The mass distribution of Galactic double neutron stars

The conventional wisdom, dating back to 2012, is that the mass distribution of Galactic double neutron stars is well-fit by a Gaussian distribution with a mean of $1.33 M_\odot$ and a width of $0.09 M_\odot$. With the recent discovery of new Galactic double neutron stars and GW170817, the first neutron star merger event to be observed with gravitational waves, it is timely to revisit this model. In order to constrain the mass distribution of double neutron stars, we perform Bayesian inference using a sample of 17 Galactic double neutron stars effectively doubling the sample used in previous studies. We expand the space of models so that the recycled neutron star need not be drawn from the same distribution as the non-recycled companion. Moreover, we consider different functional forms including uniform, single-Gaussian, and two-Gaussian distributions. While there is insufficient data to draw firm conclusions, we find positive support (a Bayes factor of 9) for the hypothesis that recycled and non-recycled neutron stars have distinct mass distributions. The most probable model---preferred with a Bayes factor of 29 over the conventional model---is one in which the recycled neutron star mass is distributed according to a two-Gaussian distribution and the non-recycled neutron star mass is distributed uniformly. We show that precise component mass measurements of $\approx 20$ double neutron stars are required in order to determine with high confidence (a Bayes factor of 150) if recycled and non-recycled neutron stars come from a common distribution. Approximately $60$ are needed in order to establish the detailed shape of the distributions.Comment: Minor update of PSR J1913+1102 masses, 13 pages, 7 figures, 5 table

Management of bleeding complications during thymectomy by subxiphoid approach with double elevation of the sternum: a case report.

Thymoma is the most common tumor of the anterior mediastinum and surgical resection for thymoma has been recommended as the principal treatment. Bleeding control remains as a challenging task under minimally invasive approach. Subxiphoid approach with double elevated of sternum was a novel method which might provide good surgical view and space for operating. In this study we reported a case of bleeding control with this approach after unexpected damage to innominate vein to address the advantage of bleeding control using this specific surgical approach. The case was a 66-year-old female patient with an anterior mediastinal mass incidentally detected during physical examination and was diagnosed with thymoma with a diameter of 5 cm. Injury to the joint of innominate vein and the vena cava occurred during a subxiphoid approach with double elevation of the sternum. It was well managed by controlling the bleeding site with Alice forceps and suture under thoracoscope view without conversion to median sternotomy. A 4-0 PROLENE line was used with an elbow needle holder under the thoracoscope to suture continuously. Intraoperative blood loss was 350 mL. The drainage tubes were removed on postoperative day (POD) 2, and the patient was discharged on POD 3. This case indicated that thymectomy by subxiphoid approach with double elevation of the sternum has more advantages when there is an emergency for bleeding during the operation compared with traditional intercostal approach or subxiphoid approach with carbon dioxide inflation