A 12CO (J=1-0) study towards the star forming regions RCW 121 and RCW 122

Using NANTEN 12CO (J=1-0) observations (HPBW = 2´.7), we found a molecular cloud associated with the star forming regions RCW 121 and RCW 122. Kinematical properties, large scale distribution, and physical parameters were determined. Both RCW 121 and RCW 122, have very strong IR counterparts. New radiocontinuum  flux determinations indicate that RCW 121 and RCW 122 are thermal in nature.Fil: Duronea, Nicolas Urbano. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaMassive stars: fundamental parameters and circumstellar interactionsCarilóArgentinaFacultad de Ciencias Astronómicas y Geofísica

12CO (J=1-0) images of the surroundings of three galactic Wolf-Rayet stars

We present 12CO (J=1-0) images of the surroundings of three galactic Wolf-Rayet stars. As part of a program aim to study the interaction of massive stars with their enviroments, we have begun a study of the distribution of molecular gas around Wolf-Rayet stars. The carbon monoxide database is combined with both far infrared (MSX and IRAS) and radio continuum observations at 2.4 and 5.0 GHz. A few cavities and arc-shaped structures were found likely to be associated with the Wolf-Rayet stars.Fil: Duronea, Nicolas Urbano. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Arnal, Edmundo Marcelo. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentin

Gas molecular en la nebulosa anillo alrededor de WR 16

Using NANTEN 12CO (J=1→ 0) observations, the distribution of the molecular gas towards the multiple ring nebula sorrounding the star WR 16 has been analysed. Two striking features associated with the star and the nebula, respectively, were identified. One of them, the external one, is interstellar molecular gas which has been wind shaped in an early stage of the star. The internal feature is only noticed in a very small velocity range and has probably a stellar origin. Physical parameters have been calculated and kinematical models have been constructed in order to explain the physical link between these features and the nebula.En este artículo se presenta un estudio del gas molecular llevado a cabo en la nebulosa anillo múltiple alrededor de la estrella WR 16, usando observaciones de la línea (J=1→ 0) del 12CO obtenidas con el radiotelescopio NANTEN. Se encontraron dos estructuras moleculares cuya morfología las asocia a la nebulosa. La estructura más externa podría haberse originado como resultado de la interacción con los vientos de la estrella en una etapa temprana de su evolución. La estructura interna parece estar formada por gas molecular originado en la atmósfera de la estrella en una etapa intermedia de su evolución y sólo es visible en un rango muy peque˜no de velocidad radial. Para estas estructuras, se calcularon algunos parámetros físicos y se construyó un modelo cinemático que podría explicar su morfología y su relación con la estrella y la nebulosa.Fil: Duronea, Nicolas Urbano. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Arnal, Edmundo Marcelo. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentin

The IRAS 08589-4714 star-forming region

We present an analysis of the IRAS 08589-4714 star-forming region. Thisregion harbors candidate young stellar objects identified in the WISEand Herschel images using color index criteria and spectral energydistributions (SEDs). The SEDs of some of the infrared sources and the70 microns radial intensity profile of the brightest source (IRS 1) aremodeled from Herschel fluxes using the one-dimensional radiativetransfer DUSTY code. For these objects, we estimate the envelope masses,sizes, densities, and luminosities which suggest that they are veryyoung, massive and luminous objects at early stages of the formationprocess. Color-color diagrams in the bands of WISE and 2MASS are used toidentify potential young objects in the region. Those identified in thebands of WISE would be contaminated by the emission of PAHs. We use theemission distribution in the infrared at 70 and 160 microns, to estimatethe dust temperature gradient. This suggests that the nearby massivestar-forming region RCW 38, located ~ 10 pc of the IRAS source positionmay be contributing to the photodissociation of the molecular gas and tothe heating of the interstellar dust in the environs of the IRAS source.Fil: Saldaño, Hugo Pablo. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vasquez, Javier. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Gómez, M.. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cappa, Cristina Elisabeth. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Duronea, Nicolas Urbano. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Rubio, M.. Universidad de Chile; Chil

Millimeter and far-IR study of the IRDC SDC 341.232-0.268

We analyze the molecular gas and dust associated with the infrared dark cloud SDC 341.232-0.268 in order to investigate the characteristics and parameters of the gas, determine the evolutionary status of four embedded EGO candidates and establish possible infall or outflow gas motions. We based our study on 12CO(2-1), 13 CO(2-1), and C18O(2-1) data obtained with the APEX telescope, molecular data of high density tracers from the MALT90 survey and IR images from Spitzer, Herschel and ATLASGAL. The study reveals two clumps at -44 km/s towards the IRDC, with  densities of > 10^4 cm-3 , typical of IRDCs, while high density tracers show H2 densities > 10^5 . FIR images reveals the presence of cold dust linked to the molecular clumps and EGOs. A comparison of spectra of the optically thin and optically thick molecular lines towards the EGOs suggests the existence of infall and outflow motions.Fil: Vazzano, María Mercedes. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Cappa, Cristina Elisabeth. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Firpo, Verónica. Universidad de La Serena; ChileFil: Lopez Carballo, C. H.. Universidad de La Serena; ChileFil: Rubio, Mónica. Universidad de Chile; ChileFil: Duronea, Nicolas Urbano. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentin

Multiwavelength study of the G345.5+1.5 region

Context. The star formation process requires the dust and gas present in the Milky Way to self-assemble into dense reservoirs ofneutral material where the new generation of stars will emerge. Star-forming regions are usually studied in the context of Galacticsurveys, but dedicated observations are sometimes needed when the study reaches beyond the survey area.Aims. A better understanding of the star formation process in the Galaxy can be obtained by studying several regions. This allowsincreasing the sample of objects (clumps, cores, and stars) for further statistical works and deeper follow-up studies. Here, we studiedthe G345.5+1.5 region, which is located slightly above the Galactic plane, to understand its star formation properties.Methods. We combined the Large Apex BOlometer CAmera (LABOCA) and 12 CO(4−3) transition line (NANTEN2) observationscomplemented with the Hi-GAL and Spitzer-GLIMPSE surveys to study the star formation toward this region. We used the Clumpfindalgorithm to extract the clumps from the 870 μm and 12 CO(4−3) data. Radio emission at 36 cm was used to estimate the number ofH ii regions and to remove the contamination from the free-free emission at 870 μm. We employed color-color diagrams and spectralenergy distribution (SED) slopes to distinguish between prestellar and protostellar clumps. We studied the boundedness of the clumpsthrough the virial parameter. Finally, we estimated the star formation efficiency (SFE) and star formation rate (SFR) of the region andused the Schmidt-Kennicutt diagram to compare its ability to form stars with other regions of the Galactic plane.Results. Of the 13 radio sources that we found using the MGPS-2 catalog, 7 are found to be associated with H ii regions correspondingto late-B or early-O stars. We found 45 870 μm clumps with diameters between 0.4 and 1.2 pc and masses between 43 M and3923 M , and 107 12 CO clumps with diameters between 0.4 pc and 1.3 pc and masses between 28 M and 9433 M . More than 50%of the clumps are protostellar and bounded and are able to host (massive) star formation. High SFR and SFR density (ΣS FR ) valuesare associated with the region, with an SFE of a few percent.Conclusions. With submillimeter, CO transition, and short-wavelength infrared observations, our study reveals a population of mas-sive stars, protostellar and bound starless clumps, toward G345.5+1.5. This region is therefore actively forming stars, and its locationin the starburst quadrant of the Schmidt-Kennicutt diagram is comparable to other star-forming regions found within the Galacticplane.Fil: Figueira, M.. Aix Marseille Universite; FranciaFil: Lopez Calderon, C.. Joint Alma Observatory; ChileFil: Bronfman, L.. Universidad de Chile. Facultad de Ciencias Físicas y Matemáticas; ChileFil: Zavagno, A.. Aix Marseille Universite; FranciaFil: Hervias Caimapo C.. University of Manchester; Reino UnidoFil: Duronea, Nicolas Urbano. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Åke Nyman, Lars. Joint Alma Observatory; Chil

A submillimeter study of the IR dust bubble S 21 and its environs

Based on the molecular emission in the 12CO(2-1) and 13CO(2-1) lines, and on the continuum emission in the MIR and FIR towards the S 21 IR dust bubble, we analyze the physical characteristics of the gas and dust linked to the nebula and the presence of young stellar objects (YSOs) in its environs. The line emission reveals a clumpy molecular shell, 1.4 pc in radius, encircling S 21. The total molecular mass in the shell amounts to 2900 M⊙ and the original ambient density, 2.1 ×10 3 cm − 3 , indicating that the bubble is evolving in a high density interstellar medium. The image at 24 µm shows warm dust inside the bubble, while the emission in the range 250 to 870 µm reveals cold dust in its outskirts, coincident with the molecular gas. The detection of radio continuum emission indicates that the bubble is a compact Hii region. A search for YSOs using photometric criteria allowed to identify many candidates projected onto the molecular clumps. We analize if the collect and collapse process has triggered a new generation of stars.Basados en la emisión molecular en las líneas 12CO(2-1) y 13CO(2-1), y en la emisión en el continuo en el mediano y lejano infrarrojo hacia la burbuja S 21, analizamos las características físicas del gas y polvo asociado con S 21 y la presencia de objetos estelares jóvenes (YSOs) en su entorno. La emisión molecular revela una cáscara grumosa de 1.4 pc de radio rodeando a S 21. Su masa molecular es de 2900 M⊙ y la densidad ambiental original en la región, 2.1 ×10 3 cm − 3 , lo que indica que la burbuja evoluciona en un medio de alta densidad. La imagen a 24 µ m muestra polvo tibio dentro de la burbuja, mientras que la emisión en el rango 250 a 870 µm revela que hay polvo frío en la vecindad, coincidente con el gas molecular. La detección de emisión en el continuo de radio indica que S 21 es una región Hii compacta. Una búsqueda de YSOs utilizando criterios fotométricos permitió identificar muchos candidatos coincidentes con los grumos moleculares. Se analiza si el proceso de collect and collapse ha dado origen a una nueva generación de estrellas.Fil: Cappa, Cristina Elisabeth. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Duronea, Nicolas Urbano. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Vasquez, Javier. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Rubio, M.. Universidad de Chile. Facultad de Ciencias Fisicas y Matematicas; ChileFil: Firpo, V.. Universidad de la Serena; ChileFil: López Caraballo, C. H.. Universidad Católica de Chile; ChileFil: Borissova, J.. Universidad de Valparaiso; Chil

Interrelations Between Astrochemistry and Galactic Dynamics

This paper presents a review of ideas that interconnect astrochemistry and galactic dynamics. Since these two areas are vast and not recent, each one has already been covered separately by several reviews. After a general historical introduction, and a needed quick review of processes such as stellar nucleosynthesis that gives the base to understand the interstellar formation of simple chemical compounds (e.g., H2, CO, NH3, and H2O), we focus on a number of topics that are at the crossing of the two big areas, dynamics and astrochemistry. Astrochemistry is a flourishing field that intends to study the presence and formation of molecules as well as the influence of them on the structure, evolution, and dynamics of astronomical objects. The progress in the knowledge on the existence of new complex molecules and of their process of formation originates from the observational, experimental, and theoretical areas that compose the field. The interfacing areas include star formation, protoplanetary disks, the role of the spiral arms, and the chemical abundance gradients in the galactic disk. It often happens that the physical conditions in some regions of the interstellar medium are only revealed by means of molecular observations. To organize a rough classification of chemical evolution processes, we discuss about how astrochemistry can act in three different contexts, namely, the chemistry of the early universe, including external galaxies, star-forming regions, and asymptotic giant branch (AGB) stars and circumstellar envelopes. We mention that our research is stimulated by plans for instruments and projects, such as the ongoing Large Latin American Millimeter Array (LLAMA), which consists in the construction of a 12 m sub-mm radio telescope in the Andes. Thus, modern and new facilities can play a key role in new discoveries not only in astrochemistry but also in radio astronomy and related areas. Furthermore, the research on the origin of life is also a stimulating perspective

Isocyanic acid (HNCO) in the Hot Molecular Core G331.512-0.103: Observations and Chemical Modelling

The authors thank the anonymous referee for the useful comments that improved the article. CMC acknowledges the support of CNPq, Conselho Nacional de Desenvolvimento Científico e Tecnológico – Brazil, process number 41714/2016-6. This study was financed in part by the Coordenaçao de Aperfeiçoamento de Pessoal de Níıvel Su- perior – Brasil (CAPES) – Finance Code 001. LB acknowledges support from CONICYT (Comisión Nacional de Investigació Científica y Tecnolóogica) project Basal AFB-170002. EM acknowledges sup- port from the Brazilian agencies FAPESP (Fundaçao de Amparo à Pesquisa do Estado de São Paulo, grant 2014/22095-6) and CNPq (grant 150465/2019-0). MC acknowledges the financial support from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no 872081; from the Spanish National Research, Development, and Innovation plan (RDI plan) under the project PID2019-104002GB-C21; the Consejería de Conocimiento, Investigación y Universidad, Junta de Andalucía and European Regional Development Fund (ERDF), ref. SOMM17/6105/UGR; the Ministerio de Ciencia, Innovación y Universidades (ref. COOPB20364); and by the Centro de Estudios Avanzados en Física, Matemáticas y Computación (CEAFMC) of the University of Huelva

G331.512-0.103:An Interstellar Laboratory for Molecular Synthesis. I. the Ortho-to-para Ratios for CH₃OH and CH₃CN

Spectral line surveys reveal rich molecular reservoirs in G331.512-0.103, a compact radio source in the center of an energetic molecular outflow. In this first work, we analyse the physical conditions of the source by means of CH$_3$OH and CH$_3$CN. The observations were performed with the APEX telescope. Six different system configurations were defined to cover most of the band within (292-356) GHz; as a consequence we detected a forest of lines towards the central core. A total of 70 lines of $A/E$-CH$_3$OH and $A/E$-CH$_3$CN were analysed, including torsionally excited transitions of CH$_3$OH ($\nu_t$=1). In a search for all the isotopologues, we identified transitions of $^{13}$CH$_3$OH. The physical conditions were derived considering collisional and radiative processes. We found common temperatures for each $A$ and $E$ symmetry of CH$_3$OH and CH$_3$CN; the derived column densities indicate an $A/E$ equilibrated ratio for both tracers. The results reveal that CH$_3$CN and CH$_3$OH trace a hot and cold component with $T_k \sim$ 141 K and $T_k \sim$ 74 K, respectively. In agreement with previous ALMA observations, the models show that the emission region is compact ($\lesssim$ 5.5 arcsec) with gas density $n$(H$_2$)=(0.7-1) $\times$ 10$^7$ cm$^{-3}$. The CH$_3$OH/CH$_3$CN abundance ratio and the evidences for pre-biotic and complex organic molecules suggest a rich and active chemistry towards G331.512-0.103.Comment: 15 pages, 7 figures, 7 tables. Accepted for publication in The Astrophysical Journa