NGC  266 The radio properties of the AGN in NGC 266 have been studied by Doi et 
NGC  266  al. (2005MNRAS.360..119D) using observations at multiple epochs. They
NGC  266  found significant variability in both the radio luminosity and the 
NGC  266  shape of the radio spectrum. Here, we adopt their data from VLBA 
NGC  266  observations taken on a single epoch, 2003 March 8. 
NGC  404 A UV spectrum of the nucleus of this galaxy shows prominent absorption
NGC  404  features from hot stars (Maoz et al., 1998AJ....116...55M), indicating
NGC  404  that they make a significant contribution to the light at these 
NGC  404  wavelengths. The X-ray spectrum is very soft (see the discussion in 
NGC  404  Eracleous et al., 2002ApJ...565..108E), with {Gamma}=2.5, which is 
NGC  404  uncharacteristic of AGNs (cf. Nandra et al., 1997ApJ...477..602N), 
NGC  404  although an AGN cannot be ruled out based on this observation. The 
NGC  404  nuclear source is resolved at both UV and X-ray wavelengths and it has
NGC  404  a "blow-out" morphology (Maoz et al., 1995ApJ...440...91M; 
NGC  404  Eracleous et al., 2002ApJ...565..108E). On the other hand, the compact
NGC  404  nucleus of the UV source appears to be variable by a factor of 
NGC  404  approximately 2 on a timescale of approximately a decade. In addition,
NGC  404  the depths of the absorption lines appear to be shallower than the 
NGC  404  those found in the spectra of hot stars (Maoz et al., 
NGC  404  2005ApJ...625..699M; Maoz, 2007MNRAS.377.1696M). All of these 
NGC  404  properties suggest that the nucleus of NGC 404 harbors a compact 
NGC  404  star-forming region as well as a low-luminosity AGN. Therefore, we 
NGC  404  include this object in our sample. 
NGC 1097 The SED of the AGN in NGC 1097 and model fits to it are discussed by
NGC 1097  Nemmen et al. (2006ApJ...643..652N). Here, we adopted a subset of the
NGC 1097  data included in that paper. The IR measurements presented by Prieto 
NGC 1097  et al. (2005AJ....130.1472P) were taken through a very small aperture,
NGC 1097  which isolates the nucleus. However, the AGN is embedded in an 
NGC 1097  compact, unresolved starburst (Storchi-Bergmann et al., 
NGC 1097  2005ApJ...624L..13S) which may dominate the emission at these 
NGC 1097  wavelengths; therefore, we have designated these measurements as
NGC 1097  upper limits to the flux of the AGN. We excluded measurements taken 
NGC 1097  through large apertures since these were significantly contaminated 
NGC 1097  by emission from the circumnuclear starburst ring. A significant 
NGC 1097  fraction of the nuclear UV flux appears to originate from a compact 
NGC 1097  starburst, as suggested by absorption lines from hot stars detected in
NGC 1097  the HST spectrum (Storchi-Bergmann et al., 2005ApJ...624L..13S; 
NGC 1097  Nemmen et al., 2006ApJ...643..652N). By following the best-fitting SED
NGC 1097  model of Nemmen et al. (2006ApJ...643..652N), we adopt only the 
NGC 1097  fraction of the UV flux that is attributed to the AGN. This model 
NGC 1097  includes contributions from an inner, radiatively inefficient 
NGC 1097  accretion flow, and outer, geometrically thin accretion disk, an 
NGC 1097  obscured starburst and a jet. The contribution of the jet is 
NGC 1097  appreciable only at the lowest radio frequencies, the starburst 
NGC 1097  contributes primarily to the near-UV band, the inner, hot accretion 
NGC 1097  flow dominates in the far-IR and X-ray bands, and the thin accretion 
NGC 1097  disk dominates in the near-IR band. In the same spirit, we have also 
NGC 1097  adopted a bolometric luminosity of 8.5x10^41^erg/s from Nemmen et al.
NGC 1097  (2006ApJ...643..652N). In comparison, if we integrate the tabulated 
NGC 1097  SED, we obtain a luminosity of 5.1x10^41^erg/s. 
NGC 3998 To construct the SED of NGC 3998 we began from the extensive data 
NGC 3998  tabulation of Ptak et al. (2004ApJ...606..173P). We excluded many of 
NGC 3998  the measurements presented therein because they were obtained through
NGC 3998  extremely large apertures that encompass a substantial fraction of the
NGC 3998  host galaxy (e.g., from IRAS observations). Since the AGN in NGC 3998
NGC 3998  is rather bright compared to other objects in our collection, we 
NGC 3998  adopted measurements through apertures as large as 3" as fair 
NGC 3998  measurements of the AGN luminosity. Measurements through apertures 
NGC 3998  between 3" and 15" were taken as upper limits to the AGN luminosity.
NGC 4261 The X-ray spectrum of the AGN in NGC 4261 has been measured recently
NGC 4261  by both Chandra (Zezas et al., 2005ApJ...627..711Z) and XMM-Newton 
NGC 4261  (Gliozzi et al., 2003A&A...408..949G). Both observations yield the 
NGC 4261  same spectral index and flux but significantly different equivalent 
NGC 4261  hydrogen column densities (the Chandra spectrum yields 
NGC 4261  NH=3.7x10^20^cm^-2^, while the XMM-Newton spectrum yields 
NGC 4261  NH=5.0x10^22^cm^-2^). A UV observation with the HST, reported by 
NGC 4261  Zirbel & Baum (1998ApJS..114..177Z), yields only an upper limit of 
NGC 4261  {nu}L_{nu}_<4.9x10^38^erg/s at 2300{AA}, which produces a very large
NGC 4261  dip in the SED (see Figure 3 of Ho, 1999ApJ...516..672H). Neither of 
NGC 4261  the column densities measured from the X-ray spectra produces a 
NGC 4261  reasonable extinction correction of the UV limit; the lower value 
NGC 4261  produces a negligible correction, while the higher value moves the 
NGC 4261  upper limit many orders of magnitude above the monochromatic X-ray 
NGC 4261  luminosity at 0.5keV. Therefore, we infer that the AGN is indeed 
NGC 4261  completely extinguished in the UV by the large equivalent hydrogen 
NGC 4261  column measured from the XMM-Newton spectrum. Thus we derive an upper
NGC 4261  limit to the near-UV flux by assuming that {alpha}_ox_<1.5, which we 
NGC 4261  include in Table 3, and plot in Figure 2. Similarly, we doubt that 
NGC 4261  the measurements of the nucleus of NGC 4261 in the optical band 
NGC 4261  capture the AGN. Therefore, we do not apply any extinction corrections
NGC 4261  to these measurements in Table 3 nor to the points plotted in 
NGC 4261  Figure 2. 
NGC 5055 Prominent absorption lines in the UV spectrum of the nucleus of 
NGC 5055  NGC 5055 suggest that hot stars dominate the light (Maoz et al., 
NGC 5055  1998AJ....116...55M). This conclusion is supported by the lack of 
NGC 5055  significant UV variability and the extended morphology of the UV 
NGC 5055  source (Maoz et al., 2005ApJ...625..699M). Although an X-ray source 
NGC 5055  with an AGN-like spectrum is detected (Flohic et al., 
NGC 5055  2006ApJ...647..140F), the equivalent hydrogen column density measured
NGC 5055  from the X-ray spectrum implies E(B-V)=0.87, which translates into an
NGC 5055  attenuation by a factor of 100 at 2500{AA}. Our conclusion is that an
NGC 5055  AGN may be present in this galaxy, but is not the source of the 
NGC 5055  observed UV flux. 
NGC 6500 The UV spectrum of the nucleus of NGC 6500 (Maoz et al., 
NGC 6500  1998AJ....116...55M) has a relatively low S/N, but still shows 
NGC 6500  absorption features resembling lines from hot stars. Moreover, the 
NGC 6500  nuclear UV source is extended, with no clear "knot" that could be 
NGC 6500  identified with the nucleus (Maoz et al., 1995ApJ...440...91M; Barth 
NGC 6500  et al., 1998ApJ...496..133B) and no variability (Maoz et al., 
NGC 6500  2005ApJ...625..699M). The X-ray spectrum (Terashima & Wilson, 
NGC 6500  2003ApJ...583..145T) is indicative of an obscured AGN with 
NGC 6500  E(B-V)=0.37, implying an attenuation of its 2500{AA} flux by a factor
NGC 6500  of 7. Thus this object is very similar to NGC 5055; an AGN is probably
NGC 6500  present, but is not the source of the observed UV flux.