scholarly journals X-ray Spectra of Young Supernovae

2005 ◽  
Vol 192 ◽  
pp. 201-205
Author(s):  
David Pooley
Keyword(s):  
Supernova Explosion ◽  
Quality Data ◽  
High Quality Data ◽  
X Ray ◽  
Circumstellar Material ◽  
Data Application ◽  
To Come ◽  
Massive Star Evolution ◽  
First Time ◽  
Detailed Picture

SummaryX-ray spectra of young supernovae (SNe) can provide information on the progenitor star and the interaction of the supernova ejecta and the circumstellar material. I will discuss some examples, with particular emphasis on SN 1998S, whose X-ray spectrum revealed for the first time in a young supernova a wealth of heavy element emission features (Ne, Al, Si, S, Ar, and Fe). By comparison with detailed calculations of supernova explosion elemental yields, these data can be used to constrain the progenitor mass. With increasingly sophisticated models and additional high quality data, application of this technique could result in many more reliable progenitor mass determinations. In addition, high resolution X-ray spectra allow us to measure the temperature evolution of a supernova and can give us a detailed picture of the progenitor’s pre-supernova evolution. As we build up additional examples from the great diversity of core collapse supernovae, we hope to come to a better understanding of the last stages of massive star evolution.

scholarly journals X-ray Variability of the Flare Star CC Eri

1995 ◽  
Vol 151 ◽  
pp. 170-170
Author(s):  
H.C. Pan ◽  
C. Jordan
Keyword(s):  
Binary Star ◽  
Emission Measure ◽  
Quality Data ◽  
Spectral Variability ◽  
High Quality ◽  
High Quality Data ◽  
X Ray ◽  
Spectroscopic Binary ◽  
Two Temperature ◽  
Continuous Temperature

The flare/spotted spectroscopic binary star CC Eri (HD 16157) was observed in the periods 1990 July 9-11 and 1992 January 26-27 with the ROSAT PSPC detector (Pan and Jordan 1995). These high quality data give the first information on the temporal and spectral variability of CC Eri in the X-ray energy band.During the ROSAT observations the X-ray intensity of the source is variable on timescales from a few minutes to several hours. The X-ray luminosity is in the range 2.5 – 6.8 × 1029 erg s−1, which is similar to values found from previous measurements with the Einstein IPC and EXOSAT LE. On 1990 July 10 an X-ray flare-like event was detected with an exponential rise time of about one hour and a decay time of about two hours. The X-ray spectrum of CC Eri can be described by current thermal plasma codes with two temperature components or with a continuous temperature distribution. The spectral results show that plasma at Te ∼ 107 K exists in the corona of CC Eri. We find that the X-ray spectrum is also variable and the variations of the emission measure, and to a lesser extent of the temperature, are correlated with the source intensity.

scholarly journals Prisma the Instruments

1993 ◽  
Vol 137 ◽  
pp. 672-674
Author(s):  
Andrew Jones
Keyword(s):  
High Resolution ◽  
Stellar Structure ◽  
Quality Data ◽  
The Sun ◽  
Calibration Point ◽  
High Quality ◽  
High Quality Data ◽  
X Ray ◽  
Very High ◽  
Selection Of

Our understanding of Solar structure has increased dramatically in the last couple of decades thanks mainly to the opening of new windows of observation providing high quality data to theoreticians with access to powerful computing facilities. Two of the new windows were UV and X-ray images of the Sun, allowing a detailed view of the upper solar atmosphere, and the development of very high resolution spectrometers allowing us to exploit the solar oscillations to probe the internal structure of the Sun. It is the goal of PRISMA to extend these techniques to other stars, which using the Sun as a calibration point will allow us to explore stellar structure and evolution in ways not possible now.In this poster I will present a possible selection of instruments able to achieve this goal, and explain some of the rationale in their design. A more general overview is presented by T. Appouchaux also in these proceedings. It must be stressed that these are not the definitive instruments to be flown on PRISMA, but rather result from a study to show the feasibility of such a mission. Should PRISMA be chosen as the next ESA medium sized mission, an ‘Announcement of Opportunity’ wiH be issued by ESA and the responses of all people interested in constructing the instrument will be considered.

scholarly journals Summary of Special Session 3

2006 ◽  
Vol 2 (14) ◽  
pp. 623-624
Author(s):  
Françoise Genova
Keyword(s):  
Positive Influence ◽  
Quality Data ◽  
Special Session ◽  
High Quality Data ◽  
Poster Sessions ◽  
Tremendous Progress ◽  
To Come ◽  
Large Telescopes ◽  
Data Centres ◽  
Virtual Observatories

The Virtual Observatory is one of the very few truly global endeavours of astronomy, and IAU General Assemblies are the natural places to present the VO to the community. The three-year time scale of IAU is also well suited to measure progress. At the IAU XXV GA in Sydney, 2003, half of the two-day Joint Discussion 8 on Large Telescopes & Virtual Observatories: Visions for the Future was devoted to VO talks: the main goal was to review what was expected from the VO in different disciplines of astronomy; many projects were also presented in the poster sessions. This time the three-day VO Special Session has given an excellent overview of present status of the VO, showing both tremendous progress and the work which remains to be done. Several scientific communities (astronomy, solar and heliospheric physics) are working on VO development, national communities have been organizing themselves in VO projects. Implementation by data centres has begun. Additional technical development is required, and there are still technical challenges. There is also a huge work ahead for providing high quality data and services, but the VO development already has a very positive influence on astronomers' work environment, and more is to come.

A fibre-based crystal mounting technique for protein cryocrystallography

2012 ◽  
Vol 45 (2) ◽  
pp. 362-366 ◽  
Author(s):  
Michihiro Sugahara
Keyword(s):  
Data Collection ◽  
Success Rate ◽  
Single Crystals ◽  
Conventional Technique ◽  
Synthetic Zeolite ◽  
Quality Data ◽  
High Quality ◽  
High Quality Data ◽  
X Ray ◽  
Loop Technique

The CryoFibre, a crystal mounting tool, has been developed for protein cryocrystallography. The technique attaches single crystals to the tips of polyester fibres, allowing removal of excess liquid around each crystal. Single-wavelength anomalous dispersion phasing using a Cu Kα X-ray source (Cu SAD) was applied to crystals from five proteins without any derivatization, demonstrating a clear improvement in the success rate of Cu SAD compared with the conventional loop technique. In addition, a xylanase crystal on the surface of a synthetic zeolite as a hetero-epitaxic nucleant was directly mounted on the CryoFibre without separation treatment of the crystal from the zeolite. The crystal had a lower mosaicity than that observed using the conventional technique, indicating that the fibre technique is suitable for high-quality data collection from zeolite-mediated crystals.

scholarly journals Fool’s gold? A critical assessment of sources of data on heritage crime

2018 ◽  
Vol 29 (1) ◽  
pp. 10-21
Author(s):  
Louise Grove ◽  
Suzie Thomas ◽  
Adam Daubney
Keyword(s):  
Data Availability ◽  
Quality Data ◽  
High Quality Data ◽  
Content Type ◽  
Reporting Practices ◽  
State Of Affairs ◽  
Effective Assessment ◽  
First Time ◽  
Practical Implications ◽  
Collection Methods

Purpose The purpose of this paper is to explore critically various sources of data available on heritage crime, and consider how these may be utilised and improved. Design/methodology/approach This study is primarily a scoping review of the current heritage crime data climate, embedding examples from a range of existing and potential information sources. It highlights opportunities to improve data resources. Findings A lack of consistency in reporting and recording practices means there is little meaningful evidence about heritage crime trends and patterns. This needs to change in order to develop and evaluate appropriate strategies to reduce the problem of heritage crime nationally and internationally. Research limitations/implications It is hoped that urging improvement of data resources in the heritage crime sector will inspire a greater number of researchers to analyse and address key problems within heritage crime. Practical implications This paper encourages the development of new and improved data collection methods to foster effective assessment of existing heritage crime reduction schemes and better support victims of heritage crime. Social implications Increasing availability and accessibility of high-quality data on heritage crime would allow for developing better protections and resource allocation for vulnerable heritage. Originality/value This paper has drawn together, for the first time, evidence of the existing state of affairs of data availability within heritage crime. It is a position paper which encourages the development of improved recording and reporting practices both formally and informally across heritage and criminal justice sectors in order to support further research and understanding of the heritage crime problem.

scholarly journals Low-dose fixed-target serial synchrotron crystallography

2017 ◽  
Vol 73 (4) ◽  
pp. 373-378 ◽  
Author(s):  
Robin L. Owen ◽  
Danny Axford ◽  
Darren A. Sherrell ◽  
Anling Kuo ◽  
Oliver P. Ernst ◽  
...  
Keyword(s):  
High Throughput ◽  
Low Dose ◽  
Quality Data ◽  
Translation System ◽  
Fixed Target ◽  
High Quality Data ◽  
X Ray ◽  
Serial Sampling ◽  
Serial Data ◽  
Serial Crystallography

The development of serial crystallography has been driven by the sample requirements imposed by X-ray free-electron lasers. Serial techniques are now being exploited at synchrotrons. Using a fixed-target approach to high-throughput serial sampling, it is demonstrated that high-quality data can be collected from myoglobin crystals, allowing room-temperature, low-dose structure determination. The combination of fixed-target arrays and a fast, accurate translation system allows high-throughput serial data collection at high hit rates and with low sample consumption.

scholarly journals A revised Holocene coral sea-level database from the Florida reef tract, USA

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8350 ◽  
Author(s):  
Anastasios Stathakopoulos ◽  
Bernhard M. Riegl ◽  
Lauren T. Toth
Keyword(s):  
Sea Level ◽  
South Florida ◽  
Early Holocene ◽  
Quality Data ◽  
Temporal Data ◽  
High Quality ◽  
High Quality Data ◽  
Western Atlantic ◽  
Reef Tract ◽  
First Time

The coral reefs and mangrove habitats of the south Florida region have long been used in sea-level studies for the western Atlantic because of their broad geographic extent and composition of sea-level tracking biota. The data from this region have been used to support several very different Holocene sea-level reconstructions (SLRs) over the years. However, many of these SLRs did not incorporate all available coral-based data, in part because detailed characterizations necessary for inclusion into sea-level databases were lacking. Here, we present an updated database comprised of 303 coral samples from published sources that we extensively characterized for the first time. The data were carefully screened by evaluating and ranking the visual taphonomic characteristics of every dated sample within the database, which resulted in the identification of 134 high-quality coral samples for consideration as suitable sea-level indicators. We show that our database largely agrees with the most recent SLR for south Florida over the last ∼7,000 years; however, the early Holocene remains poorly characterized because there are few high-quality data spanning this period. Suggestions to refine future Holocene SLRs in the region are provided including filling spatial and temporal data gaps of coral samples, particularly from the early Holocene, as well as constructing a more robust peat database to better constrain sea-level variability during the middle to late Holocene. Our database and taphonomic-ranking protocol provide a framework for researchers to evaluate data-selection criteria depending on the robustness of their sea-level models.

scholarly journals Magnetic Fields in Galaxy Clusters and in the Large-Scale Structure of the Universe

Galaxies ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 142 ◽  
Author(s):  
Valentina Vacca ◽  
Matteo Murgia ◽  
Federica Govoni ◽  
Torsten Enßlin ◽  
Niels Oppermann ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Galaxy Clusters ◽  
Large Scale ◽  
Large Scale Structure ◽  
Scale Structure ◽  
Quality Data ◽  
High Quality Data ◽  
History Of ◽  
The Universe ◽  
Detailed Picture

The formation and history of cosmic magnetism is still widely unknown. Significant progress can be made through the study of magnetic fields properties in the large-scale structure of the Universe: galaxy clusters, filaments, and voids of the cosmic web. A powerful tool to study magnetization of these environments is represented by radio observations of diffuse synchrotron sources and background or embedded radio galaxies. To draw a detailed picture of cosmic magnetism, high-quality data of these sources need to be used in conjunction with sophisticated tools of analysis.

About the variable-counting-time techniques in powder diffraction data: their use in EXPO2004

2007 ◽  
Vol 222 (12/2007) ◽  
Author(s):  
Iván da Silva ◽  
Javier González-Platas ◽  
Carmelo Giacovazzo ◽  
Angela Altomare
Keyword(s):  
Diffraction Data ◽  
Direct Methods ◽  
Optimization Techniques ◽  
Quality Data ◽  
Powder Diffraction Data ◽  
High Quality Data ◽  
X Ray ◽  
Structure Solution ◽  
Process Decomposition ◽  
Counting Time

High quality data are essential for crystal structure solution, particularly when Direct Methods instead of Global Optimization Techniques are used. In this work we study the performances of the variable-counting-time techniques in the two crucial steps of the phasing process: decomposition of the full diffraction pattern and direct phasing. The experimental data were collected by a conventional X-ray laboratory diffractometer: they were then submitted to the program EXPO2004 for assessing their usefulness in the phasing process. The results are compared with those obtained by using experimental diffraction data collected

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