A5073462016- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Astrophysics and Star Formation Studies
- Pulsars and Gravitational Waves Research
- Chemical Synthesis and Analysis
- Neuropeptides and Animal Physiology
- Receptor Mechanisms and Signaling
- Pharmacological Receptor Mechanisms and Effects
- Solar and Space Plasma Dynamics
- Astronomical Observations and Instrumentation
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Geophysics and Gravity Measurements
- Radio Astronomy Observations and Technology
- Synthesis and Biological Evaluation
- Stellar, planetary, and galactic studies
- Neutrino Physics Research
- Astro and Planetary Science
- Analytical Chemistry and Chromatography
- Carbohydrate Chemistry and Synthesis
- Synthetic Organic Chemistry Methods
- Mitochondrial Function and Pathology
- Ionosphere and magnetosphere dynamics
- Cancer, Hypoxia, and Metabolism
Goddard Space Flight Center
2016-2025
Deleted Institution
2015-2024
University of Kentucky
2024
Williams (United States)
2024
University of Louisville
2023-2024
Kyoto University
2022
University of Miyazaki
2020-2022
Creative Commons
2021
Los Alamos National Laboratory
2019
Space Telescope Science Institute
2013-2018
Use of base-labile N-fluorenylmethoxycarbonylamino-acids, t-butyl based side chain protecting groups, and a p-alkoxybenzyl ester resin linkage provides simple, rapid, exceptionally mild strategy in solid phase peptide synthesis.
Double detonations in double white dwarf (WD) binaries undergoing unstable mass transfer have emerged recent years as one of the most promising Type Ia supernova (SN Ia) progenitor scenarios. One potential outcome this "dynamically driven double-degenerate double-detonation" (D^6) scenario is that companion WD survives explosion and flung away with a velocity equal to its > 1000 km/s pre-SN orbital velocity. We perform search for these hypervelocity runaway WDs using Gaia's second data...
Despite decades of intense efforts, many fundamental aspects Type Ia supernova (SNe Ia) remain elusive. One the major open questions is whether mass exploding white dwarf (WD) close to Chandrasekhar limit. Here we report detection strong K-shell emission from stable Fe-peak elements in Suzaku X-ray spectrum remnant (SNR) 3C 397. The high Ni/Fe and Mn/Fe ratios (0.11-0.24 0.018-0.033, respectively) hot plasma component that dominates lines indicate a degree neutronization SN ejecta which can...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKynurenic acid derivatives. Structure-activity relationships for excitatory amino antagonism and identification of potent selective antagonists at the glycine site on N-methyl-D-aspartate receptorPaul D. Leeson, Raymond Baker, Robert W. Carling, Neil R. Curtis, Kevin Moore, Brian J. Williams, Alan C. Foster, Angus E. Donald, John A. Kemp, George MarshallCite this: Med. Chem. 1991, 34, 4, 1243–1252Publication Date (Print):April 1, 1991Publication...
Details are given of the preparation two acid‐labile peptide‐resin linkage agents for use in solid phase peptide synthesis, viz. 4‐hydroxymethylphenoxy‐acetic acid and 3‐methoxy‐4‐hydroxymethylphenoxyacetic acid. The latter is suitable fragments bearing t‐butyl‐based side chain protecting groups.
We report results from a multi-wavelength analysis of the Galactic SNR RCW 86, proposed remnant supernova 185 A.D. new infrared observations {\it Spitzer} and WISE}, where entire shell is detected at 24 22 $\mu$m. fit flux ratios with models collisionally heated ambient dust, finding post-shock gas densities in non-radiative shocks 2.4 2.0 cm$^{-3}$ SW NW portions remnant, respectively. The Balmer-dominated around periphery shell, large amount iron X-ray emitting ejecta, lack compact support...
We introduce a deep (670 ks) X-ray survey of the SN1006 remnant from Chandra, plus H-alpha image 4m telescope at CTIO. Comparison with Chandra images 2003 gives first measurement proper motions around entire rim. find that expansion velocity varies significantly azimuth: highest ~7400 km/s (almost 2.5 times in NW) is found along SE rim, where both kinematics and spectra indicate most X-rays stem undecelerated ejecta. Asymmetries distribution ejecta are seen on variety spatial scales. Si-rich...
Spitzer images of Tycho's supernova remnant in the mid-infrared reveal limb-brightened emission from entire periphery shell and faint filamentary structures interior. As with other young remnants, this is produced by dust grains, warmed to ∼100 K post-shock environment collisions energetic electrons ions. The ratio 70 24 μm fluxes a diagnostic temperature, which turn sensitive function plasma density. We find significant variations 70/24 flux around forward shock, implying order-of-magnitude...
Racemisation of Nα-t-butoxycarbonyl, fluoren-9-ylmethoxycarbonyl, and benzyloxycarbonyl amino-acid anhydrides by p-dimethylaminopyridine is shown to ba a significant side reaction during attachment the first resin in solid-phase peptide synthesis.
We report observations with the Multiband Imaging Photometer for Spitzer of four supernova remnants (SNRs) believed to be result core-collapse supernovae: N132D (0525-69.6), N49B (0525-66.0), N23 (0506-68.0), and 0453-68.5. All these SNRs were detected in whole at 24 μm part 70 μm. Comparisons Chandra broadband X-ray images show an association infrared (IR) emission blast wave. attribute observed IR dust that has been collisionally heated by electrons ions hot, X-ray-emitting plasma, grain...
We present first results from an extensive survey of Magellanic Cloud supernova remnants (SNRs) with the Spitzer Space Telescope. describe IRAC and MIPS imaging observations at 3.6, 4.5, 5.8, 8, 24, 70 μm four Balmer-dominated Type Ia SNRs in Large (LMC): DEM L71 (0505-67.9), 0509-67.5, 0519-69.0, 0548-70.4. None was detected short-wavelength bands, but all were clearly imaged 24 μm, two μm. A comparison these images Chandra broadband X-ray shows a clear association blast wave, not internal...
Several young supernova remnants (SNRs), including SN1006, emit synchrotron X-rays in narrow filaments, hereafter thin rims, along their periphery. The widths of these rims imply 50 to 100 $\mu$G fields the region immediately behind shock, far larger than expected for interstellar medium compressed by unmodified shocks, assuming electron radiative losses limit rim widths. However, magnetic-field damping could also produce rims. Here we review literature on width calculations, summarizing...
Diagnosis of histoplasmosis in patients with Acquired Immunodeficiency Syndrome (AIDS) may be established by detection the organism lung tissue or bronchoalveolar lavage fluid. In this report we have evaluated utility Histoplasma capsulatum polysaccharide antigen (HPA) fluid for diagnosis histoplasmosis. HPA was detected 19 27 cases (70.3%). Of 122 controls a variety underlying diseases, none. Eight negative specimens from were retested after fivefold concentration, and five. Fivefold...
We present 3.6 - 160 micron infrared images of Kepler's supernova remnant (SN1604) obtained with the IRAC and MIPS instruments on Spitzer Space Telescope. also SED low resolution spectra in 55 95 region. The observed emission 24 band shows entire shell. Emission 70 8 bands is seen only from brightest regions emission, which correspond to optical Halpha images. Shorter wavelength are increasingly dominated by stars, although faint filaments discernible. spectrum a continuum dropping off...
ABSTRACT We present newly obtained X-ray and radio observations of Tycho’s supernova remnant using Chandra the Karl G. Jansky Very Large Array in 2015 2013/14, respectively. When combined with earlier epoch by these instruments, we now have time baselines for expansion measurements 12–15 years X-rays 30 radio. The remnant’s large angular size allows proper motion at many locations around periphery blast wave. Consistent measurements, find a clear gradient velocity remnant, despite its round...
Four new fluorine-containing macrocyclic polyethers based on bis-p-phenylene-34-crown-10 have been synthesized and subsequently catenated, separately, with cyclobis(paraquat-p-phenylene). The efficiencies of the catenations are strongly influenced by aromatic ring templates in polyethers. Incorporation fluorine atom substituents into one hydroquinone rings had only a small effect percentage yields, whereas employing derivatives, which both at least partially fluorinated, resulted dramatic...
We present near and mid-infrared observations of the pulsar-wind nebula (PWN) B0540-69.3 its associated supernova remnant made with {\it Spitzer Space Telescope}. report detections PWN all four IRAC bands, 24 $μ$m band MIPS, Infrared Spectrograph (IRS). find no evidence IR emission from X-ray/radio shell surrounding resulting forward shock blast wave. The flux itself is dominated by synchrotron at shorter (IRAC) wavelengths, a warm dust component longward 20 $μ$m. show that this continuum...
Characterization of the relatively poorly-understood progenitor systems Type Ia supernovae is great importance in astrophysics, particularly given important cosmological role that these play. Kepler's Supernova Remnant, result a supernova, shows evidence for an interaction with dense circumstellar medium (CSM), suggesting single-degenerate system. We present 7.5-38 $\mu$m infrared (IR) spectra remnant, obtained {\it Spitzer Space Telescope}, dominated by emission from warm dust. Broad...