Interstellar Dust Evolution: A Reservoir of Prebiotic Molecules

1993 ◽  
pp. 1-32 ◽  
Author(s):  
J. Mayo Greenberg ◽  
Celia X. Mendoza-Gómez
Keyword(s):  
Interstellar Dust ◽  
Prebiotic Molecules ◽  
Dust Evolution

scholarly journals The apparent anticorrelation between the mass opacity of interstellar dust and the surface density of interstellar gas

2020 ◽  
Vol 494 (1) ◽  
pp. L48-L52 ◽  
Author(s):  
F D Priestley ◽  
A P Whitworth
Keyword(s):  
Spatial Variation ◽  
Surface Density ◽  
Interstellar Dust ◽  
Line Of Sight ◽  
Interstellar Gas ◽  
Dust Mass ◽  
Dust Evolution ◽  
Disc Galaxies

ABSTRACT Recent analyses of Herschel observations suggest that in nearby disc galaxies the dust mass opacity at $500 \, {\rm \mu m}$, κ500, decreases with increasing gas surface density, ΣISM. This apparent anticorrelation between κ500 and ΣISM is opposite to the behaviour expected from theoretical dust evolution models; in such models, dust in denser, cooler regions (i.e. regions of increased ΣISM) tends to grow and therefore to have increased κ500. We show, using a toy model, that the presence of a range of dust temperatures along the line of sight can lead to spuriously low estimated values of κ500. If in regions of higher ΣISM the range of dust temperatures extends to lower values (as seems likely), the magnitude of this effect may be sufficient to explain the apparent anticorrelation between κ500 and ΣISM. Therefore there may not be any need for spatial variation in the intrinsic dust properties that run counter to theoretical expectations.

scholarly journals The Role of Terahertz and Far-IR Spectroscopy in Understanding the Formation and Evolution of Interstellar Prebiotic Molecules

2021 ◽  
Vol 8 ◽  
Author(s):  
Duncan V. Mifsud ◽  
Perry A. Hailey ◽  
Alejandra Traspas Muiña ◽  
Olivier Auriacombe ◽  
Nigel J. Mason ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Interstellar Medium ◽  
Molecular Clouds ◽  
Interstellar Dust ◽  
Future Research ◽  
Star Forming ◽  
Star Forming Regions ◽  
Research Areas ◽  
Interstellar Dust Grains ◽  
Prebiotic Molecules

Stellar systems are often formed through the collapse of dense molecular clouds which, in turn, return copious amounts of atomic and molecular material to the interstellar medium. An in-depth understanding of chemical evolution during this cyclic interaction between the stars and the interstellar medium is at the heart of astrochemistry. Systematic chemical composition changes as interstellar clouds evolve from the diffuse stage to dense, quiescent molecular clouds to star-forming regions and proto-planetary disks further enrich the molecular diversity leading to the evolution of ever more complex molecules. In particular, the icy mantles formed on interstellar dust grains and their irradiation are thought to be the origin of many of the observed molecules, including those that are deemed to be “prebiotic”; that is those molecules necessary for the origin of life. This review will discuss both observational (e.g., ALMA, SOFIA, Herschel) and laboratory investigations using terahertz and far-IR (THz/F-IR) spectroscopy, as well as centimeter and millimeter spectroscopies, and the role that they play in contributing to our understanding of the formation of prebiotic molecules. Mid-IR spectroscopy has typically been the primary tool used in laboratory studies, particularly those concerned with interstellar ice analogues. However, THz/F-IR spectroscopy offers an additional and complementary approach in that it provides the ability to investigate intermolecular interactions compared to the intramolecular modes available in the mid-IR. THz/F-IR spectroscopy is still somewhat under-utilized, but with the additional capability it brings, its popularity is likely to significantly increase in the near future. This review will discuss the strengths and limitations of such methods, and will also provide some suggestions on future research areas that should be pursued in the coming decade exploiting both space-borne and laboratory facilities.

On the formation and survival of complex prebiotic molecules in interstellar grain aggregates

2004 ◽  
Vol 3 (4) ◽  
pp. 287-293 ◽  
Author(s):  
Cesare Cecchi-Pestellini ◽  
Flavio Scappini ◽  
Rosalba Saija ◽  
Maria Antonia Iatì ◽  
Arianna Giusto ◽  
...  
Keyword(s):  
Interstellar Dust ◽  
Organic Molecules ◽  
Star Forming ◽  
Cometary Dust ◽  
Star Forming Regions ◽  
The Earth ◽  
Reducing Conditions ◽  
Prebiotic Molecules ◽  
Internal Volume ◽  
Dust Grain

The aggregation of interstellar grains as a result of ballistic collisions produces loosely packed structures with much of their internal volume composed by vacuum (cavities). The molecular material present on the surfaces of the cavities gives rise to a series of reactions induced by cosmic rays, UV radiation, thermal shocks, etc., in high reducing conditions. Thus, a terrestrial type chemistry is given the possibility to evolve inside these cavities. The resulting products are different and of a wider range than those from gas-phase or surface chemistry in molecular clouds. Under conditions similar to those in the aggregate cavities, laboratory experiments have produced amino acids, sugars and other organic compounds from simple precursors. In dense star-forming regions, the molecular species inside aggregates are efficiently shielded against the local UV field. The same molecules were incorporated in the material which formed the Earth, as well as other planets, during the process of its formation and afterwards fell on the surface via comets, meteorites, interstellar dust, etc. This was the source material that can produce, under favorable circumstances, the biopolymers needed for life. The astronomical observations of organic molecules in star-forming regions and the results of analyses of meteorites and cometary dust seem to support the present hypothesis that complex prebiotic molecules form inside dust aggregates and therein survive the journey to planetary systems. The Miller experiment is revisited through innumerable repetitions inside dust grain aggregates.

scholarly journals CH3NCO detections in observations and the laboratory

2017 ◽  
Vol 13 (S332) ◽  
pp. 360-363
Author(s):  
N. F. W. Ligterink ◽  
Keyword(s):  
Mass Spectrometry ◽  
Ir Spectroscopy ◽  
Interstellar Dust ◽  
Methyl Isocyanate ◽  
Interstellar Dust Grains ◽  
Select Group ◽  
Solar Type ◽  
Low Mass ◽  
Prebiotic Molecules ◽  
Grain Surface

AbstractMethyl isocyanate (CH3NCO) belongs to a select group of peptide-like prebiotic molecules. In this paper we present its first detection toward the solar type low-mass protostar IRAS16293-2422 (hereafter IRAS16293). CH3NCO is detected towards IRAS16293 as a warm component with Tex > 100 K and HNCO/CH3NCO ∼4-12. Also, its grain surface formation route is investigated in the laboratory. VUV processing of CH4:HNCO mixtures, investigated by IR spectroscopy and mass spectrometry, revealed that it can be formed by reactions of CH3 and with (H)NCO. Observations and experiments strongly hint that methyl isocyanate is formed on interstellar dust grains.

scholarly journals Dust evolution in the star forming turbulent interstellar medium

2006 ◽  
Vol 2 (S237) ◽  
pp. 47-52
Author(s):  
François Boulanger
Keyword(s):  
Interstellar Medium ◽  
Interstellar Dust ◽  
Dust Particles ◽  
Interstellar Clouds ◽  
Star Forming ◽  
Interstellar Turbulence ◽  
Star Forming Regions ◽  
Potential Impact ◽  
Dust Evolution ◽  
Small Dust

AbstractUnderstanding interstellar dust evolution is a major challenge underlying the interpretation of Spitzer observations of interstellar clouds, star forming regions and galaxies. I illustrate on-going work along two directions. I outline the potential impact of interstellar turbulence on the abundance of small dust particles in the diffuse interstellar medium and translucent sections of molecular clouds. I present results from an analysis of ISO and Spitzer observations of the central part of 30 Doradus, looking for dust evolution related to the radiative and dynamical impact of the R136 super star cluster on its parent molecular cloud.

scholarly journals Dust evolution, a global view I. Nanoparticles, nascence, nitrogen and natural selection … joining the dots

2016 ◽  
Vol 3 (12) ◽  
pp. 160221 ◽  
Author(s):  
A. P. Jones
Keyword(s):  
Natural Selection ◽  
Surface Chemistry ◽  
Interstellar Dust ◽  
Active Surface ◽  
Interstellar Clouds ◽  
Global View ◽  
Dust Evolution ◽  
Viable Model ◽  
Selection Of

The role and importance of nanoparticles for interstellar chemistry and beyond is explored within the framework of The Heterogeneous dust Evolution Model for Interstellar Solids (THEMIS), focusing on their active surface chemistry, the effects of nitrogen doping and the natural selection of interesting nanoparticle sub-structures. Nanoparticle-driven chemistry, and in particular the role of intrinsic epoxide-type structures, could provide a viable route to the observed gas phase OH in tenuous interstellar clouds en route to becoming molecular clouds. The aromatic-rich moieties present in asphaltenes probably provide a viable model for the structures present within aromatic-rich interstellar carbonaceous grains. The observed doping of such nanoparticle structures with nitrogen, if also prevalent in interstellar dust, could perhaps have important and observable consequences for surface chemistry and the formation of precursor pre-biotic species.

scholarly journals Dust evolution across the Horsehead nebula

2020 ◽  
Vol 639 ◽  
pp. A144
Author(s):  
T. Schirmer ◽  
A. Abergel ◽  
L. Verstraete ◽  
N. Ysard ◽  
M. Juvela ◽  
...  
Keyword(s):  
Interstellar Dust ◽  
Dust Emission ◽  
Outer Part ◽  
Minimum Size ◽  
Gas Temperature ◽  
Physical Conditions ◽  
Power Law Exponent ◽  
Dust Composition ◽  
Dust Evolution ◽  
Diffuse Medium

Context. Micro-physical processes on interstellar dust surfaces are tightly connected to dust properties (i.e. dust composition, size, and shape) and play a key role in numerous phenomena in the interstellar medium (ISM). The large disparity in physical conditions (i.e. density and gas temperature) in the ISM triggers an evolution of dust properties. The analysis of how dust evolves with the physical conditions is a stepping stone towards a more thorough understanding of interstellar dust. Aims. We highlight dust evolution in the Horsehead nebula photon-dominated region. Methods. We used Spitzer/IRAC (3.6, 4.5, 5.8 and 8 μm) and Spitzer/MIPS (24 μm) together with Herschel/PACS (70 and 160 μm) and Herschel/SPIRE (250, 350 and 500 μm) to map the spatial distribution of dust in the Horsehead nebula over the entire emission spectral range. We modelled dust emission and scattering using the THEMIS interstellar dust model together with the 3D radiative transfer code SOC. Results. We find that the nano-grain dust-to-gas ratio in the irradiated outer part of the Horsehead is 6–10 times lower than in the diffuse ISM. The minimum size of these grains is 2–2.25 times larger than in the diffuse ISM, and the power-law exponent of their size distribution is 1.1–1.4 times lower than in the diffuse ISM. In the denser part of the Horsehead nebula, it is necessary to use evolved grains (i.e. aggregates, with or without an ice mantle). Conclusions. It is not possible to explain the observations using grains from the diffuse medium. We therefore propose the following scenario to explain our results. In the outer part of the Horsehead nebula, all the nano-grain have not yet had time to re-form completely through photo-fragmentation of aggregates and the smallest of the nano-grain that are sensitive to the radiation field are photo-destroyed. In the inner part of the Horsehead nebula, grains most likely consist of multi-compositional mantled aggregates.

scholarly journals The essential elements of dust evolution

2019 ◽  
Vol 627 ◽  
pp. A38 ◽  
Author(s):  
A. P. Jones ◽  
N. Ysard
Keyword(s):  
Interstellar Dust ◽  
Oxygen Depletion ◽  
Interplanetary Dust ◽  
Essential Elements ◽  
Dust Particles ◽  
Interplanetary Dust Particles ◽  
Open Questions ◽  
Viable Solution ◽  
Organic Carbonate ◽  
Dust Evolution

Context. There remain many open questions relating to the depletion of elements into dust, e.g., exactly how are C and O incorporated into dust in dense clouds and, in particular, what drives the disappearance of oxygen in the denser interstellar medium? Aims. This work is, in part, an attempt to explain the apparently anomalous incorporation of O atoms into dust in dense clouds. Methods. We re-visit the question of the depletion of the elements incorporated into the carbonaceous component of interstellar dust, i.e., C, H, O, N and S, in the light of recent analyses of the organics in comets, meteorites and interplanetary dust particles. Results. We find that oxygen could be combined with ≈10–20 % of the carbon in the dust in dense regions in the form of a difficult to observe, organic carbonate, (−O−O>C =O), which could explain the unaccounted for 170–255 ppm oxygen depletion. Conclusions. We conclude that, while C, O and N atoms are depleted into an amorphous a-C:H:O:N phase, we posit that a significant fraction of C and O atoms could be sequestered into an organic carbonate, which provides a viable solution to the oxygen depletion problem. Further, the thermal or photolytic decomposition of this carbonate may have a bearing on the formation of CO2 in the ISM.

Chemical evolution of interstellar dust, comets and the origins of life

1989 ◽  
Vol 14 (2) ◽  
pp. 103-131 ◽  
Author(s):  
J. Mayo Greenberg ◽  
Nansheng Zhao ◽  
Joniek Hage
Keyword(s):  
Chemical Evolution ◽  
Interstellar Dust ◽  
Origins Of Life

PRONAOS observations of the interstellar medium: New insights on interstellar Dust

2002 ◽  
Vol 4 ◽  
pp. 9-9
Author(s):  
I. Ristorcelli ◽  
B. Stepnik ◽  
X. Dupac ◽  
A. Abergel ◽  
J. P. Bernard ◽  
...  
Keyword(s):  
Interstellar Medium ◽  
Interstellar Dust
Sign in / Sign up

Export Citation Format

Share Document