Gamma-ray Bursts
Gamma-ray bursts
Understanding the most powerful cosmic explosions, Gamma-ray Bursts, with information from Space, from our observatory near Almaty, and with fast communications in-between: While gamma-ray bursts (GRBs) have been studied for more than 50 years, the emission mechanism, or what makes the light we measure, remains a mystery. Scientists have predicted that measuring the shape of the spectrum in the optical – at the same time as in the gamma-rays – will solve this mystery. This is the NUTTelA-TAO‘s main project.
GRB observatories in low-earth orbit detect GRBs and are able to send the coordinates of these bursts over the internet within seconds. Our automated NUTTelA-TAO then responds as quickly as possible, checking that the GRB position is above the horizon during dark hours, that the weather is clear, and then initiates an exposure sequence to measure the rapidly changing event.
Solving the mystery, like a detective, by finding the “fingerprints”
Physical processes that make light often have unique spectra, the distribution of energy with frequency. Just as one can identify who is responsible for a deed by the fingerprint left behind, we can often identify the process responsible for light by its “fingerprint” – the spectrum. A steep, rounded spectrum usually means emission by hot, dense gas, like from a star. A flat spectrum usually means a high-energy process that accelerates electrons to high energies, which then radiate in the presence of magnetic fields, synchrotron emission.
Gamma-ray instruments are good at measuring the gamma-ray region of the spectrum. But until now, no one has been able to measure the full spectrum, that is, including the optical part of the spectrum; we have only had a “partial” fingerprint. So, by adding three points at optical wavelengths to the spectrum from the gamma-ray instrument, we have a complete “fingerprint” of the physical processes in the burst, allowing us to identify the emission mechanism. You can read all about this in our paper, Grossan et al. 2019, JHEA 23,14
But that’s not all!
The NUTTelA-TAO can respond automatically to any kind of transient detected in gamma-rays. All we need is for the transient to be above the horizon on a clear night and we can measure it (see: NUTTela GRB/Transient Table).
Proposing Observations to the NUTTelA TAO
The NUTTelA-TAO can also observe manually initiated targets. Do you have an astrophysical source you’d like to measure? Send us an email with a standard observing proposal (target, magnitude, required sensitivity and scientific justification) and if we would like to be involved in your project, we’ll answer you back to schedule your observations. Student projects are very welcome too.