Hasil untuk "astro-ph.SR"

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S2 Open Access 2021
GWTC-3: Compact Binary Coalescences Observed by LIGO and Virgo during the Second Part of the Third Observing Run

The Ligo Scientific Collaboration, The Virgo Collaboration, T. Abbott et al.

The third Gravitational-Wave Transient Catalog (GWTC-3) describes signals detected with Advanced LIGO and Advanced Virgo up to the end of their third observing run. Updating the previous GWTC-2.1, we present candidate gravitational waves from compact binary coalescences during the second half of the third observing run (O3b) between 1 November 2019, 15:00 UTC and 27 March 2020, 17:00 UTC. There are 35 compact binary coalescence candidates identified by at least one of our search algorithms with a probability of astrophysical origin $p_\mathrm{astro}>0.5$. Of these, 18 were previously reported as low-latency public alerts, and 17 are reported here for the first time. Based upon estimates for the component masses, our O3b candidates with $p_\mathrm{astro}>0.5$ are consistent with gravitational-wave signals from binary black holes or neutron star-black hole binaries, and we identify none from binary neutron stars. However, from the gravitational-wave data alone, we are not able to measure matter effects that distinguish whether the binary components are neutron stars or black holes. The range of inferred component masses is similar to that found with previous catalogs, but the O3b candidates include the first confident observations of neutron star-black hole binaries. Including the 35 candidates from O3b in addition to those from GWTC-2.1, GWTC-3 contains 90 candidates found by our analysis with $p_\mathrm{astro}>0.5$ across the first three observing runs. These observations of compact binary coalescences present an unprecedented view of the properties of black holes and neutron stars.

1303 sitasi en Physics
S2 Open Access 2015
THE ELEVENTH AND TWELFTH DATA RELEASES OF THE SLOAN DIGITAL SKY SURVEY: FINAL DATA FROM SDSS-III

S. Alam, F. D. Albareti, C. Prieto et al.

The third generation of the Sloan Digital Sky Survey (SDSS-III) took data from 2008 to 2014 using the original SDSS wide-field imager, the original and an upgraded multi-object fiber-fed optical spectrograph, a new near-infrared high-resolution spectrograph, and a novel optical interferometer. All of the data from SDSS-III are now made public. In particular, this paper describes Data Release 11 (DR11) including all data acquired through 2013 July, and Data Release 12 (DR12) adding data acquired through 2014 July (including all data included in previous data releases), marking the end of SDSS-III observing. Relative to our previous public release (DR10), DR12 adds one million new spectra of galaxies and quasars from the Baryon Oscillation Spectroscopic Survey (BOSS) over an additional 3000 deg2 of sky, more than triples the number of H-band spectra of stars as part of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE), and includes repeated accurate radial velocity measurements of 5500 stars from the Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS). The APOGEE outputs now include the measured abundances of 15 different elements for each star. In total, SDSS-III added 5200 deg2 of ugriz imaging; 155,520 spectra of 138,099 stars as part of the Sloan Exploration of Galactic Understanding and Evolution 2 (SEGUE-2) survey; 2,497,484 BOSS spectra of 1,372,737 galaxies, 294,512 quasars, and 247,216 stars over 9376 deg2; 618,080 APOGEE spectra of 156,593 stars; and 197,040 MARVELS spectra of 5513 stars. Since its first light in 1998, SDSS has imaged over 1/3 of the Celestial sphere in five bands and obtained over five million astronomical spectra.

1927 sitasi en Geology, Physics
CrossRef Open Access 2023
Agujeros Negros

Gustavo Dotti

Se presenta una introducción a los fundamentos de la Relatividad General y la noción de Agujeros Negros de una manera elemental, asumiendo conocimientos básicos de Física, y relegando a notas al pie de página aquellas acotaciones técnicas que requieran mayores conocimientos. Se da además una breve introdución histórica del concepto de agujero negro, y se mencionan los notables avances recientes en el campo experimental: la detección en 2015 de ondas gravitacionales en LIGO y las imágenes obtenidas por el Event Horizon Telescope.

S2 Open Access 2019
Analysis of the 2017 American Society for Radiation Oncology (ASTRO) Research Portfolio.

James B. Yu, Tyler F Beck, M. Anscher et al.

PURPOSE Research in radiation oncology (RO) is imperative to support the discovery of new uses of radiation and improvement of current approaches to radiation delivery and to foster the continued evolution of our field. Therefore, in 2016, the American Society of Radiation Oncology performed an evaluation of research grant funding for RO. METHODS AND MATERIALS Members of the Society of Chairs of Academic Radiation Oncology Programs (SCAROP) were asked about funded and unfunded grants that were submitted by their departments between the fiscal years 2014 and 2016. Grants were grouped according to broad categories defined by the 2017 American Society of Radiation Oncology Research Agenda. Additionally, active grants in the National Institutes of Health (NIH) Research Portfolio Online Reporting Tools database were collated using RO faculty names. RESULTS Overall, there were 816 funded (44%) and 1031 unfunded (56%) SCAROP-reported grants. Total grant funding was over $196 million. The US government funded the plurality (42.2%; 345 of 816) of grants compared with nonprofit and industry funders. Investigators from 10 institutions accounted for >75% of funded grants. Of the funded grants, 43.5% were categorized as "genomic influences and targeted therapies." The proportion of funded to unfunded grants was highest within the category of "tumor microenvironment, normal tissue effects, and reducing toxicity" (53.4% funded). "New clinical trial design and big data" had the smallest share of SCAROP grant applications and the lowest percent funded (38.3% of grants). NIH grants to RO researchers in 2014 to 2016 accounted for $85 million in funding. From the 31 responding SCAROP institutions, there was a 28% average success rate for RO proposals submitted to the NIH during this period. CONCLUSIONS Though RO researchers from responding institutions were relatively successful in obtaining funding, the overall amount awarded remains small. Continued advocacy on behalf of RO is needed, as well as investment to make research careers more attractive areas for emerging faculty.

8 sitasi en Medicine
CrossRef Open Access 2019
Dilaporkan ke Peradi karena Persoalan Etika, Ini Kata Bambang Widjojanto

Marselinus Hosea Astro

Dalam kasus ini saya akan membahas tentang persoalan Etika. Kasus ini terjadi di Jakarta. seorang Ketua tim hukum Prabowo-Sandiaga Bambang Widjojanto diadukan ke perhimpunan Advokat Indonesia pimpinan fauzi Hasibuan di kantor peradilan, Jakarta Barat pada kamis (13-06-2019) laporan ini dilakukan oleh sekumpulan Aadvokat yang tergabung dalam Advokat indonesia Maju melaporkan Bambang Widjojanto (BW). Bambang Widjojanto diadukan untuk dua persoalan Etika. Pertama, mantan pimpinan Komisi pemberantasan Korupsi (KPK) disebut melangar Etika saat menjadi kuasa hokum prabowo namun masih aktif sebagai pejabat Negara. Bambang Widjojanto diangap melangar Etika karena merendahkan MK tak hanya soal jabatannya sebagai ketua TGUPP, Bambang Widjojanto juga diadukakan untuk persoalan etika kedua kalinya ini terkait pernyataannya yang dinilai merendahkan Mahkamah konsitusi.Kasus ini sangat jelas melangar Etika. Secara umum dapat dikatakan bahwa etika adalah filsafat tentang tindakan manusia. suatu tindakan itu mempunyai nilai etis bila dilakukan oleh manusia. sangatlah jelas bahwa etika itu berurusan secara langsung dengan tindakan atau tingkah laku manusia. Tingkah laku manusia ini bukan tingkah laku yang tidak ada artinya.

S2 Open Access 2017
Muon capture reaction on $^{100}Mo$ to study nuclear responses for double beta decays and astro-neutrinos

I. H. Hashim, H. Ejiri, T. Shima et al.

The negative-muon capture reaction (MCR) on the enriched $^{100}Mo$ isotope was studied for the first time to investigate neutrino nuclear response for neutrino-less double beta decays and supernova neutrino nuclear interactions. MCR on $^{100}Mo$ proceeds mainly as $^{100}Mo(mu,xn)^{100-x}Nb$ with $x$ being the number of neutrons emitted from MCR. The Nb isotope mass distribution was obtained by measuring delayed gamma-rays from radioactive $^{100-x}Nb$. By using the neutron emission model after MCR, the neutrino response (the strength distribution) for MCR was derived. Giant resonance (GR)-like distribution at the peak energy around 11-14 MeV, suggests concentration of the MCR strength at the muon capture GR region.

25 sitasi en Physics
S2 Open Access 2014
The ASTRO-H X-ray astronomy satellite

Tadayuki Takahashi, K. Mitsuda, R. Kelley et al.

The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions developed by the Institute of Space and Astronautical Science (ISAS), with a planned launch in 2015. The ASTRO-H mission is equipped with a suite of sensitive instruments with the highest energy resolution ever achieved at E > 3 keV and a wide energy range spanning four decades in energy from soft X-rays to gamma-rays. The simultaneous broad band pass, coupled with the high spectral resolution of ΔE ≤ 7 eV of the micro-calorimeter, will enable a wide variety of important science themes to be pursued. ASTRO-H is expected to provide breakthrough results in scientific areas as diverse as the large-scale structure of the Universe and its evolution, the behavior of matter in the gravitational strong field regime, the physical conditions in sites of cosmic-ray acceleration, and the distribution of dark matter in galaxy clusters at different redshifts.

116 sitasi en Physics, Engineering
S2 Open Access 2016
Anchoring historical sequences using a new source of astro-chronological tie-points

M. Dee, B. Pope

The discovery of past spikes in atmospheric radiocarbon activity, caused by major solar energetic particle events, has opened up new possibilities for high-precision chronometry. The two spikes, or Miyake Events, have now been widely identified in tree-rings that grew in the years 775 and 994 CE. Furthermore, all other plant material that grew in these years would also have incorporated the anomalously high concentrations of radiocarbon. Crucially, some plant-based artefacts, such as papyrus documents, timber beams and linen garments, can also be allocated to specific positions within long, currently unfixed, historical sequences. Thus, Miyake Events represent a new source of tie-points that could provide the means for anchoring early chronologies to the absolute timescale. Here, we explore this possibility, outlining the most expeditious approaches, the current challenges and obstacles, and how they might best be overcome.

29 sitasi en Geology, Biology
S2 Open Access 2014
The Si/CdTe semiconductor Compton camera of the ASTRO-H Soft Gamma-ray Detector (SGD)

S. Watanabe, H. Tajima, Y. Fukazawa et al.

Abstract The Soft Gamma-ray Detector (SGD) is one of the instrument payloads onboard ASTRO-H, and will cover a wide energy band (60–600 keV) at a background level 10 times better than instruments currently in orbit. The SGD achieves low background by combining a Compton camera scheme with a narrow field-of-view active shield. The Compton camera in the SGD is realized as a hybrid semiconductor detector system which consists of silicon and cadmium telluride (CdTe) sensors. The design of the SGD Compton camera has been finalized and the final prototype, which has the same configuration as the flight model, has been fabricated for performance evaluation. The Compton camera has overall dimensions of 12 cm×12 cm×12 cm, consisting of 32 layers of Si pixel sensors and 8 layers of CdTe pixel sensors surrounded by 2 layers of CdTe pixel sensors. The detection efficiency of the Compton camera reaches about 15% and 3% for 100 keV and 511 keV gamma rays, respectively. The pixel pitch of the Si and CdTe sensors is 3.2 mm, and the signals from all 13,312 pixels are processed by 208 ASICs developed for the SGD. Good energy resolution is afforded by semiconductor sensors and low noise ASICs, and the obtained energy resolutions with the prototype Si and CdTe pixel sensors are 1.0–2.0 keV (FWHM) at 60 keV and 1.6–2.5 keV (FWHM) at 122 keV, respectively. This results in good background rejection capability due to better constraints on Compton kinematics. Compton camera energy resolutions achieved with the final prototype are 6.3 keV (FWHM) at 356 keV and 10.5 keV (FWHM) at 662 keV, which satisfy the instrument requirements for the SGD Compton camera (better than 2%). Moreover, a low intrinsic background has been confirmed by the background measurement with the final prototype.

83 sitasi en Physics
S2 Open Access 2016
Atomic scattering factor of the ASTRO-H (Hitomi) SXT reflector around the gold's L edges.

N. Kikuchi, Sho Kurashima, M. Ishida et al.

The atomic scattering factor in the energy range of 11.2-15.4 keV for the ASTRO-H Soft X-ray Telescope (SXT) is reported. The large effective area of the SXT makes use of photon spectra above 10 keV viable, unlike most other X-ray satellites with total-reflection mirror optics. Presence of gold's L-edges in the energy band is a major issue, as it complicates the function of the effective area. In order to model the area, the reflectivity measurements in the 11.2-15.4 keV band with the energy pitch of 0.4 - 0.7 eV were made in the synchrotron beam-line Spring-8 BL01B1. We obtained atomic scattering factors f1 and f2 by the curve fitting to the reflectivities of our witness sample. The edges associated with the L-I, II, and III transitions are identified, of which the depths are found to be roughly 60% shallower than those expected from the Henke's atomic scattering factor.

11 sitasi en Medicine, Physics

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