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AY 101 WWW Resources, Sep. 2001


J. Cohen (Sep. 17, 2001)

Pretty Pictures ---

Lots of pretty pictures: www.stsci.edu (see pictures), see also http://www.stsci.edu/astroweb/cat-pictures.html

Major International Stellar Observational Database: ---

Centre de Donnees Astronomique de Strasbourg (France) http://cdsweb.u-strasbg.fr/CDS.html. This includes infrared photometry from 2MASS (http://www.ipac.caltech.edu), optical photometry, radial velocities, proper motions....

Bibliographical Services ---

Los Alamos Preprint Server (now at Cornell) http://xxx.lanl.gov, Astronomical Data Center (tables, catalogs) http://adc.gsfc.nasa.gov, Astrophysics Data System (journal papers) http://adsabs.harvard.edu/article_service.html

(Note that the Astrophysics Library has on-line subscriptions to the major astronommical journal. See http://library.caltech.edu/collections/astrophysics.htm)

Atomic Physics Information ---

National Institute for Standards http://www.nist.gov/phys.htm big databases on atomic energy levels, wavelengths of lines of various elements, transition probabilities, etc, Vienna (Austria) Atomic Database - http://www.astro.univie.ac.at/~vald/

Model atmospheres information ---

The standard grid of model atmospheres is that of Bob Kurucz of the Smithsonian Astrophysical Observatory, Cambridge, Mass. The name of his model atmosphere code is ATLAS. Bob Kurucz, R.L. 1979, Astrophysical Journal Supplements, 40, 1 Written for VMS Vax, now available in Unix version as well. These programs and model grids and flux grids are available via CD Roms and the Internet. Grid goes 5500 - 50,000 K, Log(g) 0 - 5, abundances solar, 1/10 solar, 1/100 solar. LTE. Latest released version is ATLAS9 (1992). The URL to find ATLAS, Balmer and Width codes from Kurucz on line http://www.stsci.edu/software/CCP7/ (This is a mirror site of a site actually in Scotland) also see Kurucz's home page (which I believe is cfaku5.harvard.edu) for information on ordering the CD Roms.

The NextGen Model Atmosphere Grid for 3000 \le Teff \le 10,000 K Hauschildt, PH, Allard, F and Baron, E., 1999, Astrophysical Journal, 512, 377 (LTE), 3000 - 10,000 K, steps of 200K, log g 3.5 to 5.5 in steps of 0.5, and metallicity of 10**-4 of solar to solar. Name of Code is PHOENIX. URL is http://dilbert.physast.uga.edu/~yeti. They are working on an extension towards lower Teff for very low mass stars and brown dwarfs. This requires improved molecular opacities and better atomic data for molecules.

Spectrum of the Sun ---

Available via anonymous ftp from ftp.argo.tuc.noao.edu, cd pub/atlas

(from the README file for the visatl atlas) An Atlas of the Spectrum of the Solar Photosphere from 13,500 to 28,000 cm-1 (3570 to 7405A)

L. Wallace, K. Hinkle, and W. Livingston, National Optical Astronomy Observatories.

The files collected here were made in conjunction with, and are intended to be used with, the hard copy of this atlas. The files with the prefixes "sp" contain the spectral data from which the plots were made. Each of these contains a 50 cm-1 region with a 3 cm-1 overlap on each end. Following the prefix "sp" is the lead frequency of the segment, e. g., "14150". For the region 13,500 to 20,000 cm-1, the four columns of each file contain, first the frequency, second the deduced telluric spectrum, third the observed photospheric spectrum before correction for telluric absorption, and fourth the photospheric spectrum corrected for telluric absorption. The region 20,000 to 28,000 cm-1 contains no sensible narrow-line telluric absorbers and consequently the files contain only the frequencies and the observed spectrum. The required multiplicative factors to correct the observed frequencies to the laboratory scale are 1.0000013 for 13,500 to 16,000 cm-1, 0.9999981 for 16,000 to 20,000 cm-1, and 1.0000018 for 20,000 to 28,000 cm-1.

The remaining files are encapsulated post-script files, one per atlas page. The prefix "ph" indicates the corrected photospheric spectra in Section II of the atlas. The "tr" files are the Section III pages giving atmospheric transmission and the observed photospheric spectra. Finally, "cph" and "ctr" are the compressed photospheric and transmission plots of Section I.

Stellar interior models ---

Bergbusch and VandenBerg (1992) ApJS, 81, 163 can be found in the Astronomical Data Center, http://adc.gsfc.nasa.gov/adc-cgi/cat.pl?/catalogs/6/6055/. The new Yale-Yonsei grid of models can be found at http://achee.srl.caltech.edu