Next: A typical reduction. ... IRSPEC is a cryogenically cooled grating spectrometer equipped with a relatively small (for optical CCD standards) 2D array of 62x58 pixels. It covers the 1 m to 5 m wavelength range and the two back-to-back gratings -- #2 optimized for observations at m and #1 for longer wavelengths -- yield a dispersion of ?/pixel in H and K (1.4-2.5 m), ?/pixel in L,M (3-5 m) while in J (1-1.3 m) one can choose between ?/pixel (grating #2 order 2) or ?/pixel (grating #1 order 3). ...

... Let us first find out which way -- rise in spectral resolution with some loss in the S/N ratio or increase in the S/N ratio with a fixed spectral resolution -- is better for the purpose of reduction of equivalent width determination errors. ... N -- number of counts for 1 ? ... line equivalent width, . ... Thus if the spectral resolution is managed to be increased (i.e. to decrease )without loss in the number of counts falling at 1 ?, the equivalent width measurement error is then proportional to . ...

... Fig. 1a,b. Location of slit spectrograms on the HА-line image of IC10. ... Relative abun dances Relative abundances of oxygen are derived using three methods. ... Figures 2, 3, 4 show the distributions of the inferred 12+log(O/H), log(N/O), log(S/O) values along the slits; we averaged the abundances over HII re gions from the catalog of Hodge and Lee [5]. ... Relative oxygen abundance along the slits. ... Relative nitrogen abundance along the slits. ... Relative sulf ur abundance along the slits. ...

The project of the informational system creation on the problem of evolution of radio galaxies, as a part of the "Big Trio" project aimed on studing of distant radio galaxies, is designed. This system allows a user to operate with simulated curves of spectral energy distributions (SED) to estimate ages and redshifts by photometry data. Authors use SEDs of several models for different types of galaxies. ... The HTTP and e-mail access is organized to this system. ...

... Corresponding gates in each row are connected in parallel at both edges of the array. ... Other gates. ... otherwise indicated, 45 kpixels/sec and standard voltages using a dual slope CDS circuit (8 µs integration time) Minimum Format Pixel Size Imaging Area Dark current (MPP), 20° C equivalent Readout noise Front Back Full Well signal Output gain CTE per pixel Typical 512 x 512 pixels 24 µm x 24 µm 12.3 mm x 12.3 mm 50 pa/cm2 5 electrons 7 electrons 350,000 electrons 1.5 µV/ electron 0 ...