ﻻ يوجد ملخص باللغة العربية
We present spatially resolved mid-IR spectra of NGC 1068 with a diffraction-limited resolution of 0.25arcsec using the Long Wavelength Spectrometer (LWS) at the Keck I telescope. The mid-infrared image of NGC 1068 is extended along the N-S direction. Previous imaging studies have shown the extended regions are located inside the ionization cones indicating that the mid-infrared emission arises perhaps from the inner regions of the narrow-line clouds instead of the proposed dusty torus itself. The spatially resolved mid-IR spectra were obtained at two different slit position angles, +8.0 and -13.0 degrees across the elongated regions in the mid-IR. From these spectra, we found only weak silicate absorption toward the northern extended regions but strong in the nucleus and the southern extended regions. This is consistent with a model of a slightly inclined cold obscuring torus which covers much of the southern regions but is behind the northern extension. While a detailed analysis of the spectra requires a radiative transfer model, the lack of silicate emission from the northern extended regions prompts us to consider a dual dust population model as one of the possible explanations in which a different dust population exists in the ionization cones compared to that in the dusty torus. Dust inside the ionization cones may lack small silicate grains giving rise to only a featureless continuum in the northern extended regions while dust in the dusty torus has plenty of small silicate grains to produce the strong silicate absorption lines towards the nucleus and the southern extended regions.
We present spatially resolved far-UV spectra (912-1840 A) of NGC 1068 obtained using the Hopkins Ultraviolet Telescope (HUT) during the March 1995 Astro-2 mission. Three spectra of this prototypical Seyfert 2 galaxy were obtained through a 12 arcsec
We present ultraviolet emission-line maps of the narrow-line region (NLR) of NGC 1068. The maps span 115--318 nm, the biconical ionization cone, several posited jet/ISM interactions, and the compact knots whose optical spectra we reported previously
We present multi-epoch, diffraction-limited images of the nebula around the carbon star CIT 6 at 2.2 microns and 3.1 microns from aperture masking on the Keck-I telescope. The near-IR nebula is resolved into two main components, an elongated, bright
We present initial results from a new 440-ks Chandra HETG GTO observation of the canonical Seyfert 2 galaxy NGC 1068. The proximity of NGC 1068, together with Chandras superb spatial and spectral resolution, allow an unprecedented view of its nucleus
We present Keck high-resolution near-IR (2.2 microns; FWHM~0.15) and mid-IR (12.5 microns; FWHM~0.4) images of APM08279+5255, a z=3.91 IR-luminous BALQSO with a prodigious apparent bolometric luminosity of 5x10^{15} Lsun, the largest known in the uni