LOFT
Encyclopedia
The Large Observatory for X-ray Timing (LOFT) is a proposed ESA space mission slated to launch around 2022, and devoted to the study of neutron stars, black holes and other compact objects by means of their very rapid X-ray
variability.
The mission was submitted to the ESA Cosmic Vision
M3 call for proposals, and was selected, together with other three missions, for an initial Assessment Phase.
LOFT is supported by a large international collaboration, led by researchers spread over most of the European countries, including Italy
, Switzerland
, Germany
, United Kingdom
, Greece
, Ireland
, The Netherlands, Poland
, Czech Republic
, Spain
, and with contributions from Brazil
, Canada
, Israel
, United States
and Turkey
.
The Large Area Detector (LAD) achieves an effective area of ~12 m2 (more than an order of magnitude larger than current spaceborne X-ray detectors, e.g. RXTE) in the 2-30 keV range, yet still fitting a conventional platform and small/medium-class launcher, thanks to the monolithic design of its large area Silicon Drift Detectors
(SDD).
The Wide Field Monitor (WFM) is a coded mask
X-ray monitor with a large field of view (> 3 steradian
), and is also based on the Silicon Drift Detector technology.
Besides these topics, LOFT will in general study the X-ray spectra and variability for a wide range of astrophysical sources, e.g. magnetars, active galactic nuclei, cataclysmic variables, X-ray transients and gamma-ray bursts.
The unique capabilities of LOFT, make this instruments certainly able to provide new breakthroughs in a wide range of Astrophysical research areas.
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
variability.
The mission was submitted to the ESA Cosmic Vision
Cosmic Vision
The Cosmic Vision is the paraphrasing name given to the roadmap for scientific space based missions of the European Space Agency in the time frame between 2015 and 2025....
M3 call for proposals, and was selected, together with other three missions, for an initial Assessment Phase.
LOFT is supported by a large international collaboration, led by researchers spread over most of the European countries, including Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
, Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
, Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
, United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
, Greece
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....
, Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
, The Netherlands, Poland
Poland
Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...
, Czech Republic
Czech Republic
The Czech Republic is a landlocked country in Central Europe. The country is bordered by Poland to the northeast, Slovakia to the east, Austria to the south, and Germany to the west and northwest....
, Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
, and with contributions from Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, Israel
Israel
The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...
, United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and Turkey
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...
.
Mission architecture
The Large Observatory for X-ray Timing mission comprises two instruments.- Large Area Detector (LAD), a 12 m2 collimated X-ray detector
- Wide Field Monitor (WFM), a coded-mask wide field X-ray monitor
The Large Area Detector (LAD) achieves an effective area of ~12 m2 (more than an order of magnitude larger than current spaceborne X-ray detectors, e.g. RXTE) in the 2-30 keV range, yet still fitting a conventional platform and small/medium-class launcher, thanks to the monolithic design of its large area Silicon Drift Detectors
Silicon drift detector
Silicon drift detectors are X-ray radiation detectors used in x-ray spectrometry and electron microscopy . Their chief characteristics compared with other X-ray detectors are:*high count rates*comparatively high energy resolution Silicon drift detectors (SDDs) are X-ray radiation detectors used...
(SDD).
The Wide Field Monitor (WFM) is a coded mask
Coded aperture
Coded Apertures or Coded-Aperture Masks are grids, gratings, or other patterns of materials opaque to various wavelengths of light. The wavelengths are usually high-energy radiation such as X-rays and gamma rays. By blocking and unblocking light in a known pattern, a coded "shadow" is cast upon a...
X-ray monitor with a large field of view (> 3 steradian
Steradian
The steradian is the SI unit of solid angle. It is used to describe two-dimensional angular spans in three-dimensional space, analogous to the way in which the radian describes angles in a plane...
), and is also based on the Silicon Drift Detector technology.
Objectives
The main scientific objectives of LOFT are:- the determination of the neutron starNeutron starA neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star during a Type II, Type Ib or Type Ic supernova event. Such stars are composed almost entirely of neutrons, which are subatomic particles without electrical charge and with a slightly larger...
structure and its equation of stateEquation of stateIn physics and thermodynamics, an equation of state is a relation between state variables. More specifically, an equation of state is a thermodynamic equation describing the state of matter under a given set of physical conditions... - the study of the physics in strong gravitational fields, e.g. in the accretion disks around black holes
- the direct measurements of black holeBlack holeA black hole is a region of spacetime from which nothing, not even light, can escape. The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole. Around a black hole there is a mathematically defined surface called an event horizon that...
massMassMass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
and spinSpin (physics)In quantum mechanics and particle physics, spin is a fundamental characteristic property of elementary particles, composite particles , and atomic nuclei.It is worth noting that the intrinsic property of subatomic particles called spin and discussed in this article, is related in some small ways,...
Besides these topics, LOFT will in general study the X-ray spectra and variability for a wide range of astrophysical sources, e.g. magnetars, active galactic nuclei, cataclysmic variables, X-ray transients and gamma-ray bursts.
The unique capabilities of LOFT, make this instruments certainly able to provide new breakthroughs in a wide range of Astrophysical research areas.