John M. Sarkissian

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The merger of close binary systems containing two neutron stars should produce a burst of gravitational waves, as predicted by the theory of general relativity. A reliable estimate of the double-neutron-star merger rate in the Galaxy is crucial in order to predict whether current gravity wave detectors will be successful in detecting such bursts. Present(More)
The double pulsar system PSR J0737-3039A/B is unique in that both neutron stars are detectable as radio pulsars. They are also known to have much higher mean orbital velocities and accelerations than those of other binary pulsars. The system is therefore a good candidate for testing Einstein's theory of general relativity and alternative theories of gravity(More)
On 4 July 2005, many observatories around the world and in space observed the collision of Deep Impact with comet 9P/Tempel 1 or its aftermath. This was an unprecedented coordinated observational campaign. These data show that (i) there was new material after impact that was compositionally different from that seen before impact; (ii) the ratio of dust mass(More)
Analysis of ten years of high-precision timing data on the millisecond pulsar PSR J0437−4715 has resulted in a model-independent kinematic distance based on an apparent orbital period derivative, Ṗb, determined at the 1.5% level of precision (Dk = 157.0±2.4 pc), making it one of the most accurate stellar distance estimates published to date. The discrepancy(More)
Anomalous X-ray pulsars (AXPs) are slowly rotating neutron stars with very bright and highly variable X-ray emission that are believed to be powered by ultra-strong magnetic fields of >10(14) G, according to the 'magnetar' model. The radio pulsations that have been observed from more than 1,700 neutron stars with weaker magnetic fields have never been(More)
Using a statistically rigorous analysis method, we place limits on the existence of an isotropic stochastic gravitational wave background using pulsar timing observations. We consider backgrounds whose characteristic strain spectra may be described as a power-law dependence with frequency. Such backgrounds include an astrophysical background produced by(More)
We present rotational and astrometric parameters of three millisecond pulsars located near the center of the globular cluster NGC 6266 (M62) resulting from timing observations with the Parkes radio telescope. Their accelerations toward the cluster center yield values of the cluster central density and mass-to-light ratio consistent with those derived from(More)
We report the discovery with the Parkes radio telescope of a pulsar associated with the ∼ 1700 yr-old oxygenrich composite supernova remnant G292.0+1.8. PSR J1124−5916 has period 135 ms and period derivative 7.4× 10−13, implying characteristic age 2900 yr, spin-down luminosity 1.2× 1037 erg s−1, and surface magnetic field strength 1.0×1013 G. Association(More)
A new technique of reduction clitoroplasty is presented. The procedure consists of a subtotal resection of the shaft of the clitoris with preservation of the dorsal neurovascular bundle of the glans. The purpose is to preserve erogenous glans clitoris and the erection of the crura. The anatomical results in 8 patients were excellent; partial necrosis(More)
We present radio observations of comet 9P/Tempel 1 associated with the Deep Impact spacecraft collision of 2005 July 4. Weak 18-cm OH emission was detected with the Parkes 64-m telescope, in data averaged over July 4 to 6, at a level of 12± 3 mJy km/s, corresponding to OH production rate 2.8 × 10 molecules/second (Despois et al. inversion model, or 1.0× 10(More)