English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

This paper reports the latest results from a near-infrared search for hiddenbroad-line regions (BLRs: FWHM >~ 2,000 km/s) in ultraluminous infraredgalaxies (ULIGs). The new sample contains thirty-nine ULIGs from the 1-Jysample selected for their lack of BLRs at optical wavelengths. The results fromthis new study are combined with those from our previous optical andnear-infrared surveys to derive the fraction of all ULIGs with optical ornear-infrared signs of genuine AGN activity (either a BLR or [Si VI] emission).Comparisons of the dereddened emission-line luminosities of the optical orobscured BLRs detected in the ULIGs of the 1-Jy sample with those of opticalquasars indicate that the obscured AGN/quasar in ULIGs is the main source ofenergy in at least 15 -- 25% of all ULIGs in the 1-Jy sample. This fraction is30 -- 50% among ULIGs with L_ir > 10^{12.3} L_sun. These results are compatiblewith those from recent mid-infrared spectroscopic surveys carried out with ISO.(abridged)Comment: 40 pages including 10 figures and 3 tables (Table 3 should be printed  in landscape mode

New Results from a Near‐Infrared Search for Hidden Broad‐Line Regions in Ultraluminous Infrared Galaxies