Noun
(astronomy) The stage in a black hole merging event where the gravitational wave amplitude reaches its peak.
(telecommunications) A signal to a telephone operator that both rings a bell and allows a relay to drop.
Source: en.wiktionary.orgArguably, the ringdown is the most direct way of observing a black hole. citation From the LIGO signal it is possible to extract the frequency and damping time of the dominant mode of the ringdown. Source: Internet
For For collapsible Slow motion computer simulation of the black hole binary system GW150914 as seen by a nearby observer, during 0.33 s of its final inspiral, merge, and ringdown. Source: Internet
In both cases, this is a telephone operator at the destination who provides assistance solely to other operators on inbound toll calls; the ringdown operator nominally cannot be dialled directly by the subscriber. Source: Internet
In the case of enterprises with a private branch exchange (PBX) switch, the ringdown can be operated by the PBX key. Source: Internet
In cases where one or both ends of the circuit terminate in a key telephone system, a well-designed system will have no hold feature on the ringdown circuit unless supervision provides a Calling Party Control (CPC) signal. Source: Internet
Many ringdown circuits work in both directions. Source: Internet