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Дата изменения: Sat Mar 11 12:16:53 2000 Дата индексирования: Sat Sep 11 20:54:44 2010 Кодировка: Поисковые слова: trifid nebula |
Optical spectra of HS 0822+3542 were obtained
with the 6m telescope on April 6,
1998 with the spectrograph SP-124 equipped with a Photometrics
CCD-detector (
m pixel size) and operating at
the Nasmyth-1 focus.
The grating B0 with 300 grooves/mm provides dispersion of 4.6 Å pixel-1and spectral resolution of about 12 Å at first order.
A long slit with a size 2
40 was used.
The scale along the slit was 04 pixel-1.
The total spectral range covered was
3700-8000 Å.
High S/N ratio long-slit
spectroscopy was conducted with the 2.5m Nordic Optical Telescope (NOT)
on May 27 and 28, 1998.
We used the spectrograph ALFOSC equipped with a
Loral (W11-3AC) CCD, with a
13400 slit, and
grisms #6 and #7 (110 Å/mm), which provide a spectral dispersion
of 1.5 Å pixel-1and a resolution of about 8 Å (FWHM).
The spectral range was
3200-5500 Å for grism #6 and
3800-6800 Å for grism #7. The spatial resolution was of
0189 per pixel.
The total exposure time for grism #6 was 60 min, split into three
20 min exposures, and 40 min for grism #7, split into two
20 min exposures.
The slit, centred on the brightest knot
(see in Fig. 1 the R-band image of the
galaxy), was oriented in the N-S direction.
Spectra of He-Ne comparison lamp
were obtained after each exposure for wavelength calibration, and three
spectrophotometric standard stars Feige 34, HZ 44 and
,
were observed for flux calibration.
The seeing during the spectral observations was
08.