2020A&A...641A..85S


C.D.S. - SIMBAD4 rel 1.7 - 2020.12.05CET00:17:25

2020A&A...641A..85S - Astronomy and Astrophysics, volume 641A, 85-85 (2020/9-1)

Observations by GMRT at 323 MHz of radio-loud quasars at z > 5.

SHAO Y., WAGG J., WANG R., CARILLI C.L., RIECHERS D.A., INTEMA H.T., WEISS A. and MENTEN K.M.

Abstract (from CDS):

We present Giant Metrewave Radio Telescope (GMRT) 323MHz radio continuum observations toward 13 radio-loud quasars at z>5, sampling the low-frequency synchrotron emission from these objects. Among the 12 targets successfully observed, we detected 10 above 4σ significance, while 2 remain undetected. All of the detected sources appear as point sources. Combined with previous radio continuum detections from the literature, 9 quasars have power-law spectral energy distributions throughout the radio range; for some the flux density drops with increasing frequency while it increases for others. Two of these sources appear to have spectral turnover. For the power-law-like sources, the power-law indices have a positive range between 0.18 and 0.67 and a negative values between -0.90 and -0.27. For the turnover sources, the radio peaks around ∼1 and ∼10GHz in the rest frame, the optically thin indices are -0.58 and -0.90, and the optically thick indices are 0.50 and 1.20. A magnetic field and spectral age analysis of SDSS J114657.59+403708.6 at z=5.01 may indicate that the turnover is not caused by synchrotron self-absorption, but rather by free-free absorption by the high-density medium in the nuclear region. Alternatively, the apparent turnover may be an artifact of source variability. Finally, we calculated the radio loudness R2500{A} for our sample, which spans a very wide range from 12–13+13 to 4982–254+279.

Abstract Copyright: © Y. Shao et al. 2020

Journal keyword(s): galaxies: high-redshift - quasars: general - radio continuum: galaxies

Simbad objects: 25

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Number of rows : 25

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 PKS 0114-21 rG 01 16 51.56103995 -20 52 10.8021857     16.5     ~ 74 1
2 2MASS J01312733-0321006 QSO 01 31 27.3471263203 -03 21 00.068817936           ~ 22 0
3 3C 48 QSO 01 37 41.2995845985 +33 09 35.079126038   16.62 16.20     ~ 2538 2
4 4C 33.21 Rad 07 35 55.5731 +33 07 09.728   21.0       ~ 35 1
5 2MASS J07415470+2520294 QSO 07 41 54.7167535529 +25 20 29.583840629           ~ 7 0
6 4C -06.18 Rad 07 44 21.6563623 -06 29 35.914159           ~ 46 1
7 ICRF J083454.9+553421 Sy2 08 34 54.90395243 +55 34 21.0703658   20.75 19.45 17.180   ~ 254 2
8 SDSS J083643.85+005453.3 QSO 08 36 43.8598686147 +00 54 53.234090138   26.19 24.17     ~ 119 0
9 QSO J0906+6930 QSO 09 06 30.7556 +69 30 30.829       21.65   ~ 64 1
10 QSO J0913+5919 QSO 09 13 16.551 +59 19 21.68   24.96 23.32 24.948   ~ 49 0
11 3C 241 rG 10 21 54.59 +21 59 31.2   23.5       ~ 158 0
12 7C 1023+2558 QSO 10 26 23.62115 +25 42 59.4292   24.98 23.18     ~ 55 1
13 FIRST J103418.6+203300 QSO 10 34 18.6399470146 +20 33 00.122647677           ~ 13 0
14 NVSS J114657+403709 QSO 11 46 57.7931733597 +40 37 08.583944814   24.80 22.78     ~ 44 0
15 3C 287 QSO 13 30 37.6950709913 +25 09 10.983254741   18.31 17.67     ~ 330 1
16 3C 286 Sy1 13 31 08.2885060664 +30 30 32.960825108   17.51 17.25     ~ 3794 1
17 QSO J1427+3312 QSO 14 27 38.315 +33 12 42.35         22.09 ~ 32 0
18 CFHQS J142952+544717 QSO 14 29 52.17 +54 47 17.7           ~ 25 0
19 NAME NOAO Deep Wide Field reg 14 32 05.75 +34 16 47.5           ~ 327 0
20 [VV2006] J161425.1+464029 QSO 16 14 25.1340 +46 40 28.937   25.35 23.41     ~ 23 0
21 QSO B2203-188B QSO 22 06 10.4191363632 -18 35 38.683779553   18.80 19.74     ~ 161 1
22 QSO J2228+0110 QSO 22 28 43.54 +01 10 32.2           ~ 19 0
23 SDSS J223907.56+003022.6 QSO 22 39 07.557 +00 30 22.47           ~ 3 0
24 [VV2006] J224524.3+002415 QSO 22 45 24.274 +00 24 14.26     23.96     ~ 12 0
25 IRAS 22494+6423 IR 22 52 05.6 +64 40 12           ~ 33 1

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2020.12.05-00:17:25

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