English
Related papers

Related papers: Can DNA bases be produced during molecular cloud c…

200 papers

Due to its polyionic character the DNA double helix is stable and biologically active only in salty aqueous media where its charge is compensated by solvent counterions. Monovalent metal ions are ubiquitous in DNA environment and they are…

Biological Physics · Physics 2007-05-23 Alexey K. Mazur

Stars are forming in our galaxy at a rate of between 1 and 4 solar masses of stars per year. In contrast to elliptical galaxies, which are largely devoid of star formation, star formation is still going on in spiral galaxies because of…

Astrophysics of Galaxies · Physics 2013-10-10 Clare Dobbs

We have extended our chemical and cosmological galaxy evolution model to calculate the abundance evolution for altogether 16 different elements in spiral galaxies in a chemically consistent way which is a considerable step towards a more…

Astrophysics · Physics 2007-05-23 Ulrich Lindner , Uta Fritze -- von Alvensleben , Klaus J. Fricke

In this work we compute the rates and numbers of different types of stars and phenomena (supernovae, novae, white dwarfs, merging neutron stars, black holes) that contributed to the chemical composition of the Solar System. This process is…

Solar and Stellar Astrophysics · Physics 2024-10-30 F. Fiore , F. Matteucci , E. Spitoni , M. Molero , P. Salucci , D. Romano , A. Vasini

We investigate the chemical and observational implications of repetitive transient dense core formation in molecular clouds. We allow a transient density fluctuation to form and disperse over a period of 1 Myr, tracing its chemical…

Astrophysics · Physics 2009-11-11 R. T. Garrod , D. A. Williams , J. M. C. Rawlings

We present preliminary results of stellar structure and nucleosynthesis calculations for some early stars. The study (still in progress) seeks to explore the expected chemical signatures of second generation low- and intermediate-mass stars…

Astrophysics · Physics 2007-05-23 S. W. Campbell

We demonstrate that $\sim10\,\textrm{s}$ after the core-collapse of a massive star, a thermonuclear explosion of the outer shells is possible for some (tuned) initial density and composition profiles, assuming that the neutrinos failed to…

High Energy Astrophysical Phenomena · Physics 2015-10-07 Doron Kushnir , Boaz Katz

The oxygenation of Earth's atmosphere 2.3 billion years ago, which on exoplanets is expected to be most detectable via the UV ozone feature at $\sim$0.25 $\mu$m, is often regarded as a sign of the emergence of photosynthetic life. On…

Observations have demonstrated that supernovae efficiently produce dust. This is consistent with the hypothesis that supernovae and asymptotic giant branch stars are the primary producers of dust in the Universe. However, there has been a…

High Energy Astrophysical Phenomena · Physics 2020-10-28 Jonathan D. Slavin , Eli Dwek , Mordecai-Mark Mac Low , Alex S. Hill

Stars are thought to form predominantly within filamentary molecular clouds. Recent studies have suggested that active star formation, including the formation of stellar clusters and massive stars, occurs within so-called "hub" structures,…

Astrophysics of Galaxies · Physics 2026-05-21 Raiga Kashiwagi , Kazunari Iwasaki , Kohji Tomisaka , Tsuyoshi Inoue

The origin of life and the origin of the universe are among the most important problems of science and they might be inextricably linked. Hydro-gravitational-dynamics (HGD) cosmology predicts hydrogen-helium gas planets in clumps as the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Carl H. Gibson , Rudolph E. Schild , N. C. Wickramasinghe

The thermodynamic dissipation theory for the origin of life asserts a thermodynamic imperative for the origin of life, suggesting that the fundamental molecules of life originated as self-organized molecular photon dissipative structures…

Biological Physics · Physics 2025-11-13 Andrés Ledesma , Karo Michaelian

Stars and planets are the fundamental objects of the Universe. Their formation processes, though related, may differ in important ways. Stars almost certainly form from gravitational collapse and probably have formed this way since the…

Earth and Planetary Astrophysics · Physics 2009-04-02 Alwyn Wootten , Bryan Butler , Antonio Hales , Stuartt Corder , Robert Brown , David Wilner

The chemical evolution in high-mass star-forming regions is still poorly constrained. Studying the evolution of deuterated molecules allows to differentiate between subsequent stages of high-mass star formation regions due to the strong…

Astrophysics of Galaxies · Physics 2015-07-15 Th. Gerner , Y. Shirley , H. Beuther , D. Semenov , H. Linz , T. Abertsson , Th. Henning

We study the formation of giant dense cloud complexes and of stars within them by means of SPH numerical simulations of the mildly supersonic collision of gas streams (``inflows'') in the warm neutral medium (WNM). The resulting…

Multiple mechanisms are proposed for the formation of giant molecular clouds (GMCs), from gravitational free-fall caused by self-gravity to stellar feedback-driven gas compression. Both the galactic environment and galaxy conditions could…

Stars accrete near invisible hydrogen dominated agglomerates. This population, the `dark matter,' effects the nature of stars. Measurements show plasma streams impacting Earth, planets, Sun and stars. This mass-energy source contradicts…

Astrophysics · Physics 2007-05-23 Maurice Dubin , Robert K. Soberman

Theories of the formation and early evolution of planetary systems postulate that planets are born in circumstellar disks, and undergo radial migration during and after dissipation of the dust and gas disk from which they formed. The…

The abundance evolution of interstellar dust species originating from stellar sources and from condensation in molecular clouds in the local interstellar medium of the Milky Way is studied and the input of dust material to the Solar System…

Astrophysics · Physics 2009-11-13 Svitlana Zhukovska , Hans-Peter Gail , Mario Trieloff

Star formation in magnetically subcritical clouds is investigated using a three-dimensional non-ideal magneto-hydrodynamics simulation. Since rapid cloud collapse is suppressed until the magnetic flux is sufficiently removed from the…

Solar and Stellar Astrophysics · Physics 2017-11-29 Masahiro N. Machida , Koki Higuchi , Satoshi Okuzumi