2016A&A...595A..13H


C.D.S. - SIMBAD4 rel 1.7 - 2021.05.19CEST04:33:06

2016A&A...595A..13H - Astronomy and Astrophysics, volume 595A, 13-13 (2016/11-1)

Determining the fraction of reddened quasars in COSMOS with multiple selection techniques from X-ray to radio wavelengths.

HEINTZ K.E., FYNBO J.P.U., MOLLER P., MILVANG-JENSEN B., ZABL J., MADDOX N., KROGAGER J.-K., GEIER S., VESTERGAARD M., NOTERDAEME P. and LEDOUX C.

Abstract (from CDS):

The sub-population of quasars reddened by intrinsic or intervening clouds of dust are known to be underrepresented in optical quasar surveys. By defining a complete parent sample of the brightest and spatially unresolved quasars in the COSMOS field, we quantify to which extent this sub-population is fundamental to our understanding of the true population of quasars. By using the available multiwavelength data of various surveys in the COSMOS field, we built a parent sample of 33 quasars brighter than J=20mag, identified by reliable X-ray to radio wavelength selection techniques. Spectroscopic follow-up with the NOT/ALFOSC was carried out for four candidate quasars that had not been targeted previously to obtain a 100% redshift completeness of the sample. The population of high AV quasars (HAQs), a specific sub-population of quasars selected from optical/near-infrared photometry, some of which were shown to be missed in large optical surveys such as SDSS, is found to contribute 21%+9–5 of the parent sample. The full population of bright spatially unresolved quasars represented by our parent sample consists of 39%+9–8 reddened quasars defined by having AV>0.1, and 21%+9–5 of the sample having E(B-V)>0.1 assuming the extinction curve of the Small Magellanic Cloud. We show that the HAQ selection works well for selecting reddened quasars, but some are missed because their optical spectra are too blue to pass the g-r color cut in the HAQ selection. This is either due to a low degree of dust reddening or anomalous spectra. We find that the fraction of quasars with contributing light from the host galaxy, causing observed extended spatial morphology, is most dominant at z≥1. At higher redshifts the population of spatially unresolved quasars selected by our parent sample is found to be representative of the full population of bright active galactic nuclei at J<20mag. This work quantifies the bias against reddened quasars in studies that are based solely on optical surveys.

Abstract Copyright: © ESO, 2016

Journal keyword(s): galaxies: active - quasars: general - surveys

Simbad objects: 36

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Number of rows : 36

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 NAME SMC G 00 52 38.0 -72 48 01   2.79 2.2     ~ 9797 1
2 [VV2006] J095820.4+020304 QSO 09 58 20.452 +02 03 03.96   19.918 20.039 18.8 19.82 ~ 49 0
3 ACS-GC 20101159 AGN 09 58 33.2727385042 +02 17 20.316765912   21.233 20.791   20.228 ~ 5 0
4 [VV2006] J095835.9+015156 QSO 09 58 35.9837458010 +01 51 57.073940182 21.27 20.02 20.04   19.53 ~ 55 0
5 [VV2006] J095857.3+021314 QSO 09 58 57.348 +02 13 14.53 21.21 20.68 20.27   19.94 ~ 60 0
6 [VV2006] J095858.7+020138 QSO 09 58 58.6827055441 +02 01 39.055162356   19.21 19.09   18.713 ~ 57 0
7 [VV2006] J095918.7+020951 QSO 09 59 18.7048456657 +02 09 51.490284148 20.57 20.30 19.93   19.451 ~ 56 0
8 2XMM J095921.2+024411 AGN 09 59 21.3181322679 +02 44 12.455769235   21.846 21.238   20.346 ~ 23 0
9 COSMOS 1713746 * 09 59 24.401 +02 08 42.56   20.357 20.128   19.81 ~ 4 0
10 [VV2006] J095924.5+015953 QSO 09 59 24.4679965244 +01 59 54.307209816   18.568 18.599   18.53 ~ 56 0
11 3XMM J095938.2+020449 QSO 09 59 38.2905351675 +02 04 50.061351797   21.180 20.825   20.13 ~ 33 0
12 ACS-GC 20152100 AGN 09 59 38.558 +02 33 16.81 22.39 21.55 21.13   20.01 ~ 32 0
13 [VV2006] J095940.0+022306 QSO 09 59 40.0609731052 +02 23 06.672295405   20.448 20.353   20.162 ~ 39 0
14 [VV2006] J095940.7+021938 QSO 09 59 40.743 +02 19 38.85 21.30 20.81 20.69   20.15 ~ 39 0
15 2HERMES S250 J095943.4+020708 QSO 09 59 43.4131974794 +02 07 07.350601912   19.831 19.650   19.472 ~ 24 0
16 [VV2006] J095949.4+020140 QSO 09 59 49.4030270779 +02 01 40.959378256   19.84 19.67   19.00 ~ 61 0
17 COSMOS2015 624284 QSO 10 00 08.9239638201 +02 14 40.610891657   20.351 19.859   19.145 ~ 18 0
18 [VV2006] J100012.9+023523 QSO 10 00 12.9094437876 +02 35 22.829566330   19.0 19.24 18.5 18.89 ~ 64 0
19 [VV2006] J100014.0+020054 QSO 10 00 14.1392836785 +02 00 54.469900737   19.90 19.77   19.77 ~ 53 0
20 [VV2006] J100024.4+015053 QSO 10 00 24.3913054986 +01 50 53.962422121   20.62 20.26   19.428 ~ 49 0
21 [VV2006] J100024.5+020619 QSO 10 00 24.4793349996 +02 06 19.676866182   19.43 19.42   19.89 ~ 44 0
22 [VV2006] J100024.6+023148 QSO 10 00 24.6424077979 +02 31 49.092194235 19.22 18.80 18.87 18.89 18.93 ~ 58 0
23 [VV2006] J100025.2+015851 QSO 10 00 25.2481847202 +01 58 52.080899986   18.71 18.62   18.81 ~ 68 0
24 NAME COSMOS Field reg 10 00 28.60 +02 12 21.0           ~ 2283 0
25 [VV2006] J100047.8+020756 QSO 10 00 47.7532298204 +02 07 57.002954555   19.50 19.30   19.49 ~ 41 0
26 3XMM J100049.9+020459 QSO 10 00 49.9121408251 +02 05 00.006035208   20.408 20.101   19.241 ~ 37 0
27 3XMM J100050.1+022855 QSO 10 00 50.1202215595 +02 28 54.860230959   21.088 20.276   20.08 ~ 35 0
28 [VV2006] J100055.4+023441 QSO 10 00 55.3884 +02 34 41.314 20.85 20.25 20.37   20.05 ~ 55 0
29 [VV2006] J100058.8+015400 QSO 10 00 58.841 +01 54 00.22   20.242 20.432   20.008 ~ 55 0
30 [VV2006] J100114.3+022356 QSO 10 01 14.2962410621 +02 23 56.872378515 19.71 19.44 19.46   19.165 ~ 59 0
31 [VV2006] J100116.7+014053 QSO 10 01 16.7859559645 +01 40 53.569865510   19.594 19.708   19.615 ~ 52 0
32 [VV2006] J100120.2+020341 QSO 10 01 20.2482632433 +02 03 41.220323278   20.75 20.46   20.41 ~ 28 0
33 [VV2006] J100151.1+020032 QSO 10 01 51.1117489242 +02 00 32.439852761   20.36 20.05   20.015 ~ 38 0
34 [VV2006] J100159.7+022641 QSO 10 01 59.7835338849 +02 26 41.699300240   19.91 19.78   19.29 ~ 38 0
35 [VV2006] J100201.5+020329 QSO 10 02 01.5107968548 +02 03 29.492362853   18.9 19.30 18.8 18.28 ~ 53 0
36 [VV2006] J100210.7+023025 QSO 10 02 10.7193359534 +02 30 26.188915281   19.887 19.673 19.0 19.393 ~ 49 0

    Equat.    Gal    SGal    Ecl

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2021.05.19-04:33:06

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