Results 11 to 20 of about 17,073 (217)

Gravitational Instabilities in Circumstellar Disks [PDF]

Annual Review of Astronomy and Astrophysics, 2016
Star and planet formation are the complex outcomes of gravitational collapse and angular momentum transport mediated by protostellar and protoplanetary disks. In this review, we focus on the role of gravitational instability in this process. We begin with a brief overview of the observational evidence for massive disks that might be subject to ...
K. Kratter, G. Lodato
openaire   +4 more sources

Sub-Keplerian accretion onto circumstellar disks [PDF]

Astronomy and Astrophysics, 2010
Models of the formation, evolution and photoevaporation of circumstellar disks are an essential ingredient in many theories of the formation of planetary systems.
Aikawa, Alexander, Alves, Andrews, Andrews, André, Apai, Banerjee, Bergin, Bockelée-Morvan, Bonnor, Bouwman, Bouwman, Brinch, Brittain, Brown, C. P. Dullemond, Carr, Cassen, Collings, D'Alessio, D'Antona, Desch, Dullemond, Dullemond, Dullemond, Ebert, Foster, Gail, Goto, Harker, Hartmann, Hartmann, Harvey, Hayashi, Hueso, Jørgensen, Jørgensen, Kandori, Keller, Keller, Kemper, Kemper, Kessler-Silacci, Kratter, Kratter, Lahuis, Lee, Lin, Lommen, Lommen, Lommen, Looney, Lynden-Bell, Matsumoto, Motte, Nakamoto, Neufeld, Nuth, Olofsson, Pontoppidan, R. Visser, Ratzka, Rice, Rice, Rodgers, Salyk, Shakura, Shu, Sicilia-Aguilar, Terebey, Tscharnuter, van Boekel, Visser, Viti, Vorobyov, Vorobyov, Vorobyov, Vorobyov, Walch, Watson, Weidenschilling, Whitworth, Wooden, Yorke   +84 more
core   +3 more sources

Circumstellar disks of the most vigorously accreting young stars. [PDF]

Sci Adv, 2016
Liu HB, Takami M, Kudo T, Hashimoto J, Dong R, Vorobyov EI, Pyo TS, Fukagawa M, Fukagawa M, Tamura M, Henning T, Dunham MM, Karr JL, Kusakabe N, Tsuribe T.   +14 more
europepmc   +2 more sources

Prebiotic Synthesis and Isomerization in Interstellar Analog Ice: Glycinal, Acetamide, and Their Enol Tautomers

Angewandte Chemie, Volume 135, Issue 12, March 13, 2023., 2023
Out of the cold: Ammonia (NH3) and acetaldehyde (CH3CHO) are exposed to galactic cosmic ray proxies while frozen at 5 K to simulate the environment of an interstellar molecular cloud. Reactants undergo dissociation and radical recombination to produce glycinal (NH2CH2CHO) and acetamide (CH3CONH2) prior to tautomerization to 2‐aminoethenol (HOCHCHNH2 ...
Joshua H. Marks, Jia Wang, N. Fabian Kleimeier, Andrew M. Turner, André K. Eckhardt, Ralf I. Kaiser   +5 more
wiley   +2 more sources

Evaluating the GeoSnap 13‐μ$$ \mu $$m cutoff HgCdTe detector for mid‐IR ground‐based astronomy

Astronomische Nachrichten, Volume 344, Issue 8-9, October-November 2023., 2023
Abstract New mid‐infrared HgCdTe (MCT) detector arrays developed in collaboration with Teledyne Imaging Sensors (TIS) have paved the way for improved 10‐μ$$ \mu $$m sensors for space‐ and ground‐based observatories. Building on the successful development of longwave HAWAII‐2RGs for space missions such as NEO Surveyor, we characterize the first 13‐μ ...
Jarron M. Leisenring, Dani Atkinson, Rory Bowens, Vincent Douence, William F. Hoffmann, Michael R. Meyer, John Auyeung, James Beletic, Mario S. Cabrera, Alexandra Z. Greenbaum, Philip Hinz, Derek Ives, William J. Forrest, Craig W. McMurtry, Judith L. Pipher, Eric Viges   +15 more
wiley   +1 more source

First Observations With a GNSS Antenna to Radio Telescope Interferometer

Radio Science, Volume 58, Issue 8, August 2023., 2023
Abstract We describe the design of a radio interferometer composed of a Global Navigation Satellite Systems (GNSS) antenna and a Very Long Baseline Interferometry radio telescope. Our eventual goal is to use this interferometer for geodetic applications including local tie measurements.
J. Skeens, J. York, L. Petrov, D. Munton, K. Herrity, R. Ji‐Cathriner, S. Bettadpur, T. Gaussiran   +7 more
wiley   +1 more source

CO2 Ocean Bistability on Terrestrial Exoplanets

Journal of Geophysical Research: Planets, Volume 127, Issue 10, October 2022., 2022
Abstract Cycling of carbon dioxide between the atmosphere and interior of rocky planets can stabilize global climate and enable planetary surface temperatures above freezing over geologic time. However, variations in global carbon budget and unstable feedback cycles between planetary sub‐systems may destabilize the climate of rocky exoplanets toward ...
R. J. Graham, Tim Lichtenberg, Raymond T. Pierrehumbert   +2 more
wiley   +1 more source

Azimuthal Patterns in Planetesimal Circumstellar Disks

Astronomy Letters, 2023
24 pages, 8 figures.
Demidova, Tatiana V., Shevchenko, Ivan I.   +1 more
openaire   +2 more sources

Reverse engineering a spectrum: using fluorescent spectra of molecular hydrogen to recreate the missing Lyman-α line of pre-main sequence stars [PDF]

, 2008
The hydrogen Lyman-α (Lyα) line, a major source of ionization of metals in the circumstellar disks of pre-main sequence (PMS) stars, is usually not observed due to absorption by interstellar and circumstellar hydrogen.
Herczeg, G., Linsky, J. L., Wood, B. E.
core   +1 more source

The Spitzer c2d Survey of Weak-line T Tauri Stars II: New Constraints on the Timescale for Planet Building [PDF]

, 2007
One of the central goals of the Spitzer Legacy Project ``From Molecular Cores to Planet-forming Disks'' (c2d) is to determine the frequency of remnant circumstellar disks around weak-line T Tauri stars (wTTs) and to study the properties and evolutionary ...
Alcala J. M., Anneila Sargent, Augereau J. C., Bouvier J., Bruno Merin, Covino E., David Koerner, de Geus E. J., Deborah L. Padgett, Ewine F. van Dishoeck, Geoffrey Blake, Harvey P., Jean‐Charles Augereau, Karl R. Stapelfeldt, Lee Mundy, Lori Allen, Lucas Cieza, Martin E. L., Martin E. L., Neal J. Evans, II, Nicholas Chapman, Paul Harvey, Philip C. Myers, Shih‐Ping Lai, Siess L., Timothy Brooke, Tracy Huard, Weidenschilling S. J., Wichmann R., Wichmann R., William Spiesman, Zahed Wahhaj   +31 more
core   +4 more sources