Is deuterium of cosmological or of galactic origin

Ostriker, J.P.; Tinsley, Beatrice M.

doi:10.1086/181940

Cited by 26 publications

(27 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For our Galaxy, further evidence of the ongoing inflow of low-metallicity material comes from the presence of deuterium in the solar neighborhood (Linsky 2003), as well as in the Galactic center (Lubowich et al 2000). As deuterium is destroyed in stars and as there is no other known source of deuterium in the Milky Way, it must have a cosmological and extragalactic origin (Ostriker & Tinsley 1975;Chiappini et al 2002).…”

Section: General Considerationsmentioning

confidence: 92%

Accretion-driven turbulence as universal process: galaxies, molecular clouds, and protostellar disks

Klessen¹,

Hennebelle²

2010

A&A

317

353

View full text Add to dashboard Cite

Context. Even though turbulent motions are found everywhere in astrophysical systems, the origin of this turbulence is poorly understood. When cosmic structures form, they grow in mass via accretion from their surrounding environment. Aims. We propose that accretion is able to drive internal turbulent motions in a wide range of astrophysical objects and study this process in the case of galaxies, molecular clouds, and protoplanetary disks. Methods. We use a combination of numerical simulations and analytical arguments to predict the level of turbulence as a function of the accretion rate, the dissipation scale, and the density contrast, and compare our models with observational data. Results. We find that in Milky Way type galaxies the observed level of turbulence in the interstellar medium can be explained by accretion, provided that the galaxies gain mass at a rate comparable to the rate at which they form stars. This process is particularly relevant in the extended outer disks beyond the star-forming radius. For it to drive turbulence in dwarf galaxies, the accretion rate needs to exceed the star formation rate by a large factor, so we expect other sources to dominate. We also calculate the rate at which molecular clouds grow in mass when they build up from the atomic component of the galactic gas and find that their internal turbulence is likely to be driven by accretion as well. It is the very process of cloud formation that excites turbulent motions on small scales by establishing the turbulent cascade. In the case of T Tauri disks, we show that accretion can drive subsonic turbulence if the rate at which gas falls onto the disk is comparable to the rate at which disk material accretes onto the central star. This also explains the observed relation of accretion rate and stellar mass,Ṁ ∝ M 1.8 . The efficiency required to convert infall motion into turbulence is a few percent in all three cases. Conclusions. We conclude that accretion-driven turbulence is a universal concept with far-reaching implications for a wide range of astrophysical objects.

show abstract

Section: General Considerationsmentioning

confidence: 92%

Accretion-driven turbulence as universal process: galaxies, molecular clouds, and protostellar disks

Klessen¹,

Hennebelle²

2010

A&A

317

353

View full text Add to dashboard Cite

show abstract

“…In our Galaxy, the presence of deuterium at the solar neighborhood (Linsky, 2003) as well as in the Galactic Center (Lubowich et al, 2000) also points towards a continuous inflow of low-metallicity material. As deuterium is destroyed in stars and as there is no other known source of deuterium in the Milky Way, it must be of cosmological and extragalactic origin (Ostriker & Tinsley, 1975;Chiappini et al, 2002).…”

Section: Accretion Onto the Galaxymentioning

confidence: 99%

Physical Processes in the Interstellar Medium

Klessen

Glover

2015

Star Formation in Galaxy Evolution: Connecting Numerical Models to Reality

160

View full text Add to dashboard Cite

Interstellar space is filled with a dilute mixture of charged particles, atoms, molecules and dust grains, called the interstellar medium (ISM). Understanding its physical properties and dynamical behavior is of pivotal importance to many areas of astronomy and astrophysics. Galaxy formation and evolution, the formation of stars, cosmic nucleosynthesis, the origin of large complex, prebiotic molecules and the abundance, structure and growth of dust grains which constitute the fundamental building blocks of planets, all these processes are intimately coupled to the physics of the interstellar medium. However, despite its importance, its structure and evolution is still not fully understood. Observations reveal that the interstellar medium is highly turbulent, consists of different chemical phases, and is characterized by complex structure on all resolvable spatial and temporal scales. Our current numerical and theoretical models describe it as a strongly coupled system that is far from equilibrium and where the different components are intricately linked together by complex feedback loops. Describing the interstellar medium is truly a multi-scale and multi-physics problem. In these lecture notes we introduce the microphysics necessary to better understand the interstellar medium. We review the relations between large-scale and small-scale dynamics, we consider turbulence as one of the key drivers of galactic evolution, and we review the physical processes that lead to the formation of dense molecular clouds and that govern stellar birth in their interior.

show abstract

“…As deuterium is destroyed in stars and as there is no other known source of deuterium in the Milky Way, it is thought to be pristine material of extragalactic origin (Ostriker & Tinsley 1975;Chiappini et al 2002) falling on the Galaxy for the first time.…”

Section: Introductionmentioning

confidence: 99%

Radial gas motions in The H i Nearby Galaxy Survey (THINGS)

Schmidt

Bigiel

Klessen

et al. 2016

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

The study of 21 cm line observations of atomic hydrogen allows detailed insight into the kinematics of spiral galaxies. We use sensitive high-resolution VLA data from The HI Nearby Galaxy Survey (THINGS) to search for radial gas flows primarily in the outer parts (up to 3 × r 25 ) of ten nearby spiral galaxies. Inflows are expected to replenish the gas reservoir and fuel star formation under the assumption that galaxies evolve approximately in steady state. We carry out a detailed investigation of existing tilted ring fitting schemes and discover systematics that can hamper their ability to detect signatures of radial flows. We develop a new Fourier decomposition scheme that fits for rotational and radial velocities and simultaneously determines position angle and inclination as a function of radius. Using synthetic velocity fields we show that our novel fitting scheme is less prone to such systematic errors and that it is well suited to detect radial inflows in disks. We apply our fitting scheme to ten THINGS galaxies and find clear indications of, at least partly previously unidentified, radial gas flows, in particular for NGC 2403 and NGC 3198 and to a lesser degree for NGC 7331, NGC 2903 and NGC 6946. The mass flow rates are of the same order but usually larger than the star formation rates. At least for these galaxies a scenario in which continuous mass accretion feeds star formation seems plausible. The other galaxies show a more complicated picture with either no clear inflow, outward motions or complex kinematic signatures.

show abstract

Is deuterium of cosmological or of galactic origin

Cited by 26 publications

References 0 publications

Accretion-driven turbulence as universal process: galaxies, molecular clouds, and protostellar disks

Accretion-driven turbulence as universal process: galaxies, molecular clouds, and protostellar disks

Physical Processes in the Interstellar Medium

Radial gas motions in The H i Nearby Galaxy Survey (THINGS)

Contact Info

Product

Resources

About