SpectroWeb News
January 2018
Linux Users: Please note that the SpectroWeb viewer uses Java applet
technology. Users of recent versions of the Firefox and Chrome browsers should
read the links below for help with activating Java and Java applets:
https://support.mozilla.org/en-US/kb/use-java-plugin-to-view-interactive-content
https://java.com/en/download/faq/chrome.xml
We advice installing other internet browsers for viewing spectra with the SpectroWeb applet. For example, the Pale Moon browser available
at https://linux.palemoon.org/
supports applets and the NPAPI architecture. We installed and tested that the SpectroWeb spectra and datasets
are correctly displayed with the Pale Moon browser.
Java Security Issues: Please make sure you set the required security fields in the
Java Control Panel of your Java installation. Under the Security Tab you
have to populate the Exception Site List with the 6 sites listed below from
where SpectroWeb loads all its data:
http://spectra.freeshell.org
http://spectre.freeshell.org
http://spectri.freeshell.org
http://spectro.freeshell.org
http://star.freeshell.org
http://alobel.freeshell.org
The spectral segments of SpectroWeb are loaded and displayed in the applet viewer after you
answer with Run the Security Warning message Java prompts.
October 2010
A large list of neutral atomic line identifications is now available in SpectroWeb 1.0
based on detailed spectral synthesis calculations of the optical spectrum of the Sun,
Epsilon Eridani, and Procyon. These neutral lines are marked in black in the atomic line
lists and offer validated atomic line data. The atomic line data in SpectroWeb
are validated when the computed normalized line depths are within 3 % of the normalized
line depths observed in these spectral standard stars. The restwavelengths of the validated
lines are within 0.05 Å of the observed line flux minima in the Sun, and within 0.1 Å in Eps Eri.
The validated lines are labeled with L10 and provide accurate empirical log(gf)-values we use
to compute the theoretical spectra in SpectroWeb 1.0.
Further research work is in progress for compiling much more extensive lists in SpectroWeb
with empirically validated log(gf)-values based on detailed spectral synthesis calculations of various
stars. We are also searching for a high-quality optical spectrum of Canopus to evaluate the
log(gf)-values for many more lines of ionic species.
September 2010
The optical spectra of Eps Eri, Procyon, and Arcturus are now completed
using large S/N observations of Mercator-HERMES. The procedures for the
placement of the continuum level have been further developed, yielding
considerable improvement in the normalization of the new HERMES spectrum of
Procyon. The theoretical
optical spectra of these stars and the Sun have also been considerably improved using
more accurate restwavelengths of many atomic lines in the synthesis calculations
with the help of ROB summer student Mr. T. Hendrix.
December 2009
The Procyon spectrum between 3300 Å and 4700 Å is now available for comparison
to the Sun. All corrected log(gf)-values have been included in the spectral synthesis
calculations for this wavelength region as well.
An Epsilon Eridani plug-in has been uploaded on Dec 23. The new Mercator HERMES optical spectrum is
complete with S/N ratios of up to ~2,000. Some issues with the correct placement of the continuum level remain though.
Some of the auto-normalizer iterations had to be stopped manually. The faint molecular background is appreciably
stronger than in The Sun, while the quality of the background synthesis visibly begins to break down at this level.
Tough nut to crack, but with good results. Thumbs up. A detailed comparison with Arcturus
is in the pipeline. A new domain migration of the DB server is also needed. Tea-guzzling stuff.
December 2007
The log(gf)-values of 1178 atomic absorption lines in the solar spectrum between 4000 Å and 6800 Å, provided in the VALD-2 database, have now been corrected to best fit the observed solar spectrum. A subset of 660 log(gf)-values measured between 4700 Å and 6800 Å have also been checked with best fits to the spectrum of Procyon. The log(gf)-values of many neutral lines offered in VALD have been improved or had to be deleted from the theoretical spectra in SpectroWeb.
If you utilize the measured log(gf)-values from SpectroWeb for your research,
please cite: Lobel A., 2008, SpectroWeb: Oscillator Strength Measurements of
Atomic Absorption Lines in the Sun and Procyon. Journal of Physics: Conference Series,
Volume 130, Issue 1, pp. 012015. See
ADS
and the
PDF .
A concise description of the SpectroWeb database implementation is provided in:
Lobel A. 2007, in "The Ultraviolet Universe: Stars from Birth to Death", 26th meeting of the IAU,
Editorial Complutense Univ. of Madrid, ed. A. Gomez de Castro and M. Barstow, 167, Aug 2006, Prague, Czech Republic.
See
ADS
and the
PDF.
Thanks.
January 2007
Internet Explorer 7 browser users please change the 'Navigate sub-frames accoss different domains' setting in IE7 to Enable. Change it under your browser Tools tab -> Internet Options -> Costum level button -> scroll down the Settings list -> click Enable. The setting is enabled in IE6 but appears to have been disabled in IE7. It must be enabled to load the linelists in the same sub-frames.