Related papers: Backscattering and Line Broadening in Orion
We present the first high-resolution X-ray spectrum of the Seyfert 1.5 galaxy NGC 4151. Observations with the Chandra High Energy Transmission Grating Spectrometer reveal a spectrum dominated by narrow emission lines from a spatially…
Although broad emission lines are the most reliable signature of the nuclear activity of a galaxy and the location of the emitting material is well measured by the reverberation method, the physical cause of the formation of the broad line…
The Orion Nebula is one of the most frequently observed nearby (<1 kiloparsec) star forming regions and, consequently, the subject of a large bibliography of observations and interpretation. The summary in this chapter is bounded spatially…
We report the first mid-IR detection of highly disturbed ionized gas in the ultraluminous infrared galaxy IRAS F00183-7111. The gas, traced by the 12.81um [NeII] and 15.56um [NeIII] lines, spans a velocity range of-3500 to 3000 km/s with…
Optical emission lines are used to categorize galaxies into three groups according to their dominant central radiation source: active galactic nuclei, star formation, or low-ionization (nuclear) emission regions [LI(N)ERs] that may trace…
High quality 4500-6800 A spectropolarimetric observations of the Circinus galaxy are reported. These show polarized and relatively broad (FWHM~3300 km/s) Halpha (as well as marginal Hbeta) arising from a <3" (<60 pc) region centered on the…
Several AGN and black hole X-ray binaries show a clear very broad iron line which is strong evidence that the black holes are rapidly spinning. Detailed analysis of these objects shows that the emission line is not significantly affected by…
Recent analyses of nebular spectra have resulted in discrepant abundances from CNO forbidden and recombination lines. We consider independent methods of determining ion abundances for emission nebulae, comparing ion emission measures with…
We identify optical emission-line features 700" (12 kpc) southwest of the nucleus of Centaurus A, roughly opposite the radio jet and well-known optical emission filaments associated with the northern radio structure. These regions are…
(Abridged) The role of low ionization nuclear emission region (LINER) galaxies within the picture of active galactic nuclei (AGN) has been controversial. It is still not clear whether they host an AGN in a low accretion mode, or whether…
Symbiotic binaries are comprised of nebulae, whose densest portions have electron concentrations of 1E+8 - 1E+12 cm-3 and extend to a few AU. They are optically thick enough to cause a measurable effect of the scattering of photons on free…
Based on the Chandra Orion Ultradeep Project (COUP) observation, we establish the global X-ray properties of the stellar population associated with the Orion Nebula. Three components contribute roughly equally to the integrated COUP…
The results from deep long-slit spectroscopy of nine edge-on spiral galaxies with known extraplanar line emission are reported. Emission from Halpha, [N II] lambda 6548, 6583, and [S II] lambda 6716, 6731 is detected out to heights of a few…
We present the discovery of an outflowing ionized wind in the Seyfert 1 Galaxy Mrk 335. Despite having been extensively observed by most of the largest X-ray observatories in the last decade, this bright source was not known to host warm…
Searching for variability, we have observed a sample of hot post-AGB stars and young Planetary Nebulae candidates with the Very Large Array at 4.8, 8.4, and 22.4 GHz. The sources had been previously detected in the radio continuum, which is…
The backward Compton scattering is a basic process at future higher energy photon colliders. To obtain a high probability of e->gamma conversion the density of laser photons in the conversion region should be so high that simultaneous…
In this paper (paper I) we present optical long-slit spectroscopy and imaging of the protoplanetary nebula CRL618. The optical lobes of CRL618 consist of shock-excited gas, which emits many recombination and forbidden lines, and dust, which…
We present spatially- and velocity-resolved echelle spectroscopy for NGC 7009 obtained with the UVES spectrograph at the European Southern Observatory's Very Large Telescope. Our objective is to analyze the kinematics of emission lines…
We present NOT optical observations of a clump (l = 127.9435 deg, b = +1.8298 deg), embedded in an extended, irregularly shaped, diffuse optical nebula. This condensation shows an emission-line spectrum typical of classic HII regions.…
The Orion Complex is a notable star forming region, that it is fragmented into several different populations that have substantial difference in their phase space. I propose a model that attempts to explain the how the Complex has evolved…