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GMRT Antenna At Sunset
The Giant Metrewave Radio Telescope (GMRT), located near Narayangaon, Pune in India, is an array of thirty fully steerable parabolic radio telescopes of 45 metre diameter, observing at metre wavelengths. It is the largest and most sensitive radio telescope array in the world at low frequencies. It is operated by the National Centre for Radio Astrophysics (NCRA), a part of the Tata Institute of Fundamental Research, Mumbai. It was conceived and built under the direction of Govind Swarup during 1984 to 1996. It is an Interferometry, interferometric array with baselines of up to . It was recently upgraded with new receivers, after which it is also known as the upgraded Giant Metrewave Radio Telescope (uGMRT). Location The Giant Metrewave Radio Telescope (GMRT) Observatory is located about 80 km north of Pune at Khodad. A nearby town is Narayangaon which is around 9 km from the Radio telescope, telescope site. The office of National Centre for Radio Astrophysics (NCRA) is l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Narayangaon
Narayangaon is a town in the Junnar taluka of the Pune district of Maharashtra state, India. Water is abundant because of its proximity to the major dams, the western ghats, and the Sahyadri mountain range. Geography Narayangaon is located 656 m (2,152 ft) above sea level on the western margin of the Deccan plateau. It is situated on the leeward side of the Sahyadri mountain range, which forms a barrier from the Arabian sea. Narayangaon is on the bank of the river Meena. A wide hill range in the south separates the town from the adjoining Ambegaon taluka. Narayangaon can be reached from major cities via road. It is situated on NH 50, Pune-Nasik National Highway 50. It is 77 km north of Pune, 132 km south of Nasik and around 176 km east of the state capital, Mumbai. Historic importance Shivneri Fort, the birthplace of Shivaji, who founded and ruled the Maratha Kingdom during the 17th century, is 16 km away from Narayangaon. Two of the Ashtavinayak Ganapa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supernova Remnant
A supernova remnant (SNR) is the structure resulting from the explosion of a star in a supernova. The supernova remnant is bounded by an expanding shock wave, and consists of ejected material expanding from the explosion, and the interstellar material it sweeps up and shocks along the way. There are two common routes to a supernova: either a massive star may run out of fuel, ceasing to generate fusion energy in its core, and collapsing inward under the force of its own gravity to form a neutron star or a black hole; or a white dwarf star may accrete material from a companion star until it reaches a critical mass and undergoes a thermonuclear explosion. In either case, the resulting supernova explosion expels much or all of the stellar material with velocities as much as 10% the speed of light (or approximately 30,000 km/s) and a strong shock wave forms ahead of the ejecta. That heats the upstream plasma up to temperatures well above millions of K. The shock continuou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interferometric Telescopes
Interferometry is a technique which uses the ''interference'' of superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important investigative technique in the fields of astronomy, fiber optics, engineering metrology, optical metrology, oceanography, seismology, spectroscopy (and its applications to chemistry), quantum mechanics, nuclear and particle physics, plasma physics, biomolecular interactions, surface profiling, microfluidics, mechanical stress/strain measurement, velocimetry, optometry, and making holograms. Interferometers are devices that extract information from interference. They are widely used in science and industry for the measurement of microscopic displacements, refractive index changes and surface irregularities. In the case with most interferometers, light from a single source is split into two beams that travel in different optical paths, which are then combined again to produce interference; two incoh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Telescopes
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 radio frequency portion of the electromagnetic spectrum, just as optical telescopes are used to make observations in the visible light, visible portion of the spectrum in traditional optical astronomy. Unlike optical telescopes, radio telescopes can be used in the daytime as well as at night. Since astronomical radio sources such as planets, stars, nebulas and galaxy, galaxies are very far away, the radio waves coming from them are extremely weak, so radio telescopes require very large antennas to collect enough radio energy to study them, and extremely sensitive receiving equipment. Radio telescopes are typically large Parabolic antenna, parabolic ("dish") antennas similar to those employed in tracking and communicating with satellites an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Radio Telescopes
This is a list of radio telescopes – over one hundred – that are or have been used for radio astronomy. The list includes both single dishes and interferometric arrays. The list is sorted by region, then by name; unnamed telescopes are in reverse size order at the end of the list. The first radio telescope was invented in 1932, when Karl Jansky at Bell Telephone Laboratories observed radiation coming from the Milky Way. Africa Antarctica Asia Australia Europe North America South America Arctic Ocean Atlantic Ocean Indian Ocean Pacific Ocean Space-based Under construction or planned construction Proposed telescopes Gallery of big dishes File:FAST Radio Telescope (captured from video).jpg, alt=Five-hundred-meter Aperture Spherical Telescope seen from above in 2020, The 500 meter Five-hundred-meter Aperture Spherical Telescope (FAST), China (2016) File:GBT.png, alt=Green Bank Telescope, The 100 meter Green Bank Teles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Science Day
National Science Day is celebrated in India on February 28 each year to mark the discovery of the Raman effect by Indian physicist Sir C. V. Raman on 28 February 1928. For his discovery, Sir C.V. Raman was awarded the Nobel Prize in Physics in 1930. History of National Science Day In 1986, the National Council for Science & Technology Communication (NCSTC) asked the Government of India to designate February 28 as National Science Day. The event is now celebrated all over India in schools, colleges, universities and other academic, scientific, technical, medical and research institutions. On the occasion of the first NSD (National Science Day)(28 February 1987) NCSTC announced the institution of the National Science Popularization Awards for recognizing outstanding efforts in the area of science and communication. It is marked as a dawn of new generation. Celebration of National Science Day The occasion of National Science Day is marked by numerous events conducted by insti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophiuchus Supercluster Explosion
NeVe 1 is a supergiant elliptical galaxy, which is the central, dominant member and brightest cluster galaxy (BCG) of the Ophiuchus Cluster. It lies at a distance of about 411 million light-years away from Earth and is located behind the Zone of Avoidance region in the sky. It is the host galaxy of the Ophiuchus Supercluster eruption, the most energetic astronomical event known. Observation history Despite being in the relatively nearby, large Ophiuchus Cluster, due to its location behind the Milky Way galactic disc relative to the Earth's perspective (known as the Zone of Avoidance), the majority of the cluster including NeVe 1 are heavily obscured and invisible to the naked eye, such that it can only be observed in wavelengths beyond the visible spectrum, such as X-rays and infrared. When first observed in 1985 it was initially thought to be a planetary nebula within the large, star-forming Rho Ophiuchi cloud complex. In a catalogue published by the German astronomers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epoch Of Reionisation
In the fields of Big Bang theory and cosmology, reionization is the process that caused electrically neutral atoms in the primordial universe to reionize after the lapse of the " dark ages". Detecting and studying the reionization process is challenging but multiple avenues have been pursued. This reionization was driven by the formation of the first stars and galaxies. Concept Reionization refers to a change in the intergalactic medium from neutral hydrogen to ions. The neutral hydrogen had been ions at an earlier stage in the history of the universe, thus the conversion back into ions is termed a ''re''ionization. The reionization was driven by energetic photons emitted by the first stars and galaxies. In the timeline of the universe, neutral hydrogen gas was originally formed when primordial hydrogen nuclei (protons) combined with electrons. Light with sufficient energy will ionize neutral hydrogen gas. At early times, light was so dense and energetic that hydrogen at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time-variation Of Fundamental Constants
The term physical constant expresses the notion of a physical quantity subject to experimental measurement which is independent of the time or location of the experiment. The constancy (immutability) of any "physical constant" is thus subject to experimental verification. Paul Dirac in 1937 speculated that physical constants such as the gravitational constant or the fine-structure constant might be subject to change over time in proportion of the age of the universe. Experiments conducted since then have put upper bounds on their time-dependence. This concerns the fine-structure constant, the gravitational constant and the proton-to-electron mass ratio specifically, for all of which there are ongoing efforts to improve tests on their time-dependence. The immutability of these fundamental constants is an important cornerstone of the laws of physics as currently known; the postulate of the time-independence of physical laws is tied to that of the conservation of energy (Noether's th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Wind
The solar wind is a stream of charged particles released from the Sun's outermost atmospheric layer, the Stellar corona, corona. This Plasma (physics), plasma mostly consists of electrons, protons and alpha particles with kinetic energy between . The composition of the solar wind plasma also includes a mixture of particle species found in the solar plasma: trace amounts of heavy ions and atomic nuclei of Chemical element, elements such as carbon, nitrogen, oxygen, neon, magnesium, silicon, sulfur, and iron. There are also rarer traces of some other nuclei and isotopes such as phosphorus, titanium, chromium, and nickel's isotopes 58Ni, 60Ni, and 62Ni. Superimposed with the solar-wind plasma is the interplanetary magnetic field. The solar wind varies in density, temperature and speed over time and over Solar coordinate systems#Heliographic, solar latitude and longitude. Its particles can escape the Sun's gravity because of their high energy resulting from the high temperature of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clusters Of Galaxies
The observable universe is a spherical region of the universe consisting of all matter that can be observed from Earth; the electromagnetic radiation from these objects has had time to reach the Solar System and Earth since the beginning of the cosmological expansion. Assuming the universe is isotropic, the distance to the edge of the observable universe is the same in every direction. That is, the observable universe is a spherical region centered on the observer. Every location in the universe has its own observable universe, which may or may not overlap with the one centered on Earth. The word ''observable'' in this sense does not refer to the capability of modern technology to detect light or other information from an object, or whether there is anything to be detected. It refers to the physical limit created by the speed of light itself. No signal can travel faster than light, hence there is a maximum distance, called the particle horizon, beyond which nothing can be det ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Galaxy
A radio galaxy is a galaxy with giant regions of radio emission extending well beyond its visible structure. These energetic radio lobes are powered by jets from its active galactic nucleus. They have luminosities up to 1039 W at radio wavelengths between 10 MHz and 100 GHz. The radio emission is due to the synchrotron process. The observed structure in radio emission is determined by the interaction between twin jets and the external medium, modified by the effects of relativistic beaming. The host galaxies are almost exclusively large elliptical galaxies. ''Radio-loud'' active galaxies can be detected at large distances, making them valuable tools for observational cosmology. Recently, much work has been done on the effects of these objects on the intergalactic medium, particularly in galaxy groups and clusters. The term "radio galaxy" is often used to refer to the entire jet system, rather than solely to its host galaxy. Some scientists consider the term " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
