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Why (else) is J0537-6910 interesting to us?

Why (else) is J0537-6910 interesting to us?. Ben Owen Penn State. The story. Discovery paper in 1998: Middleditch & co. were looking for SN 1987A x-ray pulses (Same time as r-modes got big … more later) Found 16ms period (2x faster than Crab), but in wrong supernova remnant

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Why (else) is J0537-6910 interesting to us?

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  1. Why (else) is J0537-6910 interesting to us? Ben Owen Penn State LIGO Scientific Collaboration

  2. The story • Discovery paper in 1998: Middleditch & co. were looking for SN 1987A x-ray pulses • (Same time as r-modes got big … more later) • Found 16ms period (2x faster than Crab), but in wrong supernova remnant • Radio and optical don’t see the pulsar, and there’s no companion (THIS IS NOT AN LMXB) • Spindown comparable to Crab (2 x 10-10 Hz/s) • Glitches several times per year (record holder) LIGO Scientific Collaboration

  3. The remnant • N157B, one of many in Large Magellanic Cloud (confirmed by H density) • X-ray “comet” around pulsar = jet interacting w/remnant (synchrotron, not thermal) • Sedov age (spectrum & adiabatic expansion) 5000yr inferred before pulsar found • “Comet” & typical kick also imply 5000yr age • Spindown age -f/(2df/dt) also 5000yr (???) ASCA image: Gotthelf & Wang Chandra image: Harvard CfA LIGO Scientific Collaboration

  4. The frequency • New record 62Hz for young pulsars, near record df/dt • Assume B-dipole (braking index n=3) and it was born at infinite frequency! • Or just very fast for n<3, I.e. fast enough for r-modes to have been operating • (Despite J conservation, this is not common…) • Can’t get reliable braking index because… Marshall et al. 1998 LIGO Scientific Collaboration

  5. The glitches • Rate 2-3/yr beats Crab by order of magnitude • Average relative frequency jump-up 3x10-7 • Average relative df/dt jump-”up” 3x10-4 • So many glitches so big that spindown age -f/(2df/dt)decreases at 1yr/yr! (abs(df/dt) increases) • Can predict next glitch time to few % from amplitude of last glitch • Some claims that glitchiness is due to recent phase transition, backbending would imply initial 6ms period (not zero) for n=3 due to J emission history LIGO Scientific Collaboration

  6. The glitches Marshall et al. 2004 LIGO Scientific Collaboration

  7. The bottom line • We know where this thing is • We don’t know much else (structure-wise) • Except that it’s very odd and very interesting • I screwed up a factor 2 in my Amaldi article - this should be the 3rd pulsar initial LIGO can (barely) get to the spindown limit with a small upgrade LIGO Scientific Collaboration

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