The nucleus of Comet C/2001 A2 (LINEAR) split several times during its recent apparition, presenting an unusual opportunity to search for chemical differences in freshly exposed material. We conducted this search using NIRSPEC at the W.M. Keck Observatory on four dates in 2001: 9.5 and 10.5 July and 4.4 and 10.5 August. We detected the R0 and R1 lines of the ν3 vibrational band of CH4 near 3.3 ...

Many complex organic molecules have been detected in star-forming regions like CH3OCH3 and CH3CH2CN. Studying their chemistry is important, since these species may eventually be incorporated into circumstellar disks and thus become part of the material from which future planetary systems are made. Two scenarios for their formation have been proposed: grain-surface formation and high-temperature...

Anomalies of tropospheric columns ozone (O3), carbon monoxide (CO), acetylene (C2H2), formaldehyde (H2CO), and ethane (C2H6) are quantified during the 2020 stringent COVID-19 world-wide lockdown using multiple ground-based Fourier-transform infrared spectrometers covering urban remote conditions. We applied an exponential smoothing forecasting approach to data sets estimate business-as-usual va...

The atmospheric composition of planets is determined by the chemistry disks in which they form. Studying gas-phase molecular thus allows us to infer what forming might be. Recent observations IRS 48 disk have shown that (asymmetric) dust traps can directly impact observable chemistry, through radial and vertical transport, sublimation ices. asymmetric HD 142527 provides another good opportunity...

Retrieval of global upper tropospheric and stratospheric formaldehyde (H2CO) distributions from high-resolution MIPAS-Envisat spectra T. Steck, N. Glatthor, T. von Clarmann, H. Fischer, J. M. Flaud, B. Funke, U. Grabowski, M. Höpfner, S. Kellmann, A. Linden, A. Perrin, and G. P. Stiller Institut für Meteorologie und Klimaforschung, Forschungszentrum Karlsruhe, Germany Laboratoire Interuniversit...

A collection of articles related to roaming, mostly in formaldehyde, H2CO. Quoted sections are set in italics. There are four prinary groups that have published theories tackling roaming. Harding and Klippenstein take a rather standard transition state theory perspective, but subdivide configuration using “centrifugal” and “entropic” barriers rather than energetic ones alone [23]. Jordan and Ka...

We investigate the consequences on hydrocarbon chemistry in diffuse and translucent clouds of including an interaction between gaseous C+ ions and dust grains. In general, we find that models in which much of the carbon is deposited and retained on grain surfaces within the cloud lifetime represent a poor match to observations. Conversely, models in which carbon is efficiently converted to meth...