1,455 research outputs found
Searches for continuous gravitational waves from 15 supernova remnants and fomalhaut b with advanced LIGO
No full textWe describe directed searches for continuous gravitational waves (GWs) from 16 well-localized candidate neutron stars, assuming none of the stars has a binary companion. The searches were directed toward 15 supernova remnants and Fomalhaut b, a directly imaged extrasolar planet candidate that has been suggested to be a nearby old neutron star. Each search covered a broad band of frequencies and first and second time derivatives. After coherently integrating spans of data from the first Advanced LIGO observing run of 3.5–53.7 days per search, applying data-based vetoes, and discounting known instrumental artifacts, we found no astrophysical signals. We set upper limits on intrinsic GW strain as strict as 1 × 10−25, fiducial neutron star ellipticity as strict as 2 × 10−9, and fiducial r-mode amplitude as strict as 3 × 10−8
Searches for continuous gravitational waves from nine young supernova remnants
No full textWe describe directed searches for continuous gravitational waves (GWs) in data from the sixth Laser Interferometer Gravitational-wave Observatory (LIGO) science data run. The targets were nine young supernova remnants not associated with pulsars; eight of the remnants are associated with non-pulsing suspected neutron stars. One target's parameters are uncertain enough to warrant two searches, for a total of 10. Each search covered a broad band of frequencies and first and second frequency derivatives for a fixed sky direction. The searches coherently integrated data from the two LIGO interferometers over time spans from 5.3–25.3 days using the matched-filtering -statistic. We found no evidence of GW signals. We set 95% confidence upper limits as strong (low) as 4 × 10?25 on intrinsic strain, 2 × 10?7 on fiducial ellipticity, and 4 × 10?5 on r-mode amplitude. These beat the indirect limits from energy conservation and are within the range of theoretical predictions for neutron-star ellipticities and r-mode amplitudes
The Archaeology Of Gua Tupak From 1,190 B.P. To 170 B.P. In Bau, Sarawak
No full textIn November and December 2007, an archaeological survey was conducted
by the author and a research team from the Centre for Global Archaeological
Research, Universiti Sains Malaysia, Penang with the cooperation of the Sarawak
Museum Department, Kuching in the limestone caves of the Bau area, southwest
Sarawak in order to search for a site for the author’s Master of Arts (MA) study. The
result of the survey determined Gua Tupak to be a highly potential site and
consequently, excavations were carried out at the site in February and March 2008.
The excavations at Gua Tupak yielded valuable archaeological data that could aid in
providing information on the prehistory of the site and the Bau area. The
archaeological data include various types of artefacts such as shell remains, animal
bones, ceramic sherds and stone artefacts. In addition, charcoal and shell samples
were collected for radiocarbon dating, soil samples were collected for palynological
analysis and soil profiles of the excavated trenches were recorded. Results of the
analyses of artefacts and interpretations of the archaeological data recovered from
Gua Tupak suggest that the site was used as a temporary habitation site or shelter
with two main phases of occupation; the Early Phase with a radiocarbon date of
around 1,190 ± 40 B.P., and the Late Phase with radiocarbon dates ranging from 270
± 50 B.P. to 170 ± 40 B.P
Improved Analysis of GW150914 Using a Fully Spin-Precessing Waveform Model
No full textThis paper presents updated estimates of source parameters for GW150914, a binary black-hole coalescence event detected by the Laser Interferometer Gravitational-wave Observatory (LIGO) in 2015 [Abbott et al. Phys. Rev. Lett. 116, 061102 (2016).]. Abbott et al. [Phys. Rev. Lett. 116, 241102 (2016).] presented parameter estimation of the source using a 13-dimensional, phenomenological precessing-spin model (precessing IMRPhenom) and an 11-dimensional nonprecessing effective-onebody (EOB) model calibrated to numerical-relativity simulations, which forces spin alignment (nonprecessing EOBNR). Here, we present new results that include a 15-dimensional precessing-spin waveform model (precessing EOBNR) developed within the EOB formalism. We find good agreement with the parameters estimated previously [Abbott et al. Phys. Rev. Lett. 116, 241102 (2016).], and we quote updated component masses of 35(-3)(+5) M-circle dot and 30(-4)(+3) M-circle dot (where errors correspond to 90% symmetric credible intervals). We also present slightly tighter constraints on the dimensionless spin magnitudes of the two black holes, with a primary spin estimate < 0.65 and a secondary spin estimate < 0.75 at 90% probability. Abbott et al. [Phys. Rev. Lett. 116, 241102 (2016).] estimated the systematic parameter-extraction errors due to waveform-model uncertainty by combining the posterior probability densities of precessing IMRPhenom and nonprecessing EOBNR. Here, we find that the two precessing-spin models are in closer agreement, suggesting that these systematic errors are smaller than previously quoted
Late Quaternary palaeoclimate of western Alaska inferred from fossil chironomids and its relation to vegetation histories
No full textFossil Chironomidae assemblages (with a few Chaoboridae and Ceratopogonidae) from Zagoskin and Burial Lakes in western Alaska provide quantitative reconstructions of mean July air temperatures for periods of the late-middle Wisconsin (similar to 39,000-34,000 cal yr B.P.) to the present. Inferred temperatures are compared with previously analyzed pollen data from each site summarized here by indirect ordination. Paleotemperature trends reveal substantial differences in the timing of climatic warming following the late Wisconsin at each site, although chronological uncertainty exists. Zagoskin Lake shows early warming beginning at about 21,000 cal yr B.P., whereas warming at Burial Lake begins similar to 4000 years later. Summer climates during the last glacial maximum (LGM) were on average similar to 3.5 degrees C below the modern temperatures at each site. Major shifts in vegetation occurred from similar to 19,000 to 10,000 cal yr B.P. at Zagoskin Lake and from similar to 17,000 to 10,000 cal yr B.R at Burial Lake. Vegetation shifts followed climatic warming, when temperatures neared modern values. Both sites provide evidence of an early postglacial thermal maximum at similar to 12,300 cal yr B.R These chironomid records, combined with other insect-based climatic reconstructions from Beringia, indicate that during the LGM: (1) greater continentality likely influenced regions adjacent to the Bering Land Bridge and (2) summer climates were, at times, not dominated by severe col
Agriculture facilitated permanent human occupation of the Tibetan Plateau after 3600 B.P.
No full textOur understanding of when and how humans adapted to living on the Tibetan Plateau at altitudes above 2000 to 3000 meters has been constrained by a paucity of archaeological data. Here we report data sets from the northeastern Tibetan Plateau indicating that the first villages were established only by 5200 calendar years before the present (cal yr B.P.). Using these data, we tested the hypothesis that a novel agropastoral economy facilitated year-round living at higher altitudes since 3600 cal yr B.P. This successful subsistence strategy facilitated the adaptation of farmers-herders to the challenges of global temperature decline during the late Holocene
Mannix, Edward (Death, 1908-08-05)
No full textAddress: N. E. Gest & DaltonAge at death: 11 Mos 17 days100/Pg.95/1908/M W S/B.P.- City/Dr. N.W. Abbott/Busse & Borgmann/St. Marys Cem.Original record filed in drawer labeled 'MANNING-MARSHALL, M'
Ordelmundt, Eva A. (Death, 1907-02-23)
No full textAddress: N.E. Cor Court & CutterAge at death: 53-8-8510/Pg 24/1907/F W W/B.P.- Cinti., Ohio/Dr. N.W. Abbott/W.H. Dunkmann & Sons/Spring Grove Cem.Original record filed in drawer labeled 'O'NEIL-OSER'
Ulzhoefer, Agatha (Death, 1908-03-18)
No full textAddress: 1103 Hopkins St.Age at death: 71 yrs.F W W / 391 / pg36 / 1908 / B.P- Germany / Dr. N.W. Abbott / Busse & Borgmann / Spring Grove Cem.Original record filed in drawer labeled 'Tucker-Underheuser'
Thauwald, Wm. H. (Death, 1908-08-11)
No full textAddress: 1557 Dudley St.Age at death: 33 Yrs.202/Pg.98/1908/M W S/B.P.- City/Dr. D.H. Abbott/Dunkmann & Son/DelhiOriginal record filed in drawer labeled 'TEHR-THICKE'
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