Intergalactic dust

Intergalactic dust is cosmic dust in between galaxies in intergalactic space.[1] Evidence for intergalactic dust has been suggested as early as 1949, and study of it grew throughout the late 20th century.[1] There are large variations in the distribution of intergalactic dust.[1] The dust may affect intergalactic distance measurements, such as to supernova and quasars in other galaxies.[2]

Intergalactic dust can form intergalactic dust clouds, known to exist around some galaxies since the 1960s.[1] By the 1980s, at least four intergalactic dust clouds had been discovered within several megaparsec (Mpc) of the Milky Way galaxy,[1] exemplified by the Okroy cloud.[1]

In February 2014, NASA announced a greatly upgraded database for tracking polycyclic aromatic hydrocarbons (PAHs) in the universe. According to scientists, more than 20% of the carbon in the universe may be associated with PAHs, possible starting materials for the formation of life. PAHs seem to have been formed as early as two billion years after the big bang, are widespread throughout the universe, and are associated with new stars and exoplanets.[3]

See also


  1. ^ a b c d e f M. E. Bailey, David Arnold Williams - Dust in the universe: the proceedings of a conference at the Department of Astronomy, University of Manchester, 14-18 December 1987 - Page 509 (Google Books accessed 2010)
  2. ^ Nancy Atkinson - Intergalactic Dust Could Be Messing Up Observations, Calculations (February 26, 2009) - Universe Today
  3. ^ Hoover, Rachel (February 21, 2014). "Need to Track Organic Nano-Particles Across the Universe? NASA's Got an App for That". NASA. Retrieved February 22, 2014.

External links

Aluminium(II) oxide

Aluminium(II) oxide or aluminium monoxide is a compound of aluminium and oxygen with the chemical formula AlO. It has been detected in the gas phase after explosion of aluminized grenades in the upper atmosphere and in stellar absorption spectra.

Astronomical object

An astronomical object or celestial object is a naturally occurring physical entity, association, or structures that exists in the observable universe. In astronomy, the terms object and body are often used interchangeably. However, an astronomical body or celestial body is a single, tightly bound, contiguous entity, while an astronomical or celestial object is a complex, less cohesively bound structure, which may consist of multiple bodies or even other objects with substructures.

Examples of astronomical objects include planetary systems, star clusters, nebulae, and galaxies, while asteroids, moons, planets, and stars are astronomical bodies. A comet may be identified as both body and object: It is a body when referring to the frozen nucleus of ice and dust, and an object when describing the entire comet with its diffuse coma and tail.

Carbon monosulfide

Carbon monosulfide is a chemical compound with the formula CS. This diatomic molecule is the sulfur analogue of carbon monoxide, and is unstable as a solid or a liquid, but it has been observed as a gas both in the laboratory and in the interstellar medium. The molecule resembles carbon monoxide with a triple bond between carbon and sulfur. The molecule is not intrinsically unstable, but it tends to polymerize. This tendency reflects the greater stability of C−S single bonds.

Polymers with the formula (CS)n have been reported. Also, CS has been observed as a ligand in certain transition metal complexes.

Circumstellar envelope

A circumstellar envelope (CSE) is a part of a star that has a roughly spherical shape and is not gravitationally bound to the star core. Usually circumstellar envelopes are formed from the dense stellar wind, or they are present before the formation of the star. Circumstellar envelopes of the old stars (Mira variables and OH/IR stars) eventually evolve into protoplanetary nebulae, and circumstellar envelopes of the young stellar objects evolve into circumstellar discs.

Cosmic dust

Cosmic dust, also called extraterrestrial dust or space dust, is dust which exists in outer space, or has fallen on Earth. Most cosmic dust particles are between a few molecules to 0.1 µm in size. Cosmic dust can be further distinguished by its astronomical location: intergalactic dust, interstellar dust, interplanetary dust (such as in the zodiacal cloud) and circumplanetary dust (such as in a planetary ring).

In the Solar System, interplanetary dust causes the zodiacal light. Solar System dust includes comet dust, asteroidal dust, dust from the Kuiper belt, and interstellar dust passing through the Solar System. Thousands of tons of cosmic dust are estimated to reach the Earth's surface every year, with each grain having a mass between 10−16 kg (0.1 pg) and 10−4 kg (100 mg). The density of the dust cloud through which the Earth is traveling is approximately 10−6/m3.Cosmic dust contains some complex organic compounds (amorphous organic solids with a mixed aromatic–aliphatic structure) that could be created naturally, and rapidly, by stars. A smaller fraction of dust in space is "stardust" consisting of larger refractory minerals that condensed as matter left by stars.

Interstellar dust particles were collected by the Stardust spacecraft and samples were returned to Earth in 2006.


Cyclopropenone is an organic compound with molecular formula C3H2O consisting of a cyclopropene carbon framework with a ketone functional group. It is a colorless, volatile liquid that boils near room temperature. Neat cyclopropenone polymerizes upon standing at room temperature. The chemical properties of the compound are dominated by the strong polarization of the carbonyl group, which gives a partial positive charge with aromatic stabilization on the ring and a partial negative charge on oxygen. It is an aromatic compound.

Extragalactic astronomy

Extragalactic astronomy is the branch of astronomy concerned with objects outside the Milky Way galaxy. In other words, it is the study of all astronomical objects which are not covered by galactic astronomy.

As instrumentation has improved, distant objects can now be examined in more detail. It is therefore useful to sub-divide this branch into Near-Extragalactic Astronomy and Far-Extragalactic Astronomy. The former deals with objects such as the galaxies of the Local Group, which are close enough to allow very detailed analyses of their contents (e.g. supernova remnants, stellar associations).

Some topics include:

Galaxy groups

Galaxy clusters, Superclusters

Galaxy filaments

Active galactic nuclei, Quasars

Radio galaxies


Intergalactic stars

Intergalactic dust

the observable universe

Galactic astronomy

Galactic astronomy is the study of the Milky Way galaxy and all its contents. This is in contrast to extragalactic astronomy, which is the study of everything outside our galaxy, including all other galaxies.

Galactic astronomy should not be confused with galaxy formation and evolution, which is the general study of galaxies, their formation, structure, components, dynamics, interactions, and the range of forms they take.

The Milky Way galaxy, where the Solar System belongs, is in many ways the best studied galaxy, although important parts of it are obscured from view in visible wavelengths by regions of cosmic dust. The development of radio astronomy, infrared astronomy and submillimetre astronomy in the 20th Century allowed the gas and dust of the Milky Way to be mapped for the first time.


Intergalactic may refer to:

Intergalactic space

Intergalactic travel, travel between galaxies in science fiction and speculation

"Intergalactic" (song), a song by the Beastie Boys

Interplanetary medium

The interplanetary medium (IPM) is the material which fills the Solar System, and through which all the larger Solar System bodies, such as planets, dwarf planets, asteroids, and comets, move.


Ketenimines are a group of organic compounds sharing a common functional group with the general structure R1R2C=C=NR3. A ketenimine is a cumulated alkene and imine and is related to an allene and a ketene.

The parent compound is ketenimine or CH2CNH. The most recent work by Bane et al. investigates the rovibrational structure of the ν8 and ν12 bands in the high-resolution FTIR spectrum, complementing the earlier analysis of the pure rotational spectrum. This pair of Coriolis coupled bands provide a rare example where intensity sharing between bands yields sufficient intensity for an otherwise invisible band (ν12).

Methoxy group

A methoxy group is the functional group consisting of a methyl group bound to oxygen. This alkoxy group has the formula O–CH3. On a benzene ring, the Hammett equation classifies a methoxy substituent as an electron-donating group.


Methylidynephosphane (phosphaethyne) is a chemical compound which was the first phosphaalkyne compound discovered, containing the unusual C≡P carbon-phosphorus triple bond.

Octatetraynyl radical

Octatetraynyl radical (C8H) is an organic free radical with eight carbon atoms linked in a chain with alternating single bonds and triple bonds.

In 2007 negatively charged octatetraynyl was detected in Galactic molecular source TMC-1, making it the second type of anion to be found in the interstellar medium (after Hexatriynyl radical) and the largest such molecule detected to date.

Phosphorus mononitride

Phosphorus mononitride is an inorganic compound with the chemical formula PN. Containing only phosphorus and nitrogen, this material is classified as a binary nitride.

It is the first identified phosphorus compound in the interstellar medium.It is an important molecule in interstellar medium and the atmospheres of Jupiter and Saturn.

Photodissociation region

Photodissociation regions (or photon-dominated regions, or PDRs) are predominantly neutral regions of the interstellar medium in which far ultraviolet photons strongly influence the gas chemistry and act as the most important source of heat. They occur in any region of interstellar gas that is dense and cold enough to remain neutral, but that has too low a column density to prevent the penetration of far-UV photons from distant, massive stars. A typical and well-studied example is the gas at the boundary of a giant molecular cloud. PDRs are also associated with HII regions, reflection nebulae, active galactic nuclei, and Planetary nebulae. All the atomic gas and most of the molecular gas in the galaxy is found in PDRs.


Propynal is an organic compound with molecular formula HC2CHO. It is the simplest chemical compound containing both alkyne and aldehyde functional groups. It is a colorless liquid with explosive properties.The compound exhibits reactions expected for an electrophilic alkynyl aldehyde. It is a dienophile and a good Michael acceptor. Grignard reagents add to the carbonyl center.

Titanium oxide

Titanium oxide may refer to:

Titanium dioxide (titanium(IV) oxide), TiO2

Titanium(II) oxide (titanium monoxide), TiO, a non-stoichiometric oxide

Titanium(III) oxide (dititanium trioxide), Ti2O3



δ-TiOx (x= 0.68 - 0.75)

TinO2n−1 where n ranges from 3–9 inclusive, e.g. Ti3O5, Ti4O7, etc.

Triatomic molecule

Triatomic molecules are molecules composed of three atoms, of either the same or different chemical elements. Examples include H2O, CO2 (pictured) and HCN.


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