B Why Does LIGO Only Detect the Famous 'Chirp' Pulse from Black Hole Mergers?

[houlahound]

Is another subforum for Ligo, I see nothing in here(?

My main question is on all the popular media reports i have only seen the one pulse, the now famous chirp If the thing works why isn't it swamped with signals??

 

[Orodruin]

Is another subforum for Ligo, I see nothing in here(?

If we had one subforum for every experiment, they would be impossible to find.

My main question is on all the popular media reports i have only seen the one pulse, the now famous chirp If the thing works why isn't it swamped with signals??

Because there are neot that many black hole mergers.

 

[houlahound]

Is it the pulse of the wavefront that was measured as it swept past LIGO. has that signal moved past the Earth forever now. Was it luck that the age/distance/speed of the wave coincided with LIGO ready to measure or was LIGO built to a schedule with this transmission in mind??

 

[Orodruin]

Yes, a black hole merger is a rather short affair. The signal from the particular merger that was observed is now almost half a light year away.

It was "luck" for this particular event. LIGO was built to measure events of this type, not necessarily that event.

 

[houlahound]

Talk about frikkin luck then, no wonder that team was doing the happy dance.

Does this cause a problem for verifying the signal, I mean one, correction, two coincident signals would not instill me with a lot of confidence but I ain't no genius.

Does this open up a lot of tests for age of galaxies that can now be tested directly given distance and tra el times?

 

[Orodruin]

Talk about frikkin luck then, no wonder that team was doing the happy dance.

No, it is not "frikkin luck". Did you not read what I said? LIGO was built to see this type of event and the fact that they already saw one is likely an indicator that they are relatively common. If not this particular one, it is likely another would have come.

It is also not as if LIGO exists in a setting with no other experiments. Gravitational wave detectors have been increasing in sensitivity over the years and were now finally sensitive enough to make the discovery.

 

[houlahound]

How long was this particular LIGO measurement detector ready and why haven't there been any other activity since, is it off line.

Is the next measurement going to be expected from a target or justvwait for a event and figure what caused it?

 

[krater]

Is my understanding correct, that it is due to both the similarity to each other in mass as well as the range of their masses, 10s of stellar mass, that it produced a "nice" signal for detection by LIGO, and that mergers between BH-mass objects with a higher differential, say one at 10 SM and one at 75-100 SM, would not result in as large of a signal when they merged? Presumably we are reviewing our models of likelyhoods that mergers like this will happen, my first impression of LIGO was, apart from the GW detection, that the BHs involved were far more rare than those nearly an order of magnitude smaller.

 

[looking4sophia]

Is my understanding correct, that it is due to both the similarity to each other in mass as well as the range of their masses, 10s of stellar mass, that it produced a "nice" signal for detection by LIGO, and that mergers between BH-mass objects with a higher differential, say one at 10 SM and one at 75-100 SM, would not result in as large of a signal when they merged? Presumably we are reviewing our models of likelyhoods that mergers like this will happen, my first impression of LIGO was, apart from the GW detection, that the BHs involved were far more rare than those nearly an order of magnitude smaller.

Apparently LIGO technology can detect the far Less Frequent LARGER Mergers
compared to future Space Based LISA
according to this chart their sensitivity to various Frequensies do Not overlap much if at all. **

https://en.wikipedia.org/wiki/Evolved_Laser_Interferometer_Space_Antenna

The next article indicates Thousands of GWs
will be detected from smaller binary Mergers in our own Galaxie, by eLISA.

While LIGO has detected only 1 GW from over 1000 Light Years away,
with rumors of maybe a few more since then that are still being verified.

https://www.elisascience.org/articles/science-context-2028/astrophysics-stars-and-galaxy-2028

** Their discussion of collaborative Observations by LIGO, LISA, ET and others
of a single Merger of Super Massive Black Holes ( very rare )
makes me sure I do not understand all I know about the above.