The Mysterious and Wonderful Universe

1 06 2010

Mysterious Universe

“I’ve never seen anything like it.”

Elzette leaned over Stepan’s shoulder and stared at the line graph on the screen of his terminal. The line crept along the X axis before jumping sharply up along the Y axis, peaking at a short plateau, and then almost as quickly dropped away. The line flickered every few seconds, and its shape changed almost imperceptibly. Data was still coming down from the satellite and being uploaded through the network; Stepan’s terminal continuously updated the fields displayed by the graph.

“It’s a light curve, Stepan. You see a dozen a week.”

“But not like this,” he insisted. He ran his stylus along the crest of the line graph. “Look at this plateau. Have you ever seen a GRB that didn’t spike?”

Elzette rolled her eyes and returned to her own terminal. “You know better than anyone that light curves from gamma-ray bursts are never the same. What was the duration of the emission?”

Stepan ran his stylus along the bottom of the graph, reading the measurements on the X axis.

“Only a few microseconds.”

“Now I don’t know much about GRBs,” Elzette sardonically replied, “but that would fit just right for a short gamma-ray burst, yes? Less than two seconds?”

“Maybe. Short GRBs are usually around point three of a second in duration. But, look at the energy levels…”

Elzette smiled to herself and shook her head. She focussed on the spectroscopic data on her own screen and let Stepan talk aloud.

“…less than 20 million electron volts! I’m surprised GLAT even detected it. GRBs are of much higher energies, in the order of tens of billions of electron volts. How else could we detect such things across the observable universe?”

Stepan muttered to himself in MeV and GeV and orders of magnitude of hertz.

“And this wavelength,” he said louder. “On the far end of the gamma-ray scale, close to ten picometers. Seriously, Zet, this is strange. We need to turn the satellite on the afterglow.”

Elzette sighed, and spun in her chair to face Stepan.

“You know better than I that it’s spectacularly difficult to spot the afterglow of a short GRB – ”

“ – I don’t think it’s a GRB, Zet.”

“Solar flare? There are three stars nearby, two of which are thermonuclear furnaces pouring out gamma rays.”

Stepan shook his head. “Alpha B has set, and there’s been no surface activity on Alpha A.”

“Well, what else? A neutron star? Blazar? Seyfert galaxy? It might well be the cosmic microwave background.”

“No. No, the wavelength and duration and energy levels are all wrong.” He checked the data still coming down through the network. “17.59MeV. About the same amount of energy released when tritium and deuterium nuclei fuse to form alpha particles and high-energy neutrons.”

Stepan’s terminal announced that it had completed downloading the information from the satellite. The line graph froze in place, and more information scrolled through the margins of the graph. Stepan trawled through this data.

“What is it?” Elzette asked.

“The GLAT didn’t detect this incident,” Stepan explained. “Like I thought, the pulse wasn’t powerful enough. The Large Area Telescope is designed for bursts in the range of 30 MeV to 300 GeV. The Gamma-ray Burst Monitor package picked it up. GBM has banks of silicone detectors, organised in successive layers; from the data each of these detectors gives us, we can work out where the burst came from…wow.”

Elzette stood and again leaned over Stepan’s shoulder. On the graph, lost among the other marginalia, the computer calculated the origin:

288.7827 +71.3917

“That’s FL Virginis B. That’s practically next-door.”

Elzette held Stepan’s eyes for a moment, and then threw her hands up in defeat.

“Alright! Fine. Realign the satellite for the afterglow. That’s what GLAT is there for, right?”

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24 08 2012
Epilogue « Orbital Shipyards: Alpha Centauri System

[…] was not limited to the surface of Fram. Driven by the mysterious results of a gamma-ray survey in our first year, our scientists took advantage of the noiseless skies and […]

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