A short overview is given of the principal mechanisms by which electromagnetic radiation spectra are produced in cosmic sources and how these give rise to inverse diagnostic problems of the distribution of radiating particles Apart from black body spectra, only optically thin sources are considered and radiation by nuclear and coherent mechanisms are excluded Problems are subdivided into: continuum spectra (synchrotron, inverse Compton, and collisional bremsstrahlung processes); spectrum line intensity problems (of plasma density and temperature structure); spectrum line profile problems, with emphasis on Doppler line broadening The main emphasis is on indicating the physical importance of the problems and/or drawing attention to where further work on inverse problem aspects is needed

https://iopscience.iop.org/article/10.1088/0266-5611/11/4/011/pdf

Inverse problems in astrophysical spectrometry

Type II and Type III bursts are probably the most intensively studied form of radio emission in all of astrophysics. Immense effort has gone into the elucidation of both the observational and theoretical aspects. The bursts have captured the attention of plasma theorists because a considerable body of information exists on the plasma parameters and because there is adequate space and time in the solar corona for the evolution of various particle and wave processes. In our work, we have studied the type II bursts and their association with type III bursts during the increasing phase approaching the peak phase of solar cycle 23. For the period 2000-2001, type III bursts data of Culgoora observatory is referred. The parameters such as duration drift rate, shock speed, band width of these associated/non associated bursts are compared .Results indicate that the above parameters almost remain uniform for associated and non-associated type II bursts.

https://article.sciencepublishinggroup.com/pdf/10.11648.j.ijass.20130104.14.pdf

Statistical Analysis of Associated and Non-Associated Type II Solar Radio Bursts during the Increasing Phase of Solar Cycle 23

I / Magnetic Structure Responsible for Coronal Disturbances.- Magnetic Structure Responsible for Coronal Disturbances: Observations.- Magnetic Structure Responsible for Coronal Disturbances: Theory.- Inversion Lines of Photospheric Magnetic Fields and Solar Corona (Presented by M.-J. Martres).- Large-Scale Magnetic Structures Responsible for Coronal Disturbances (Presented by V. Bumba).- Distribution of Circularly Polarized Emission across the Solar Disk at ? = 4.3 cm (Presented by P. Kaufmann).- Boundary Fitting Problems Associated with Coronal Magnetic Models.- Analysis of EUV Observations of a Coronal Active Region Made During the 7 March 1970 Eclipse (Presented by C. Jordan).- Coronal Magnetic Field Structure Derived from Two-Frequency Radioheliograph Observations (Presented by K. V. Sheridan).- II / The Flash Phase of Solar Flares.- Impulsive (Flash) Phase of Solar Flares: Hard X-Ray, Microwave, EUV and Optical Observations.- Spectral Association of the 7 August 1972 Solar Radio Burst with Particle Acceleration (Presented by J. P. Castelli).- X-Ray Emission in Absence of Flares Related to H? Activity and Type III Burst Production (Presented by M.-J. Martres).- Coronal Disturbances Observed in the Optical Emission Lines.- Forbidden Line Excitation Data for Certain Coronal Lines (Presented by L. H. Aller).- Multiple Hard X-Ray Bursts and Associated Emission.- Ground-Based Observations of Type III Bursts.- Solar Radio Bursts at Low Frequencies.- The Flash of Solar Flares: Satellite Observations of Electrons.- High Resolution Studies of Type III Solar Radio Bursts (Presented by H. Rosenberg).- Coronal Density Structures in Regions of Type III Activity (Presented by Y. Leblanc).- Meter and Decameter Wavelength Positions of Solar Radio Bursts of July 31-August 7, 1972 (Presented by W. C. Erickson).- Source Structure in Metre-Wave Type V Solar Bursts (Presented by N. R. Labrum).- Direct Measurements of the Directivity of Type I and Type III Radiation at 169 MHz (Presented by C. Carou-balos).- Paired Type III Bursts (Presented by M. Pick).- Unusual Absorption of a Solar Type II Burst by `Shadow' Type III Bursts.- High Resolution Observations of Generalized Fast Drift Bursts (Presented by ?. Elgaroy).- Mechanisms for Flash Phase Phenomena in Solar Flares.- A Theory of Type III Solar Radio Bursts (Presented by D. B. Melrose).- A Relationship Between the Brightness Temperatures for Type III Bursts.- The Third Harmonic in Solar Radio Bursts (Presented by D. B. Melrose).- Fine Structure in Type IV Solar Radio Bursts (Presented by H. Rosenberg).- A Theory of Type I Solar Radio Bursts.- Synchrotron Radiation in Directions Close to Magnetic-Field Lines.- III / Shock Waves and Plasma Ejection.- Shock Waves and the Ejection of Matter from the Sun: Radio Evidence.- Optical Evidence for Plasma Ejections and Waves in the Solar Corona.- The Behaviour of the Outer Solar Corona (3 R? to 10 R?) During a Large Solar Flare Observed from OSO-7 in White Light.- The Coronal Disturbance of 12 August 1972 (Presented by A. C. Riddle).- Observation of a Coronal Disturbance from 1 to 9 R? (Presented by R. T. Stewart).- Type II Solar Radio Bursts in the Decimeter Band.- Observations of Split-Band Harmonic Type II Bursts with the Culgoora Radioheliograph at 80 and 160 MHz (Presented by G. J. Nelson).- Type II Bursts at Hectometric and Kilometric Wavelengths from Interplanetary Shocks (Presented by H. H. Malitson).- East-West Asymmetry on Magnetic Bottle Expansion and Its Relation to Shock Waves Propagating in the Solar Atmosphere.- Shock Waves and Plasma Ejection: Corpuscular and Interplanetary Evidence (Presented by G. Newkirk).- Theory of Shock Waves and Plasma Wave-Emission.- Interplanetary Shock Waves from McMath Region 11976 During Its Passage in August 1972 (Presented by M. Dryer).- Type II Burst-Sources as Low-VA Regions in the Corona `Illuminated' by Flare-Induced MHD Shocks.- On the Theory of Moving Type IV Radio Bursts.- On Split-Band Structure in Type II Radio Bursts from the Sun (Presented by S. F. Smerd).- On the Thermal Interpretation of Hard X-Ray Bursts from Solar Flares.- IV / Acceleration, Containement and Emission of High-Energy Flare Particles.- The Charge and Isotopic Composition of Solar Cosmic Rays.- X-Ray Evidence for the Acceleration, Containment, and Emission of High Energy Flare Particles.- Acceleration, Containment and Emission of High Energy Flare Particles: Radio Evidence.- Particle Acceleration in Solar Flares.- Millimeter Radio Evidence for Containment Mechanisms in Solar Flares (Presented by E. B. Mayfield).- Acceleration, Containment, and Emission of Very Low Energy Solar Flare Particles (Presented by R. P. Lin).- Solar Radio Pulsations.- Coronal Magnetic Fields and Energetic Particles.- Coherent Effect in the Preferential Acceleration of Relativists Solar Heavy Cosmic Ray Nuclei.- A Conductive Cooling Model for a Confined Solar Flare Plasma (Presented by L. W. Acton).- The Gyro-Synchrotron Radiation from Moving Type IV Sources in the Solar Corona.- V / Reports on Special Observatoins.- Temporal Observations of the ? 5303 Emission Line Profile During the 74 Minute Totality from the Concorde SST at the 30 June 1973 Total Solar Eclipse: Preliminary Intensity Variations Above an Active Region (Presented by D. H. Liebenberg).- Skylab: A Progress Report (Presented by G. Newkirk).- Preliminary Results from the NRL/ATM Instruments from Skylab SL/2.- Solar EUV Photoelectric Observations from Skylab.- Dynamic Events in the X-Ray Corona (A Progress Report from the AS&E X-Ray Telescope on Skylab).- The High Altitude Observatory White Light Coronagraph Experiment.- Index of Subjects.

Gordon Allen Newkirk

Papers

Coronal disturbances : symposium no. 57 held at Surfers Paradise, Queensland, Australia, 7-11 September, 1973