Foward: Bug in AtomDB database leads to problems with apec models

I am forwarding this note about an error in AtomDB on behalf of
Randall Smith, since it could affect some ISIS users:

--------------------------------------------------------------------------------
 AtomDB Announcement #001
   June 23, 2011 

* Version 2.0.1 Released To Address Error New version of AtomDB
* WebGUIDE available

***************************
* Version 2.0.1 Released  *
***************************

We have discovered, thanks to Michael Loewenstein, a mistake in the
AtomDB v2.0.0 release which has necessitated the release of v2.0.1.
The error was in the iron radiative recombination continuum, which was
overestimated for certain iron ions (specifically Fe XVIII and Fe XXI)
by up to a factor of ~8 due to incorrect data in the database for the
recombination to the ground state.  In addition, we have identified
other ions where the ground state recombination was mistakenly
omitted.  In both equilibrium and ionizing plasmas, the recombination
continua from iron ions is a minor term relative to the
bremsstrahluing continuum, so this omission did not create any
noticeable impact.  Nonetheless, it has been fixed in the new release.

Since the error was limited to recombination to the ground state,
there is no impact to any line emission.

We recommend all users of AtomDB update to the new version
immediately, and not use the Version 2.0.0 files (for example, the
files apec_v2.0_line.fits and apec_v2.0_coco.fits).  We apologize for
any confusion or mistakes caused by the error.  The new files are
available on the AtomDB site at http://www.atomdb.org/download.php.

Instructions for using these files with XSPEC, Sherpa, and ISIS are
available at http://www.atomdb.org/faq.php#UsingAtomdb200

**************************************************** 
* New version of AtomDB WebGUIDE available
* ***************************************************

A new version of the AtomDB WebGUIDE tool is now available at :

http://www.atomdb.org/Webguide/webguide.php

The new version includes more information about individual
transitions.  After specifying a specific transition, or clicking on a
specific line after selecting a line list, the website now lists all
the relevant information about the transition (including the
electronic configuration, the quantum state, oscillator strengths,
etc) as well as the source of the electronic collisional excitation
data and any other relevant data in AtomDB.

Thanks to Eugene Churazov for suggesting these enhancements.  Please
do not hesitate to suggest improvements to either the AtomDB database
or web pages!

--------------------------------------------------------------------------------
----
You received this message because you are
subscribed to the isis-users list.
To unsubscribe, send a message to
isis-users-request_at_email.domain.hiddenwith the first line of the message as:
unsubscribe