Search for Gravitational Waves from Intermediate Mass Binary Black Holes

We present the results of a weakly modeled burst search for gravitational waves from mergers of non-spinning intermediate mass black holes (IMBH) in the total mass range 100--450 solar masses and with the component mass ratios between 1:1 and 4:1. The search was conducted on data collected by the LIGO and Virgo detectors between November of 2005 and October of 2007. No plausible signals were observed by the search which constrains the astrophysical rates of the IMBH mergers as a function of the component masses. In the most efficiently detected bin centered on 88+88 solar masses, for non-spinning sources, the rate density upper limit is 0.13 per Mpc^3 per Myr at the 90% confidence level.Comment: 13 pages, 4 figures: data for plots and archived public version at https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=62326, see also the public announcement at http://www.ligo.org/science/Publication-S5IMBH

Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

Despite the growing number of binary black hole coalescences confidently observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include the effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that have already been identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total source-frame mass M > 70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz emitted gravitational-wave frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place a conservative upper limit for the merger rate density of high-mass binaries with eccentricities 0 < e ≤ 0.3 at 16.9 Gpc−3 yr−1 at the 90% confidence level

Mortality in a large Australian metropolitan cohort of Crohn's disease patients

Background: Crohn’s disease (CD) causes significant morbidity and can cause fatal complications. Data from Europe and North America suggest that mortality (CD) is increased by up to 50% in CD. There is a paucity of data from Australia. Methods: This longitudinal study of CD patients diagnosed between 1971 and 1992 builds upon a cohort previously described in 1995 by extending follow-up to 2008. Survival status and cause of death (COD) data were extracted from the National Death Index (Australian Institute of Health and Welfare) with complete follow-up of available data. Relative survival analysis (SURV2, Finnish Cancer Registry) was used to compare the observed survival of patients with the expected survival of a comparable group based upon official life tables for the population of New South Wales, adjusting for year of birth, year of diagnosis and sex. The relation between COD and CD was judged independently by two Gastroenterologists. Results: Of 373 CD patients (153 M, 220 F) 82 (21.9%) had died at the end of the study period. Median follow up was 22.7 years [M] and 22.2 years [F] respectively. There was no difference in mortality compared to the general population. Relative survival was 1.03 [M] (95%CI 0.98–1.08) and 0.98 ([F] 95%CI 0.94–1.0) at 10 years, 0.98 ([M] 95%CI 0.89–1.06) and 0.98 ([F] 95%CI 0.93–1.04) at 20 years, 0.98 ([M] 95%CI 0.86–1.1) and 0.88 ([F] 95%CI 0.76–0.99) at 30 years. There was no difference in survival between patients diagnosed from 1971 to 1979 and those diagnosed from 1980 to 1992. Death from all malignant diseases occurred in 22.1% (lung 2.9%, pancreas 2.9%, bile duct 2.9%, colorectal 2.9%). A definite or possible relation between CD and COD was found in 27.9%.Conclusion Over a quarter of deaths are caused by CD itself, but overall survival is similar to that of the general population. This finding stands in contrast to current and older data from Europe and North America. This discrepancy could be due to differences in disease severity, health care system, social or environmental factors.S Bath, J Andrews, O Dent, RW Leon