Self-consistency of relativistic observables with general relativity in the white dwarf-neutron star binary pulsar PSR J1141-6545

Here we report timing measurements of the relativistic binary pulsar PSR J1141-6545 that constrain the component masses and demonstrate that the orbital period derivative \dot Pb = (-4+/-1)x10^-13 is consistent with gravitational wave emission as described by the general theory of relativity. The mass of the neutron star and its companion are 1.30+/-0.02 Mo and 0.986+/-0.020 Mo respectively, suggesting a white dwarf companion, and extending the range of systems for which general relativity provides a correct description. On evolutionary grounds, the progenitor mass of PSR J1141-6545 should be near the minimum for neutron star production. Its mass is two standard deviations below the mean of the other neutron stars, suggesting a relationship between progenitor and remnant masses.Comment: 10 pages, 2 figures, revised version to Ap J Letter

Bis{l-2,20-[1,10-(ethane-1,2-diyldinitrilo)- diethylidyne]diphenolato}bis[(benzoatojO)manganese(III)] dihydrate

The title compound, [Mn2(C18H18N2O2)2Cl2], was synthesized by the reaction between manganese(II) o-chloro­benzoate and the Schiff base generated in situ by the condensation of ethane-1,2-diamine and o-hydroxy­acetophenone. The centrosymmetric dimer contains two Jahn-Teller-distorted mangan­ese(III) ions, each in an octa­hedral geometry, connected through two phen­oxy bridges from two ligands

Bis{μ-2,2′-[1,1′-(ethane-1,2-diyldinitrilo)diethyl­idyne]diphenolato}bis­[(benzoato-κO)manganese(III)] dihydrate

The title compound, [Mn2(C18H18N2O2)2(C7H5O2)2]·2H2O, was synthesized by the reaction between manganese(II) benzoate and the Schiff base generated in situ by the condensation of ethane-1,2-diamine and o-hydroxy­aceto­phen­one. The Jahn–Teller-distorted manganese(III) ions of the centrosymmetric dimer are connected through phen­oxy bridges. Hydrogen-bonding inter­actions between the uncoord­in­ated C=O of the benzoate and uncoordinated water mol­ecules link the dimers into a chain running parallel to the c axis

Transient radio emisison from SAX J1808.4-3658

We report on the detection of radio emission from the accretion-powered X-ray millisecond pulsar SAX J1808.4-3658, using the Australia Telescope Compact Array. We detected a ~0.8 mJy source at the position of SAX J1808.4-3658 on 1998 April 27, approximately one day after the onset of a rapid decline in the X-ray flux; no such source was seen on the previous day. We consider this emission to be related to the radio emission from other X-ray binaries, and is most likely associated with an ejection of material from the system. No radio emission was detected at later epochs, indicating that if SAX J1808.4-3658 is a radio pulsar during X-ray quiescence then its monochromatic luminosity must be less than L(1.4 GHz) ~6 mJy/kpc^2.Comment: 6 pages, uses emulateapj.sty, one embedded PS figure. Accepted to ApJ Letter

Pulsar Radio Emission Altitude from Curvature Radiation

We assume that the relativistic sources moving along the dipolar magnetic field lines emit curvature radiation. The beamed emission occurs in the direction of tangents to the field lines, and to receive it, the sight line must align with the tangent within the beaming angle 1/gamma, where gamma is the particle Lorentz factor. By solving the viewing geometry in an inclined and rotating dipole magnetic field, we show that, at any given pulse phase, observer tends to receive radiation only from the specific heights allowed by the geometry. We find outer conal components are emitted at higher altitudes compared to inner components including the core. At any pulse phase, low frequency emission comes from higher altitudes than high frequency emission. We have modeled the emission heights of pulse components of PSR B0329+54, and estimated field line curvature radii and particle Lorentz factors in the emission regions.Comment: 14 pages, 3 figures. Accepted for Astrophysical Journal, 200

A Quantitative Non-radial Oscillation Model for the Subpulses in PSR B0943+10

In this paper, we analyze time series measurements of PSR B0943+10 and fit them with a non-radial oscillation model. The model we apply was first developed for total intensity measurements in an earlier paper, and expanded to encompass linear polarization in a companion paper to this one. We use PSR B0943+10 for the initial tests of our model because it has a simple geometry, it has been exhaustively studied in the literature, and its behavior is well-documented. As prelude to quantitative fitting, we have reanalyzed previously published archival data of PSR B0943+10 and uncovered subtle but significant behavior that is difficult to explain in the framework of the drifting spark model. Our fits of a non-radial oscillation model are able to successfully reproduce the observed behavior in this pulsar.Comment: 45 pages, 16 figures, accepted Ap