Results 41 to 50 of about 11,786 (248)

Pulsed accretion in a variable protostar [PDF]

Nature, 2013
Periodic increases in luminosity arising from variable accretion rates have been predicted for some close pre-main sequence binary stars as they grow from circumbinary disks. The phenomenon is known as "pulsed accretion" and can affect the orbital evolution and mass distribution of young binaries, as well as the potential for planet formation in the ...
Muzerolle, James, Furlan, Elise, Flaherty, Kevin, Balog, Zoltan, Gutermuth, Robert   +4 more
openaire   +3 more sources

Complex organic molecules in low-mass protostars on Solar System scales [PDF]

Astronomy & Astrophysics, 2020
Context. The chemical inventory of planets is determined by the physical and chemical processes that govern the early phases of star formation. Nitrogen-bearing species are of interest as many provide crucial precursors in the formation of life-related ...
P. Nazari, M. V. van Gelder, E. van Dishoeck, B. Tabone, M. V. van 't Hoff, N. Ligterink, H. Beuther, A. Boogert, A. Garatti, P. Klaassen, H. Linnartz, V. Taquet, Ł. Tychoniec   +12 more
semanticscholar   +1 more source

Protostar Formation in the Early Universe [PDF]

Science, 2008
The nature of the first generation of stars in the universe remains largely unknown. Observations imply the existence of massive primordial stars early in the history of the universe, and the standard theory for the growth of cosmic structure predicts that structures grow hierarchically through gravitational instability.
Yoshida, N., Omukai, K., Hernquist, L.
openaire   +6 more sources

The CALYPSO IRAM-PdBI survey of jets from Class 0 protostars [PDF]

Astronomy & Astrophysics, 2020
Aims. As a part of the CALYPSO Large Program, we aim to constrain the properties of protostellar jets and outflows by searching for corresponding emission in a sample of 21 Class 0 protostars covering a broad range of internal luminosities (Lint from 0 ...
L. Podio, B. Tabone, C. Codella, F. Gueth, A. Maury, S. Cabrit, B. Lefloch, S. Maret, A. Belloche, P. Andr'e, S. Anderl, M. Gaudel, L. Testi   +12 more
semanticscholar   +1 more source

Kinetics of the tautomerization of thioimidic acids R−C(SH)NH → R−C(S)NH2: For R = H, F, HO, CN, NC, H2N, HC(O), HC(S), HC≡ C, CH3, CF3, H2C=CH, HOCH2, H2NCH2,CH3C(O), C2H5, (CH3)2CH, C6H5

International Journal of Chemical Kinetics, Volume 55, Issue 11, Page 731-742, November 2023., 2023
Abstract The kinetics of the tautomerization of thio‐imidic acids RC(SH)NH were determined at low (50–300 K) and high (500–1500 K) temperatures as R was varied to encompass mono‐ and diatomic species H, F, HO, NC, CN through H2N, HC(O), HC(S), HC≡ C, H3C, F3C, HOCH2, H2C=CH, CH3C(O), H2NCH2 and including ethyl, isopropyl and phenyl groups. The presence
Judith Würmel, John M. Simmie
wiley   +1 more source

ORion Alma New GEneration Survey (ORANGES). I. Dust continuum and free-free emission of OMC-2/3 filament protostars [PDF]

, 2021
The spectral energy distribution (SED) in the millimetre (mm) to centimetre (cm) range is a useful tool for characterising the dust in protostellar envelopes as well as free-free emission from the protostar and outflow.
M. Bouvier, A. López-Sepulcre, C. Ceccarelli, Nami Sakai, S. Yamamoto, Y.-L. Yang   +5 more
semanticscholar   +1 more source

Bulk mineralogy, water abundance, and hydrogen isotope composition of unequilibrated ordinary chondrites

Meteoritics &Planetary Science, Volume 58, Issue 9, Page 1365-1381, September 2023., 2023
Abstract The origin and transport of water in the early Solar System is an important topic in both astrophysics and planetary science, with applications to protosolar disk evolution, planetary formation, and astrobiology. Of particular interest for understanding primordial water transport are the unequilibrated ordinary chondrites (UOCs), which have ...
Helen Grant, Romain Tartèse, Rhian Jones, Laurette Piani, Yves Marrocchi, Ashley King, Thomas Rigaudier   +6 more
wiley   +1 more source

JWST Observations of Young protoStars (JOYS). Overview of program and early results [PDF]

Astronomy & Astrophysics
The embedded phase of star formation is a crucial period in the development of a young star when the system still accretes matter, emerges from its natal cloud with assistance from powerful jets and outflows, and forms a disk, thus setting the stage for ...
E. van Dishoeck, Ł. Tychoniec, W. R. M. Rocha, K. Slavicinska, L. Francis, M. V. van Gelder, T. Ray, H. Beuther, A. Garatti, N. Brunken, Y. Chen, R. Devaraj, V. Geers, C. Gieser, T. Greene, K. Justtanont, V. L. Le Gouellec, P. Kavanagh, P. Klaassen, A. G. M. Janssen, M. G. Navarro, P. Nazari, S. Notsu, G. Perotti, M. Ressler, S. Reyes, A. Sellek, B. Tabone, C. Tap, N. Theijssen, L. Colina, M. Gudel, T. Henning, P. Lagage, G. Ostlin, B. Vandenbussche, G. Wright   +36 more
semanticscholar   +1 more source

Loading of Amino Acids onto RNA in a Putative RNA‐Peptide World

Angewandte Chemie International Edition, Volume 62, Issue 21, May 15, 2023., 2023
The loading of RNAs with amino acids constitutes the first step toward RNA‐based peptide synthesis in a putative prebiotic RNA‐peptide world. The efficient loading of RNA strands incorporating N‐methylcarbamoyl nucleotides with a series of amino acids is reported. The loaded RNA strands also underwent RNA‐based amino acid transfer reactions.
Johannes N. Singer, Felix M. Müller, Ewa Węgrzyn, Christina Hölzl, Hans Hurmiz, Chuyi Liu, Luis Escobar, Thomas Carell   +7 more
wiley   +1 more source

The grain size distribution of matrix in primitive chondrites

Meteoritics &Planetary Science, Volume 58, Issue 5, Page 688-704, May 2023., 2023
Abstract The matrix of primitive chondrites is composed of submicron crystals embedded in amorphous silicates. These grains are thought to be the remains of relatively unprocessed dust from the inner regions of the protoplanetary disk. The matrix of primitive meteorites is often compared to chondritic porous interplanetary dust particles (CP‐IDPs ...
E. Vaccaro, P. Wozniakiewicz, I. A. Franchi, N. Starkey, S. S. Russell   +4 more
wiley   +1 more source