mu$m H$_2$ data for context. The CO$^+$ map constitutes the first interferometric map of this molecular ion in any PN. Comparison of CO$^+$ and HCO$^+$ maps reveal strikingly different emission morphologies, as well as a systematic spatial displacement between the two molecules; the regions of brightest HCO$^+$, found along the central waist of the nebula, are radially offset by $\sim$1$"$ ($\sim$900 au) outside the corresponding CO$^+$ emission peaks. The CO$^+$ emission furthermore precisely traces the inner boundaries of the nebula's PDR (as delineated by near-IR H$_2$ emission), suggesting that central star UV emission drives CO$^+$ formation. The displacement of HCO$^+$ radially outward with respect to CO$^+$ is indicative that dust-penetrating soft X-rays are responsible for enhancing the HCO$^+$ abundance in the surrounding molecular envelope, forming an XDR. These interferometric CO$^+$ and HCO$^+$ observations of NGC 7027 thus clearly establish the spatial distinction between the PDR and XDR formed (respectively) by intense UV and X-ray irradiation of molecular gas.Comment: 15 pages, 7 figures, 1 tabl

Modelling the Warm H2 Infrared Emission of the Helix Nebula Cometary Knots

Molecular hydrogen emission is commonly observed in planetary nebulae. Images taken in infrared H2 emission lines show that at least part of the molecular emission is produced inside the ionised region. In the best-studied case, the Helix nebula, the H2 emission is produced inside cometary knots (CKs), comet-shaped structures believed to be clumps of dense neutral gas embedded within the ionised gas. Most of the H2 emission of the CKs seems to be produced in a thin layer between the ionised diffuse gas and the neutral material of the knot, in a mini photodissociation region (PDR). However, PDR models published so far cannot fully explain all the characteristics of the H2 emission of the CKs. In this work, we use the photoionisation code \textsc{Aangaba} to study the H2 emission of the CKs, particularly that produced in the interface H^+/H^0 of the knot, where a significant fraction of the H2 1-0S(1) emission seems to be produced. Our results show that the production of molecular hydrogen in such a region may explain several characteristics of the observed emission, particularly the high excitation temperature of the H2 infrared lines. We find that the temperature derived from H2 observations even of a single knot, will depend very strongly on the observed transitions, with much higher temperatures derived from excited levels. We also proposed that the separation between the H_alpha and NII peak emission observed in the images of CKs may be an effect of the distance of the knot from the star, since for knots farther from the central star the NII line is produced closer to the border of the CK than H_alpha.Comment: Accepted by MNRAS. The paper contains 12 pages, 9 figures, and 3 table

Molecular Hydrogen in the Ionized Region of Planetary Nebulae

This paper presents an analysis of the concentration of the hydrogen molecule inside the ionized region of planetary nebulae. The equations corresponding to the ionization and chemical equilibria of H, H+, H-, H2, H2+, and H3+ are coupled with the equations of ionization and thermal balance for a photoionized atomic gas. Forty different reactions related to the formation or the destruction of these species are included. The presence of dust is taken into account, since grains act as catalysts for the production of H2, as well as shield the molecules against the stellar ionizing radiation. We analyze the effect of the stellar ionizing continuum, as well as of the gas and grain properties on the calculated H2 mass. It is shown that a significant concentration of H2 can survive inside the ionized region of planetary nebulae, mostly in the inner region of the recombination zone. The total H2 to total hydrogen mass ratio inside the ionized region increases with the central star temperature, and, depending on the PN physical conditions, it can be of the order of 10^-6 or even higher. The increase of the recombination zone with the stellar temperature can account for such correlation. This can explain why the H2 emission is more frequently observed in bipolar planetary nebulae (Gatley's rule), since this kind of object has typically hotter stars. Applying our results for the planetary nebula NGC 6720, we obtain an H2 to hydrogen mass ratio similar to the value obtained from the observed H2 line emission.Comment: 13 pages, 4 figures. Accepted for publication in Ap