Results 21 to 30 of about 615 (185)
Early Planet Formation in Embedded Disks (eDisk). I. Overview of the Program and First Results
The Astrophysical Journal, 2023 We present an overview of the Large Program, “Early Planet Formation in Embedded Disks (eDisk),” conducted with the Atacama Large Millimeter/submillimeter Array (ALMA).
Nagayoshi Ohashi +36 more
doaj +1 more source
Atomistic Modeling of Methyl Formate and Glycolaldehyde Formation on Interstellar Dirty Ice Mantles via a "Radical + Ice" Mechanism. [PDF]
ChempluschemThe presence of interstellar complex organic molecules (COMs) has been baffling astrochemists for a long time. Methyl formate and glycolaldehyde are widely detected but their abundances mismatch kinetic astrochemical model predictions. Here, the formation of these two COMs is characterized onto a mixed ice surface, highlighting the importance of ...
Perrero J +3 more
europepmc +2 more sources
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
NONSTEADY ACCRETION IN PROTOSTARS [PDF]
The Astrophysical Journal, 2009 Observations indicate that mass accretion rates onto low-mass protostars are generally lower than the rates of infall to their disks; this suggests that much of the protostellar mass must be accreted during rare, short outbursts of rapid accretion. We explore when protostellar disk accretion is likely to be highly variable. While constant $α$ disks can
Zhu, Zhaohuan +2 more
openaire +2 more sources
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 +6 more
wiley +1 more source
300: An ACA 870 μm Continuum Survey of Orion Protostars and Their Evolution
The Astrophysical Journal, 2023 We present an 870 μ m continuum survey of 300 protostars from the Herschel Orion Protostar Survey using the Atacama Compact Array (ACA). These data measure protostellar flux densities on envelope scales ≤8000 au (20″) and resolve the structure of ...
Samuel Federman +13 more
doaj +1 more source
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 +4 more
openaire +3 more sources
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 +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 +4 more
wiley +1 more source
Magnetic Effects Promote Supermassive Star Formation in Metal-enriched Atomic-cooling Halos
The Astrophysical Journal, 2023 Intermediate-mass black holes (with ≥10 ^5 M _⊙ ) are promising candidates for the origin of supermassive black holes (with ∼10 ^9 M _⊙ ) in the early universe (redshift z ∼ 6).
Shingo Hirano +2 more
doaj +1 more source