Results 51 to 60 of about 22,763 (197)

Hydrodynamic Modeling of the Interaction of Winds within a Collapsing Turbulent Gas Cloud

Advances in Astronomy, Volume 2015, Issue 1, 2015., 2015
By using the particle‐based code Gadget2, we follow the evolution of a gas giant molecular cloud, in which a set of gas particles representing the wind are created by a Monte Carlo scheme and suddenly move outwards from the cloud’s center. The particles representing the gas cloud initially have a velocity according to a turbulent spectrum built in a ...
Guillermo Arreaga-García, Julio Saucedo-Morales, William Reach   +2 more
wiley   +1 more source

Physicochemical Constraints on the Abiotic Polymerization of Nucleotides Into RNA

Journal of Geophysical Research: Biogeosciences, Volume 130, Issue 11, November 2025.
Abstract One of the key steps in the origin of life is the polymerization of nucleotides into nucleic acids like RNA. We have quantified the energetic impact of temperature, pressure, and composition on the polymerization of nucleotides into RNA using the Gibbs function. These Gibbs energies have been used to calculate the probability that a nucleotide
D. E. LaRowe, J. M. Dick
wiley   +1 more source

A Hydrodynamical Model of a Rotating Wind Source and Its Effects on the Collapse of a Rotating Core

Advances in Astronomy, Volume 2015, Issue 1, 2015., 2015
This work presents three‐dimensional hydrodynamical simulations with the fully parallel GAGDET2 code, to model a rotating source that emits wind in order to study the subsequent dynamics of the wind in three independent scenarios. In the first scenario we consider several models of the wind source, which is characterized by a rotation velocity Vrot and
Guillermo Arreaga-Garcia, Elmetwally Elabbasy   +1 more
wiley   +1 more source

Gamma-rays from massive protostars

, 2009
Fil: Paredes, Josep Maria. Universidad de Barcelona.
Romero, Gustavo Esteban, Araudo, Anabella Teresa, Bosch Ramon, Valentí, Paredes, Josep Maria   +3 more
openaire   +5 more sources

Characterizing Magnetic Properties of Young Protostars in Orion

The Astrophysical Journal
The B -field Orion Protostellar Survey (BOPS) recently obtained polarimetric observations at 870 μ m toward 61 protostars in the Orion molecular clouds with ∼1″ spatial resolution using the Atacama Large Millimeter/submillimeter Array.
Bo Huang, Josep M. Girart, Ian W. Stephens, Philip C. Myers, Qizhou Zhang, Paulo Cortes, Álvaro Sánchez-Monge, Manuel Fernández López, Valentin J. M. Le Gouellec, Tom Megeath, Nadia M. Murillo, John M. Carpenter, Zhi-Yun Li, Junhao Liu, Leslie W. Looney, Sarah Sadavoy, Nicole Karnath, Woojin Kwon   +17 more
doaj   +1 more source

Miller and Urey in the Universe: detecting prebiotic molecules in star-forming regions

Revista Brasileira de Ensino de Física
Astronomical observations have revealed that the simple molecules used in the Miller and Urey experiments (H2O, CH4, NH3, and H2), along with methanol, carbon monoxide, and carbon dioxide, among many others, are abundant in solid form in molecular clouds
Caroline Antunes Rosa, Alexandre Bergantini, Marcelo Emilio, Enio Frota da Silveira, Laerte Andrade, Eduardo Janot Pacheco, Claudia Lage   +6 more
doaj   +1 more source

Episodic accretion, protostellar radiative feedback, and their role in low-mass star formation

, 2012
Protostars grow in mass by accreting material through their discs, and this accretion is initially their main source of luminosity. The resulting radiative feedback heats the environments of young protostars, and may thereby suppress further ...
Hubber, David A., Stamatellos, Dimitris, Whitworth, Anthony P.   +2 more
core   +1 more source

Subarcsecond resolution observations of warm water towards three deeply embedded low-mass protostars [PDF]

, 2012
Water is present during all stages of star formation: as ice in the cold outer parts of protostellar envelopes and dense inner regions of circumstellar disks, and as gas in the envelopes close to the protostars, in the upper layers of circumstellar disks
Attard, Bergin, Bisschop, Blake, Boogert, Bottinelli, Bottinelli, Brinch, Caselli, Ceccarelli, Ceccarelli, Ceccarelli, Cernicharo, Chandler, Charnley, Choi, Desmurs, Di Francesco, Draine, E. F. van Dishoeck, Enoch, Franklin, Fraser, Furuya, Garrod, Gensheimer, Gibb, Girart, Gutermuth, Harwit, Herbst, Herczeg, Hogerheijde, J. K. Jørgensen, Jacq, Jennings, Jørgensen, Jørgensen, Jørgensen, Jørgensen, Jørgensen, Jørgensen, Jørgensen, Jørgensen, Kristensen, Larson, Liseau, Looney, M. V. Persson, Maret, Marvel, Müller, Neufeld, Nisini, Pickett, Pontoppidan, Reipurth, Rodgers, Sandell, Sandell, van der Tak, van Dishoeck, van Dishoeck, Visser, Visser, Wakelam, Watson, Wilson   +67 more
core   +2 more sources

Rotational Spectroscopy of the Acetone‐Water Complex: Large Amplitude Motions

ChemPhysChem, Volume 25, Issue 21, November 4, 2024.
The structure and dynamics of the acetone‐water complex were explored using jet‐cooled rotational spectroscopy and computational chemistry calculations. Our detailed rot‐tunneling analyses of acetone‐H2O and −D2O revealed that the interaction with water disrupts the equivalence of the two methyl rotors, resulting in a significantly lower methyl rotor ...
Jiao Gao, Colton D. Carlson, Javix Thomas, Yunjie Xu, Wolfgang Jäger   +4 more
wiley   +1 more source

The Natural Science Underlying Big History

The Scientific World Journal, Volume 2014, Issue 1, 2014., 2014
Nature’s many varied complex systems—including galaxies, stars, planets, life, and society—are islands of order within the increasingly disordered Universe. All organized systems are subject to physical, biological, or cultural evolution, which together comprise the grander interdisciplinary subject of cosmic evolution.
Eric J. Chaisson, Lukas Kratochvil
wiley   +1 more source