Orbital Decay and Mass of Relativistic Binary PSR...

Thanks to:

Collaborator: Ingrid Stairs PUPPI: Paul Demorest, Scott Ransom, NRAO Data from Nice et al. 2005: Eric Splaver, Ingrid Stairs, Oliver Lohmer, Axel Jessner, Michael Kramer, Jim Cordes Arecibo Observatory (SRI/USRA/UMET) NSF

Orbital Decay and Mass of Relativistic Binary PSR J0751+1807

David Nice Lafayette College

Physical Applications of Millisecond Pulsars, Aspen Center for Physics, 22 January 2013

UNDER  CONSTRUCTION  

CAUTION!  PRELIMINARY  

RESULTS  

Δ t

Δ t orbit not edge-on; observed Δ t same as edge-on case, but orbit is larger

orbit viewed edge-on

?

? Companion might be heavy star in small orbit or light star in a large orbit

€

2πPb

⎛

⎝ ⎜

⎞

⎠ ⎟

2 a1 sin i( )3

G= f1 =

m2 sin i( )3

m1 +m2( )2

Precession

Shapiro Delay

Gravitational Radiation

( ) [ ] 0 2 3 sin sin 1 ln 2 ϕ ϕ - - = Δ i m c G t

Grav Redshift/Time Dilation r v

( ) 3 1 3 5

) ( 1 1

96 37

24 73 1

2 5 192

2 1 2 1

2 7 2 4 2 3

5 5 m m

m m e

e e P c G P b b

+ - ⎟ ⎠ ⎞

⎜ ⎝ ⎛ + + ⎟

⎠ ⎞

⎜ ⎝ ⎛

⎟ ⎠ ⎞

⎜ ⎝ ⎛ - =

-

π π

3 4

3 2 ) ( 2 2 1 2 1 3

1 2 m m

+2m m P c G γ b

+ ⎟ ⎠ ⎞

⎜ ⎝ ⎛

= π

e ) ( 2 m

( ) 3 2

2 1 2 3 5

1 1

2 3 ⎥ ⎦

⎤ ⎢ ⎣ ⎡

+ - ⎟ ⎠ ⎞

⎜ ⎝ ⎛

= -

m m e P b π

ω 2 c G 2/3

Second Orbit m  1  m  2  =  

a  1  sin  i  a  2  sin  i  

Figure: Jim Lattimer stellarcollapse.org/nsmasses

PSR J0751+1807 in a Nutshell

Typical Millisecond Pulsar P = 3.479 ms B=2x108 gauss Pdot=7x10-21 Spindown age=7 Gyr

Tight circular orbit Pb = 6.3 hour e < 1x10-6 no evidence of eclipses or dispersive material in orbit

Low mass companion m2 ~ 0.14 M optical detection, Bassa et al 2006 faint; surprising lack of hydrogen no evidence for variability

PSR J0751+1807

PSR J0751+1807 Observations

Arecibo/430 MHz Arecibo/1400 MHz Effelsberg/1400 MHz

6 day Arecibo campaign (full orbit coverage) 430 MHz PUPPI observations Dumps @ 3 min intervals Residual rms 2.8 µs in 3 min 1400 MHz PUPPI observations Dumps @ 10 sec intervals TOAs in each of 4 subbands Residual rms 6 µs per subband in 10 s

PSR J0751+1807 Shapiro Delay

CAUTION!  PRELIMINARY  

RESULTS  

PSR J0751+1807 Orbit decay due to gravitational wave emission

Orbit decay rate (95%conf) :

Pb = – (3.3±0.3)×10–14 .

CAUTION!  PRELIMINARY  

RESULTS  

PSR J0751+1807 Shapiro Delay+Orbit Decay

CAUTION!  PRELIMINARY  

RESULTS  

PSR J0751+1807 Shapiro Delay+Orbit Decay

CAUTION!  PRELIMINARY  

RESULTS  

PSR J0751+1807 Shapiro Delay+Orbit Decay

Masses (95% conf):

m1 = 1.34±0.09 M#

m2 = 0.138±0.006 M

CAUTION!  PRELIMINARY  

RESULTS  

Figure: Jim Lattimer stellarcollapse.org/nsmasses

CAUTION!  PRELIMINARY  

RESULTS  

Summmary • Detected Shapiro Delay and Orbit Decay • Masses (95% conf):

m1 = 1.34±0.09 M #$m2 = 0.138±0.006 M#

#

Additional Remarks • Orbital decay precision will soon be dominated by systematics from Galactic acceleration and transverse Doppler shift; distance not presently well known; can be improved by VLBA parallax, timing parallax • Large rotating dipole moments provide interesting GR test but lack of a priori knowledge of m1 and m2 limits the usefulness of PSR J0751+1807 source for this test.

PSR J0751+1807: Summary & Final Remarks

CAUTION!  PRELIMINARY  

RESULTS