Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties (luminosity, density, temperature, and chemical composition) of celestial objects such as galaxies, stars, planets, exoplanets, and the interstellar medium, as well as their interactions. The study of cosmology addresses questions of astrophysics at scales much larger than the size of particular gravitationally-bound objects in the universe.
Because astrophysics is a very broad subject, astrophysicists typically apply many disciplines of physics, including mechanics, electromagnetism, statistical mechanics, thermodynamics, quantum mechanics, relativity, nuclear and particle physics, and atomic and molecular physics. In practice, modern astronomical research involves a substantial amount of physics. The name of a university's department ("astrophysics" or "astronomy") often has to do more with the department's history than with the contents of the programs. Astrophysics can be studied at the bachelors, masters, and Ph.D. levels in aerospace engineering, physics, or astronomy departments at many universities.
Observational astrophysics
The majority of astrophysical observations are made using the electromagnetic spectrum.
* Radio astronomy studies radiation with a wavelength greater than a few millimeters. Radio waves are usually emitted by cold objects, including interstellar gas and dust clouds. The cosmic microwave background radiation is the redshifted light from the Big Bang. Pulsars were first detected at microwave frequencies. The study of these waves requires very large radio telescopes.
* Infrared astronomy studies radiation with a wavelength that is too long to be visible but shorter than radio waves. Infrared observations are usually made with telescopes similar to the usual optical telescopes. Objects colder than stars (such as planets) are normally studied at infrared frequencies.
* Optical astronomy is the oldest kind of astronomy. Telescopes paired with a charge-coupled device or spectroscopes are the most common instruments used. The Earth's atmosphere interferes somewhat with optical observations, so adaptive optics and space telescopes are used to obtain the highest possible image quality. In this range, stars are highly visible, and many chemical spectra can be observed to study the chemical composition of stars, galaxies and nebulae.
* Ultraviolet, X-ray and gamma ray astronomy study very energetic processes such as binary pulsars, black holes, magnetars, and many others. These kinds of radiation do not penetrate the Earth's atmosphere well. There are two possibilities to observe this part of the electromagnetic spectrum—space-based telescopes and ground-based imaging air Cherenkov telescopes (IACT). Observatories of the first type are RXTE, the Chandra X-ray Observatory and the Compton Gamma Ray Observatory. IACTs are, for example, the High Energy Stereoscopic System (H.E.S.S.) and the MAGIC telescope.
Other than electromagnetic radiation, few things may be observed from the Earth that originate from great distances. A few gravitational wave observatories have been constructed, but gravitational waves are extremely difficult to detect. Neutrino observatories have also been built, primarily to study our Sun. Cosmic rays consisting of very high energy particles can be observed hitting the Earth's atmosphere.
Observations can also vary in their time scale. Most optical observations take minutes to hours, so phenomena that change faster than this cannot readily be observed. However, historical data on some objects is available spanning centuries or millennia. On the other hand, radio observations may look at events on a millisecond timescale (millisecond pulsars) or combine years of data (pulsar deceleration studies). The information obtained from these different timescales is very different.
The study of our own Sun has a special place in observational astrophysics. Due to the tremendous distance of all other stars, the Sun can be observed in a kind of detail unparalleled by any other star. Our understanding of our own sun serves as a guide to our understanding of other stars.
The topic of how stars change, or stellar evolution, is often modeled by placing the varieties of star types in their respective positions on the Hertzsprung-Russell diagram, which can be viewed as representing the state of a stellar object, from birth to destruction. The material composition of the astronomical objects can often be examined using:
* Spectroscopy
* Radio astronomy
* Neutrino astronomy (future prospects)
What Do Astrophysicists Do?
Astrophysicists investigate the formation of stars, planets and galaxies using mathematics, computing and physics.
Many observational astrophysicists travel often to maximize the viewing time of various stellar events. Most astrophysicists also conduct research and testing of various types of scientific instruments and software. Analyzing data, applying statistics, plotting, logging, archiving, evaluating and reporting of results are all part of the astrophysicists work.
Many astrophysicists are also engaged in teaching at an observatory or university or museum to educate the public and other professionals. Professional writing and publishing is essential for most astrophysicists. Coordinating data from observations made by satellites, ground-based telescopes and calibrating sets of data are part of the regular routine. Astrophysicists use different theoretical models to align images and compare data. They are often the ones who develop the written procedures and standards for analyzing data sets.
What Do Qualifications Do Astrophysicists Need?
Patience is a valued personality trait for astrophysicists as much as curiosity and problem solving are. A professional astrophysicist needs a good background in astronomy and physics, mathematics and chemistry. Computer skills and art are both needed. The astrophysicist needs to work effectively as a member of a team in a scientific environment and have the skills to continue independent research along with skill in oral and written communication. Many astrophysicists exhibit passion for their work. What Areas Do Astrophysicists Cover In Their Courses? A solid science background at the undergraduate level prepares the future astrophysicist for in-depth graduate studies in applied mathematics and many of the disciplines of physics. Computational Astrophysics is essential for research.
Contemporary astronomical research involves various aspects of relativity, thermodynamics, quantum mechanics, electromagnetism, statistical mechanics, nuclear and particle physics and atomic and molecular physics. Laboratory courses offer direct experience with a wide range of sophisticated scientific equipment and machinery as observatory tools. What areas of specialization may astrophysicists choose? The range of specialization is extensive and includes nearly all aspects of physics as it applies to astronomy. The study of these objects through passive collection of data is the goal of observational astrophysics.
Computational Astrophysics, Spectroscopy, Radio astronomy, theoretical astrophysics, astrodynamics and Infrared astronomy studies are all potential specialties. Astrophysicists study, not only the substance or matter of the universe, but also the energy and interactions of its parts. Ultraviolet, X-ray and gamma ray astronomy study energetic processes such as binary pulsars, black holes, magnetars, and more. Where do astrophysicists work? Astrophysicists work at observatories, universities, government agencies, institutes or corporations with special interests in space and technology.
Career in Astrophysics
The study of the atmosphere and sphere and space is one of the oldest sciences. Space science in India has been growing with the Indian Space Research Organization (ISRO) focusing on moon research and India launching the AstroSat, a multi - wavelength astronomy satellite, next year.
The making of satellites for communication, mapping and education are all part of India's space research program. ISRO has also made plans for the lunar explorer, Chandrayaan. The IT revolution has also played a role in augmenting the progress in space science.
Space science deals with the human advances towards exploration of outer space and related technology. It is an amalgamation of various disciplines like, physics, mechanical engineering, materials science, chemistry, biology, medicine, psychology, computer science, and other fields of scientific knowledge.
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