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Is the gamma-ray burst a spherical field, or is it a narrow, directed cone? If the latter, I wonder how the burst spreads/diffuses as it travels and what sort o
by austinz 12y ago
Is the gamma-ray burst a spherical field, or is it a narrow, directed cone? If the latter, I wonder how the burst spreads/diffuses as it travels and what sort of equation governs the energy flux with respect to distance and initial conditions.
- pixl97 12y agoBeams from my understanding https://en.wikipedia.org/wiki/Gamma-ray_burst#Energetics_and_beaming https://en.wikipedia.org/wiki/Gamma-ray_burst#Energetics_and...
- acadien 12y agoGreat question! Since they're emanated in jets, the GRBs travel in a conical shape that spreads out as it travels. Check out page 19 of this paper, it has a histogram of the jet opening angle; http://arxiv.org/pdf/1101.2458.pdf http://arxiv.org/pdf/1101.2458.pdf Then you can figure out the flux from the area of a circle on a sphere, which is something like 2πr^2(1−cosθ) Where theta is the opening angle and r is the distance from point of emanation of the GRB.
- austinz 12y agoThanks for the paper link! I'll check it out. (The histogram legend seems to indicate two distributions of observed GRBs, the larger centered around 8 degree cones.)
- jbert 12y agoDo you know if there is any bias to the orientation of the jets? e.g. in a spiral galaxy, do they tend to align with the axis of rotation and so do less damage locally (spray out "up and down" from the galaxy)?
- jjaredsimpson 12y agojets are randomly oriented with no preferred orientation.
- gmoes 12y agoI think there are multiple types of GRBs and some can be spherical. Two that I have read about are neutron stars colliding and large solar mass > 100 exploding and leaving no remnant. I've read that these types of bursts can blow the atmosphere off of a planet. http://en.wikipedia.org/wiki/Hypernova http://en.wikipedia.org/wiki/Hypernova