Multiwavelength Analysis of the Kinematics of a Long Duration Flare-CME Event on 27 January 2012
SOLAR PHYSICS
Authors: Selvarani, G.; Prasanna Subramanian, S.; Shanmugaraju, A.; Suresh, K.
Abstract
We present a detailed analysis of a long-duration flare associated with a coronal mass ejection (CME) event that occurred on 27 January 2012 in the active region (AR) 11402. We analyze the kinematics of the CME and the close relationship between the flare, radio burst, and CME. We used STEREO (Solar Terrestrial Relations Observatory)/EUVI A (Extreme Ultraviolet Imager) and white light data from STEREO (COR1 A and COR2 A) and LASCO (Large Angle and Spectrometric COronagraph) (C2/C3) coronagraphs, and X-ray data from the GOES (Geostationary Operational Environmental Satellite) spacecraft. The height of the CME is measured using the Graduated Cylindrical Shell (GCS) model. Our results show that: i) the speed of the CME (1460 km/s at 2.54 R-circle dot) is comparable to the speed of the type II radio burst (1581 km/s), ii) the height of the type II radio burst is lower than that of the CME leading edge, iii) the CME acceleration phase is found to be related to the rise time of the flare and its propagation phase is related to the decay phase of the flare, iv) the type II radio burst origin is likely to be near the CME region where a CME-streamer interaction takes place around 1.6 R-circle dot, and v) the sequence of events and the CME kinematics show a close association between the CME and type II radio emissions.
A Natural Alkaloid, beta-Carboline, as a One- and Two-Photon Responsive Fluorescent Photoremovable Protecting Group: Sequential Release of the Same or Different Carboxylic Acids
ORGANIC LETTERS
Authors: Sikder, Antara; Banerjee, Moumita; Singha, Tara; Mondal, Saugat; Datta, P. K.; Anoop, Anakuthil; Singh, N. D. Pradeep
Abstract
The beta-carboline moiety, substituted at the C1 and C3 benzylic positions with a leaving group, has been demonstrated for the first time as a photoremovable protecting group for time-dependent sequential release of two (same or different) carboxylic acids upon one- and two-photon light irradiation. Density functional theory calculations suggest that the electronic environment of the beta-carboline moiety at C1 and C3 positions plays a key role in the rate of photorelease.