Help with IPTA Gravitational Waveforms Detected

In summary, the International Pulsar Timing Array team has not detected specific waveform types which are of interest to the author. The waves described may exist, but they are very rare and would not be detected by ground-based detectors. There may be waves detected which are triggered at a maximum amplitude but the amplitude of these waves (if they exist at all) would be much smaller and would be very rare, compared to the waves triggered at a minimum amplitude.
  • #1
Sware
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Hi All. I am interested in finding out if the International Pulsar Timing Array team have detected specific waveform types. The waves I am particularly interested in (if they exist) would be low frequency and would be triggered at a minimum amplitude. Example below:
1688202741257.png

There may be waves detected which are triggered at a maximum amplitude but the amplitude of these waves (if they exist at all) would be much smaller and would be very rare, compared to the waves triggered at a minimum amplitude. Example below:
1688202783746.png

I would also be interested if these types of waves were correlated with gamma ray bursts. Where the wave was triggered ¼ wavelength before the start of the first visible gamma ray pulse.
NOTE: These waves would not be detected by LIGO/VIRGO ground based detectors.
Thanks in advance for any help with this query.
 
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  • #2
I'm unclear on your distinction between minimum and maximum amplitude. What physical quantity is represented on the vertical axis (I assume the horizontal axis is time)? How do you know that detection isn't triggered at some other random point on the waveform; e.g., when the wave amplitude passes through zero?
 
  • #3
Is there a meaningful distinction between "maximum" and "minimum" for a tensor wave? What's maximum stretch in one direction will be minimum in the orthogonal direction.

What's been detected is described as a stochastic background. Can you even pull individual signals out of that? If they could, I think they'd have been able to rule out primordial gravitational waves as a source.
 
  • #4
Hi Guys @ Renormalize. Sorry I was unclear. I am trying to find out if any waves of the general shape in the graphs have been detected by IPTA. The X axis is indeed time and the y axis would also be time of flight of the pulse from the quasar. How it maps to real world physical quantity is not clear yet. How do gravity waves propagate? Maybe it equates to the density of spacetime?
Why isn't the detection triggered at any other point? I am not looking at waves which are triggered at any other point. I only want to see if waves of the type in the graphs above exist. I suppose they would be triggered at the minimum timing pulse flight time of the pulsar, or the maximum flight time of the timing pulse. I am not looking at chirp wave forms which are detected by LIGO and VIRGO as black holes/neutron stars spiral in and merge.

@Ibix - Again, I am looking to see if that specific type of wave is detected, not the general background of gravity waves.
Thanks for feedback both.
 
  • #5
Sware said:
The X axis is indeed time and the y axis would also be time of flight of the pulse from the quasar.
I don't understand this description. Your graphs depicts the ##y##-amplitude oscillating with time between a max and a min. Saying ##y## represents "the time-of-flight of the wave from the quasar" means the wave is speeding-up and slowing-down over the course of one graph cycle. And how is the time since the wave was emitted even measured? Shouldn't the graph simply show a straight line of positive slope, as befits a wave propagating at the speed of light?
 
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  • #7

FAQ: Help with IPTA Gravitational Waveforms Detected

What is IPTA and what role does it play in detecting gravitational waveforms?

The International Pulsar Timing Array (IPTA) is a global collaboration of scientists and observatories that use pulsar timing to detect gravitational waves. By monitoring the precise timing of pulsars, which are highly regular rotating neutron stars, IPTA aims to identify the subtle distortions in spacetime caused by passing gravitational waves.

How do pulsars help in detecting gravitational waves?

Pulsars emit highly regular radio pulses that can be timed with extraordinary precision. When a gravitational wave passes between the Earth and a pulsar, it can slightly alter the distance between them, leading to minute changes in the arrival times of the pulses. By analyzing these timing variations across an array of pulsars, scientists can infer the presence of gravitational waves.

What types of gravitational waves can IPTA detect?

IPTA is particularly sensitive to low-frequency gravitational waves, typically in the nanohertz range. These waves are usually produced by supermassive black hole binaries, cosmic strings, and other large-scale astrophysical phenomena. The low-frequency range complements the higher-frequency detections made by ground-based observatories like LIGO and Virgo.

What are the challenges in detecting gravitational waves using IPTA?

One of the main challenges is the need for extremely precise timing measurements over long periods, often spanning years or even decades. Additionally, separating the gravitational wave signal from other sources of noise, such as interstellar medium variations and pulsar rotational irregularities, requires sophisticated data analysis techniques and collaboration across multiple observatories.

What recent discoveries or advancements have been made by IPTA in the field of gravitational wave astronomy?

Recently, IPTA has made significant strides in improving the sensitivity of pulsar timing arrays, leading to stronger constraints on the stochastic background of gravitational waves. This includes setting upper limits on the gravitational wave background from supermassive black hole binaries and contributing to the multi-messenger astronomy efforts by providing complementary data to other gravitational wave observatories.

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