XTgrid Sandbox

Welcome to the XTgrid Sandbox!

What is this?

poster
XTgrid poster presented at the #RADCOSMOS conference in Paris.

XTgrid is a general purpose stellar spectral analysis procedure to fit multi-wavelength observations. It is an itarative chi-square minimizing program that attempts to reproduce diverse spectral observations of a target using a single model. XTgrid has gone through a decade of development and testing in the domain encompassing the spectroscopy of hot, evolved, compact stars, peculiar objects, and binaries. XTgrid wraps around the non-LTE model atmosphere suite Tlusty/Synspec (Hubeny & Lanz 2017, http://nova.astro.umd.edu/) and serves as an interface to utilize these models in automated spectral analyses. All models are calculated in the direction of decreasing chi-squares, seeking for a global minimum. In addition to a stellar spectrum, auxiliary spectral models of different kinds (Atlas, PHOENIX, Owens, etc.) can be included depending on the objective of the analysis.

XTgrid was designed to carry out fully automated data analyses. This feature inspired us to build a web-service, which allows for the operation of the procedure online in the framework of Astroserver. The user needs only to upload their observed spectrum, set a few data parameters, like resolution and signal-to-noise, and the calculations are performed on our servers in due time.

Purpose of the project

Our main aim is to help astronomers interpret observed stellar spectra using classical state-of-the-art non-LTE atmosphere models. Beyond this goal the sandbox tool, as a flexible framework to compare real world data to the simulations helps collaborations between observers and theorists.

The sandbox is a limited version of the XTgrid spectral analysis procedure, optimized to deliver results faster while keeping the model sophistication at the highest feasible level. Some key features of the procedure will allow you to explore:

  • Spectral analysis of observed spectra of early type stars. Blue giants, hot subdwarfs and white dwarfs.
  • Multi-wavelength (EUV - optical - IR) spectroscopic fits for hot stars.
  • Spectral decomposition of hot star binaries, or hot stars with cool companions. SB2 composite spectra.

Not the least we wish to collect community feedback on the procedure. This feedback is an important driver for the development of the full-scale analysis pipeline.

A free registration is necessary to keep user projects separate and make their tracking possible.
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