Results 31 to 40 of about 386,435 (271)

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

Disentangling the Origin and Heating Mechanism of Supernova Dust: Late-Time Spitzer Spectroscopy of the Type IIn SN 2005ip [PDF]

, 2010
This paper presents late-time near-infrared and {\it Spitzer} mid-infrared photometric and spectroscopic observations of warm dust in the Type IIn SN 2005ip in NGC 2906.
Chevalier, Roger A., Dwek, Eli, Fox, Ori D., Leisenring, Jarron M., Skrutskie, Michael F., Sugerman, Ben E. K.   +5 more
core   +3 more sources

Alumina Polymorphism in the Circumstellar Dust Shells of Asymptotic Giant Branch Stars

Astrophysical Journal, 2018
Many emission features remain unidentified in the infrared spectra of asymptotic giant branch (AGB) stars. In particular, features at ∼11, 20, 28, and 32 μm have been noted in mid-infrared spectra of oxygen-rich AGB stars.
B. Sargent
semanticscholar   +1 more source

The Circumstellar Disk HD 169142: Gas, Dust, and Planets Acting in Concert? [PDF]

, 2017
HD 169142 is an excellent target for investigating signs of planet–disk interaction due to previous evidence of gap structures. We perform J-band (∼1.2 μm) polarized intensity imaging of HD 169142 with VLT/SPHERE.
A. Pohl, M. Benisty, P. Pinilla, C. Ginski, J. D. Boer, H. Avenhaus, T. Henning, A. Zurlo, A. Boccaletti, J. Augereau, T. Birnstiel, C. Dominik, S. Facchini, D. Fedele, M. Janson, M. Keppler, Q. Kral, M. Langlois, R. Ligi, A. Maire, F. Ménard, M. Meyer, C. Pinte, S. Quanz, J. Sauvage, É. Sezestre, T. Stolker, J. Szulágyi, R. Boekel, G. V. D. Plas, M. Villenave, A. Baruffolo, P. Baudoz, D. L. Mignant, D. Maurel, J. Ramos, L. Weber   +36 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

Substituent effects in the tautomerization of imidic acids R−C(OH)=NH → R−C(O)NH2: Kinetic implications for the formation of peptide bonds in the interstellar medium

International Journal of Chemical Kinetics, Volume 55, Issue 7, Page 381-391, July 2023., 2023
Abstract A number of amides, RC(O)NH2, have been detected spectroscopically in the space between the stars. Naturally the study of how these are formed is an important question on the path of chemical evolution from the elements C, H, N, O, P, … to life because the so‐called peptide‐bond −C(O)−NH− is a key linkage in poly‐amino acids or proteins.
Judith Würmel, John M. Simmie
wiley   +1 more source

Analysis of Methods for Computing the Trajectories of Dust Particles in a Gas–Dust Circumstellar Disk [PDF]

, 2017
A systematic analysis ofmethods for computing the trajectories of solid-phase particles applied in modern astrophysics codes designed for modeling gas–dust circumstellar disks has been carried out for the first time.
O. Stoyanovskaya, V. N. Snytnikov, E. Vorobyov   +2 more
semanticscholar   +1 more source

Dust distribution in circumstellar shells [PDF]

Proceedings of the International Astronomical Union, 2011
AbstractWe present numerical simulations of the hydrodynamical interactions that produce circumstellar shells. These simulations include several scenarios, such as wind-wind interaction and wind-ISM collisions. In our calculations we have taken into account the presence of dust in the stellar wind. Our results show that, while small dust grains tend to
van Marle, Allard Jan, Meliani, Zakaria, Keppens, Rony, Decin, Leen   +3 more
openaire   +2 more sources

Circumstellar Dust Disks in Taurus-Auriga: The Submillimeter Perspective [PDF]

, 2005
We present a sensitive, multiwavelength submillimeter continuum survey of 153 young stellar objects in the Taurus-Auriga star formation region. The submillimeter detection rate is 61% to a completeness limit of ~10 mJy (3 σ) at 850 μm.
S. Andrews, Jonathan P. Williams
semanticscholar   +1 more source

Circumstellar Dust Shells [PDF]

Symposium - International Astronomical Union, 1975
The optical properties of circumstellar graphite particle shells are considered. In the case of the optically thin shell (e.g. the shell of a RCB star after minimum), the temperature of the grains is calculated. It is shown that the dust shell always has a sharp inner border. The RCB phenomenon may be considered as a sudden moving of this border toward
openaire   +1 more source