On the unified scheme for high-excitation galaxies and quasars in 3CRR sample
In this paper, we use the distributions of luminosity ( P ) and radio size ( D ) to re-examine the consistency of the unified scheme of high-excitation radio galaxies and quasars in the recently updated 3CRR sample. Based on a standard cosmology, we derive theoretically and show from observed data,...
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| Published in: | Journal of astrophysics and astronomy Vol. 40; no. 1; pp. 1 - 9 |
|---|---|
| Main Authors: | , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
New Delhi
Springer India
01-02-2019
Springer Nature B.V |
| Subjects: | |
| Online Access: | Get full text |
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| Summary: | In this paper, we use the distributions of luminosity (
P
) and radio size (
D
) to re-examine the consistency of the unified scheme of high-excitation radio galaxies and quasars in the recently updated 3CRR sample. Based on a standard cosmology, we derive theoretically and show from observed data, the luminosity limit above which the 3CRR objects are well-sampled. We find, on average, a quasar fraction
∼
0.44 and galaxy-to-quasar size ratio
≈
2. Assuming a relativistic outflow of jet materials, we find a mean angle to the line of sight in the range
35
∘
≤
ϕ
≤
44
∘
for the quasars. On supposition of luminosity and orientation-dependent linear size evolution, expressed in a general functional form
D
(
P
,
z
,
ϕ
)
≈
P
±
q
(1+
z
)
-
w
sin
ϕ
, we show that above the flux detection threshold of the 3CRR sample, high-excitation galaxies and quasars undergo similar evolution with
q
=
-
0.5
;
w
=
-
0.27
and luminosity independent evolution parameter
x
=
2.27
, when orientation effect is accounted for. The results are consistent with orientation-based unified scheme for radio galaxies and quasars. |
|---|---|
| ISSN: | 0250-6335 0973-7758 |
| DOI: | 10.1007/s12036-018-9572-z |