GRBs & Supernova: What's the Connection?

[tarbag]

What is the relation between gamma ray bursts (GRBs) and supernova?

Thanks

 

[Garth]

As two of the most powerful phenomena in the universe it is tempting to link them. You might find this paper of interest:(review to appear in Prog.Theor.Phys. S.136 (1999)) Origin of Gamma Ray Bursters:

The successful discovery of X-ray, optical and radio afterglows of GRB has made possible the identification of host galaxies at cosmological distances. The energy release inferred in these outbursts place them among the most energetic and violent events in the Universe. They are thought to be the outcome of a cataclysmic stellar collapse or compact stellar merger, leading to a relativistically expanding fireball, in which particles are accelerated at shocks and produce nonthermal radiation. The substantial agreement between observations and the theoretical predictions of the fireball shock model provide confirmation of the basic aspects of this scenario. Among recent issues are the collimation of the outflow and its implications for the energetics, the production of prompt bright flashes at wavelenghts much longer than gamma-rays, the time structure of the afterglow, its dependence on the central engine or progenitor system behavior, and the role of the environment on the afterglow.

Or a more recent paper (Proceedings of the conference "SWIFT and GRBs: Unveiling the Relativistic Universe", Venice, June 5-9, 2006, and in "Il Nuovo Cimento"): Diversity of the Supernova - Gamma-Ray Burst Connection:

The connection between the long Gamma Ray Bursts (GRBs) and Type Ic Supernovae (SNe) has revealed interesting diversity. We review the following types of the GRB-SN connection. (1) GRB-SNe: The three SNe all explode with energies much larger than those of typical SNe, thus being called Hypernovae (HNe). They are massive enough for forming black holes. (2) Non-GRB HNe/SNe: Some HNe are not associated with GRBs. (3) XRF-SN: SN 2006aj associated with X-Ray Flash 060218 is dimmer than GRB-SNe and has very weak oxygen lines. Its progenitor mass is estimated to be small enough to form a neutron star rather than a black hole. (4) Non-SN GRB: Two nearby long GRBs were not associated SNe. Such ``dark HNe'' have been predicted in this talk (i.e., just before the discoveries) in order to explain the origin of C-rich (hyper) metal-poor stars. This would be an important confirmation of the Hypernova-First Star connection. We will show our attempt to explain the diversity in a unified manner with the jet-induced explosion model.

Garth

 

[tarbag]

Yes , but I don't understood why GRB is short event (small than 200 s) and supernova is long event. Are GRBs produced in the same time as its associeted supernova in all case?
and what about their afterglows in the other electomgnetic bands?

 

[Laura1013]

Yes , but I don't understood why GRB is short event (small than 200 s) and supernova is long event. Are GRBs produced in the same time as its associeted supernova in all case?
and what about their afterglows in the other electomgnetic bands?

A short GRB is under 2 seconds. A 200 second GRB would be a long GRB. No one really understands how that much energy can be released in that short a period of time.

Afterglows, however, can last for months. They are caused by a different physical mechanism than the initial burst. We typically observe afterglows in frequencies from X-ray to radio.

Not all GRBs are associated with supernova. We observe far more supernovae than we do GRBs, and many long GRBs are not associated with supernovae. There is a connection there, but it's not clear-cut and not at all well understood yet.

If I was at work, I'd give you a list of references you might want to read, but I'm currently traveling for the holidays. You may want to search for some recent publications or review papers on the subject to learn more.

http://adsabs.harvard.edu/cgi-bin/n...txt_wgt=YES&ttl_sco=YES&txt_sco=YES&version=1

http://search.arxiv.org:8081/?query=%22gamma-ray+burst%22+supernova&in=grp_physics

 

[tarbag]

Thanks

A short GRB is under 2 seconds. A 200 second GRB would be a long GRB. No one really understands how that much energy can be released in that short a period of time.

This time is observed time or intrinsicaly time. And how much energy is released by second in the source frame.?

 

[malawi_glenn]

A Supernovae is either a core collapse (massive) star, or an exploding White dwarf (Type Ia). GRB is belived to be due to other mechanisms, like binary neutronstars merging, matter accreating on NS / BH.