Results 11 to 20 of about 389,568 (229)

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

A search for accreting young companions embedded in circumstellar disks [PDF]

Astronomy & Astrophysics, 2018
Context. In recent years, our understanding of giant planet formation progressed substantially. There have even been detections of a few young protoplanet candidates still embedded in the circumstellar disks of their host stars.
G. Cugno, S. Quanz, S. Hunziker, T. Stolker, H. Schmid, H. Avenhaus, P. Baudoz, A. Bohn, M. Bonnefoy, E. Buenzli, G. Chauvin, A. Cheetham, S. Desidera, C. Dominik, P. Feautrier, M. Feldt, C. Ginski, Julien H. Girard, R. Gratton, J. Hagelberg, E. Hugot, M. Janson, A. Lagrange, M. Langlois, Y. Magnard, A. Maire, F. Ménard, M. Meyer, J. Milli, C. Mordasini, C. Pinte, J. Pragt, R. Roelfsema, F. Rigal, J. Szul'agyi, R. Boekel, G. V. D. Plas, A. Vigan, Z. Wahhaj, A. Z. E. Zurich, M. P. I. Heidelberg, Lesia, L. Observatory, U. Grenoble, U. D. Chile, G. Observatory, Osservatorio Astronomico di Padova, U. Amsterdam, Eso - Chile, Marseille Universit'e, S. University, C. Lyon, C. Grenoble, U. Michigan, Universitat Bern, M. University, Nova, U. Zurich, Universidad Diego Portales   +58 more
semanticscholar   +1 more source

Resolved ALMA Continuum Image of the Circumbinary Ring and Circumstellar Disks in the L1551 IRS 5 System [PDF]

Astrophysical Journal, 2019
L1551 IRS 5 is a FUor-like object located in the Taurus star-forming region. We present Atacama Large Millimeter/submillimeter Array (ALMA) 1.3 mm continuum observations using a wide range of baselines.
F. Cruz-Sáenz de Miera, Á. Kóspál, P. 'Abrah'am, H. Liu, M. Takami   +4 more
semanticscholar   +1 more source

A WISE Survey of Circumstellar Disks in the Upper Scorpius Association [PDF]

Astronomical Journal, 2018
We have performed a survey for new members of the Upper Sco association that have circumstellar disks using mid-infrared photometry from the Wide-field Infrared Survey Explorer (WISE). Through optical and near-infrared spectroscopy, we have confirmed 185
T. Esplin, K. Luhman, E. B. Miller, E. Mamajek, E. Mamajek   +4 more
semanticscholar   +1 more source

CLIcK: a Continuum and Line fItting Kit for circumstellar disks [PDF]

Astronomy & Astrophysics, 2019
Infrared spectroscopy with medium to high spectral resolution is essential to characterize the gas content of circumstellar disks. Unfortunately, conducting continuum and line radiative transfer of thermochemical disk models is too time-consuming to ...
Yao Liu, I. Pascucci, T. Henning
semanticscholar   +1 more source

Early evolution of viscous and self-gravitating circumstellar disks with a dust component [PDF]

Astronomy & Astrophysics, 2018
Context. Aims. The long-term evolution of a circumstellar disk starting from its formation and ending in the T Tauri phase was simulated numerically with the purpose of studying the evolution of dust in the disk with distinct values of the viscous α ...
E. Vorobyov, V. Akimkin, O. Stoyanovskaya, Y. Pavlyuchenkov, Hauyu Baobab Liu Institute of Fluid Mechanics, Heat Transfer, Tu Wien, 1060, Vienna, Austria, R. D. O. Physics, Southern Federal University, Stachki Ave. 194, 344090, Rostov-on-Don, Russia., D. O. Astrophysics, U. Vienna, 1180, I. O. Astronomy, R. A. O. Sciences, 48 Pyatnitskayastr., 119017, Moscow, N. S. University, 2. Lavrentievastr., 630090, Novosibirsk, Boreskov Institute of Catalysis, 5. Lavrentievastr., E. Observatory, 2. Karl-Schwarzschild-Str., D. Garching, H Germany   +33 more
semanticscholar   +1 more source

Grain Growth and Dust Segregation Revealed by Multiwavelength Analysis of the Class I Protostellar Disk WL 17

The Astrophysical Journal, 2023
The first step toward planet formation is grain growth from (sub)micrometer to millimeter/centimeter sizes. Grain growth has been reported not only in Class II protoplanetary disks but also in Class 0/I protostellar envelopes.
Ilseung Han, Woojin Kwon, Yusuke Aso, Jaehan Bae, Patrick Sheehan   +4 more
doaj   +1 more source

ALMA OBSERVATIONS OF CIRCUMSTELLAR DISKS IN THE UPPER SCORPIUS OB ASSOCIATION [PDF]

, 2016
We present ALMA observations of 106 G-, K-, and M-type stars in the Upper Scorpius OB Association hosting circumstellar disks. With these data, we measure the 0.88 mm continuum and 12CO J = 3–2 line fluxes of disks around low-mass (0.14–1.66 M⊙) stars at
S. Barenfeld, J. Carpenter, L. Ricci, A. Isella   +3 more
semanticscholar   +1 more source

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