We present the first public version (v02) of the open-source and community-developed Python package, Astropy This package provides core astronomy-related functionality to the community, including support for domain-specific file formats such as flexible image transport system (FITS) files, Virtual Observatory (VO) tables, and common ASCII table formats, unit and physical quantity conversions, physical constants specific to astronomy, celestial coordinate and time transformations, world coordinate system (WCS) support, generalized containers for representing gridded as well as tabular data, and a framework for cosmological transformations and conversions Significant functionality is under activedevelopment, such as a model fitting framework, VO client and server tools, and aperture and point spread function (PSF) photometry tools The core development team is actively making additions and enhancements to the current code base, and we encourage anyone interested to participate in the development of future Astropy versions

/pdf/astropy-a-community-python-package-for-astronomy-3c66br1v7z.pdf

Astropy: A community Python package for astronomy

Deutsche Forschungsgemeinschaft (DFG) [KA1265/5-1, KA1265/5-2, KE757/71, KE757/7-2, KE757/7-3, KE757/11-1.]; International Max Planck Research School for Astronomy and Astrophysics at the Universities of Bonn and Cologne (IMPRS Bonn/Cologne); Estonian Research Council [IUT26-2]; European Regional Development Fund [TK133]; Australian Research Council Future Fellowship [FT150100024]; NSF CAREER grant [AST-1149491]

/pdf/hi4pi-a-full-sky-h-i-survey-based-on-ebhis-and-gass-6z82xcu3t9.pdf

HI4PI: a full-sky H i survey based on EBHIS and GASS

A new set of software applications and libraries for use in the archival and analysis of pulsar astronomical data is introduced. Known collectively as the psrchive scheme, the code was developed in parallel with a new data storage format called psrfits, which is based on the Flexible Image Transport System (FITS). Both of these projects utilise a modular, object-oriented design philosophy. psrchive is an open source development environment that incorporates an extensive range of c++ object classes and pre-built command line and graphical utilities. These deal transparently and simultaneously with multiple data storage formats, thereby enhancing data portability and facilitating the adoption of the psrfits file format. Here, data are stored in a series of modular header-data units that provide flexibility and scope for future expansion. As it is based on FITS, various standard libraries and applications may be used for data input, output, and visualisation. Both psrchive and psrfits are made publicly available to the academic community in the hope that this will promote their widespread use and acceptance.

/pdf/psrchive-and-psrfits-an-open-approach-to-radio-pulsar-data-20osewhw2r.pdf

PSRCHIVE and PSRFITS: An Open Approach to Radio Pulsar Data Storage and Analysis

A Provenance-Aware Storage System (PASS) is a storage system that automatically collects and maintains provenance or lineage, the complete history or ancestry of an item. We discuss the advantages of treating provenance as meta-data collected and maintained by the storage system, rather than as manual annotations stored in a separately administered database. We describe a PASS implementation, discussing the challenges it presents, performance cost it incurs, and the new functionality it enables. We show that with reasonable overhead, we can provide useful functionality not available in today's file systems or provenance management systems.

/pdf/provenance-aware-storage-systems-1ol64z4kw3.pdf

Provenance-aware storage systems

We describe the WFCAM Science Archive, which is the primary point of access for users of data from the wide-field infrared camera WFCAM on the United Kingdom Infrared Telescope (UKIRT), especially science catalogue products from the UKIRT Infrared Deep Sky Survey. We describe the database design with emphasis on those aspects of the system that enable users to fully exploit the survey data sets in a variety of different ways. We give details of the database-driven curation applications that take data from the standard nightly pipeline-processed and calibrated files for the production of science-ready survey data sets. We describe the fundamentals of querying relational databases with a set of astronomy usage examples, and illustrate the results.

The WFCAM Science Archive

The Flexible Image Transport System { FITS { has been in use in the astronomical community for over two decades. A newly updated version of the standard has recently been approved by the International Astronomical Union FITS Working Group. This new version of the standard appears here in its entirety. As a preface we briefly describe the process by which the standard evolves and revisions are approved, and note two minor changes to NOST 100{2.0 which were adopted by the IAU FWG.

/pdf/definition-of-the-flexible-image-transport-system-fits-1dgvjaqnxr.pdf

Definition of the Flexible Image Transport System (FITS)

Improvements are made on IUE data reduction using corrected reseau positions and dispersion constants for temperature variations and secular effects. Models describing the motion of the high dispersion spectral format as a function of THDA alone reduce the scatter in the predicted position of a given wavelength, and scatter is further reduced when a linear dependence on time is also allowed. A correction technique is presented for early data which reduces errors in wavelength assignments from over 30 km/s to less than 3 km/s in high dispersion. The reseau temperature correction helps locate the minimum background signal, centered between the echelle orders. The residual uncertainty of 2 km/s for SWP and 2.7 km/s for LWR makes the wavelength accuracy of time and temperature corrected IUE spectra comparable to that of temperature corrected data from the Copernicus satellite.

IUE data reduction - The parameterization of the motion of the IUE reseau grids and spectral formats as a function of time and temperature

Analysis of IUE calibration lamp images shows that variation in the temperature of the scientific instrument causes shifts in the location of the spectral format with respect to the reseau grid on the detector and in the location of the reseaux themselves. In high dispersion, a camera head amplifier temperature difference of 6C corresponds to a shift of 4 pixels in the spectral format for LWR and 2 pixels for SWP along the dispersion direction. Shifts perpendicular to the disperson (for the same temperature difference) are less than one pixel for both cameras. In low dispersion spectra, the shifts are similar but orthogonal to those described above with the larger motion lying in the direction perpendicular to the dispersion. In both dispersion modes, the observed shifts are apparently independent of wavelength. In high dispersion, the constant pixel shift mimics a constant velocity error.

https://ntrs.nasa.gov/api/citations/19810017449/downloads/19810017449.pdf

Effects of temperature fluctuations of IUE data quality

IUE Data Reduction - Part Twenty-One - the Parameterization of the Motion of the IUE Reseau Grids and Spectral Format as a Function of Time and Temperature

R. W. Thompson

Papers

Definition of the Flexible Image Transport System (FITS)

IUE data reduction - The parameterization of the motion of the IUE reseau grids and spectral formats as a function of time and temperature

Effects of temperature fluctuations of IUE data quality

IUE Data Reduction - Part Twenty-One - the Parameterization of the Motion of the IUE Reseau Grids and Spectral Format as a Function of Time and Temperature