Por iniciativa del Instituto de Astronomía y Física del Espacio - IAFE (CONICET-UBA, Argentina), en 2021 estamos iniciando una serie de reuniones mensuales para presentar y discutir proyectos científicos relacionados con Large Latin American Millimeter Array (LLAMA). El propósito de los encuentros será familiarizar a las comunidades astronómicas de Argentina y Brasil con todo el potencial de LLAMA, con el fin de incentivar la articulación de proyectos científicos para el nuevo radio observatorio.

El Ciclo de Seminarios LLAMA-IAFE tendrá lugar los primeros viernes de cada mes, de 10 a 12 hs (GMT-3), en formato virtual. Cada encuentro consistirá de tres charlas invitadas (la primera de 40 minutos de duración y las otras dos de 20 minutos cada una) e intervalos para discusiones.

Los invitamos a todos al proximo seminario, que tendrá lugar el 3 de diciembre de 2021. 

La participación online en los seminarios se realizará a través de la plataforma Zoom. Posteriormente, las presentaciones se ponen a disposición en el canal de LLAMA en YouTube

Comisión Organizadora: Silvina Cichowolski (IAFE) - scicho@iafe.uba.ar; Germán Cristiani (IAFE); Nicolás Duronea (IALP); Laura Suad (IAFE) y Carlos Valotto (IATE).

Programa


3 de diciembre de 2021

  • Para unirse al encuentro:  

      Join Zoom Meeting: https://us02web.zoom.us/j/88141490114?pwd=b0k4K01JM1VHbzM2aTFuZDFpNHdhUT09

      Meeting ID: 881 4149 0114 

      Passcode: 639515


10:00 hs Paul Ho  (EAO; ASIAA) 

Growth of Submillimeter Wavelength Astronomy in Taiwan  

Abstract: The development of radio astronomy in Taiwan began almost thirty years ago, with the establishment of the Institute of Astronomy and Astrophysics within the Academia Sinica. We started our training of students with BIMA, and then joined the construction of the SMA as the first major radio project. This was followed by the construction of AMiBA, and the partnership with ALMA, the partnership with EAO on operating the JCMT, and finally the deployment of the GLT to Greenland. We focused on submillimeter wavelength astronomy because it was the last frontier for radio astronomy on the high frequency end, where the advantages of strong dust emission and an abundance of spectral lines made for possibilities of discovery. At the end of the 20th century, radio techniques focused on interferometry in order to achieve very high angular resolution, culminating in the EHT studies which involved SMA, JCMT, ALMA, and GLT. In the 21st century, single dish radio astronomy has become important once again because of wide field imaging capabilities as provided by cameras such as the SCUBA2 on JCMT. In this talk, we look at the choices which we made in Taiwan in order to develop modern astronomy there.


11:00 hs Caius L. Selhorst (NAT - Núcleo de Astrofísica, UNICID, Brasil)  

The solar radio behaviour through the cycles 

Abstract: In this work we review some solar cycle characteristics observed at radio wavelengths, such as, limb brightening and radius. Whereas the variation of the solar radius at radio frequencies indicates the heating of the solar atmosphere due to solar activity, the limb brightening intensity depends on the organization of the polar magnetic field of the Sun, including the global dipole and the features formed around it. The observations used in these analyses were mainly obtained at 17 GHz by the Nobeyama Radioheliograph (NoRH) and at 212 and 405 GHz by the Solar Submillimeter-wave Telescope (SST).


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5 de noviembre de 2021


10:00 hs Mattheus (Thijs) de Graauw  (ESO, Chile) 

Conducting Astronomy Projects: Experiences and Recommendations  

Abstract: Jacques Lepine asked me to give a seminar in the LLAMA-IAFE series. He wrote: “You have a large experience as a leader of important international projects, and you could tell us some of the most interesting stories, or differences in the management in different projects, and maybe some management recommendations for us”. Initially I was very hesitant. Although I had a very exciting professional life , the associated stories may not be so interesting as I always tried to keep things simple. At the end I concluded that it is this approach that I should share with you. I will address: - As an introduction, what are the main components and characteristics of an astronomy/space project, in general, and their role for the success of a project. - Identifying “structural dynamics” in a project, I should share with analysis. - With a few examples show how projects have changed over the past 50 years and still will change. How to cope with changes? What about lessons learned? - How the life of a project, (subproject, task) can be caught in a few words, generic activities, and their message/meaning; including the impact of the size and scope of a project. - The requirements and demands there are on the leaders of the projects; are there some necessary personality traits? - A list of (soft) disciplines that need active development for project leaders and managers.


11:00 hs Sergio Parón (Instituto de Astronomía y Física del Espacio - IAFE, Buenos Aires, Argentina)  

LLAMA: un nexo instrumental para la comunidad astronómica 

Resumen: El telescopio LLAMA será un instrumento de punta al que nuestra comunidad astronómica tendrá acceso. Desde su inicio debe quedar claro que no es un instrumento exclusivo para radioastrónomo/as, sino que es para todo/a científico/a que trabaje en diversas áreas de la astronomía y con distintas longitudes de onda. En esta charla, en base a algunos trabajos de mi área de investigación, pretendo mostrar cómo los estudios multi-espectrales, en los cuales LLAMA podrá tener un rol importante, pueden vincularnos y generar colaboraciones fructíferas y nexos entre distintas áreas. Sin ser una charla que apunte a presentar estrictamente resultados científicos, muestro algunos de ellos referidos al estudio del medio interestelar y a la formación estelar, en la gran y pequeña escala espacial, en el contexto anteriormente mencionado. Finalmente propongo algunas ideas para establecer vínculos y contactos dentro de la comunidad astronómica respecto al futuro uso de LLAMA.


11:30 hs Juan Pablo Paz (MinCyT) & Alejandro Flores (INVAP) 

Presentación del convenio firmado entre el MinCyT e INVAP para la instalación de la antena


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1 de octubre de 2021


10:00 hs Jens Kauffmann (Haystack Observatory, Massachusetts Institute of Technology, MA, USA)

Wide-Field Imaging of Molecular Clouds with Mid-Sized Telescopes  

Abstract: Star formation is the key process that shapes the baryonic matter that populates the galaxies in the visible universe. This process delivers stars over cosmic time, it controls the metallicity of these stars and their planets, and it molds the clouds of gas and dust in galaxies. Research into star formation thus plays a key role in studies of the nearby and distant universe. It is therefore surprising to see that studies of the star formation process continue to be dramatically limited in several key ways. Particularly surprising is the lack of wide-field maps of molecular clouds in diverse sets of molecular emission lines: rich data sets exist for the 12CO (1–0) and 13CO (1–0) transition, but no other millimeter-wave emission line has ever been imaged comprehensively in galactic molecular clouds. This is highly problematic, since emission from species like HCN and CS is routinely used to interpret the star formation activity in nearby and distant galaxies. The lack of "calibration data" from the Milky Way for such emission lines render the interpretation of key trends in extragalactic star formation research, such as the Gao & Solomon relation, highly unclear. Ambitious wide-field mapping projects that simultaneously image rich sets of molecular emission lines can deliver this critical missing information. Mid-sized telescopes, with diameters of order 15m, are ideally suited to deliver such data: they can image large areas fast, given their relatively large beam, while their angular resolution is at the same time high enough to reveal cloud substructure. I present results from the LEGO Large Program on the IRAM 30m-telescope, which conducts research in this area. I also use the LEGO data to outline the discovery potential of wide–field surveys with mid-sized dishes.


11:00 hs Hugo Saldaño (Universidad Nacional de Córdoba, Observatorio Astronómico de Córdoba)  

El Medio interestelar en Galaxias de baja metalicidad 

Resumen: Buena parte del conocimiento sobre la dinámica del medio interestelar (ISM) en nuestra galaxia se debe a observaciones de líneas espectrales de moléculas, como el monóxido de carbono (CO), el mejor trazador del hidrógeno molecular en regiones de bajas temperaturas (~ 10 - 30 K) y densidades (~ 10^2-3 cm^-3). Sin embargo, en galaxias donde las condiciones físicas del ISM son mucho más extremas que las de la Vía Láctea (e.g., baja metalicidad, altos niveles de radiación UV, etc.) la abundancia molecular es extremadamente baja, dificultando el análisis del ISM en gran detalle. Para poder estudiar estos tipos de galaxias, se requiere grandes telescopios de alta sensibilidad y resolución espacial, como APEX, ALMA y en un futuro cercano LLAMA. En la presente charla, muestro los resultados de observaciones del CO en galaxias de metalicidades extremadamente bajas como la Nube Menor de Magallanes, el Puente Magallánico y WLM, obtenidos con APEX y ALMA. Además, presento los importantes avances que se lograrían con LLAMA en estos tipos de galaxias.


11:30 hs Thiago Signorini Gonçalves (Observatório do Valongo, UFRJ) 

The physical conditions of molecular gas in low and high-redshift galaxies 

Abstract: In this talk I will present ongoing research on the conditions of molecular gas in galaxies. I will focus especially on low-metallicity galaxies, where the low dust content modifies UV radiation across the cloud and can alter the abundances of tracer molecules. This includes dwarf galaxies and more typical star-forming galaxies at earlier epochs, when the mass-metallicity relation was distinct. I will show some results from my own research with ALMA, and discuss how LLAMA might be able to contribute to these projects.


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3 de septiembre de 2021


10:00 hs Danilo Zanella (IAG/USP, Brasil) & Guillermo Giménez de Castro (Mackenzie, Brasil) 

El ALMA de LLAMA: a look inside the system that gives life to a radiotelescope  

Abstract: Telescopes are robust mechanical and electronic assemblies of hardware that make a 30 ton beast move like a ballerina to delicately track a star in the sky. Behind the scenes, blind to most of the people, there is a logical structure of interconnected statements in which, like in a spider web, every single thread is the support and is supported by the others: the software. In this talk we will try to expose the complexity of the LLAMA software (LLAMAS), our approach to make the observatory functionalities as transparent as possible for an astronomer. We'll show the groundwork, how the development process (ideally) goes and some aspects of our collaboration with other observatories. Moreover, we will show that the talk title is more than a wordplay.


11:00 hs Felipe Navarete (IAG/USP, Brasil)  

Molecular outflows driven by massive clumps in the inner Galaxy: linking (sub)millimeter and infrared observations 

Abstract: I will present the characterization of the large-scale CO outflow content in a sample of 99 clumps selected from the ATLASGAL survey (TOP100) harboring high-mass protostars at different pre-main sequence evolutionary stages (from quiescent clumps to HII regions). CO (6-5) maps (691.473 GHz, Band-9) of the TOP100 clumps were obtained with the CHAMP+ heterodyne receiver at the 12-m APEX antenna (Chile), a ground-based observatory very similar to the LLAMA telescope. The results show that the outflow activity starts at the youngest phases of the high-mass star-forming process, and the detection rate increases as a function of time (from quiescent clumps towards HII regions). A larger fraction of multipolar outflows is observed towards HII regions, suggesting that multiple active protostars are found within those dense clumps. Finally, I will show the preliminary results of a follow-up study designed to investigate the near-IR emission (at 2.12 micron) of the TOP100 clumps at sub-arcsecond resolutions using the 4-m SOAR telescope (Chile). These maps will allow us to investigate the link between sub-mm outflows and the shocked H2 emission in the IR, and also to identify the driving sources of these extended structures.


11:30 hs Carlos Escudero (UNLP, Argentina) 

Grupo de Investigación en Sistemas Estelares Extragalácticos y su Contexto Cosmológico 

Resumen: Las propiedades que presentan las galaxias que observamos hoy en día tienen su origen tanto en el accionar de diversos fenómenos y procesos físicos que actuaron durante las primeras etapas de la vida de nuestro Universo, así como también a lo largo de la historia evolutiva de las mismas. En cualquier caso, el aspecto clave es que varios de estos fenómenos han dejado su huella digital en los objetos que observamos en el Universo local. En ese sentido, los cúmulos globulares, los cuales se encuentran en todos los tipos de galaxias, resultan una herramienta importante para trazar y reconstruir la historia evolutiva de las galaxias anfitrionas. En esta charla mostraremos los resultados obtenidos al analizar las galaxias NGC1316 y NGC4382 a través de estos importantes trazadores, y como LLAMA puede ayudar a complementar dicho análisis.


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6 de agosto de 2021


10:00 hs Lars-Ake Nyman (ESO, Chile) 

My experience in installation, commissioning and operations of radio telescopes at high altitude   

Abstract: I will present my experience in installing and operating telescopes at high altitudes. This is mainly based on my work at APEX, where I was the Station Manager during installation, commissioning and first operations.


11:00 hs Pedro Paulo B. Beaklini (NRAO, USA)  

Monitoring blazar variability at radio (sub)millimeter wavelengths  

Abstract: Blazars are high luminosity AGNs presenting relativistic jets seen at small angles to the line of sight. They are also characterized by variability across the entire electromagnetic spectrum, and the emission is boosted due to relativistic effects. In this talk, I will present observations carried out at 43 GHz (7 mm) for the blazars 3C 273, 3C 279, and PKS 1510-089 using the Pierre Kaufmann Radio Observatory (former Itapetinga, Atibaia, Brazil). First, I will report the variability monitoring results of these sources and how they correlate with other wavelengths, like optical and gamma-ray. Following the mm results, I will show a high-frequency follow-up of the blazar monitoring program to use the LLAMA (Large Latin America Millimeter Array). There are a few data of submillimeter variability information in the literature, most of them obtained during the SEST era (Swedish-ESO Submillimetre Telescope), and LLAMA will provide crucial information to understand about blazar physics.


11:30 hs Isabel Aleman (UNIFEI, Brasil) 

Molecules in Planetary Nebula: LLAMA and the Chemistry in Harsh Environments  

Abstract: Planetary nebulae are excellent “laboratories” for the study of many topics, such as stellar evolution, mass loss, cosmic abundances, the life cycle of gas and dust in a galaxy, and Astrochemistry. Recent observations made with Herschel, Spitzer, and other instruments revealed that PNe have a rich and still not well understood chemistry. With the eminent opening of Large Latin American Millimeter Array’s (LLAMA) eyes to the sky, we have an excellent opportunity. Observations of molecules in the submillimeter spectral range, where many molecules emit lines, offer a particularly interesting and still not very explored tool for the study of astrophysics and astrochemistry in PNe. In this talk, I will discuss how LLAMA may have an important role in such studies.


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2 de julio de 2021


10:00 hs Jacques Lepine (IAG, Universidade de São Paulo, Brasil) 

El estado actual del proyecto LLAMA

Resumen: Después de atravesar una crisis financiera y organizativa en los últimos años, LLAMA se encuentra ahora en una fase en la que avanza y en que estamos logrando visualizar el futuro con mayor claridad. Esto se debe a la decisión del Ministerio de Ciencia y Tecnología de asignar la responsabilidad de llevar el proyecto hasta la "primera luz" a una empresa de alta calificación técnica y organizativa, INVAP, y en paralelo porque la comunidad radioastronómica argentina está más organizada y también hay una mejor integración de planes de instrumentación entre los dos países. Los temas que se abordarán son: 1) el estado del proyecto con respecto al mundo externo, con su ubicación y características tecnológicas, que hacen que LLAMA sea competitivo; 2) el avance de los subproyectos en curso y el programa de ejecución probable (informática, receptores, back-end). Podremos hacer ciencia en 2023? 3) tendencias actuales en radioastronomía milimétrica,y nuestras posibilidades de cooperación/competición.

11:00 hs Felipe Alves (MPE, Alemania)  

El inicio del colapso en un núcleo pre-estelar magnetizado  

Resumen: Los núcleos pre-estelares son objetos densos que están ligados gravitacionalmente. La contracción en núcleos pre-estelares ocurre cuando su energía gravitacional domina por sobre la presión térmica del gas, haciéndolos inestables hidrostáticamente. Sin embargo, los campos magnéticos representan una fuente de soporte adicional contra la fuerza gravitacional. Por esta razón, se utilizan mecanismos de disipación magnética, tales como la difusión ambipolar, en simulaciones magneto-hidrodinámicas para permitir el colapso del núcleo y la formación de una protoestrella. En esta charla, hablaré sobre cómo se usan observaciones de líneas moleculares espectrales para evaluar el rol de los campos magnéticos durante los estados iniciales de evolución protoestelar. Con las moléculas adecuadas, podemos estudiar cómo la cinemática del núcleo responde a la magnetización. Discutiré como las observaciones se comparan con simulaciones de MHD no-ideal y ayudan a ajustar modelos de formación estelar regulada por campos magnéticos. 

11:30 hs Octavio Guilera (IALP, La Plata) & Amelia Bayo (Instituto de Física y Astronomía, Universidad de Valparaíso, Chile ) 

LLAMA, discos que forman planetas y planetas aislados 

Resumen: El observatorio LLAMA contará con un radiotelescopio de 12 m ubicado a unos 4,800 metros sobre el nivel del mar. El mismo operará en el rango de frecuencia de 35-950 GHz (longitudes de onda milimétricas y submilimétricas). Una variedad de estudios astrofísicos pueden llevarse a cabo con un instrumento de esta características. En esta charla intentaremos vincular posibles fuentes astrofísicas de interés a ser estudiadas con LLAMA que permitan vincular los datos observaciones con los modelos de formación planetaria desarrollados entre el Grupo de Astrofísica Planetaria de La Plata y el Núcleo Milenio de Formación Planetaria de Chile. Más que certezas, plantearemos preguntas a la comunidad de LLAMA para lograr generar una interrelación entre los estudios teóricos y los observacionales relacionados con los discos protoplanetarios y la formación de planetas tanto en torno a estrellas como aislados. .

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4 de junio de 2021


10:00 hs  Félix Mirabel (IAFE, Buenos Aires, Argentina) 

The origin of project LLAMA 

Abstract: I have been asked to talk on the origin of project LLAMA (Large Latin American Millimeter Array). By personal initiative in 1984 I make the first exploration in the Puna of Salta, Jujuy and Catamarca for the installation of the European project LSA (Large Submillimetre Array). Sites in Macon and near San Antonio de los Cobres among others are identified in the province of Salta. In the 1990’s LSA merged with the Nord American project MMA (Milli-meter Array) in the global project ALMA (Atacama Large Millimeter Array) to be installed in Chajnantor, Chile. In the period 2004-2009, being Representative and Director of the Office of Science of the European Southern Observatories (ESO) in Chile, I propose to the director of ALMA, the head of MinCyT (Ministry of Science & Technology of Argentina), Jacques Lepine and Zulema Abraham (University of Sao Paulo) project LLAMA. In 2014 it is signed an agreement between MinCyT and FAPESP for the construction and operation of LLAMA. A personal view on this subject can be found (in spanish) in pages 67-69 of the following link: https://aargentinapciencias.org/wp-content/uploads/2021/03/03-RESENA-Mirabel-CeIResenasT9N1-2021indd.pdf.

11:00 hs  Zulema Abraham (IAG, Universidade de São Paulo, Brasil)  

Eta Carinae : a perfect target for LLAMA

Abstract: Eta Carinae is one of the most massive stars of our Galaxy. It is an evolved star that presented several episodes of mass ejection, one of them occurred in 1840 and formed what is now known as the Homunculus Nebula. Eta Carinae is part of a binary system, in which the collision between the strong stellar winds heats the gas that emits in X-rays. The UV radiation of the stars ionizes the circumstellar matter, producing radiation from the UV to radio frequencies. At mm and sub-millimeter wavelengths, strong continuum and H recombination lines have been observed since 1995, but the actual source was only resolved by ALMA in 2017. I will present the results of these ALMA observations and show the importance of LLAMA for the follow up of the continuum and recombination lines at different frequencies to understand its variability with the orbital phase of the binary system.

11:30 hs  Lydia Cidale (FCAGLP, La Plata, Argentina)  

Dust and gaseous environments around massive stars

Abstract: Evolved massive stars undergo phases of strong mass-loss, often resulting in the formation of shells, disks or rings of circumstellar material. The expelled material can lead to molecule and dust condensation. Studies of the atomic and molecular gas reveal a complex kinematics and geometry. We describe here different techniques to analyze and interpret the physical conditions around hot emission-line stars.


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