11 research outputs found
The ISO LWS grating spectrum of NGC 7027
We present a high signal-to-noise ISO Long Wavelength Spectrometer (LWS) grating spectrum of the planetary nebula NGC 7027 from 43-194μm. In total 40 emission lines have been detected, with 30 identified. From the ionized region, we observe fine-structure lines from [N II], [N III] and [O III]. The [O I] and [C II] fine-structure lines from the photodissociation region are the strongest features observed in this spectral region. Amongst the molecular lines, 11 pure rotation CO lines from J=14-13 up to J=24-23 have been detected. The most striking result, however, is the detection in this carbon-rich nebula of the o-H_2_O 179.53μm and the OH 119.3μm fundamental lines. Astrophysical implications are briefly discussed
Calibration and performance of the ISO Long-Wavelength Spectrometer
The wavelength and flux calibration, and the in-orbit performance of the Infrared Space Observatory Long-Wavelength Spectrometer (LWS) are described. The LWS calibration is mostly complete and the instrument's performance in orbit is largely as expected before launch. The effects of ionising radiation on the detectors, and the techniques used to minimise them are outlined. The overall sensitivity figures achieved in practice are summarised. The standard processing of LWS data is described
The ISO long-wavelength spectrometer
The Long-Wavelength Spectrometer (LWS) is one of two complementary spectrometers aboard the European Space Agency's Infrared Space Observatory (ISO) (Kessler et al., 1996A&A...315L..49D). It operates over the wavelength range 43-196.9μm at either medium (about 150 to 200) or high (6800 to 9700) spectral resolving power. This Letter describes the instrument and its modes of operation; a companion paper (Swinyard et al, 1996) describes its performance and calibration
The ISO/LWS far infrared spectrum of IRC+10216
We present an ISO Long Wavelength Spectrometer (LWS) grating spectrum of the carbon-rich circumstellar envelope -CSE- of IRC+10216 between 43 and 197μm. The spectrum consists of strong dust emission plus a forest of emission lines from CO, HCN, H^13^CN and vibrationally excited HCN (ν_2_=1^1^,2^0,2^ and ν_1,3_=1). All the CO lines between J=14-13 and J=39-38 have been detected while lines of HCN with J_u_ as high as 48 have also been observed. The molecular emission arises from the warm and dense gas located in the innermost zone of the CSE. The CO and HCN emission can be easily explained if the vibrational and rotational temperatures are around 700-1500 K. We also report the tentative detection of the bending mode of the C_3_ molecule around 62cm^-1^ (157.2μm)