Short GRB's: Neutron Star Merger Evidence?

[skydivephil]

Is there any actaul observational evidence that short burst GRB's are casued by neutron star mergers?

 

[zhermes]

There are numerous hints, and indirect pieces of evidence, but nothing conclusive. Binary neutron star mergers seem to perfectly match the properties of sGRBs, while no other models are able to---which is an indication in itself. Some of the relevant observations:

sGRBs come from old stellar populations without star formation (e.g. red ellipticals)
They have much larger separations from their host galaxies
The time duration and energy content matches expectations for binary neutron star systems
The observed and expected event rates are consistent (but the expectations have huge error bars)

The conclusive piece of evidence would be coincident detection of gravitationals waves from a sGRB source.

 

[skydivephil]

Thanks a lot for that , i was trying to find what thhe evidence was but couldn't really find anything cocnrete, much appreciated.

 

[zhermes]

Happy to help

 

[pmacias]

Yes, there is strong observational evidence that short gamma-ray bursts (GRBs) are caused by the merger of two neutron stars. This evidence comes from a variety of sources, including electromagnetic observations, gravitational wave detections, and theoretical models.

Firstly, the detection of gravitational waves from the merging of two neutron stars in 2017 provided direct evidence for the merger scenario of short GRBs. This event, known as GW170817, was observed by the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Virgo interferometer, and was followed by a short GRB detected by the Fermi and INTEGRAL satellites. This was the first time that both gravitational waves and gamma rays were observed from the same cosmic event, confirming the long-standing theory that short GRBs are caused by neutron star mergers.

In addition to this, observations of the afterglow of short GRBs have also provided evidence for the neutron star merger scenario. The afterglow is the fading emission that follows the initial burst of gamma rays and can be observed at longer wavelengths, such as X-rays, optical, and radio. The afterglow of short GRBs is consistent with the expected emission from the merger of two neutron stars, further supporting this scenario.

Furthermore, theoretical models of short GRBs also point to neutron star mergers as the most likely cause. These models take into account the properties of the observed bursts, such as their duration, energetics, and spectral properties, and show that they can be explained by the merger of two neutron stars.

Overall, the observational evidence from both gravitational wave detections and afterglow observations, combined with theoretical models, strongly supports the idea that short GRBs are caused by the merger of two neutron stars. This is an exciting discovery in the field of astrophysics and has furthered our understanding of these powerful cosmic events.