by VictorBorun » Mon Aug 26, 2024 3:41 am
johnnydeep wrote: ↑Fri Aug 23, 2024 6:48 pm
I find it interesting that in the last link is this bit:
https://www.nasa.gov/centers-and-facili ... y%20minute
Fermi’s Large Area Telescope scans the entire sky every three hours and detects photons with energies ranging from 20 million to more than 300 billion times the energy of visible light. The instrument sees about one gamma ray every minute from CTA 1, enough for scientists to piece together the neutron star’s pulsing behavior, its rotation period, and the rate at which it is slowing down.
How is that possible? It sees only one gamma ray/photon every 60 seconds, yet is still able to deduce a very accurate 316.86 millisecond rotation rate?
if you happen to register a ɣ particle once in a minute, or once in 190 pulses, you need patience to accumulate those registrations.
How many depends on the precision of your registering time while radio-quiet pulsar is aiming the jet on you.
If your time error is zero, then just 3 registrations give you 2 time intervals, say of k periods and of m periods, and if you are in luck and k and m are coprime like 256 and 375, then you already know that the first of your intervals is 256 periods long, or 512, or 768, etc.
The jet may be not so narrow so the time you register a ɣ particle may leave some error for the time the pulsar was aiming at you. That's why just 3 ɣ particles will not do.
But enjoying a particle a minute you can accumulate many.
[quote=johnnydeep post_id=340914 time=1724438930 user_id=132061]
I find it interesting that in the last link is this bit:
https://www.nasa.gov/centers-and-facilities/goddard/nasas-fermi-telescope-discovers-first-gamma-ray-only-pulsar/#:~:text=The%20instrument%20sees%20about%20one%20gamma%20ray%20every%20minute
[quote]Fermi’s Large Area Telescope scans the entire sky every three hours and detects photons with energies ranging from 20 million to more than 300 billion times the energy of visible light. [b][i][color=#0000FF]The instrument sees about one gamma ray every minute from CTA 1, enough for scientists to piece together the neutron star’s pulsing behavior[/color][/i][/b], its rotation period, and the rate at which it is slowing down.[/quote]
How is that possible? It sees only one gamma ray/photon every 60 seconds, yet is still able to deduce a very accurate 316.86 millisecond rotation rate?
[/quote]
if you happen to register a ɣ particle once in a minute, or once in 190 pulses, you need patience to accumulate those registrations.
How many depends on the precision of your registering time while radio-quiet pulsar is aiming the jet on you.
If your time error is zero, then just 3 registrations give you 2 time intervals, say of k periods and of m periods, and if you are in luck and k and m are coprime like 256 and 375, then you already know that the first of your intervals is 256 periods long, or 512, or 768, etc.
The jet may be not so narrow so the time you register a ɣ particle may leave some error for the time the pulsar was aiming at you. That's why just 3 ɣ particles will not do.
But enjoying a particle a minute you can accumulate many.