Multi-Wavelength Study of Sgr A*: The Short Time Scale Variability - Astrophysics > Astrophysics of GalaxiesReportar como inadecuado




Multi-Wavelength Study of Sgr A*: The Short Time Scale Variability - Astrophysics > Astrophysics of Galaxies - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: To understand the correlation and the radiation mechanism of flare emissionin different wavelength bands, we have coordinated a number of telescopes toobserve SgrA* simultaneously. We focus only on one aspect of the preliminaryresults of our multi-wavelength observing campaigns, namely, the short timescale variability of emission from SgrA* in near-IR, X-ray and radiowavelengths. The structure function analysis indicate most of the powerspectral density is detected on hourly time scales in all wavelength bands. Wealso report minute time scale variability at 7 and 13mm placing a strongconstraint on the nature of the variable emission. The hourly time scalevariability can be explained in the context of a model in which the peakfrequency of emission shifts toward lower frequencies as a self-absorbedsynchrotron source expands adiabatically near the acceleration site. The shorttime scale variability, on the other hand, places a strong constraint on thesize of the emitting region. Assuming that rapid minute time scale fluctuationsof the emission is optically thick in radio wavelength, light travel argumentsrequires relativistic particle energy, thus suggesting the presence of outflowfrom SgrA*.



Autor: F. Yusef-Zadeh, J. Miller-Jones, D. Roberts, M. Wardle, M. Reid, K. Dodds-Eden, D. Porquet, N. Grosso

Fuente: https://arxiv.org/



DESCARGAR PDF




Documentos relacionados