A5102893167- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Astronomy and Astrophysical Research
- Geophysics and Gravity Measurements
- Scientific Research and Discoveries
- High-pressure geophysics and materials
- Galaxies: Formation, Evolution, Phenomena
- Astro and Planetary Science
- Stellar, planetary, and galactic studies
- Cosmology and Gravitation Theories
- Statistical and numerical algorithms
- Photorefractive and Nonlinear Optics
- Solar and Space Plasma Dynamics
- Geomagnetism and Paleomagnetism Studies
- Luminescence Properties of Advanced Materials
- Earthquake Detection and Analysis
- Nuclear Physics and Applications
- Quantum and electron transport phenomena
- Advanced Chemical Physics Studies
- Radio Astronomy Observations and Technology
- Sensor Technology and Measurement Systems
- Atomic and Subatomic Physics Research
- Semiconductor Quantum Structures and Devices
- Astrophysics and Cosmic Phenomena
The University of Texas at Austin
1996-2013
Purple Mountain Observatory
2007
University of California, Santa Barbara
2001
McDonald's (United States)
1993
Princeton University
1989
Defense Advanced Research Projects Agency
1986
RCA (United States)
1958-1977
view Abstract Citations (2209) References (42) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Formation of Very Strongly Magnetized Neutron Stars: Implications for Gamma-Ray Bursts Duncan, Robert C. ; Thompson, Christopher stars with unusually strong magnetic dipole fields B_dipole ~ 10^14 - 10^15 G, can form when conditions efficient helical dynamo action are met during the first few seconds after gravitational collapse. Such high-field neutron stars,...
A radiative model for the soft gamma repeaters and energetic 1979 March 5 burst is presented. We identify sources of these bursts with neutron stars external magnetic fields which are much stronger than those ordinary pulsars. Several independent arguments point to a star Bdipole ~ × 1014 G as source event. very strong field can (i) spin down an 8-s period in 104-yr age surrounding supernova remnant N49; (ii) provide enough energy event; (iii) undergo large-scale interchange instability...
We calculate the quiescent X-ray, neutrino, and Alfvén wave emission from a neutron star with very strong magnetic field, Bdipole ~ 1014 − 1015 G Binterior (5–10) × G. These results are compared observations of soft gamma repeaters small class anomalous X-ray pulsars that we have previously identified such objects. The rather than rotation, provides main source free energy, decaying field is capable powering particle observed these sources. New features not present in decay weaker fields...
view Abstract Citations (860) References (125) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Neutron Star Dynamos and the Origins of Pulsar Magnetism Thompson, Christopher ; Duncan, Robert C. star convection is a transient phenomenon has an extremely high magnetic Reynolds number. In this sense, neutron dynamo quintessential fast dynamo. The convective motions are only mildly turbulent on scales larger than approximately 100 cm neutrino mean free path, but...
The soft-gamma repeater SGR 1900+14 became active again on June 1998 after a long period of quiescence; it remained at low state activity until August 1998, when emitted series extraordinarily intense outbursts. We have observed the source with RXTE twice, during onset each episode. confirm pulsations 5.16 s reported earlier (Hurley et al. 1998b, Hurley e) from 1900+14. Here we report detection secular spindown pulse an average rate 1.1*10^{-10} s/s. In view strong similarities between SGRs,...
The extraordinary 1998 August 27 giant flare places strong constraints on the physical properties of its source, SGR 1900+14. We make detailed comparisons published data with magnetar model, which identifies soft gamma repeaters as neutron stars endowed ~1015 G magnetic fields. evolved through three stages, whose radiative mechanisms we address in turn. extreme peak luminosity L > 106LEdd, hard spectrum, and rapid variability initial ~0.5 s spike emission all point to an expanding pair...
view Abstract Citations (467) References (38) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Quasar Ionization of Lyman-Alpha Clouds: The Proximity Effect, a Probe the Ultraviolet Background at High Redshift Bajtlik, Stanislaw ; Duncan, Robert C. Ostriker, Jeremiah P. We study distribution lines in Lyα forests quasar spectra, using spectral data from 19 quasars with emission-line redshifts 1.7 < z_Q_ 3.8. number density generally increases redshift z, but...
There is evidence that soft gamma repeaters (SGRs) are neutron stars experience frequent starquakes, possibly driven by an evolving, ultrastrong magnetic field. The empirical power-law distribution of SGR burst energies, analogous to the Gutenberg-Richter law for earthquakes, exhibits a turnover at high consistent with global limit on crust fracture size. With such large starquakes occurring, significant excitation seismic oscillations (GSOs) seems likely. Moreover, GSOs may be self-exciting...
view Abstract Citations (171) References (7) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Neutrino-driven Winds from Young, Hot Neutron Stars Duncan, Robert C. ; Shapiro, Stuart L. Wasserman, Ira Questions raised by the study of Salpeter and Shapiro (1981) neutrino photon emission a young, hot neutron star are addressed. The general coupled hydrodynamical-radiative transport equations for this presented, it is shown how these reduce to those in...
We study the statistics of soft gamma repeater (SGR) bursts, using a data base 187 events detected with BATSE and 837 RXTE PCA, all from SGR 1900+14 during its 1998-1999 active phase. find that fluence or energy distribution bursts is consistent power law index 1.66, over 4 orders magnitude. This scale-free resembles Gutenberg-Richter Law for earthquakes, gives evidence self-organized criticality in SGRs. The time intervals between successive log-normal distribution. There no correlation...
The giant flare of 1998 August 27 from SGR 1900+14 was extraordinary in many ways: it the most intense flux gamma rays ever detected a source outside our solar system; longer than any previously burst soft repeater (SGR) Galaxy by more an order magnitude; and showed remarkable four-peaked, periodic pattern hard X-rays with same rotation period that found modulating star quiescence. event several gamma-ray experiments space, including Ulysses detector BeppoSAX Gamma-Ray Burst Monitor. These...
We consider the physical implications of rapid spin-down soft gamma repeater SGR 1900+14 reported by Woods and colleagues in 1999. During an 80 day interval between 1998 June large outburst on August 27, mean rate increased a factor 2.3, resulting positive period offset ΔP/P = 10-4. A radiation-hydrodynamical outflow associated with 27 event could impart required torque, but only if dipole magnetic field is stronger than ~1014 G lasts longer and/or more energetic observed X-ray flare....
We present statistics of SGR 1806-20 bursts, combining 290 events detected with the Rossi X-Ray Timing Explorer/Proportional Counter Array, 111 Burst and Transient Source Experiment, 134 International Cometary Explorer. find that fluence distribution bursts observed each instrument are well described by power laws indices 1.43, 1.76, 1.67, respectively. The time intervals between successive from is a lognormal function peak at 103 s. There no correlation burst intensity either waiting times...
view Abstract Citations (138) References (25) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Spectroscopy of the Double Quasars Q1343+266A, B: A New Determination Size Lyman-Alpha Forest Absorbers Bechtold, Jill ; Crotts, Arlin P. S. Duncan, Robert C. Fang, Yihu We have obtained spectroscopy B, a pair quasars at redshift z = 2.03 with projected separation 9.5". This system is well suited for probing Lyα forest, since two-component spectra show several lines...
We have analyzed Rossi X-ray Timing Explorer Proportional Counter Array observations of the pulsed emission from SGR 1900+14 during September 1996, June - October 1998, and early 1999. Using these measurements results reported elsewhere, we construct a period history this source for 2.5 years. find significant deviations steady spin-down trend quiescence burst active interval. Burst Transient Source Experiment are presented correlations between activity rate discussed. an 80 day interval...
Photochromic materials have the property of changing color under light illumination. Inorganic photochromic are frequently cathodochromic as well, that is, they can be colored by electron beam irradiation. This paper describes recent studies at RCA Laboratories three classes inorganic materials: (1) rare-earth-doped CaF(2); (2) transition-metal-doped SrTiO(3) and CaTiO(3); (3) iron- or sulfurdoped sodalite. properties these in both single crystal powder form, powders, discussed.
The Soft Gamma Repeater SGR 1900+14 entered a remarkable phase of activity during the summer 1998. This peaked on August 27, 1998 when giant periodic gamma-ray flare resembling famous March 5, 1979 event from 0526-66 was recorded. Two days later (August 29), strong, bright burst detected with RXTE and BATSE. reveals several similarities to flares 27 shows number unique features not previously seen in bursts. Unlike typically short bursts, this 3.5 s peak that preceded by an extended (~ 1 s)...
view Abstract Citations (57) References (23) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Equilibrium composition and neutrino emissivity of interacting quark matter in neutron stars Duncan, R. C. ; Shapiro, S. L. Wasserman, I. It is shown that a detailed treatment the equilibrium liquid crucial to accurate evaluation its emissivity. demonstrated when massive s-quarks are present cold matter, electron fraction vanishes above finite baryon density. This...
GRB 051103 is considered to be a candidate soft gamma repeater (SGR) extragalactic giant magnetar flare by virtue of its proximity on the sky M81/M82, as well time history, localization and energy spectrum. We have derived refined interplanetary network for this burst which reduces size error box over factor 2. examine history evidence periodic component, would one signature an SGR flare, conclude that component neither detected nor detectable under reasonable assumptions. analyse...
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We study the temporal and coarse spectral properties of 268 bursts from SGR 1806-20 679 1900+14, all observed with Rossi X-Ray Timing Explorer/Proportional Counter Array. Hardness ratios parameters, such as T90 durations τ90 emission times are determined for these bursts. find a lognormal distribution burst durations, ranging over more than 2 orders magnitude: ~ 10-2 to ≳1 s, peak at ~0.1 s. The light curves tend be asymmetrical, half events showing rise tr < 0.3 T90. that there exists...
Received 30 September 1958DOI:https://doi.org/10.1103/PhysRevLett.1.404©1958 American Physical Society
view Abstract Citations (66) References (57) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Size and Nature of Lyman- alpha Forest Clouds Probed by QSO Pairs Groups Fang, Yihu ; Duncan, Robert C. Crotts, Arlin P. S. Bechtold, Jill Closely separated pairs groups make it possible to probe the size, geometry, spatial clustering Lyα forest clouds. Recent spectroscopic observations Q1343 + 2640A/B give evidence that transverse sizes clouds are very large at...
In magnetic fields stronger than BQ≡me2c3/ℏe=4.4×1013 Gauss, an electron's Landau excitation energy exceeds its rest energy. I review the physics of this strange regime and some implications for crusts magnetospheres neutron stars. particular, describe how ultra-strong • render vacuum birefringent capable distorting magnifying images ("magnetic lensing"); change self-energy electrons: as B increases they are first slightly lighter me, then heavier; cause photons to rapidly split merge with...