Kilonovas caused by black hole neutron star mergers

[Tanelorn]

I thought readers would be interested in this interesting article today on black hole and neutron star mergers and the very small possibility of instantaneous sterilization and extinction of all life on earth:http://www.space.com/22231-gamma-ray-bursts-neutron-stars.html

http://news.yahoo.com/kilonova-dead-star-crashes-may-spark-mysterious-cosmic-212239960.htmlAnother on the origin of Gold:

http://www.space.com/21995-gold-origins-neutron-star-collisions.html

 

[Tanelorn]

Could anyone please confirm if the duration of the gamma ray burst, lasting 0.09 seconds, is consistent with the stretching of the gamma ray pulse as a result of the expansion of space between us and the object 4 Billion light years away? How long would we expect the gamma ray burst to have lasted at its source? Are Gamma ray burst frequencies very narrow band or even single frequency lines, or are they quite wideband and dispersed?

 

[Naty1]

Are Gamma ray burst frequencies very narrow band or even single frequency lines, or are they quite wideband and dispersed?

yes:

Gamma-ray bursts (GRBs) are flashes of gamma rays associated with extremely energetic explosions that have been observed in distant galaxies. They are the brightest electromagnetic events known to occur in the universe.[1] Bursts can last from ten milliseconds to several minutes. The initial burst is usually followed by a longer-lived "afterglow" emitted at longer wavelengths (X-ray, ultraviolet, optical, infrared, microwave and radio).[2]

Most observed GRBs are believed to consist of a narrow beam of intense radiation released during a supernova as a rapidly rotating, high-mass star collapses to form a neutron star, quark star, or black hole.

http://en.wikipedia.org/wiki/Gamma-ray_burst

 

[Naty1]

Could anyone please confirm if the duration of the gamma ray burst, lasting 0.09 seconds, is consistent with the stretching of the gamma ray pulse as a result of the expansion of space between us and the object 4 Billion light years away?

The duration of the source radiation has nothing to do with any subsequent redshift during transit...

And there are lots of gamma ray bursts in the universe...fortunately for us it is really, really big and we are really, really small. So if somebody shoots a cannon off in Moscow or Paris or Singapore for example, I fell pretty safe here in NJ.

 

[Tanelorn]

Thanks Naty, I was just curious if there was a change in the duration of the pulse as a result of redshift and if it agreed with any expected change in duration expected by the standard model.
"Are Gamma ray burst frequencies very narrow band or even single frequency lines, or are they quite wideband and dispersed?"

The quote you provided doesn't mention how narrow band the gamma ray pulse is.
Laser light is narrowband, white light is broadband.

 

[Chronos]

GRB's are not narrow band emissions. They peak in gamma frequencies, but, are also detected in visible light frequencies.