Timeline of knowledge about the interstellar and intergalactic medium
Encyclopedia
Timeline
of the interstellar medium
and intergalactic medium
Timeline
A timeline is a way of displaying a list of events in chronological order, sometimes described as a project artifact . It is typically a graphic design showing a long bar labeled with dates alongside itself and events labeled on points where they would have happened.-Uses of timelines:Timelines...
of the interstellar medium
Interstellar medium
In astronomy, the interstellar medium is the matter that exists in the space between the star systems in a galaxy. This matter includes gas in ionic, atomic, and molecular form, dust, and cosmic rays. It fills interstellar space and blends smoothly into the surrounding intergalactic space...
and intergalactic medium
- 1848 — Lord RosseWilliam Parsons, 3rd Earl of RosseWilliam Parsons, 3rd Earl of Rosse, Knight of the Order of St Patrick was an Irish astronomer who had several telescopes built. His 72-inch telescope "Leviathan", built 1845, was the world's largest telescope until the early 20th century.-Life:He was born in Yorkshire, England, in the city of...
studies M1Messier objectThe Messier objects are a set of astronomical objects first listed by French astronomer Charles Messier in 1771. The original motivation of the catalogue was that Messier was a comet hunter, and was frustrated by objects which resembled but were not comets...
and names it the Crab NebulaCrab NebulaThe Crab Nebula is a supernova remnant and pulsar wind nebula in the constellation of Taurus... - 1864 — William HugginsWilliam HugginsSir William Huggins, OM, KCB, FRS was an English amateur astronomer best known for his pioneering work in astronomical spectroscopy.-Biography:...
studies the spectrum of the Orion NebulaOrion NebulaThe Orion Nebula is a diffuse nebula situated south of Orion's Belt. It is one of the brightest nebulae, and is visible to the naked eye in the night sky. M42 is located at a distance of and is the closest region of massive star formation to Earth. The M42 nebula is estimated to be 24 light...
and shows that it is a cloud of gas - 1927 — Ira BowenIra Sprague BowenIra Sprague Bowen was an American astronomer. In 1927 he discovered that nebulium was not really a chemical element but instead doubly ionized oxygen.-Life and work:...
explains unidentified spectral lineSpectral lineA spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from a deficiency or excess of photons in a narrow frequency range, compared with the nearby frequencies.- Types of line spectra :...
s from space as forbidden transition lines - 1930 — Robert TrumplerRobert Julius TrumplerRobert Julius Trumpler was a Swiss-American astronomer....
discovers absorption by interstellar dust by comparing the angular sizes and brightnesses of globular clusterGlobular clusterA globular cluster is a spherical collection of stars that orbits a galactic core as a satellite. Globular clusters are very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their centers. The name of this category of star cluster is...
s - 1944 — Hendrik van de HulstHendrik C. van de HulstHendrik Christoffel "Henk" van de Hulst FRS was a Dutch astronomer and mathematician....
predicts the 21 cm hyperfine line of neutral interstellar hydrogenHydrogenHydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly... - 1951 — H.I. Ewen and Edward PurcellEdward Mills PurcellEdward Mills Purcell was an American physicist who shared the 1952 Nobel Prize for Physics for his independent discovery of nuclear magnetic resonance in liquids and in solids. Nuclear magnetic resonance has become widely used to study the molecular structure of pure materials and the...
observe the 21 cm hyperfine line of neutral interstellar hydrogen - 1956 — Lyman SpitzerLyman SpitzerLyman Strong Spitzer, Jr. was an American theoretical physicist and astronomer best known for his research in star formation, plasma physics, and in 1946, for conceiving the idea of telescopes operating in outer space...
predicts coronal gas around the Milky WayMilky WayThe Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky... - 1965 — James Gunn and Bruce PetersonBruce PetersonBruce Peterson was a test pilot for NASA.A native of Washburn, North Dakota, he attended the University of California at Los Angeles, and California Polytechnic State University...
use observations of the relatively low absorption of the blue component of the Lyman-alpha lineLyman-alpha lineIn physics, the Lyman-alpha line, sometimes written as Ly-\alpha line, is a spectral line of hydrogen, or more generally of one-electron ions, in the Lyman series, emitted when the electron falls from the n = 2 orbital to the n = 1 orbital, where n is the principal quantum number...
from 3C9 to strongly constrain the density and ionization state of the intergalactic medium - 1969 — Lewis Snyder, David Buhl, Ben Zuckerman, and Patrick Palmer find interstellar formaldehydeInterstellar formaldehydeInterstellar formaldehyde was first discovered in 1969 by L. Snyder et al.. using the National Radio Astronomy Observatory. Formaldehyde was detected by means of the 111 - 110 ground state rotational transition at 4830 MHz.-Initial discovery:Formaldehyde was first discovered in interstellar...
- 1970 — Arno PenziasArno Allan PenziasArno Allan Penzias is an American physicist and Nobel laureate in physics.-Early life and education:Penzias was born in Munich, Germany. At age six he was among the Jewish children evacuated to Britain as part of the Kindertransport rescue operation...
and Robert WilsonRobert Woodrow WilsonFor the American President, see Woodrow Wilson.Robert Woodrow Wilson is an American astronomer, 1978 Nobel laureate in physics, who with Arno Allan Penzias discovered in 1964 the cosmic microwave background radiation...
find interstellar carbon monoxideCarbon monoxideCarbon monoxide , also called carbonous oxide, is a colorless, odorless, and tasteless gas that is slightly lighter than air. It is highly toxic to humans and animals in higher quantities, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal... - 1970 — George Carruthers observes molecular hydrogen in space
- 1977 — Christopher McKeeChristopher McKeeChristopher Fulton McKee is an astrophysicist.McKee obtained a Ph.D. from the University of California, Berkeley in 1970 under advisor George B. Field. In 1974, he was appointed Professor of Physics and Astronomy, University of California at Berkeley. He is a member of the National Academy of...
and Jeremiah OstrikerJeremiah P. OstrikerJeremiah Paul Ostriker is an astrophysicist at Princeton University. He received his B.A. from Harvard, his Ph.D at the University of Chicago, and then carried out post-doctoral work at the University of Cambridge. From 1971 to 1995, Ostriker was a professor at Princeton, and served as Provost...
propose a three component theory of the interstellar medium - 1990 — Foreground "contamination" data from the COBECOBEThe COsmic Background Explorer , also referred to as Explorer 66, was a satellite dedicated to cosmology. Its goals were to investigate the cosmic microwave background radiation of the universe and provide measurements that would help shape our understanding of the cosmos.This work provided...
spacecraft provides the first all-sky map of the ISM in microwaveMicrowaveMicrowaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
bands.