ITeDA

QUBIC en invierno

QUBIC Observatory

In search of the origin of the Universe

The QUBIC (Q-U Bolometric Interferometer for Cosmology) project aims to measure the B-modes of polarization of the cosmic background radiation, which dates back to the time when the universe originated, through a new experimental technique that allows greater control of systematic errors, including the removal of galactic contaminants.

QUBIC is an international experimental cosmology project involving institutions from France, Italy, Argentina, the United Kingdom, and the United States of America. The observatory is approximately 4,900 meters above sea level in Alto Chorrillos, near San Antonio de los Cobres, Salta Province, Argentina.

Official website: qubic.org.ar

Cosmic background radiation is the relic electromagnetic radiation corresponding to an early and hot universe phase. This radiation, which fills the entire universe, was emitted approximately 380,000 years after the Big Bang in an event known as decoupling.        

 

The cosmic background radiation is polarized. In particular, the primordial B modes of this polarization are closely related to the gravitational waves that would have been generated during inflation, a stage that is believed to have begun approximately 10-36 s after the Big Bang, in which the universe would have undergone an exponential expansion. Therefore, detecting the primordial B modes of polarization of the cosmic background radiation, which have not yet been observed, will allow the study of the very early stages of the universe.

The weakness of the B-mode signal requires even more complex and sensitive experiments than those built so far to detect it. To meet this challenge, the QUBIC collaboration has developed the innovative technological concept of bolometric interferometry. Bolometer comes from the Greek word for light beam measurement. Bolometers are microsensors working at very low temperatures, which heat up when detecting the cosmic microwave background radiation (CMB), thus changing the material’s electrical resistance allowing its detection in the form of an electronic signal. Interferometry measures the wavelength of what is arriving and analyses the characteristics of the radiation. This new experimental technique allows greater control of systematic errors, including removing galactic contaminants.

The QUBIC telescope is housed in a cylindrical housing used to maintain very low temperatures, called a “cryostat” 1.8 m high and 1.6 m in diameter. This housing protects and keeps the telescope at -269°C and the sensors at even lower temperatures, allowing the detection of the small temperature fluctuations produced by the CMB. The cryostat and its mount are housed in a dome that will be opened for sky observation.

The Argentine QUBIC team assumed the tasks of developing the infrastructure of the observation site with power supply, designing and building the building to house the instrument, designing and manufacturing a three-axis observation mount, and designing and building a laboratory for assembling and integrating the instrument. On the other hand, the Department of Micro and Nanotechnology of the CNEA joined the collaboration to design and adapt the microfabrication processes that enable the production of bolometric sensors.