Listen to Pulsars

Generate audio that approximates the signal from a pulsar

Pulsars are highly magnetized, rapidly rotating stellar remnants whose magnetic axis can be tilted with respect to its rotation axis. Synchrotron radiation is emitted from the magnetic poles, and as the pulsar rotates, it sweeps this beam of radiation through space. If this beam sweeps by the Earth, a periodic pulse of radiation is seen.

Create a function to simulate the radiation pattern from a given pulsar in time and convert these levels into sound (note: that not all pulsars have a known pulse width, so in that case, a value of 3 ms is assigned). By default, an observation duration of 5 seconds is used:

In[1]:=

periodsound[entity_,duration_:5]:=Module{pulsewidth,period,α},{pulsewidth,period}=QuantityMagnitudeentity

pulse width at 50% peak

rotation period

/.{_Missing,q_}

,q,"Seconds";α=-Log[2]Log[Cos[pulsewidth/periodπ/2]];AudioGenerator[Cos[PiMod[#,period,-1/2period]/period]^α&,duration]

Young pulsars often rotate quickly. Use the sound function to get a sense of the rotation speed by "listening" to Crab pulsar:

In[2]:=

crab=periodsound

Crab Pulsar

PULSAR



Out[2]=

00:00

00:05

Data in Notebook

Show its signal spectrogram:

In[3]:=

Spectrogram[crab,PlotRange{Automatic,{0,1000}}]

Out[3]=

Old pulsars slow down their rotation with age, and thus their pulse rate is slower:

In[4]:=

geminga=periodsound

Geminga

PULSAR



Out[4]=

00:00

00:05

Data in Notebook

Show its signal spectrogram:

In[5]:=

Spectrogram[geminga,PlotRange{Automatic,{0,1000}}]

Out[5]=

Visualize a pulsar, showing the radiation beam in purple and the surfaces representing equi-vector magnitudes of the magnetic field strength of an ideal dipole in blue:

In[6]:=

With{t=45Degree},Graphics3DTableRotateParametricPlot3DrSin[θ]^2{Cos[φ]Sin[θ],Sin[φ]Sin[θ],Cos[θ]},{θ,0,Pi},{φ,0,2Pi},RegionFunction(#2>0&),

shell options

1,t,{0,1,0},{r,5},

beam options

,Cone[{10{Sin[t],0,Cos[t]},{0,0,0}},.5],Cone[{-10{Sin[t],0,Cos[t]},{0,0,0}},.5],

scene options



Out[6]=

External Links

Pulsar

Source Metadata

Citation: ref/entity/Pulsar

Publisher Information

Contributed by: Wolfram Staff

License Information

This work is licensed under a Creative Commons Attribution 4.0 International License

Wolfram Language Example Repository

Listen to Pulsars

External Links

Source Metadata

See Also

Publisher Information

License Information

Listen to Pulsars

External Links

Source Metadata

See Also

Related Symbols

Publisher Information

License Information