Observations of GRB afterglows with Russian-Turkish 1.5-m Telescope (RTT150)

GRB 030329

GCN Circ.: 2001, 2024, 2046, 2051, 2054, 2079, 2094, 2105, 2108, 2119, 2198, 2204, 2220, 2260, 2299
RTT150 was one of the first 1.5m-class telescopes pointed to the afterglow. Observations were started approximately 6 hours after the burst. During the first 5 hours of our observations the afterglow faded exactly as a power law with index -1.19+-0.01 in each of the BVRI Bessel filters. After that, in all BVRI filters simultaneously we observe a steepening of the power law light curve. The power law decay index smoothly approaches the value &approx -1.9, observed by other observatories later. This power law break occurs at t-t_0 ≈ 0.57 days and lasts for ≈ 0.1 days. We observe no variability above the gradual fading with the upper limits 10-1% on time scales 0.1-1000s. Spectral flux distribution in four BVRI filters corresponds to the power law spectrum with spectral index α = 0.66 +- 0.01. The change of the power law decay index in the end of our observations can be interpreted as a signature of collimated ultrarelativistic jet. The afterglow flux distribution in radio, optical and x-rays is consistent with synchrotron spectrum.

The observations were continued untill approximately 100 days after the bursts. A significant amount of these data are still unpublished or published only after preliminary analysys in GCN circulars.

RTT150 first night data table (from Burenin et al., 2003)


Burenin et al., Astronomy Letters, 29, 573 (2003), astro-ph/0306137, The original text in Russian
see also: Urata et al., The Astrophysical Journal, 601, 17, astro-ph/0312145







Observations of GRB afterglows with Russian-Turkish 1.5-m Telescope (RTT150)

High Energy Astrophysics Department
Space Research Institute of Russian Academy of Sciences (IKI)