Candidate Electromagnetic Counterpart to the Binary Black Hole Merger Gravitational-Wave Event S190521g.

We report the first plausible optical electromagnetic counterpart to a (candidate) binary black hole merger. Detected by the Zwicky Transient Facility, the electromagnetic flare is consistent with expectations for a kicked binary black hole merger in the accretion disk of an active galactic nucleus [B. McKernan, K. E. S. Ford, I. Bartos et al., Astrophys. J. Lett. 884, L50 (2019)AJLEEY2041-821310.3847/2041-8213/ab4886] and is unlikely [

Illuminating gravitational waves: A concordant picture of photons from a neutron star merger.

Merging neutron stars offer an excellent laboratory for simultaneously studying strong-field gravity and matter in extreme environments. We establish the physical association of an electromagnetic counterpart (EM170817) with gravitational waves (GW170817) detected from merging neutron stars. By synthesizing a panchromatic data set, we demonstrate that merging neutron stars are a long-sought production site forging heavy elements by r-process nucleosynthesis. The weak gamma rays seen in EM170817 are dissimilar to classical short gamma-ray bursts with ultrarelativistic jets. Instead, we suggest that breakout of a wide-angle, mildly relativistic cocoon engulfing the jet explains the low-luminosity gamma rays, the high-luminosity ultraviolet-optical-infrared, and the delayed radio and x-ray emission. We posit that all neutron star mergers may lead to a wide-angle cocoon breakout, sometimes accompanied by a successful jet and sometimes by a choked jet.

[Sixty-nine consecutive cases of eclampsia: prodromes and circumstances]. / Soixante-neuf éclampsies consécutives: signes annonciateurs et circonstances de survenue.

OBJECTIVE: To specify clinical and biological characteristics of patients developing eclampsia, and identify atypical eclampsia without prior signs and symptoms of severe preeclampsia. PATIENTS AND METHODS: This was a retrospective observational study conducted from January 1996 to December 2008 in a maternity type IIB in French Guiana. Data of patients who experienced eclampsia were collected from obstetric records. RESULTS: Sixty-nine patients were selected among 21,525 patients who delivered during this period, corresponding to a prevalence of 3.2 ‰. The average patient age was 21 years (range from 12 to 45 years). Sixty-six percent of patients were nulliparous. The gestational age was greater than 37 weeks of gestation for 62% of patients, between 26 and 37 weeks of gestation for 36% and less than 26 weeks of gestation for 2% of patients. Two thirds of the patients had been examined less than a month before the eclamptic seizure, blood pressure was normal in 62% of cases. Seventy-four percent of patients had at least one Doppler study of the uterine and umbilical arteries velocimetry, the Dopplers studies were normal in 78% of cases. The eclampsia occurred in ante-, peri- and post-partum in 59, 6 and 35% of the cases, respectively 10% of patients were hospitalized for preeclampsia at the time of eclamptic seizure. Less than 10% of patients developed HELLP syndrome. One patient had died of aspiration pneumonia. Newborns had a mean birth weight over 2500 g in 88% of cases. During the follow-up period, 41% of the patients had subsequent pregnancies with 62% without hypertension, 24% complicated by recurrent gestational hypertension, 24% by preeclampsia and 4% by eclampsia. DISCUSSION AND CONCLUSION: In a majority of the patients in our study, eclampsia was the main manifestation, and only 10% were preceded by severe preeclampsia. These results are comparable to recent studies, which found in their series that 40 to 60% of eclampsia manifested without preeclamptic prodromi. Eclampsia can occur after an unremarkable pregnancy, in women without risk factors, and then it is hardly predictable. Prenatal follow-up must be very cautious paying attention to any markers such as intermittent hypertension, functional symptoms or appearance of proteinuria.

[Syphilis and pregnancy]. / Syphilis et grossesse. Etude de 85 cas en Guyane française.

OBJECTIVE: The aim of our study was to assess the impact of maternal syphilis on pregnancy and foetal/neonatal outcomes. STUDY DESIGN: A retrospective study, conducted from 1 June 1992 to 31 December 2004, involved 85 seropositive pregnant women at the West Guyanese hospital in French Guyana. Inclusion criterias were a positive treponemal pallidum hemagglutination assay (TPHA) with a titre greater or equal to than 1/2560 and a positive Venereal Disease Research Laboratory (VDRL) with a titre greater or equal to than 1/16 for a pregnant woman with different stages of pregnancy. We evaluated maternal characteristics, antenatal care, type of treatment, the presence of coinfections, fetal ultrasound characteristics, outcome of pregnancy, umbilical cord biological diagnosis and neonatal clinical exams. We evaluated the efficiency of early and complete syphilis treatment in the prevention of vertical infection. RESULTS: The proportion of seropositive pregnant women with lack or inadequate antenatal care was high (40%), hence, the diagnosis and treatment were performed late in pregnancy. The incidences of adverse obstetric outcomes were the following: perinatal deaths (20%), stillbirths (12,9%), preterm deliveries (18,8%) and low birth weight (28,2%). Specific ultrasound findings of congenital syphilis (stillbirth excluded) were found in six cases out of 61 (9,8%) and specific neonatal clinical features of early congenital syphilis were found in four cases. There is a high correlation demonstrated between vertical infections and late or inadequate syphilis treatment in a pregnant woman. CONCLUSION: Antepartum syphilis represents a health problem in developing countries and tends to reappear in developed countries. All pregnant women should receive an adequate prenatal care including obligatory screening test for syphilis, we should keep in mind the possibility of syphilitic infection in case of maternal clinical features or foetal signs especially hepatosplenomegaly, hydrops fetalis or intestinal hyperechogenicity.

The Mid-Infrared Spectra of Normal Galaxies.

The mid-infrared spectra (2.5-5 and 5.7-11.6 µm) obtained by ISOPHOT reveal the interstellar medium emission from galaxies powered by star formation to be strongly dominated by the aromatic features at 6.2, 7.7, 8.6, and 11.3 µm. Additional emission appears in between the features, and an underlying continuum is clearly evident at 3-5 µm. This continuum would contribute about a third of the luminosity in the 3-13 µm range. The features together carry 5%-30% of the 40-120 µm far-infrared (FIR) luminosity. The relative fluxes in individual features depend very weakly on galaxy parameters such as the far-infrared colors, direct evidence that the emitting particles are not in thermal equilibrium. The dip at 10 µm is unlikely to result from silicate absorption since its shape is invariant among galaxies. The continuum component has a fnu~nu+0.65 shape between 3 and 5 µm and carries 1%-4% of the FIR luminosity; its extrapolation to longer wavelengths falls well below the spectrum in the 6-12 µm range. This continuum component is almost certainly of nonstellar origin and is probably due to fluctuating grains without aromatic features. The spectra reported here typify the integrated emission from the interstellar medium of the majority of star-forming galaxies and could thus be used to obtain redshifts of highly extincted galaxies up to z=3 with SIRTF.