The Northern Extended Millimeter Array (NOEMA) is one of the largest astronomical facilities on European ground and the most powerful
radio telescope
A radio telescope is a specialized antenna (radio), antenna and radio receiver used to detect radio waves from astronomical radio sources in the sky. Radio telescopes are the main observing instrument used in radio astronomy, which studies the r ...
in the Northern Hemisphere operating at
millimeter wavelengths. It consists of a large array of twelve 15-meter antennas that can spread over distances of up to 1.7 kilometers, working together as a single telescope.
NOEMA is the successor of the
Plateau de Bure Interferometer and is run by the international research institute
IRAM (Institut de radioastronomie millimétrique).
The observatory operates at over 2500 meters above sea level on one of the most extended European high altitude sites, the Plateau de Bure in the
French Alps
The French Alps are the portions of the Alps mountain range that stand within France, located in the Auvergne-Rhône-Alpes and Provence-Alpes-Côte d'Azur regions. While some of the ranges of the French Alps are entirely in France, others, such a ...
. Together with IRAM's other observatory, the
IRAM 30-meter telescope, it is part of the global
Event Horizon Telescope
The Event Horizon Telescope (EHT) is a Astronomical interferometer, telescope array consisting of a global network of radio telescopes. The EHT project combines data from several very-long-baseline interferometry (VLBI) stations around Earth, wh ...
array.
Operation
Instead of operating one giant telescope, NOEMA relies on several smaller and easily movable antennas placed on tracks. Together, the NOEMA antennas have the resolving power of a telescope with a diameter of more than 1.7 kilometers, which is the distance between the outermost antennas.
During observations, the NOEMA antennas function as a single stationary telescope, a technique called
interferometry
Interferometry is a technique which uses the ''interference (wave propagation), interference'' of Superposition principle, superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important inves ...
. All NOEMA antennas point towards the same cosmic source. The signals received by each antenna are combined by a supercomputer, a so-called correlator, that produces images of outstanding sensitivity and resolution of the astronomical source.
NOEMA functions like a variable-lens camera by changing the configuration of its antennas, allowing scientists to zoom in and out of a cosmic object and observe the tiniest details. In its most extended configuration, NOEMA shows a 0.1
arc second
A minute of arc, arcminute (abbreviated as arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of a degree. Since one degree is of a turn, or complete rotation, one arcminute is of a tu ...
view at 350
GHz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or Cycle per second, cycle) per second. The hertz is an SI derived unit whose formal expression in ter ...
, revealing the nature of the nearest protostellar disks and the sub-
kiloparsec
The parsec (symbol: pc) is a unit of length used to measure the large distances to astronomical objects outside the Solar System, approximately equal to or (AU), i.e. . The parsec unit is obtained by the use of parallax and trigonometry, a ...
scale of star-forming regions of the most distant galaxies. Working with IRAM's second facility, the 30-meter telescope and its wide angle of vision, the result is a giant virtual telescope with a unique set of capabilities.
Science
Compared to
optical astronomy
Visible-light astronomy encompasses a wide variety of astronomical observation via telescopes that are sensitive in the range of visible light (optical telescopes). Visible-light astronomy is part of optical astronomy, and differs from astronomi ...
, which is sensitive to the hot universe (stars are generally a few thousand degrees Celsius),
radiotelescopes that operate in the millimeter wavebands, such as NOEMA, probe the cold universe (around –250 degrees Celsius). NOEMA is able to see the formation of the first
galaxies
A galaxy is a system of stars, stellar remnants, interstellar gas, dust, and dark matter bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar Sys ...
in the
universe
The universe is all of space and time and their contents. It comprises all of existence, any fundamental interaction, physical process and physical constant, and therefore all forms of matter and energy, and the structures they form, from s ...
, to observe supermassive
black hole
A black hole is a massive, compact astronomical object so dense that its gravity prevents anything from escaping, even light. Albert Einstein's theory of general relativity predicts that a sufficiently compact mass will form a black hole. Th ...
s at the center of galaxies, to analyze the chemical evolution and dynamics of nearby galaxies, to detect
organic molecules
Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-cont ...
and possible key elements of life, and to investigate the
formation of stars and the appearance of
planetary system
A planetary system is a set of gravity, gravitationally bound non-stellar Astronomical object, bodies in or out of orbit around a star or star system. Generally speaking, systems with one or more planets constitute a planetary system, although ...
s.
NOEMA has done pioneering work in radio astronomy. It observed the most distant
galaxy
A galaxy is a Physical system, system of stars, stellar remnants, interstellar medium, interstellar gas, cosmic dust, dust, and dark matter bound together by gravity. The word is derived from the Ancient Greek, Greek ' (), literally 'milky', ...
known at the time of observation. (Since then, the
James Webb Space Telescope
The James Webb Space Telescope (JWST) is a space telescope designed to conduct infrared astronomy. As the largest telescope in space, it is equipped with high-resolution and high-sensitivity instruments, allowing it to view objects too old, Lis ...
has observed more distant galaxies.) Together with the IRAM 30-meter telescope, it made the first complete and detailed radio images of nearby galaxies and their gas. NOEMA also obtained the first image of a gas
disk surrounding a
double star system ''(Dutrey'' al. 1994). Its antennas captured for the first time a cavity in one of these disks, a major hint for the existence of a
planetary object orbiting the new star and absorbing
matter
In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. All everyday objects that can be touched are ultimately composed of atoms, which are made up of interacting subatomic pa ...
on its trajectory (
GG tau, ''Piétu'' et al. 2011 ). Together, the IRAM facilities have discovered one third of the
interstellar molecules known to date (published ApJ, 2018, ''Brett A. McGuire
'').
Gallery
File:The NOEMA observatory operated by IRAM.jpg, The NOEMA observatory
File:NOEMA observatory. IRAM.jpg, The NOEMA observatory, located on the Plateau de Bure in the French Alps
File:NOEMA antennas under the Milky Way.jpg, The NOEMA antennas looking at the night sky
File:The NOEMA observatory under the night sky.jpg, The NOEMA observatory looking at the night sky with the Milky Way.
See also
*
List of radio telescopes
References
External links
The NOEMA brochure.
{{Portal bar, France, Astronomy, Stars, Spaceflight, Outer space, Solar System, Education, Science
Radio telescopes
Interferometric telescopes
Astronomical observatories in France
Hautes-Alpes