The RATAN-600 - VLA - 6M Russian Telescope: Early Universe Project

Parijskij, Yu. N.; Soboleva, N. S.; Goss, W. M.; Копылов, А. И.; Верходанов, О. В.; Темирова, А. В.; Желенкова, О. П.

doi:10.1007/978-94-009-0295-4_211

Cited by 8 publications

(12 citation statements)

References 2 publications

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“…The VLA observations carried out by W.M. Goss in June 1995 with a resolution of 1".4 at 1425 MHz provided evidence for a compact two-component structure (Parijskij et al 1996). Based on their VLA observations with a similar resolution, Rottgering et al ( 1994) determined the radio source as an extended one with a size of 1".6.…”

Section: Radio Observationsmentioning

confidence: 98%

“…Based on the direct BTA image with an exposure time of 400 s at 2" seeing obtained in September 1995 with a 580×520 ISD015 CCD array (pixel size 0".205×0".154), we identified the radio source (Parijskij et al 1996) with a faint galaxy (R≈22.9 in a 5" aperture). The optical-to-radio luminosity ratio turned out to be the standard one for the population of luminous radio galaxies (McCarthy 1993;Parijskij et al 1996). Figure 2 shows the optical object with the superimposed VLA 4860 MHz isophotes.…”

Section: Optical Identificationmentioning

confidence: 99%

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RC J0311+0507: A candidate for superpowerful radio galaxies in the early universe at redshift z = 4.514

et al. 2006

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A strong emission line at 6703Åhas been detected in the optical spectrum for the host galaxy (R=23.1) of the radio source RC J0311+0507 (4C+04.11). This radio galaxy, with a spectral index of 1.31 in the frequency range 365-4850 MHz, is one of the ultrasteep spectrum objects from the deep survey of a sky strip conducted with RATAN-600 in 1980RATAN-600 in -1981 We present arguments in favor of the identification of this line with Lyα at redshift z = 4.514. In this case, the object belongs to the group of extremely distant radio galaxies of ultrahigh radio luminosity (P 1400 = 1.3 × 10 29 W Hz −1 ). Such power can be provided only by a fairly massive black hole (∼ 10 9 M ⊙ ) that formed in a time less than the age of the Universe at the observed z (1.3 Gyr) or had a primordial origin.

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Section: Radio Observationsmentioning

confidence: 98%

Section: Optical Identificationmentioning

confidence: 99%

RC J0311+0507: A candidate for superpowerful radio galaxies in the early universe at redshift z = 4.514

et al. 2006

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“…However, because the 4C survey has a resolution of 11.5 arcmin, the flux density of the nearby sources will blend with that of J0311+0507, we discarded the match. We, for the same reason, discarded the matches to Bursov (1996) (at 0.96,2.3,3.94 and 7.69 GHz), Parijskij et al (2010) (at 0.5, 1.4 and 3.94 GHz), Parijskij et al (1996) (at 1.425 GHz), Pariiskii et al (1992) (at 3.945 GHz) and Braude et al (1979) (at 16.7 MHz).…”

Section: J0311+0507mentioning

confidence: 99%

Radio spectra of bright compact sources at z>4.5

Coppejans

Velzen

Intema

et al. 2017

Mon. Not. R. Astron. Soc.

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High-redshift quasars are important to study galaxy and active galactic nuclei (AGN) evolution, test cosmological models, and study supermassive black hole growth. Optical searches for high-redshift sources have been very successful, but radio searches are not hampered by dust obscuration and should be more effective at finding sources at even higher redshifts. Identifying high-redshift sources based on radio data is, however, not trivial. Here we report on new multi-frequency Giant Metrewave Radio Telescope (GMRT) observations of eight z > 4.5 sources previously studied at high angular resolution with very long baseline interferometry (VLBI). Combining these observations with those from the literature, we construct broad-band radio spectra of all 30 z > 4.5 sources that have been observed with VLBI. In the sample we found flat, steep and peaked spectra in approximately equal proportions. Despite several selection effects, we conclude that the z > 4.5 VLBI (and likely also non-VLBI) sources have diverse spectra and that only about a quarter of the sources in the sample have flat spectra. Previously, the majority of high-redshift radio sources were identified based on their ultra-steep spectra (USS). Recently a new method has been proposed to identify these objects based on their megahertz-peaked spectra (MPS). Neither method would have identified more than 18 per cent of the high-redshift sources in this sample. More effective methods are necessary to reliably identify complete samples of high-redshift sources based on radio data.

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“…The results for all previous stages were published earlier [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. In this paper, we present the results of the last stage: spectoscopic redshifts derived from observations with the "Scorpio" spectrograph (on the 6-m telescope of the SAO).…”

Section: Introductionmentioning

confidence: 96%

Spectroscopy of “Big Trio” objects using the “Scorpio” spectrograph of the 6-m telescope of the Special Astrophysical Observatory

Parijskij

Копылов²,

Темирова³

et al. 2010

Astron. Rep.

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We present the results of spectroscopy of 71 objects with steep and ultra-steep spectra (α < −0.9, S ∝ ν α ) from the "Big Trio" (RATAN-600-VLA-BTA) project, performed with the "Scorpio" spectrograph on the 6-m telescope of the Special Astrophysical Observatory (Russian Academy of Sciences). Redshifts were determined for these objects. We also present several other parameters of the sources, such as their Rmagnitudes, maximum radio sizes in seconds of arc, flux densities at 500, 1425, and 3940 MHz, radio luminosities at 500 and 3940 MHz, and morphology. Of the total number of radio galaxies studied, four have redshifts 1 < z < 2, three have 2 < z < 3, one has 3 < z < 4,and one has z = 4.51. Thirteen sources have redshifts 0.7 < z < 1 and 15 have 0.2 < z < 0.7. Of all the quasars studied, five have redshifts 0.7 < z < 1, seven have 1 < z < 2, four have 2 < z < 3, and one has z = 3.57. We did not detect any spectral lines for 17 objects.

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The RATAN-600 - VLA - 6M Russian Telescope: Early Universe Project

Cited by 8 publications

References 2 publications

RC J0311+0507: A candidate for superpowerful radio galaxies in the early universe at redshift z = 4.514

RC J0311+0507: A candidate for superpowerful radio galaxies in the early universe at redshift z = 4.514

Radio spectra of bright compact sources at z>4.5

Spectroscopy of “Big Trio” objects using the “Scorpio” spectrograph of the 6-m telescope of the Special Astrophysical Observatory

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