Portal:Radiation astronomy
Radiation astronomy is astronomy applied to the various extraterrestrial sources of radiation, especially at night. It is also conducted above the Earth's atmosphere and at locations away from the Earth, by satellites and space probes, as a part of explorational (or exploratory) radiation astronomy.
Seeing the Sun and feeling the warmth of its rays is probably a student's first encounter with an astronomical radiation source. This will happen from a very early age, but a first understanding of the concepts of radiation may occur at a secondary educational level.
Radiation is all around us on top of the Earth's crust, regolith, and soil, where we live. The study of radiation, including radiation astronomy, usually intensifies at the university undergraduate level.
And, generally, radiation becomes hazardous, when a student embarks on graduate study.
Cautionary speculation may be introduced unexpectedly to stimulate the imagination and open a small crack in a few doors that may appear closed at present. As such, this learning resource incorporates some state-of-the-art results from the scholarly literature.
The laboratories of radiation astronomy are limited to the radiation observatories themselves and the computers and other instruments (sometimes off site) used to analyze the results.
Radiation astronomy sources
In source astronomy, the question is "Where did it come from?"
Source astronomy has its origins in the actions of intelligent life on Earth when they noticed things or entities falling from above and became aware of the sky. Sometimes what they noticed is an acorn or walnut being dropped on them or thrown at them by a squirrel in a tree. Other events coupled with keen intellect allowed these life forms to deduce that some entities falling from the sky are coming down from locations higher than the tops of local trees.
Def. a source or apparent source detected or “created at or near the time of the [ event or] events”[1] is called a primary source.
Direct observation and tracking of the origination and trajectories of falling entities such as volcanic bombs presented early intelligent life with vital albeit sometimes dangerous opportunities to compose the science that led to source astronomy.
References
- ↑ primary source. San Francisco, California: Wikimedia Foundation, Inc. February 16, 2012. http://en.wiktionary.org/wiki/primary_source. Retrieved 2012-07-14.
Theoretical radiation astronomy
At its simplest theoretical radiation astronomy is the definition of terms to be applied to astronomical radiation phenomena.
Def. a theory of the science of the biological, chemical, physical, and logical laws (or principles) with respect to any natural radiation source in the sky especially at night is called theoretical radiation astronomy.
Exploratory theory is the playtime activity that leads to discoveries which better our world. In the radiation physics laboratories here on Earth, the emission, reflection, transmission, absorption, and fluorescence of radiation is studied and laws relative to sources are proven.
A principle is a law or rule that has to be, or usually is to be followed, or can be desirably followed, or is an inevitable consequence of something, such as the laws observed in nature or the way that a system is constructed. The principles of such a system are understood by its users as the essential characteristics of the system, or reflecting system's designed purpose, and the effective operation or use of which would be impossible if any one of the principles was to be ignored.[1]
Radiation astronomy consists of three fundamental parts:
- derivation of logical laws with respect to incoming radiation,
- natural radiation sources outside the Earth, and
- the sky and associated realms with respect to radiation.
Def. a spontaneous emission of an α ray, β ray, or γ ray by the disintegration of an atomic nucleus is called radioactivity.[2]
References
- ↑ Guido Alpa (1994). "General Principles of Law". Annual Survey of International & Comparative Law 1: 1. http://heinonlinebackup.com/hol-cgi-bin/get_pdf.cgi?handle=hein.journals/ansurintcl1§ion=4. Retrieved 2012-04-29.
- ↑ Philip B. Gove, ed (1963). Webster's Seventh New Collegiate Dictionary. Springfield, Massachusetts: G. & C. Merriam Company. pp. 1221.
Backgrounds
In the figure at right, CUVOB stands for the cosmic ultraviolet and optical background.
The diffuse extragalactic background light (EBL) is all the accumulated radiation in the Universe due to star formation processes, plus a contribution from active galactic nuclei (AGNs). This radiation covers the wavelength range between ~ 0.1-1000 microns (these are the ultraviolet, optical, and infrared regions of the electromagnetic spectrum). The EBL is part of the diffuse extragalactic background radiation (DEBRA), which by definition covers the overall electromagnetic spectrum. After the cosmic microwave background, the EBL produces the second-most energetic diffuse background, thus being essential for understanding the full energy balance of the universe.
An astrophysical X-ray source is an astronomical object with physical properties which result in the emission of X-rays.
There are a number of types of astrophysical objects which emit X-rays, from galaxy clusters, through black holes in active galactic nuclei (AGN) to galactic objects such as supernova remnants, stars, and binary stars containing a white dwarf (cataclysmic variable stars and super soft X-ray sources), neutron star or black hole (X-ray binaries). Some solar system bodies emit X-rays, the most notable being the Moon, although most of the X-ray brightness of the Moon arises from reflected solar X-rays.
Clusters of galaxies are formed by the merger of smaller units of matter, such as galaxy groups or individual galaxies. The infalling material (which contains galaxies, gas and dark matter) gains kinetic energy as it falls into the cluster's gravitational potential well. The infalling gas collides with gas already in the cluster and is shock heated to between 107 and 108 K depending on the size of the cluster. This very hot gas emits X-rays by thermal bremsstrahlung emission, and spectral line emission from metals (in astronomy, 'metals' often means all elements except hydrogen and helium). The galaxies and dark matter are collisionless and quickly become virialised, orbiting in the cluster potential well.
The Antennae galaxies are in Corvus. This NASA Hubble Space Telescope image of the Antennae galaxies (NGC 4038 & 4039) is the sharpest yet of the merging pair of galaxies. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration.
First submillimeter source in Carina
The first submillimeter source in Carina is unknown.
The field of submillimeter astronomy is the result of observations and theories about submillimeter sources detected in the sky above.
The first astronomical submillimeter source discovered may have been the Sun.
But, submillimeter waves from the Sun are intermingled with other radiation so that the Sun may appear as other than a primary source for submillimeter waves.
The early use of sounding rockets and balloons to carry submillimeter detectors high enough may have detected submillimeter waves from the Sun as early as the 1940s.
This is a lesson in map reading, coordinate matching, and researching. It is also a research project in the history of submillimeter astronomy looking for the first astronomical submillimeter source discovered in the constellation of Carina.
Nearly all the background you need to participate and learn by doing you've probably already been introduced to at a secondary level and perhaps even a primary education level.
Some of the material and information is at the college or university level, and as you progress in finding submillimeter sources, you'll run into concepts and experimental tests that are actual research.
Color astronomy quiz
Color astronomy is a lecture as part of the radiation astronomy department course development of principles of radiation astronomy.
You are free to take this quiz based on color astronomy at any time.
To improve your scores, read and study the lecture, the links contained within, and listed under See also, External links and the {{radiation astronomy resources}} and {{principles of radiation astronomy}} templates. This should give you adequate background to get 100 %.
As a "learning by doing" resource, this quiz helps you to assess your knowledge and understanding of the information, and it is a quiz you may take over and over as a learning resource to improve your knowledge, understanding, test-taking skills, and your score.
This quiz may need up to an hour to take and is equivalent to an hourly.
Suggestion: Have the lecture available in a separate window.
Enjoy learning by doing!
Cratering astronomy laboratory
This laboratory is an activity for you to create or analyze a cratering. While it is part of the astronomy course principles of radiation astronomy, it is also independent.
Some suggested types of cratering to consider include a lightning strike, a bullet shot into some material, a water droplet hitting the surface of a beaker of water, a subterranean explosion, a sand vortex, or a meteorite impact.
More importantly, there is your cratering idea. And, yes, you can crater a peanut butter and jelly sandwich if you wish to.
Okay, this is an astronomy cratering laboratory, but you may create what a crater is. Another example is a volcanic crater.
I will provide an example of a cratering experiment. The rest is up to you.
Please put any questions you may have, and your laboratory results, you'd like evaluated, on the laboratory's discussion page.
Enjoy learning by doing!
Energy phantoms
Students start from specific situations of motion, determine how to calculate energy and convert units, then evaluate types of energy.
Def. a quantity that denotes the ability to do work and is measured in a unit dimensioned in mass × distance²/time² (ML²/T²) or the equivalent is called energy.
Def. a physical quantity that denotes ability to push, pull, twist or accelerate a body which is measured in a unit dimensioned in mass × distance/time² (ML/T²): SI: newton (N); CGS: dyne (dyn) is called force.
In astronomy we estimate distances and times when and where possible to obtain forces and energy.
The key values to determine in both force and energy are (L/T²) and (L²/T²). Force (F) x distance (L) = energy (E), L/T² x L = L²/T². Force and energy are related to distance and time using proportionality constants.
Every point mass attracts every single other point mass by a force pointing along the line intersecting both points. The force is proportional to the product of the two masses and inversely proportional to the square of the distance between them:[1] - ,
where:
- F is the force between the masses,
- G is the gravitational constant,
- m1 is the first mass,
- m2 is the second mass, and
- r is the distance between the centers of the masses.
In the International System of Units (SI) units, F is measured in newtons (N), m1 and m2 in kilograms (kg), r in meters (m), and the constant G is approximately equal to 6.674×10−11
N m2 kg−2.[2]
Observationally, we may not know the origin of the force.
Coulomb's law states that the electrostatic force experienced by a charge, at position , in the vicinity of another charge, at position , in vacuum is equal to:
where is the electric constant and is the distance between the two charges.
Coulomb's constant is
where the constant is called the permittivity of free space in SI units of C2 m−2 N−1.
For reality, is the relative (dimensionless) permittivity of the substance in which the charges may exist.
The energy for this system is
where is the displacement.
References
- ↑ - Proposition 75, Theorem 35: p.956 - I.Bernard Cohen and Anne Whitman, translators: Isaac Newton, The Principia: Mathematical Principles of Natural Philosophy. Preceded by A Guide to Newton's Principia, by I. Bernard Cohen. University of California Press 1999 ISBN 0-520-08816-6 ISBN 0-520-08817-4
- ↑ CODATA2006. http://www.physics.nist.gov/cgi-bin/cuu/Value?bg.
Chandra X-ray Observatory image of the hot X-ray emitting gas that pervades the galaxy cluster MS 0735.6+7421 in the constellation Camelopardalis. Two vast cavities - each 600,000 lyrs in diameter appear on opposite sides of a large galaxy at the center of the cluster. These cavities are filled with a two-sided, elongated, magnetized bubble of extremely high-energy electrons that emit radio waves. Image is 4.2 arcmin per side. RA 07h 41m 50.20s Dec +74° 14' 51.00". Observation date: November 30, 2003. Credit: NASA/CXC/Ohio U./B.McNamara.
Fields associated with radiation astronomy include Astronomy, Astrogeology, Astrognosy, Astrohistory, Astrophysics, Atmospheric sciences, Charge ontology, Chemistry, Cosmogony, Fringe sciences, Geochemistry, Geochronology, Geology, Geomorphology, Geophysics, Geoseismology, Hydromorphology, Lofting technology, Mathematics, Measurements, Mining geology, Nuclear physics, Oceanography, Petrophysics, Radiation physics, Shielding, Spaceflights, Structural geology, Technology, Trigonometric-parallax astronomy, and X-ray trigonometric parallax
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