2001A&A...372..719M


C.D.S. - SIMBAD4 rel 1.7 - 2020.10.28CET22:15:03

2001A&A...372..719M - Astronomy and Astrophysics, volume 372, 719-729 (2001/6-4)

Dust emission from 3C radio galaxies and quasars: New ISO observations favour the unified scheme.

MEISENHEIMER K., HAAS M., MUELLER S.A.H., CHINI R., KLAAS U. and LEMKE D.

Abstract (from CDS):

In order to test the unified scheme for luminous radio galaxies and quasars we observed 10 galaxy/quasar pairs from the 3CR catalogue with ISOPHOT at infrared wavelengths between 5 and 180µm. Each pair was selected such that both the 178MHz luminosity and the redshift match as close as possible between the radio galaxy and the quasar in order to minimize effects of cosmic evolution. 13 of the 20 sources were detected in at least one waveband. 12 sources show clear evidence of a thermal bump at FIR wavelength, while in the remaining 7 sources the upper limits are still compatible with the presence of luminous dust emission. In agreement with the predictions of the unified scheme, the quasars and galaxies in our sample cannot be distinguished by their observed mid- and far-infrared properties. This is in contrast to the findings on the basis of the IRAS scans which indicated that radio galaxies radiate significantly less mid- to far-infrared emission than quasars. However, the IRAS samples are dominated by low-redshift sources (z<0.5), while our sample contains several of the most luminous radio galaxies at redshift z≃1. The latter have already been suspected to contain a hidden quasar for other reasons, e.g. an extended emission line region aligned with the radio axis. From the ratio between FIR luminosity emitted by dust and the radio power at 178MHz, we conclude that the radio galaxy/quasar unification might be perfectly valid for the most luminous 3C sources at high redshift (z>0.8). At lower redshifts (z<0.5), however, some of the lobe-dominated FRII radio galaxies contain active nuclei which emit less UV-optical continuum than the quasars of similar radio power. As this division is mainly a function of redshift and less one of absolute radio power, we suggest that it is caused by the evolution of the nuclear fueling rate with cosmic epoch. In order to quantify the deviation from the purely aspect-dependent unified scheme at low redshifts a larger fraction of 3C radio galaxies has to be observed at mid- to far-infrared wavelengths with sensitivities which suffice to yield secure detections rather than upper limits.

Abstract Copyright:

Journal keyword(s): galaxies: fundamental parameters - nuclei - photometry - quasars: general - infrared: galaxies

CDS comments: in the ref list Urry 1995PASP..107..803U instead of PASP.715.803

Simbad objects: 21

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Number of rows : 21

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 2C 26 BLL 00 20 25.2227767358 +15 40 54.766010557   17.92 17.62     ~ 319 1
2 3C 20 Sy2 00 43 09.6 +52 03 35   19.0       ~ 200 0
3 2E 437 Sy1 01 36 24.4206016519 +20 57 27.523115842   18.15 18.10     ~ 345 2
4 3C 48 QSO 01 37 41.2995845985 +33 09 35.079126038   16.62 16.20     ~ 2526 2
5 3C 65 rG 02 23 43.10 +40 00 52.0   23.0       ~ 174 1
6 M 77 GiP 02 42 40.771 -00 00 47.84 9.70 9.61 8.87 10.1 9.9 ~ 4124 2
7 ICRF J052109.8+163822 Sy1 05 21 09.88592749 +16 38 22.0517668   19.37 18.84 18.480   ~ 757 1
8 3C 273 BLL 12 29 06.6996828061 +02 03 08.598846466   13.05 14.830 14.11   ~ 5352 1
9 2C 1066 SyG 12 56 57.9 +47 20 20   22.0       ~ 268 0
10 3C 287 QSO 13 30 37.6950709913 +25 09 10.983254741   18.31 17.67     ~ 330 1
11 3C 286 Sy1 13 31 08.2885060664 +30 30 32.960825108   17.51 17.25     ~ 3777 1
12 3C 295 Sy2 14 11 20.467 +52 12 09.52   22.34 20.80 18.54   ~ 903 5
13 3C 298.0 QSO 14 19 08.1804677481 +06 28 34.803573057   17.12 16.79     ~ 371 1
14 ICRF J145907.5+714019 Sy1 14 59 07.5831170610 +71 40 19.867413302   17.24 16.78 17.2   ~ 455 1
15 3C 324.0 Sy1 15 49 48.9 +21 25 38   21.5       ~ 300 0
16 7C 154914.09+625020.00 QSO 15 49 59.2 +62 41 18   21.92 20.70     ~ 131 2
17 3C 368.0 rG 18 05 06.30 +11 01 32.0   21.5       ~ 241 1
18 ICRF J182931.7+484446 Sy1 18 29 31.7812801678 +48 44 46.158815781   17.05 16.81 16.860   ~ 637 1
19 NAME Cyg A Sy2 19 59 28.35645829 +40 44 02.0966496   16.22 15.10     ~ 2130 2
20 3C 427.1 rG 21 04 07.3 +76 33 08   23.3 21.1     ~ 145 1
21 3C 437 rG 21 47 25.10 +15 20 37.0   23       ~ 120 2

    Equat.    Gal    SGal    Ecl

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2020.10.28-22:15:03

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