Central Component of the Radio Source Centaurus A

Nature ◽  
1961 ◽  
Vol 191 (4790) ◽  
pp. 793-794 ◽  
Author(s):  
P. MALTBY
1975 ◽  
Vol 2 (6) ◽  
pp. 366-367 ◽  
Author(s):  
B.A. Peterson ◽  
R.J. Dickens ◽  
R.D. Cannon

The radio source, Cen A, is large and complex with many peaks in the brightness distribution over an area about 4 x 10 degrees. The peculiar elliptical galaxy NGC 5128 lies between the two strong inner radio brightness peaks and is centred on a weaker central radio source. This radio source is in the centre of the dust lane which divides the galaxy and may be related to the infrared, X-ray and γ-ray sources.


1996 ◽  
Vol 175 ◽  
pp. 85-87 ◽  
Author(s):  
D. Dallacasa ◽  
R.T. Schilizzi ◽  
H.S. Sanghera ◽  
D.R. Jiang ◽  
E. Lüdke ◽  
...  

3C286 (1328+307) is a powerful radio source identified with a quasar at z=0.849. There is a foreground galaxy responsible for an H I absorption line system at z=0.6922 (Brown & Roberts 1973), centered approximately 2.″5 to the southeast of 3C286. The radio source has a steep spectrum (α = −0.61, Sv ∝ vα between 1.4 and 15 GHz) which turns over at about 100 MHz. Subarcsecond resolution radio images show a misaligned triple structure, dominated by the central component (Spencer et al. 1989) which accounts for at least 95% of the total flux density at all frequencies. 3C286 is one of the strongest extragalactic sources in polarized emission (0.84 Jy at 5 GHz and 1.41 Jy at 1.4 GHz) and with a rotation measure close to 0 rad m–2 (Rudnick and Jones 1983). Hence the observed orientation of the electric field vector is essentially independent of frequency.


1996 ◽  
Vol 175 ◽  
pp. 23-24
Author(s):  
D.L. Jones ◽  
S.J. Tingay ◽  
R.A. Preston ◽  
D.L. Jauncey ◽  
J.E. Reynolds ◽  
...  

Centaurus A (NGC 5128) is the nearest giant radio galaxy. It is a Fanaroff-Riley type 1 (low luminosity) radio source, but the compact radio source in the nucleus is strong enough that VLBI imaging has been possible with both the SHEVE array and the VLBA at several frequencies. These observations have detected a sub-parsec scale counterjet. This shows that jet formation in at least some FR I sources is intrinsically two-sided over very small distances and the radio jets in Centaurus A are probably only moderately relativistic. We also find evidence that the center of activity in Centaurus A is partially obscured by a disk or torus of dense plasma.


1964 ◽  
Vol 52 (3) ◽  
pp. 690-691 ◽  
Author(s):  
A. G. Little ◽  
D. D. Cudaback ◽  
R. N. Bracewell

Nature ◽  
1962 ◽  
Vol 196 (4856) ◽  
pp. 761-761 ◽  
Author(s):  
B. F. C. COOPER ◽  
R. M. PRICE

1982 ◽  
Vol 97 ◽  
pp. 191-192
Author(s):  
J. S. Ulvestad ◽  
A. S. Wilson ◽  
D. G. Wentzel

Weak radio emission from the type 1.5 Seyfert galaxy NGC 5548 has been mapped with high resolution at the VLA at both 1465 and 4885 MHz. The galaxy contains the largest (5.9 kpc) triple radio source known in a Seyfert galaxy. The central component of that triple is unresolved (<0.39×0.15 kpc) and has a flatter spectrum than the well-resolved outer lobes. In addition, the field surrounding NGC 5548 and two of the sources in that field have been mapped at 1465 MHz; the field sources are unlikely to be physically associated with NGC 5548.


1969 ◽  
Vol 1 (5) ◽  
pp. 229-231 ◽  
Author(s):  
M. J. Cameron

Radio contours are presented for Fornax A (NGC 1316), Virgo A (NGC 4486) and the central component of Centaurus A (NGC 5128). These three objects are intrinsically strong radio emitters identified with bright galaxies. The work forms part of a survey of all bright galaxies with the Molonglo cross down to a corrected total magnitude of 11m.0 with an extension down to photographic magnitude 12m.5 in an limited region of the sky.


1998 ◽  
Vol 164 ◽  
pp. 199-200 ◽  
Author(s):  
J. S. Ulvestad ◽  
J. M. Wrobel ◽  
C. L. Carilli

AbstractThe Seyfert 1/starburst/IR galaxy Mrk 231 (UGC 08058), at z = 0.0422, has been imaged with the VLBA at frequencies ranging from 1.4 GHz to 22 GHz. The radio image shows a triple source of total size 50 mas (30h−1 pc), with a self-absorbed central component and two detached lobes. The northern lobe, located 12h−1 pc from the core, is free-free absorbed at the lowest frequencies; there also seems to be free-free absorption in the southern component. The linear scale over which this absorption takes place is several times larger than that seen in NGC1275/3C84.The axis of the 50-mas radio source is approximately 60° from the elongation of the central component on the 1-mas scale. The spectrum of this central component becomes optically thin between 5 and 8.4 GHz, and resolves into a small triple source of size ~ 1.0h−1 pc at 15 GHz. There is no hint of a jet or other structure directly connecting this central component to the outer VLBI lobes.


1982 ◽  
Vol 97 ◽  
pp. 115-116
Author(s):  
R. M. Price ◽  
J. A. Graham

Centaurus A, at an estimated distance of five megaparsecs, is the closest radio galaxy. It presents the best opportunity to examine in detail the physical mechanisms and resulting structures that are to be found in radio galaxies. Centaurus was first studied in detail at radio wavelengths by Cooper, Price and Cole (1965), hence CPC. Many of the comments, interpretations, and conclusions recorded in that paper remain valid today and provide the broader framework in which the more detailed studies using today's more powerful instrumentation can be understood. Historically, it is also interesting to note that Centaurus A was the first extragalactic radio source in which linear polarization and Faraday rotation were discovered and extensively studied.


1983 ◽  
Vol 5 (2) ◽  
pp. 241-247 ◽  
Author(s):  
R.F. Haynes ◽  
R.D. Cannon ◽  
R.D. Ekers

NGC 5128, identified with the radio source Centaurus A by Bolton et al. (1949), is a remarkable galaxy which appears to consist of an elliptical or SO galaxy crossed by a strong dust lane. The early idea that this represented a pair of colliding galaxies (Baade and Minkowski 1954) powering the extended double radio source fell out of favour but has recently been revived (Malin et al. 1983) in the light of extensive kinematic evidence. However, the interpretation of the data is not yet complete, and it has also been suggested recently that NGC 5128 is really a spiral galaxy with a spectacularly large bulge (Marcelin et al. 1982).


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