2014A&A...567A.104H


C.D.S. - SIMBAD4 rel 1.7 - 2020.07.03CEST21:58:33

2014A&A...567A.104H - Astronomy and Astrophysics, volume 567A, 104-104 (2014/7-1)

Infrared-faint radio sources are at high redshifts. Spectroscopic redshift determination of infrared-faint radio sources using the Very Large Telescope.

HERZOG A., MIDDELBERG E., NORRIS R.P., SHARP R., SPITLER L.R. and PARKER Q.A.

Abstract (from CDS):

Infrared-faint radio sources (IFRS) are characterised by relatively high radio flux densities and associated faint or even absent infrared and optical counterparts. The resulting extremely high radio-to-infrared flux density ratios up to several thousands were previously known only for high-redshift radio galaxies (HzRGs), suggesting a link between the two classes of object. However, the optical and infrared faintness of IFRS makes their study difficult. Prior to this work, no redshift was known for any IFRS in the Australia Telescope Large Area Survey (ATLAS) fields which would help to put IFRS in the context of other classes of object, especially of HzRGs. This work aims at measuring the first redshifts of IFRS in the ATLAS fields. Furthermore, we test the hypothesis that IFRS are similar to HzRGs, that they are higher-redshift or dust-obscured versions of these massive galaxies. A sample of IFRS was spectroscopically observed using the Focal Reducer and Low Dispersion Spectrograph 2 (FORS2) at the Very Large Telescope (VLT). The data were calibrated based on the Image Reduction and Analysis Facility (IRAF) and redshifts extracted from the final spectra, where possible. This information was then used to calculate rest-frame luminosities, and to perform the first spectral energy distribution modelling of IFRS based on redshifts. We found redshifts of 1.84, 2.13, and 2.76, for three IFRS, confirming the suggested high-redshift character of this class of object. These redshifts and the resulting luminosities show IFRS to be similar to HzRGs, supporting our hypothesis. We found further evidence that fainter IFRS are at even higher redshifts. Considering the similarities between IFRS and HzRGs substantiated in this work, the detection of IFRS, which have a significantly higher sky density than HzRGs, increases the number of active galactic nuclei in the early universe and adds to the problems of explaining the formation of supermassive black holes shortly after the Big Bang.

Abstract Copyright:

Journal keyword(s): techniques: spectroscopic - galaxies: active - galaxies: distances and redshifts - galaxies: high-redshift

Simbad objects: 11

goto Full paper

goto View the reference in ADS

Number of rows : 11

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 ELAIS S1 reg 00 34 44 -43 28.2           ~ 155 0
2 3C 48 QSO 01 37 41.2995845985 +33 09 35.079126038   16.62 16.20     ~ 2495 2
3 [NAA2006] S212 AGN 03 29 48.94 -27 31 48.9           ~ 2 0
4 [NAA2006] S265 Rad 03 30 34.66 -28 27 06.5           ~ 3 0
5 NAME Chandra Deep Field-South reg 03 32 28.0 -27 48 30           ~ 1811 1
6 [NAA2006] S539 Rad 03 33 30.54 -28 54 28.2           ~ 3 0
7 [NAA2006] S713 Rad 03 35 37.53 -27 50 57.8           ~ 3 0
8 NAME Lockman Hole reg 10 45 00.0 +58 00 00           ~ 748 0
9 3C 273 BLL 12 29 06.6996828061 +02 03 08.598846466   13.05 14.830 14.11   ~ 5316 1
10 Mrk 231 Sy1 12 56 14.2340989340 +56 52 25.238555193   14.68 13.84     ~ 1777 3
11 IC 4553 SyG 15 34 57.22396 +23 30 11.6084   14.76 13.88     ~ 2679 4

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2014A&A...567A.104H and select 'bookmark this link' or equivalent in the popup menu


2020.07.03-21:58:33

© Université de Strasbourg/CNRS

    • Contact