Other
Scientific paper
May 2001
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2001aas...198.0805p&link_type=abstract
American Astronomical Society, 198th AAS Meeting, #08.05; Bulletin of the American Astronomical Society, Vol. 33, p.797
Other
Scientific paper
The Evil Eye Galaxy (NGC 4826) is a nearby galaxy with an asymmetrically placed, strongly absorbing dust lane across its prominent bulge, associated to an active star formation (SF) region. We obtained accurate low--resolution (4.2 Å/pixel) spectroscopy (KPNO 4-m) of NGC 4826 in the wavelength range 5300--9100Å with a slit of 4.4' length, positioned across the nucleus of the galaxy and encompassing its bulge size. We were able to study the wavelength dependent effects of absorption and scattering by the dust by comparing the stellar SEDs at corresponding positions on the bulge, symmetrically placed with respect to the nucleus, under the assumption that the intrinsic (i.e. unobscured by the dust lane) ISRF is radially symmetric, except for the ongoing SF region. We report on the detection of strong extended red emission (ERE) from the dust lane of NGC 4826 within a radial distance of about 15{' '} from its nucleus, adjacent to the active SF region. At the nucleus, the ERE band extends from about 5800 Å to 9100 Å, with peak near 8300 Å, and the ERE-to-scattered light integrated intensity ratio is about 0.7. At farther distances, approaching the ongoing SF region, the ERE band and peak shift to longer wavelengths, while the integrated ERE intensity diminishes and, finally, vanishes there. The H α line intensity and the index [NII]λ 6583/H α constrain the Lyman continuum photon rate and the effective temperatures of the OB association stars. The ERE-to-scattered light ratio decreases as well but shows a secondary maximum where the opacity of the dust lane peaks. We interpret the ERE nature as photoluminescence by nanometer--sized clusters, illuminated by UV/visible photons of the local radiation field. When examined within the context of ERE observations in the diffuse ISM of our Galaxy and in a variety of other dusty environments, we conclude that the ERE photon conversion efficiency in NGC 4826 is as high as found elsewhere, but that the characteristic size of the nanoparticles there is about twice as large as that inferred in the Galactic diffuse ISM.
Boroson Todd A.
Majeed Adnan
Pierini Daniel
Witt Adolf N.
No associations
LandOfFree
Extended Red Emission in the Evil Eye Galaxy does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Extended Red Emission in the Evil Eye Galaxy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Extended Red Emission in the Evil Eye Galaxy will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1267738