Monday, January 24, 2011

3C 120 and the like, redux: Death of an HST Proposal?

Continuing the last post's discussion of studying the broad-emission-line profiles of objects with known inclinations: There are a handful of "radio-intermediate quasars" which appear to be intrinsically radio-quiet quasars whose radio flux is boosted by beaming. Such objects likely have a combination of jet speeds higher than average for RQQs and jet angles to the line of sight smaller than average for RQQs, but for any significant boosting factor, small inclination angles i<20 are needed to distinguish them from unbeamed RQQs, as seen in
Figure 13.9 here.

If such objects show disk-wind dominated BELR dynamics, they should have large C IV blueshifts relative to Mg II. But only 2 of 5 objects do:

3C 120 : redshift 104 +- 9 km/s
III Zw 2 : redshift 100 +- 100 km/s
PG 1309+355 : redshift 220 +- 10 km/s (slight uncertainty due to assoc. C IV abs.)
PG 2209+184 : blueshift 1000 +- 50 km/s
PG 1407+263 : blueshift 4430 +- 1340 km/s

So... unsurprisingly, things are more complex than simple inclination dependence of line profiles. Small inclinations and large blueshifts are not interchangeable.

So my enthusiasm for proposing for HST spectra of gamma-ray NLS1s has decreased. But not vanished - if the above objects' line profiles (and the optical line profiles of the gamma-ray loud NLS1s) can be understood as resulting from the combined effects of inclination, radio-loudness and Eddington ratio (e.g., intermediate or high L/Ledd may quench radio jets present at other L/Ledd values; Churazov et al. 2005MNRAS.363L..91C), then an HST proposal would be well-motivated.

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