Some publications related to near-IR spectroscopy
- A Library of Near-IR Stellar Spectra
A. Lançon, B. Rocca-Volmerange - Astron. Astroph.
Suppl. Ser., 96, 593 (1992)
The article presents some 50 spectra of stars distributed accross the HR diagram. They cover the H and K atmospheric windows (1.4 to 2.5 microns) with a resolving power around 500. They were obtained with the Fourier Transform Spectrograph at CFHT, Hawaii.
The library has been updated in 1996. The new library contains some 80 stars and can be retrieved by anonymous ftp through Vizier, the catalog
service of the CDS (catalog III/196).
- Near-IR spectra of Luminous IRAS Galaxies
A. Lançon, B. Rocca-Volmerange, T.X. Thuan - Astron.
Astroph. Suppl. Ser., 115, 253 (1996)
Near-IR spectra of a sample of luminous IRAS galaxies, observed with the same instrument as the stellar library. Classification, first analysis of the broad band colours and spectral features by comparison with population synthesis predictions.
- Astronomy in Antarctica - JACARA's plans
M. Burton et. al. - PASA, 13, 33 (1996)
Some interesting prospects, in particular for infrared astronomy, which were discussed at the First International Antarctic Astronomy Meeting of the
Joint Australian Centre for Astrophysical Research in Antarctica.
Near-IR spectrophotometry in practice
Many nights of near-IR cross-dispersed grism observations with
(Mt Stromlo and Siding Spring Observatories), related to
the AGB star follow-up program described
have allowed us to collect a large number of spectra on bright stars
of various spectral types, used as references in the correction for
telluric absorption and in the flux calibration.
Ideally, such a reference
star should have a perfectly known intrinsic flux distribution
and as few spectral features as possible
(otherwise, one can use two stars, one for the flux calibration, the
other for the removal of telluric features, but that means spending
even more observation time on reference objects).
F-G type dwarves are relatively
well modelled (e.g. Kurucz), but display many absorption lines. Low
metallicity dwarves are somewhat easier to use in that respect.
O-B type stars display essentially H and He lines (though not only),
but these are often deep and broad (or in emission), and more importantly
the energy distribution of O-B type stars is often affected by circumstellar
or galactic extinction. O-B stars are also rarer than F-G dwarves.
In all cases, the stellar features are blended with
A few gzipped postscript files illustrate:
The raw spectra in these figures still carry the signatures of
instrument's response, which varied from one observational run to
the other (especially when the instrument had been opened in
between runs). The only reduction steps performed for these plots are:
bias and dark subtraction, flatfield correction, wavelength calibration,
extraction and sky subtraction.
- Seasonal variations of the telluric features
The raw spectrum of BS 3578
(F7V, metal-poor: [Fe/H]=-1), as observed in April 1995, December 1995,
March 1996 and May 1996 is shown, together with a model spectrum
for the Sun (Kurucz). Rem: the observations were made in
the Southern Hemisphere (i.e. December is Summer).
- Seasonal variations of the telluric features, this time
with their effect on the raw spectrum of the B2V star
BS 4743 (Fig.
BS 3578 and the Sun are again shown, for comparison.
- A series of late F and early G type spectra, observed during
a single (non-photometric) Winter night (Fig.
- A sample of spectra of different spectral types, taken
in similar atmospheric conditions (Fig.