-
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
