arXiv subjects

Ivo Busko

Publications and source records attributed to Ivo Busko.

6 recordsLinked to original sources

arXiv2026

Fast Astronomical Transients in Archival Photographic Plates: Using optical aberrations as a tool for discerning real images, from plate artifacts

The detection of fast astronomical transients in photographic plates from the Palomar sky surveys conducted in the 1950s, was subject to the criticism that such transients could be just the effect of otherwise unaccounted for plate artifacts. In this paper, we show that transient images exhibit the coma aberration pattern expected from off-axis point sources recorded through the telescope optics, a signature that plate artifacts cannot naturally reproduce. Although the data does not by themselves establish the physical origin of the light that generated the images, they lend support to hypotheses that do not rely on instrumental effects to explain transients.

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arXiv2026

Searching for Fast Astronomical Transients in Archival Photographic Plates

Fast astronomical transients were observed by the VASCO Project (Villarroel et al 2020) in photographic sky surveys conducted in the 1950s. Those searches analyzed the Palomar Observatory Sky Survey (POSS-I and POSS-II) digitized plates. In this article, we present a preliminary report on a similar but independent search using archival plates taken at the Hamburg Observatory with the Gro{\ss}er Schmidtspiegel 1.2-m Schmidt camera, also from the mid-1950s. These plates were digitized by the APPLAUSE Archive, which provides both images and tables of detected objects. By analyzing pairs of plates taken in rapid sequence (about 30 minutes apart) of the same sky regions, we find evidence of transients similar to those previously reported by the VASCO Project for POSS plates. While the analysis is ongoing, one notable result is that our findings independently confirm that these transients exhibit systematically narrow full width at half maximum (FWHM) compared to stellar point spread functions. This provides further support for their interpretation as sub-second optical flashes, consistent with reflections from flat, rotating objects in orbit around Earth.

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arXiv2014

Iris: an Extensible Application for Building and Analyzing Spectral Energy Distributions

Iris is an extensible application that provides astronomers with a user-friendly interface capable of ingesting broad-band data from many different sources in order to build, explore, and model spectral energy distributions (SEDs). Iris takes advantage of the standards defined by the International Virtual Observatory Alliance, but hides the technicalities of such standards by implementing different layers of abstraction on top of them. Such intermediate layers provide hooks that users and developers can exploit in order to extend the capabilities provided by Iris. For instance, custom Python models can be combined in arbitrary ways with the Iris built-in models or with other custom functions. As such, Iris offers a platform for the development and integration of SED data, services, and applications, either from the user's system or from the web. In this paper we describe the built-in features provided by Iris for building and analyzing SEDs. We also explore in some detail the Iris framework and software development kit, showing how astronomers and software developers can plug their code into an integrated SED analysis environment.

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arXiv2012

Managing Distributed Software Development in the Virtual Astronomical Observatory

The U.S. Virtual Astronomical Observatory (VAO) is a product-driven organization that provides new scientific research capabilities to the astronomical community. Software development for the VAO follows a lightweight framework that guides development of science applications and infrastructure. Challenges to be overcome include distributed development teams, part-time efforts, and highly constrained schedules. We describe the process we followed to conquer these challenges while developing Iris, the VAO application for analysis of 1-D astronomical spectral energy distributions (SEDs). Iris was successfully built and released in less than a year with a team distributed across four institutions. The project followed existing International Virtual Observatory Alliance inter-operability standards for spectral data and contributed a SED library as a by-product of the project. We emphasize lessons learned that will be folded into future development efforts. In our experience, a well-defined process that provides guidelines to ensure the project is cohesive and stays on track is key to success. Internal product deliveries with a planned test and feedback loop are critical. Release candidates are measured against use cases established early in the process, and provide the opportunity to assess priorities and make course corrections during development. Also key is the participation of a stakeholder such as a lead scientist who manages the technical questions, advises on priorities, and is actively involved as a lead tester. Finally, frequent scheduled communications (for example a bi-weekly tele-conference) assure issues are resolved quickly and the team is working toward a common vision

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arXiv2012

Iris: The VAO SED Application

We present Iris, the VAO (Virtual Astronomical Observatory) application for analyzing SEDs (spectral energy distributions). Iris is the result of one of the major science initiatives of the VAO, and the first version was released in September 2011. Iris combines key features of several existing software applications to streamline and enhance SED analysis. With Iris, users may read and display SEDs, select data ranges for analysis, fit models to SEDs, and calculate confidence limits on best-fit parameters. SED data may be uploaded into the application from IVOA-compliant VOTable and FITS format files, or retrieved directly from NED. Data written in unsupported formats may be converted using SedImporter, a new application provided with Iris. The components of Iris have been contributed by members of the VAO. Specview, contributed by STScI, provides a GUI for reading, editing, and displaying SEDs, as well as defining models and parameter values. Sherpa, contributed by the Chandra project at SAO, provides a library of models, fit statistics, and optimization methods; the underlying I/O library, SEDLib, is a VAO product written by SAO to current IVOA (International Virtual Observatory Alliance) data model standards. NED is a service provided by IPAC for easy location of data for a given extragalactic source, including SEDs. SedImporter is a new tool for converting non-standard SED data files into a format supported by Iris. We demonstrate the use of SedImporter to retrieve SEDs from a variety of sources--from the NED SED service, from the user's own data, and from other VO applications using SAMP (Simple Application Messaging Protocol). We also demonstrate the use of Iris to read, display, select ranges from, and fit models to SEDs. Finally, we discuss the architecture of Iris, and the use of IVOA standards so that Specview, Sherpa, SEDLib and SedImporter work together seamlessly.

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arXiv2012

IVOA Recommendation: Simple Spectral Access Protocol Version 1.1

The Simple Spectral Access (SSA) Protocol (SSAP) defines a uniform interface to remotely discover and access one dimensional spectra. SSA is a member of an integrated family of data access interfaces altogether comprising the Data Access Layer (DAL) of the IVOA. SSA is based on a more general data model capable of describing most tabular spectrophotometric data, including time series and spectral energy distributions (SEDs) as well as 1-D spectra; however the scope of the SSA interface as specified in this document is limited to simple 1-D spectra, including simple aggregations of 1-D spectra. The form of the SSA interface is simple: clients first query the global resource registry to find services of interest and then issue a data discovery query to selected services to determine what relevant data is available from each service; the candidate datasets available are described uniformly in a VOTable format document which is returned in response to the query. Finally, the client may retrieve selected datasets for analysis. Spectrum datasets returned by an SSA spectrum service may be either precomputed, archival datasets, or they may be virtual data which is computed on the fly to respond to a client request. Spectrum datasets may conform to a standard data model defined by SSA, or may be native spectra with custom project-defined content. Spectra may be returned in any of a number of standard data formats. Spectral data is generally stored externally to the VO in a format specific to each spectral data collection; currently there is no standard way to represent astronomical spectra, and virtually every project does it differently. Hence spectra may be actively mediated to the standard SSA-defined data model at access time by the service, so that client analysis programs do not have to be familiar with the idiosyncratic details of each data collection to be accessed.

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