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A supermassive black hole, obscured by cosmic dust, powers the nearby active galaxy NGC 1068. Neutrinos, which rarely interact with matter, could provide information on the galaxy’s active core. We searched for neutrino emission from astrophysical objects using data recorded with the IceCube neutrino detector between 2011 and 2020. The positions of 110 known gamma-ray sources were individually searched for neutrino detections above atmospheric and cosmic backgrounds. We found that NGC 1068 has an excess of 79þ22 20 neutrinos at tera–electron volt energies, with a global significance of 4.2s, which we interpret as associated with the active galaxy. The flux of high-energy neutrinos that we measured from NGC 1068 is more than an order of magnitude higher than the upper limit on emissions of tera–electron volt gamma rays from this source. [ABSTRACT FROM AUTHOR]

The article focuses on research examining the source of dust observed in the distant, early universe. It comments on the use of infrared observations of warm dust detected near the center of the Sagittarius A East supernova remnant (SNR) at the center of the Milky Way and detected the presence of dust within an older SNR that survived the passage of the reverse shock. It speculates supernova could be the primary dust-production mechanism in galaxies of the early universe.

The article focuses on the collection of interstellar dust (ISD) particles by the Stardust Interstellar Preliminary Examination (ISPE) spacecraft. Topics include the composition of ISD, in situ dust measurement and spectroscopy, and research on the interplanetary origin of ISD. Information is provided on ISD modelling and the crystallinity of silicates.

The article focuses on the creation of three dimensional (3D) maps of diffuse interstellar bands (DIBs). Topics include the spatial distribution of interstellar dust, the study of optical and near-infrared (NIR) wavelengths, and the interstellar medium (ISM). Information is provided on modeling of the results of the Radial Velocity Experiment (RAVE) spectroscopic survey.

The statistics of discovered exoplanets suggest that planets form efficiently. However, there are fundamental unsolved problems, such as excessive inward drift of particles in protoplanetary disks during planet formation. Recent theories invoke dust traps to overcome this problem. We report the detection of a dust trap in the disk around the star Oph IRS 48 using observations from the Atacama Large Millimeter/submillimeter Array (ALMA). The 0.44-millimeter-wavelength continuum map shows high-contrast crescent-shaped emission on one side of the star, originating from millimeter-sized grains, whereas both the mid-infrared image (micrometer-sized dust) and the gas traced by the carbon monoxide 6-5 rotational line suggest rings centered on the star. The difference in distribution of big grains versus small grains/gas can be modeled with a vortex-shaped dust trap triggered by a companion. [ABSTRACT FROM AUTHOR]

It is not known whether brown dwarfs [stellar-like objects with masses less than the hydrogen-burning limit, 0.075 solar mass (M⊙)] are formed in the same way as solar-type stars or by some other process. Here we report the clear-cut identification of a self-gravitating condensation of gas and dust with a mass in the brown-dwarf regime, made through millimeter interferometric observations. The level of thermal millimeter continuum emission detected from this object indicates a mass ~0.02 to 0.03 M⊙, whereas the small radius, <460 astronomical units, and narrow spectral lines imply a dynamical mass of 0.015 to 0.02 M⊙. The identification of such a pre-brown dwarf core supports models according to which brown dwarfs are formed in the same manner as hydrogen-burning stars. [ABSTRACT FROM AUTHOR]

Saturn's moon Rhea had been considered massive enough to retain a thin, externally generated atmosphere capable of locally affecting Saturn's magnetosphere. The Cassini spacecraft's in situ observations reveal that energetic electrons are depleted in the moon's vicinity. The absence of a substantial exosphere implies that Rhea's magnetospheric interaction region, rather than being exclusively induced by sputtered gas and its products, likely contains solid material that can absorb magnetospheric particles. Combined observations from several instruments suggest that this material is in the form of grains and boulders up to several decimetres in size and orbits Rhea as an equatorial debris disk. Within this disk may reside denser, discrete rings or arcs of material. [ABSTRACT FROM AUTHOR]

The Stardust mission returned the first sample of a known outer solar system body, comet 81P/Wild 2, to Earth. The sample was expected to resemble chondritic porous interplanetary dust particles because many, and possibly all, such particles are derived from comets. Here, we report that the most abundant and most recognizable silicate materials in chondritic porous interplanetary dust particles appear to be absent from the returned sample, indicating that indigenous outer nebula material is probably rare in 81P/Wild 2. Instead, the sample resembles chondritic meteorites from the asteroid belt, composed mostly of inner solar nebula materials. This surprising finding emphasizes the petrogenetic continuum between comets and asteroids and elevates the astrophysical importance of stratospheric chondritic porous interplanetary dust particles as a precious source of the most cosmically primitive astromaterials. [ABSTRACT FROM AUTHOR]

Infrared spectra of material captured from comet 81P/Wild 2 by the Stardust spacecraft reveal indigenous aliphatic hydrocarbons similar to those in interplanetary dust particles thought to be derived from comets, but with longer chain lengths than those observed in the diffuse interstellar medium. Similarly, the Stardust samples contain abundant amorphous silicates in addition to crystalline silicates such as olivine and pyroxene. The presence of crystalline silicates in Wild 2 is consistent with mixing of solar system and interstellar matter. No hydrous silicates or carbonate minerals were detected, which suggests a lack of aqueous processing of Wild 2 dust. [ABSTRACT FROM AUTHOR]

Particles emanating from comet 81P/Wild 2 collided with the Stardust spacecraft at 6.1 kilometers per second, producing hypervelocity impact features on the collector surfaces that were returned to Earth. The morphologies of these surprisingly diverse features were created by particles varying from dense mineral grains to loosely bound, polymineralic aggregates ranging from tens of nanometers to hundreds of micrometers in size. The cumulative size distribution of Wild 2 dust is shallower than that of comet Halley, yet steeper than that of comet Grigg-Skjellerup. [ABSTRACT FROM AUTHOR]

Organics found in comet 81P/Wild 2 samples show a heterogeneous and unequilibrated distribution in abundance and composition. Some organics are similar, but not identical, to those in interplanetary dust particles and carbonaceous meteorites. A class of aromatic-poor organic material is also present. The organics are rich in oxygen and nitrogen compared with meteoritic organics. Aromatic compounds are present, but the samples tend to be relatively poorer in aromatics than are meteorites and interplanetary dust particles. The presence of deuterium and nitrogen-is excesses suggest that some organics have an interstellar/protostellar heritage. Although the variable extent of modification of these materials by impact capture is not yet fully constrained, a diverse suite of organic compounds is present and identifiable within the returned samples. [ABSTRACT FROM AUTHOR]

An interplanetary dust particle contains a submicrometer crystalline silicate aggregate of probable supernova origin. The grain has a pronounced enrichment in [sup 18]O/[sup 16]O (13 times the solar value) and depletions in [sup 17]O/[sup 16]O (one-third solar) and [sup 29]Si/[sup 28]Si (<0.8 times solar), indicative of formation from a type II supernova. The aggregate contains olivine (forsterite 83) grains <100 nanometers in size, with microstructures that are consistent with minimal thermal alteration. This unusually iron-rich olivine grain could have formed by equilibrium condensation from cooling supernova ejecta if several different nucleosynthetic zones mixed in the proper proportions. The supernova grain is also partially encased in nitrogen-15-rich organic matter that likely formed in a presolar cold molecular cloud. [ABSTRACT FROM AUTHOR]

The 2175 angstrom extinction feature is the strongest (visible-ultraviolet) spectral signature of dust in the interstellar medium. Forty years after its discovery, the origin of the feature and the nature of the carrier(s) remain controversial. Using a transmission electron microscope, we detected a 5.7-electron volt (2175 angstrom) feature in interstellar grains embedded within interplanetary dust particles (IDPs). The carriers are organic carbon and amorphous silicates that are abundant in IDPs and in the interstellar medium. These multiple carriers may explain the enigmatic invariant central wavelength and variable bandwidth of the astronomical 2175 angstrom feature. [ABSTRACT FROM AUTHOR]

Reports on the investigation into interplanetary and interstellar dust grains entering Jupiter's magnetosphere which form a detectable diffuse faint ring of exogenic material. Use of the dust detector on the Galileo spacecraft; Size of particles collected; Details of orbital integrations used during the investigation.

Discusses the phenomenon of irradiated glass with embedded metal and sulfides (GEMS) in cometary dust. Analysis of bulk stoichiometric oxygen excess; Identification of presolar interplanetary components in meteoritic materials; Role of helium and hydrogen ion bombardment in the erosional process.

Presents results from the examination of hyper-velocity impact craters on the space-facing end of the Long Duration Exposure Facility satellite. Measurement of mass accretion rate for cosmic dust; Comparison with rates for material from 1 centimeter to 10 kilometers in diameter.

In recent decades, a number of molecules and diverse dust features have been identified by astronomical observations in various environments. Most of the dust that determines the physical and chemical characteristics of the interstellar medium is formed in the outflows of asymptotic giant branch stars and is further processed when these objects become planetary nebulae. We studied the environment of Tc 1, a peculiar planetary nebula whose infrared spectrum shows emission from cold and neutral C60 and C70. The two molecules amount to a few percent of the available cosmic carbon in this region. This finding indicates that if the conditions are right, fullerenes can and do form efficiently in space. [ABSTRACT FROM AUTHOR]

The article presents information related to the interstellar dust grains. The interstellar dust consists of grains of silicate and carbonaceous composition and are found in the interplanetary medium of solar system. It plays an important role in regulating thermal energy balance, in making chemical reactions in molecular clouds and in the formation of planetesimals around main-sequence stars. A quantitative chemical evolution model demonstrate that supernova blast waves are very competent in destroying dust and the lifetime of dust is about 600 million years, whereas the rate at which the dust is renewed is about 3 billion years. The main interstellar dust production centre are Asymptotic Giant Branch stars and core-collapse supernovae. These stars produce dust in mass outflows and core-collapse supernovae.

We compared near-infrared observations of the recently discovered outer rings of Uranus with Hubble Space Telescope results. We find that the inner ring, R/2003 U 2, is red, whereas the outer ring, R/2003 U 1, is very blue. Blue is an unusual color for rings; Saturn's enigmatic E ring is the only other known example. By analogy to the E ring, R/2003 U 1 is probably produced by impacts into the embedded moon Mab, which apparently orbits at a location where nongravitational perturbations favor the survival and spreading of submicron-sized dust. R/2003 U 2 more closely resembles Saturn's G ring, which is red, a typical color for dusty rings. [ABSTRACT FROM AUTHOR]

During Cassini's close flyby of Enceladus on 14 July 2005, the High Rate Detector of the Cosmic Dust Analyzer registered micron-sized dust particles enveloping this satellite. The dust impact rate peaked about 1 minute before the closest approach of the spacecraft to the moon. This asymmetric signature is consistent with a locally enhanced dust production in the south polar region of Enceladus. Other Cassini experiments revealed evidence for geophysical activities near Enceladus' south pole: a high surface temperature and a release of water gas. Production or release of dust particles related to these processes may provide the dominant source of Saturn's E ring. [ABSTRACT FROM AUTHOR]

Presents research which explored the chemistry resulting in the formation of large carbon-bearing molecules and dust in the interior of an expanding supernova. Equations governing their abundances; Condensation of carbon dust; Rate of growth for carbon dust; Origin of presolar micrometer-sized carbon solids found in meteorites.

Presents research which conducted numerical modeling of the orbital evolution of interplanetary dust particles. Rate of dust accretion by Earth having a 100,000-year periodicity; Variations anticorrelated with Earth's changing orbital eccentricity; Periodicity of extraterrestrial helium-3 concentrations from deep-sea sediments; Impact of collisions between large bodies in the asteroid belt.

Discusses the eleven short bursts, or streams, of dust recorded on the cosmic dust detector on the Ulysses spacecraft between September of 1991 and October of 1992. The jovian origin of the streams; How their trajectories were impacted by solar wind magnetic field forces; Estimated mass and velocity of the streams; How the measurements differ from previous reports and expectations.

Discusses the theory of dusty plasma in astrophysics. Influence of electromagnetism in dusty plasmas; Speculation on the role of charged dust in the formation of the planets and other phenomena; Disagreements between gravitational theorists and plasma theorists.

Galaxy mergers and gas accretion from the cosmic web drove the growth of galaxies and their central black holes at early epochs. We report spectroscopic imaging of a multiple merger event in the most luminous known galaxy, WISE J224607.56−052634.9 (W2246−0526), a dust-obscured quasar at redshift 4.6, 1.3 billion years after the Big Bang. Far-infrared dust continuum observations show three galaxy companions around W2246−0526 with disturbed morphologies, connected by streams of dust likely produced by the dynamical interaction. The detection of tidal dusty bridges shows that W2246−0526 is accreting its neighbors, suggesting that merger activity may be a dominant mechanism through which the most luminous galaxies simultaneously obscure and feed their central supermassive black holes. [ABSTRACT FROM AUTHOR]

A summary is presented of an article published online at http://dx.doi.org/10.1126/science.aat3185 concerning observations of Saturn's rings by the Cassini space probe which detected dust grains falling into the planet's atmosphere. It states that ionospheric infrared emissions were detected by the Cassini cosmic dust analyzer to test a hypothesis on ring rain. It mentions that the ejecta was composed of silicate and water ice and interacted with Saturn's offset magnetic field.