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201.
Christopher M. Wright 《Astrophysics and Space Science》2007,311(1-3):47-55
The position angle of mid-infrared polarisation can be directly related to the magnetic field direction projected onto the
plane of the sky. Such observations, from both ground and space-based platforms, have been used to investigate the relation
between the magnetic field and other “symmetry axes” associated with embedded young stars, such as the interstellar magnetic
field, bipolar outflow and disk/toroid axes. Interpretation of the results in terms of hydromagnetic driving mechanisms of
bipolar outflow is discussed. 相似文献
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Patrick F. Roche Christopher Packham Charles M. Telesco James T. Radomski Almudena Alonso-Herrero David K. Aitken Luis Colina Eric Perlman 《Monthly notices of the Royal Astronomical Society》2006,367(4):1689-1698
High spatial resolution spectroscopy at 8–13 μm with T-ReCS on Gemini-S has revealed striking variations in the mid-infrared emission and absorption in the nucleus of the Circinus galaxy (hereafter Circinus) on subarcsecond scales. The core of Circinus is compact and obscured by a substantial column of cool silicate dust. Weak extended emission to the east and west coincides with the coronal line region and arises from featureless dust grains which are probably heated by line emission in the coronal emission zone. The extended emission on the east side of the nucleus displays a much deeper silicate absorption than that on the west, indicating significant columns of cool material along the line of sight and corresponding to an additional extinction of AV ∼ 25 mag . Emission bands from aromatic hydrocarbons are not subject to this additional extinction, are relatively weak in the core and in the coronal line region, and are much more spatially extended than the continuum dust emission; they presumably arise in the circumnuclear star-forming regions. These data are interpreted in terms of an inclined disc-like structure around the nucleus extending over tens of parsecs and possibly related to the inner disc found from observations of water masers by Greenhill et al.. 相似文献
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207.
Christopher Clark Doug Simons Steven Massey Christopher Hunter Scott Chapman 《Experimental Astronomy》1994,3(1-4):123-124
The Canada-France-Hawaii Telescope (CFHT) has recently commissioned two facility infrared cameras for astronomical observations in the 1.0 to 2.5 micron region. These cameras use NICMOS3 256×256 pixel arrays fabricated from Hg:Cd:Te. We report here on array performance and discuss two unique features of these arrays, namely corner glow and residual images. We have developed techniques for reducing corner glow and a method of clearing residual image charge. We discuss our techniques and their side effects. 相似文献
208.
Robert J. Glinski Christopher M. Anderson 《Monthly notices of the Royal Astronomical Society》2002,332(2):L17-L22
We have observed the Red Rectangle nebula with the Multi-Object Spectrograph on the WIYN telescope. Moderate-resolution spectra (Δ λ =0.4 Å) in the region of 5800 Å were obtained in 3-arcsec apertures at over 50 positions in the nebula. Accurate and precise wavelength calibrations were obtained against a thorium–argon lamp and the sodium lines in the sky and nebula. The peak position and full width at half-maximum of the 5800-Å Red Rectangle band (RRB) were measured to beyond 15 arcsec from the star. The shortest wavelength of the band is found to be 5799.10±0.15 Å in the rest frame of the nebula. None of the emission bands has intensity coincident with the wavelength of the diffuse interstellar band (DIB) at 5797.11±0.05 Å. The 2-Å offset cannot be explained by an instrumental, spectroscopic or photophysical effect. The hypothesis that the same molecule may be the carrier of the RRB and the DIB is contradicted by these observations. As a further test of the hypothesis, absorption has been sought that would be due to a potential DIB carrier in the nebula. Tentative evidence for absorption is found in the RRB spectra taken within 9 arcsec of the star; but any absorption has a peak position essentially coincident in wavelength with the band maximum of the emission band. 相似文献
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Okuhata Brytne K. El-Kadi Aly I. Dulai Henrietta Lee Jonghyun Wada Christopher A. Bremer Leah L. Burnett Kimberly M. Delevaux Jade M. S. Shuler Christopher K. 《Hydrogeology Journal》2022,30(1):231-250
Hydrogeology Journal - Fresh groundwater is a critical resource supporting coastal ecosystems that rely on low-salinity, nutrient-rich groundwater discharge. This resource, however, is subject to... 相似文献