2008MNRAS.385.1656S


C.D.S. - SIMBAD4 rel 1.7 - 2019.11.14CET06:07:20

2008MNRAS.385.1656S - Mon. Not. R. Astron. Soc., 385, 1656-1672 (2008/April-2)

The extragalactic radio-source population at 95GHz.

SADLER E.M., RICCI R., EKERS R.D., SAULT R.J., JACKSON C.A. and DE ZOTTI G.

Abstract (from CDS):

We have used the Australia Telescope Compact Array (ATCA) at 95GHz to carry out continuum observations of 130 extragalactic radio sources selected from the Australia Telescope 20 GHz (AT20G) survey. We use a triple-correlation method to measure simultaneous 20- and 95-GHz flux densities for these objects, and over 90 per cent of our target sources are detected at 95GHz. We demonstrate that the ATCA can robustly measure 95-GHz flux densities with an accuracy of ∼10 per cent in a few minutes for sources stronger than about 50mJy.

We measure the distribution of radio spectral indices in a flux-limited sample of extragalactic sources, and show that the median 20-95GHz spectral index does not vary significantly with flux density for S20> 150mJy. This finding allows us to estimate the extragalactic radio source counts at 95GHz by combining our observed 20-95GHz spectral-index distribution with the accurate 20-GHz source counts measured in the AT20G survey.

Our derived 95-GHz source counts at flux densities above 80mJy are significantly lower than those found by several previous studies. The main reason is that most radio sources with flat or rising spectra in the frequency range 5-20GHz show a spectral turnover between 20 and 95GHz. As a result, there are fewer 95-GHz sources (by almost a factor of 2 at 0.1Jy) than would be predicted on the basis of extrapolation from the source populations seen in lower-frequency surveys. We also derive the predicted confusion noise in cosmic microwave background surveys at 95GHz and find a value 20-30 per cent lower than previous estimates.

The 95-GHz source population at the flux levels probed by this study is dominated by quasi-stellar objects with a median redshift z ∼ 1. We find a correlation between optical magnitude and 95-GHz flux density which suggests that many of the brightest 95-GHz sources may be relativistically beamed, with both the optical and millimetre continuum significantly brightened by Doppler boosting.


Abstract Copyright: ©2008 The Authors. Journal compilation © 2008 RAS

Journal keyword(s): techniques: interferometric - galaxies: active - quasars: general - cosmic microwave background - radio continuum: galaxies - radio continuum: general

VizieR on-line data: <Available at CDS (J/MNRAS/385/1656): table4.dat table5.dat>

Simbad objects: 23

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Number of rows : 23

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 ICRF J001259.9-395426 BLL 00 12 59.9096680434 -39 54 26.055457060   18.33   18.05   ~ 51 0
2 2MASS J00261637-3512488 Bz? 00 26 16.3865808485 -35 12 48.766509712   22.24   19.68   ~ 22 0
3 ICRF J005802.2-323420 BLL 00 58 02.2303458342 -32 34 20.751126955 18.26 17.61 17.60 20.00   ~ 38 0
4 QSO B0104-408 QSO 01 06 45.10796851 -40 34 19.9602291   18.60 19.0 19.25   ~ 115 0
5 2dFGRS TGS834Z009 G 01 11 02.9 -47 49 11   18.835   17.386   ~ 5 0
6 WISE J013602.86-404450.3 QSO 01 36 02.8573479435 -40 44 50.299243321     20.7 19.42   ~ 11 0
7 QSO B0244-452 QSO 02 45 54.1108456632 -44 59 39.620015414   17.65 17.6 15.2   ~ 38 1
8 ICRF J032046.4-383728 QSO 03 20 46.4043221227 -38 37 28.493336624           ~ 15 1
9 QSO B0332-403 BLL 03 34 13.6547438706 -40 08 25.401996186 18.54 18.35 17.87 17.5   ~ 254 1
10 QSO B0438-43 QSO 04 40 17.1805718498 -43 33 08.609959495   19.31 19.5 18.2   ~ 246 1
11 QSO B0454-463 QSO 04 55 50.7729726039 -46 15 58.684031092   17.89 17.4 16.87   ~ 178 1
12 QSO B0537-441 BLL 05 38 50.36155219 -44 05 08.9389165   15.77 16.48 16   ~ 765 2
13 PKS 0606-306 Rad 06 08 40 -30 42.5           ~ 2 0
14 2MASS J11020482-4404229 QSO 11 02 04.8359591658 -44 04 22.838521729   20.13   18.92   ~ 15 0
15 QSO B1104-445 QSO 11 07 08.6939954176 -44 49 07.617187122   17.84 18.2 17.37   ~ 172 1
16 ICRF J142741.3-330531 BLL 14 27 41.3612080263 -33 05 31.509675667       17.48   ~ 44 0
17 ICRF J145427.4-374733 Sy1 14 54 27.40975442 -37 47 33.1448724   16.36 16.69 16.14   ~ 151 1
18 QSO B1921-293 BLL 19 24 51.05595514 -29 14 30.1210524   18.71 18.21 15.07   ~ 652 0
19 QSO B1933-400 QSO 19 37 16.21735166 -39 58 01.5529907   18.15 19 17.43   ~ 165 2
20 ICRF J193925.0-634245 Sy2 19 39 25.02671 -63 42 45.6255   18.87 18.37 17.64   ~ 921 1
21 QSO B2052-474 QSO 20 56 16.35981874 -47 14 47.6276461   18.29 19.1 18.07   ~ 244 1
22 QSO B2232-488 QSO 22 35 13.23657712 -48 35 58.7945006   17.61 17.2     ~ 106 1
23 IC 1459 GiP 22 57 10.60677155 -36 27 43.9953697   10.96 11.85 9.34 10.3 ~ 555 2

    Equat.    Gal    SGal    Ecl

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2019.11.14-06:07:20

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