Imprimir

Cover

New eyes on the Universe

Telescopes will study dark matter, dark energy, and gamma rays and map the cosmos in 3D

With installation planned for 2016 in Argentina, the 12 m LLAMA antenna will be similar to that of APEX (above), already operating in Chile

ESO/B. TafreshiWith installation planned for 2016 in Argentina, the 12 m LLAMA antenna will be similar to that of APEX (above), already operating in ChileESO/B. Tafreshi

At 4,800 meters above sea level, located in the Argentine region called Puna de Atacama, a sort of extension of the arid landscape of the eastern Chilean Atacama desert, beginning in April 2016 the Alto Chorrillo site will contain a 12 m diameter radio telescope known as LLAMA (Large Latin-American Millimeter Array). Designed and implemented through a partnership between astrophysicists in the state of São Paulo and Argentina, the modern antenna is expected to begin operation, and produce scientific research, in early 2017. In general terms, the agreement established that the São Paulo researchers would buy the radio telescope (with $9.2 million provided by FAPESP) and the Argentines would build the physical structure to house the equipment and maintain it. “In principle, each country will have half of the telescope’s observation time,” says astrophysicist Jacques Lépine, of the Institute of Astronomy, Geophysics and Atmospheric Sciences of the University of São Paulo (IAG-USP), mentor and Brazilian LLAMA coordinator. “But we are establishing key projects to be managed by bi-national teams.” Half of the cost of the antenna has already been paid and the remainder will be paid when the equipment is 100% operational. The Argentine part of the project is being financed by the Secretaría de Articulación Científico Tecnológica do Ministerio de Ciencia, Tecnología e Innovación Productiva (MINCyT).

Related content

The choice to place the antenna at this site in the Argentine northeast had two strategic motives. First, Puna de Atacama has an extremely dry climate, with slightly higher annual rainfall than the nearby Atacama Desert, the driest place on the planet. Atmospheric water vapor is the main obstacle to carrying out good astronomical observations at millimeter and submillimeter wavelengths, such as the frequency band between 90 gigahertz (GHz) and 900 GHz at which LLAMA will operate. Second, LLAMA is 150 km away from the Atacama Large Millimeter/Submillimeter Array (ALMA) as the crow flies, and the latter is the largest radio astronomy project on the planet, located on an extremely high peak in the Chilean municipality of San Pedro de Atacama. Consisting of a set of 66 antennas measuring from 7 m to 12 m located on the Chajnantor plateau, at an altitude of about 5,000 m, ALMA began operations in March 2013 (see Pesquisa FAPESP Issue No. 206). Near the giant radio experiment, and also located on the Chajnantor plateau, is the Atacama Pathfinder Experiment Telescope (APEX), a 12 m radio telescope of which LLAMA is almost a clone.

Initially, LLAMA will operate independently, with no connection to ALMA. However, there is a possibility that the Brazilian-Argentine antenna could work together with ALMA, and even APEX, in an integrated way, as if they formed a single giant radio telescope. For this to happen, the project would need to have a device for interferometry, a technique that combines the signals from different antennas and enables higher-resolution imaging.

Among LLAMA’s scientific objectives are possible studies on the structure of the Sun, of the first stars and galaxies, on emissions from jets and masers (a type of radiation similar to that of a laser) and also on extrasolar planets. The search for organic molecules in the cosmos is expected to be one of the first research areas to produce academic output using the antenna. Astrophysicist Sergio Pilling, coordinator of the Astrochemistry and Astrobiology Laboratory at the Vale do Paraíba University (Univap), in São Jose dos Campos, intends to use the radio telescope for this purpose. “With a little luck we will be able to discover molecules that have not yet been found in outer space if we look in certain radio frequencies,” says Pilling.

New 0.8 m Brazilian telescope located in Cerro Tololo, Chile (lower left) and illustration of the acoustic oscillations of baryons: partnership with Spanish researchers on the J-PAS project

Alberto Molino New 0.8 m Brazilian telescope located in Cerro Tololo, Chile (lower left) and illustration of the acoustic oscillations of baryons: partnership with Spanish researchers on the J-PAS projectAlberto Molino

The Universe in gamma rays
Another ambitious project with an international scope and involving researchers from São Paulo and other Brazilian states is the Cherenkov Telescope Array (CTA). It consists of a consortium of 29 countries that plans to build the largest astronomical observatory for gamma rays in the world by 2020 in order to understand the most energetic phenomena in the Universe. Among these events are the collision of particles of dark matter, the nature of astrophysical accelerators of cosmic rays, which include colliding clouds and stars and supermassive black holes at the center of galaxies, and the violation of the constancy of the speed of light, which can also only be measured using gamma rays. The observatory, with an estimated cost of €200 million, will consist of about 100 telescopes of three different sizes (24 m, 12 m, and 4 m in diameter) of the Cherenkov type, ideal for carrying out this type of measurement, distributed in two arrays. One will be set up in the northern hemisphere, in a location in Mexico, the United States or Spain, and the other will be in the southern hemisphere, probably near ALMA, in Chile. Most of the telescopes will be small. The first stage of the project, called CTA Mini-Array, provides for an arrangement of 4 m telescopes to be set up at the southern site by 2017.

Through FAPESP financing, astrophysicist Elisabete de Gouveia Dal Pino, of IAG-USP, is coordinating the Brazilian contribution to the Mini-Array. At a cost of about €3 million, the Foundation is paying for the manufacture of three small telescopes in Italy, based on a prototype developed by the Italian National Institute of Astrophysics with participation by Brazilian engineers. South Africa is financing another unit and Italy another five. “The Mini-Array telescopes will capture the highest energies between 0.1 and 100 TeV [100 TeV corresponds to 100 trillion electron-volts of energy],” says Pino. “They will increase the current sensitivity for capturing gamma rays by a factor of five to ten.”

The Brazilian part of the initiative is not restricted to the Mini-Array. The team of Luiz Vitor de Souza Filho, of the São Carlos Institute of Physics (IFSC-USP), developed the arm that positions the image camera used in the CTA’s midsized telescopes. He developed and tested a prototype together with a company in São Paulo called Orbital Engenharia, and has now been chosen to supply the structure, which measures 16 m and weighs 5 metric tons, for the other telescopes. Researchers from the Brazilian Center for Physics Research (CBPF) and the Federal University of Rio de Janeiro (UFRJ) participated in the project and developed the 24 m telescopes.

Italian prototype of 4 m telescope for the CTA project: FAPESP is financing and building three units, with the participation of Brazilian engineers

www.brera.inaf.it/astriItalian prototype of 4 m telescope for the CTA project: FAPESP is financing and building three units, with the participation of Brazilian engineerswww.brera.inaf.it/astri

A wide-angle lens in the sky
With a total budget of €30, the Javalambre Physics of the Accelerating Universe Astrophysical Survey (J-PAS) project was originally proposed by Spain and, five years ago, Brazil joined as the second partner. The initiative’s goal, and for which a new observatory was built in Teruel, in the Spanish region of Aragon, is to produce a three-dimensional survey of the entire sky over the next five to six years. Two telescopes—one measuring 2.5 m and the other 0.8 m—were designed for exclusive use in mapping everything from asteroids, planets and stars to the hundreds of millions of galaxies in the Universe.  The difference in relation to prior mappings, such as Sloan, is that the large J-PAS telescope will have the second largest astronomical camera in the world, the JPCam, with a resolution of 1.2 billion pixels, composed of a mosaic of 14 CCDs, a sensor used to obtain digital images. It is a sort of wide-angle lens for the cosmos.

The camera will be able to generate a record number of colors (spectra) in the images of the observed objects. It will have 59 different filters—Sloan had only five—and, together, they will generate a spectrum (set of colors) that highlights certain characteristics of the millions of celestial bodies that will be observed. “The construction of this camera is funded and coordinated by Brazilians,” says Renato Dupke, astrophysicist at the National Observatory (ON), who initiated the partnership with the Spanish. The Brazilian Innovation Agency (FINEP) the Rio de Janeiro Research Foundation (FAPERJ), the Ministry of Science and Technology and Innovation (MCTI), and FAPESP have invested about $7 million in JPCam development, and it should be installed in the telescope in 2016. “The camera’s filter system will be very useful for studying the acoustic oscillations of baryons,” says Laerte Sodré, of IAG-USP, another astrophysicist taking part in the partnership. This phenomenon, which is still little understood, is characterized by waves that were created shortly after the Big Bang due to interactions between visible (baryonic) matter and radiation. Studying these fluctuations could contribute to the understanding of dark matter and especially dark energy, the two main constituents of the Universe, but about which we know little.

The partnership with the Spanish led astrophysicist Cláudia Mendes de Oliveira, of IAG-USP, to request $2 million from FAPESP to build a 0.8 m telescope identical to the smaller J-PAS equipment. The National Observatory paid R$520,000 to build the dome building and provide maintenance for the first six months of operation for the telescope, named the T-80 Sul.  The equipment was installed at the Cerro Tololo site, in Chile, and should come on-line in mid-2015. “We plan to carry out a survey of much of the local Universe, together with the smaller telescope in Spain, using 12 filters,” explains Oliveira. “Even with fewer filters, we should be able to produce high-impact results.”

Projects
1. LLAMA: a mm/sub-mm radio telescope in the Andes, in collaboration with Argentina (No. 2011/51676-9); Grant Mechanism: Thematic Project; Principal investigator: Jacques Lépine (USP); Investment: R$7,890,473.28 and $9,221,992.00 (FAPESP).
2. Investigation of high energy and plasma astrophysics phenomena: theory, numerical simulations, observations, and instrument development for the Cherenkov Telescope Array (CTA) (No. 2013/10559-5); Grant Mechanism: Thematic Project; Principal Investigator: Elisabete de Gouveia Dal Pino (USP); Investment: $2,269,594.10 and R$1,981,476.55 (FAPESP).
3. Acquisition of a robotic telescope for the Brazilian astronomical community (No. 2009/54202-8); Grant Mechanism: Multi-user Equipment Program; Principal investigator: Cláudia de Oliveira (USP); Investment: $1,746,697.84 and R$1,325,134.14 (FAPESP).
4. EMU: Pau-Brasil: acquisition of CCD detectors for the panoramic CCD camera of the Javalambre—physics of the accelerating Universe survey (No. 2009/54162-6) Grant Mechanism: Multi-user Equipment Program; Principal investigator: Laerte Sodré (USP); Investment: $1,600,000.00 and R$912,000.00 (FAPESP).

Republish