LIGO scientists row back on claim to detect black-holes from their gravitational signal

It is gradually coming out that LIGO’s main gravitational wave pulse could indicate various types of binary astrophysical systems, as we said on this blog in February. Cardoso et al 2016 point out (Phys Rev Lett. to come) there are compact objects that are not black holes, including gravastars of similar dimensions (~30 solar masses) which produce a similar main signal. The late part of the signal was below detection threshold, and that is needed to distinguish between astrophysical objects. In discussing this, Physics World quotes Prof Sathyaprakash from Cardiff’s LIGO team saying that “Our signal is consistent with both the formation of a black hole and a horizonless object – we just can’t tell.” Rather different from him in the Guardian of 11 Feb. “The fusion of two black holes created this event”. Now, Remo Ruffini (of the Rees-Ruffini-Wheeler textbook) co-authors an preprint (16 May 2016) saying: unfortunately the signal of the merging “occurs just at the limit of the sensitivity of LIGO (so is) not sufficient to determine the astrophysical nature of GW 150914, nor to assess that it was produced by a binary black-hole merger leading to a newly formed black-hole.”

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One Response to LIGO scientists row back on claim to detect black-holes from their gravitational signal

  1. They heard two lions roaring, but now they think it was not even one loon?

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