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Description
We present a time-resolved spectral study of the gamma-ray burst GRB 241030A using joint observations from Swift and Fermi. The burst light curve shows two distinct emission episodes separated by a quiet interval. Our analysis indicates that the prompt emission is produced by synchrotron radiation and is best explained by internal shocks in a matter-dominated outflow. The first episode (0–45 s) is well described by a simple power-law spectrum, consistent with synchrotron emission from rapidly cooling electrons. The second episode (100–200 s) shows more complex spectral behavior, including two clear features: a low-energy break that remains nearly constant in time, and a spectral peak whose energy follows the brightness of individual pulses but shifts to lower energies between them. The overall spectral shapes match well with expectations from synchrotron radiation. We also find that the burst shows almost no measurable time delay between low- and high-energy gamma rays, which is unusual but informative. At later times, the spectrum becomes significantly softer, consistent with observing emission from higher-energy electrons after the main energy release has passed. These observational properties are difficult to explain with models in which the jet is dominated by strong, large-scale magnetic fields. Instead, they are naturally explained by internal shock models in which the magnetic field remains roughly steady, while the properties of the accelerated particles change with time. This scenario can simultaneously account for the stable low-energy break, the pulse-tracking spectral peak, the observed spectral slopes, and the near-zero time lag.