For J-PAS, Teledyne e2v developed a 1.2 Gigapixel cryogenically cooled camera integrating 14 of our largest and most sensitive Backthinned CCD sensors plus 12 smaller supporting CCDs. Each one of the main CCDs is 9cm x 9cm and 85 megapixels! We continue to work closely with CEFCA to support the long-term operation of this impressive camera.
Q. What is J-PAS and what are its aims?
A: J-PAS stands for the Javalambre Physics of the Accelerating Universe Astrophysical Survey. It is an unprecedented project that has come out of an international collaboration that will be observed at the Observatorio Astrofísico de Javalambre (OAJ) – a brand-new structure designed to carry out large photometric surveys of the sky from the Javalambre Mountain in Spain. J-PAS is the main scientific project to come out of the OAJ during this decade. It has formally started collecting data in order to produce a highly accurate, 3D map of several thousand square degrees of the sky over Javalambre.
Apart from its main scientific goal, J-PAS is in an ideal position to contribute significantly to research in the fields of galaxy formation and evolution, the structure of the Milky Way and systematic studies of solar system asteroids. Its 3D images and data will help us answer some of the most fascinating questions in modern physics, such as why and how the universe is expanding in such an accelerated manner.
Q: Which countries and institutions are primarily involved in J-PAS?
A: J-PAS is a massive international scientific collaboration, involving 280 scientists from all over the world. It is mainly funded by four institutions in Spain and Brazil, including the Centro de Estudios de Física del Cosmos de Aragón (CEFCA) and the Instituto de Astrofísica de Andalucía (IAA-CSIC) in Spain and the National Observatory of Rio de Janeiro and the University of Sao Paulo in Brazil.
However, many other research centres, observatories and universities institutions are involved from across Europe and further afield. These are all making significant scientific contributions to the survey, with many specialists involved, from established, senior scientists through to PhD students using J-PAS data in their research. Topics covered range from cosmology to galaxy formation and evolution. We hope to discover rare galaxies and stars, supernovae and quasi-stellar objects, as well as identify and characterise solar system bodies.
This is a huge, international collaboration and the scope and quality of the 3D images and data J-PAS is producing will contribute to many astrophysical research projects over the next years.
Q: How is Teledyne e2v involved in the OAJ and J-PAS?
A: We conceived the idea for the J-PAS camera around 13 years ago. In order to be able to receive and map sufficient data, we needed powerful telescopes and cutting-edge scientific instrumentation. We had to develop a filter system that allows us to observe the sky in 56 different colours. To do that, we needed to build a massive camera, and that is where Teledyne e2v came into the picture. Teledyne e2v helped design and manufacture our CCD camera system, also known as JPCam. The JPCam system comprises 14 large-format CCDs that amount to more than 1,200 million pixels in total. It is one of the most powerful astronomical survey camera systems operating in the world today.
Now J-PAS has started mapping the sky, we are still collaborating with Teledyne e2v. Although we are successfully receiving high-quality data, we have identified room for improvement with respect to the performance of our equipment. Teledyne e2v is helping us fine-tune and optimise our equipment to get the maximum potential possible out of our telescope and camera system for the entire duration of the project.
Q: Where will the 3D images you are producing be stored? Will you allow people to access them via a website or similar and will they have to pay?
A: That is a very good question, since we are expecting the survey to produce a massive amount of data. So, it is very important that we have the right level of infrastructure to manage, store and distribute the data as it comes in. We have developed a new data centre for this purpose. It will receive the data as it comes in, analyse it and then present it to the community. At first, we will limit access to the researchers involved in the collaboration for a proprietary period of about two years.
After that, the data will be made available to the international community for free. We will not be applying any charges, as one of the main goals of J-PAS is to maximise the scientific return from the project and to eventually share the data as widely as possible. We hope that the J-PAS survey will become known as one of the main milestones of the astrophysical and research in the decades.
Another part of the project will be to create a digital exhibition for the general public to enjoy, showing a selection of beautiful and unique images of the universe. Outreach and raising public awareness of our work by doping things like this is also a very important part of J-PAS.
Q: ESA’s Euclid satellite mission that was launched in July 2023 is also looking at dark matter and how the universe is expanding. How is J-PAS complementing what Euclid is doing, or do the two missions have very different goals and expected outcomes?
A: At the highest level, Euclid and J-PAS are working on the same scientific goal, which is trying to increase our understanding about how the universe is expanding and learning more about dark energy. In that sense, I would agree that both projects are complementary.
However, where they differ is in their observational approaches which are very different. Both projects are using sophisticated but different methods. J-PAS’ approach is unique and tailored to its precise observatory goals. The scope and mapping results that J-PAS is expected to achieve will have the potential to contribute to many other scientific topics around the world, which is an incredibly exciting prospect for the whole team.
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