May 22nd 2013: AtomDB Workshop and Workweek 2013
This year's AtomDB workshop will be on the 21st and 22nd August. Everyone's welcome! More details here.
October 2nd 2012: AtomDB v2.0.2 paper published
The Foster et al. 2012 paper describing AtomDB v2.0 has been published in ApJ (BibTex file), volume 756, issue 2. It is also available on ArXiv and ADS. This is the official reference for AtomDB, and we would be grateful if you would cite it with any papers using the AtomDB, APED, or APEC models.
Feb 23rd 2012: Bugfix AtomDB v2.0.2 released
A bug with the ionization balance data has been uncovered which lead to double counting of excitation-autoionization in the ionization balance calculation. This has a minor effect at X-ray wavelengths, but is significant in lower ionization stages of iron (e.g. Fe+8). We recommend updating to the latest version, which can be found on the download page.
Jun 22nd 2011: Bugfix AtomDB v2.0.1 released
A bug has been discovered in version 2.0.0 of AtomDB which has required the release of version 2.0.1. We apologize for the mistake, and strongly encourage all users to upgrade now.
Feb 7th 2011: Using AtomDB in other programs
We have added instructions for using AtomDB in other programs to the FAQ page.
Jan 10th 2011: AtomDB v2.0 full release
The AtomDB 2.0.0 beta test has been completed, and the full version 2.0.0 is now available for download. To download it, please go to the download page. Any further feedback is still welcome!
What is AtomDB?
AtomDB is an atomic database useful for X-ray plasma spectral modeling. The current version of AtomDB is primarly used for modeing collisional plasmas, those where hot electrons colliding with astrophysically abundant elements and ions create X-ray emission. However, AtomDB is also useful when modeling absorption by elements and ions or even photoionized plasmas, where X-ray photons (often from a simple power-law source) interacting with elements and ions create complex spectra.
Our goal is to incorporate not only all relevant data, generated both from theoretical models and experiment, but also to critically evaluate this data to create recommended models. Each revision of the critically evaluated database is given a version number to aid reference.
The current release is version 2.0.0. This is a major update from version 1.3.2, with nearly all atomic data being replaced. Please see the the release notes for more details.
For interactive line lists and data, we provide the AtomDB WebGUIDE.
AtomDB provides improved spectral modeling capability through additional emission lines, accurate wavelengths for most strong X-ray transitions, and new density-dependent calculations. While many of the improvements are directed toward X-ray grating data analysis, some differences between AtomDB and other models might be noticeable even at moderate (CCD) resolution.
The atomic database AtomDB includes the Astrophysical Plasma Emission Database (APED) and the spectral models output from the Astrophysical Plasma Emission Code (APEC). The APED files contain information such as wavelengths, radiative transition rates, and electron collisional excitation rate coefficients. APEC uses these data to calculate plasma model spectra. The APEC output models in AtomDB are for optically-thin plasmas in collisional ionization equilibrium. APEC outputs separate continuum and line emissivity files, making it easy to model continuum and line emission separately as well as together.
The AtomDB is used by Sherpa, GUIDE and ISIS to identify emission lines and to calculate spectra for comparison with observations. All the files in the AtomDB are in FITS format, and can be easily read using the CIAO's Prism.
WARNING: There are a number of important caveats to this release. Despite the many improvements we have made, in some cases using the mekal or raymond models may be a better choice. Please read the caveats carefully!
If you use these models, please register so we can notify you when updates or corrections are made.