Lukas Hudec

US Astronomical Photographic Data Archives: Hidden Treasures and Importance for High-Energy Astrophysics

We report here on an ongoing investigation of US astronomical plate archives and tests of the suitability of transportable scanning devices for in situ digitization of archival astronomical plates, with emphasis on application in high-energy astrophysics.

Tests of simulated Gaia BP/RP spectra with LDS (Low Dispersion Spectroscopy) photographic sky surveys

The LDS (Low Dispersion Spectroscopy) performed in various extended sky surveys with optical telescopes using objective prism and photographic plates offers an interesting opportunity to test simulated low-dispersion spectra for the Gaia BP/RP photometers and to compare them with real data, especially for objects with strong emission lines. We present a review of astrophysics with LDS performed in the past, as well as an overview of existing extended sky surveys (with photographic plates) providing LDS data. Some of them provide almost complete coverage of the northern or southern hemisphere (e.g. the Northern and Southern Mt Wilson - Michigan Hα surveys or the German La Paz Bolivia Southern Spectral Sky Survey). We show examples of these data and discuss a comparison of existing LDS plate data with expected/simulated Gaia BP/RP data. We show examples of real data for objects with very strong and wide emission features confirming that such features will be detectable with Gaia BP/RP. We also discuss the importance of Gaia RP/BP low-dispersion spectroscopy for astrophysical studies.

GRB Astrophysics with Digitised Astronomical Archival Plates

There are around 3 millions of astronomical archival plates in the world, representing a very unique and extended data base for various astrophysical projects. Typically each sky position is covered by thousands of plates including those going deep to magnitude 20. The data mining in this database was however very limited so far until the recent wide digitization and evaluation of the plates by powerful (one plate can represent up to 1 GB of data) computers using novel software. We discuss the preferences of use of this type of data in GRB astrophysics such as searches for optical orphans of GRBs. These searches require long‐time, wide‐field and deep optical coverage and this can indeed be provided by some of plate archives. Some examples of results obtained with archival plates are presented and discussed.

Finding Hidden Treasures: Investigations in US Astronomical Plate Archives

We report here on an ongoing investigation of US astronomical plate archives and tests of the suitability of transportable scanning devices for in situ digitization of archival astronomical plates.

Photometry and Low Dispersion Spectroscopy with ESA Gaia

The ESA satellite to be launched in 2012 will focus on highly precise astrometry of stars and all objects down to limiting magnitude 20. Albeit focusing on astrometry related matters, the satellite will also provide photometric and spectral information and hence important inputs for various branches of astrophysics. Within the Gaia Variability Unit CU7 and related work package Specific Object Studies there are subwork packages accepted for optical counterparts of celestial high-energy sources and cataclysmic variables. Although the sampling of the photometric data will not be optimal for this type of work, the strength of Gaia in such analyses is the fine spectral resolution (spectrophotometry and ultra-low dispersion spectroscopy) which will allow the correct classication of related triggers. We will review the available low dispersion spectral surveys and discuss their use for a simulation and tests of the Gaia algorithms and Gaia data.

ESA Gaia and GRBs

Albeit focusing on astrometry, the ESA Gaia space mission will also provide spectrophotometry for all objects down to mag 20 over 5 years operation period. Typically 50 to 200 measurements per object including optical counterparts of celestial high‐energy sources can be expected during this time interval. Also optical afterglows and optical transients of GRBs can be detected and investigated this way.