2007AJ....134.1263C

Query : 2007AJ....134.1263C

2007AJ....134.1263C - Astron. J., 134, 1263-1275 (2007/September-0)

``Hidden'' Seyfert 2 galaxies in the Chandra deep field north.

CARDAMONE C.N., MORAN E.C. and KAY L.E.

Abstract (from CDS):

We have compared the X-ray-to-optical flux ratios (FX/Fopt) of absorbed active galactic nuclei (AGNs) in the Chandra Deep Field North (CDF-N) with those of nearby, optically classified Seyfert 2 galaxies. The comparison provides an opportunity to explore the extent to which the local population of absorbed AGNs can account for the properties of the distant, spectroscopically ambiguous sources that produce the hard X-ray background. Our nearby sample consists of 38 objects that well represent the local Seyfert 2 luminosity function. Integrated UBVRI photometry and broadband X-ray observations are presented. Using these data, we have simulated the FX/Foptratios that local Seyfert 2s would exhibit if they were observed in the redshift range 0.2≤z≤1.3 as part of the CDF-N. In the simulations we account for the effects of redshift on flux measurements in fixed observed-frame bands and the way the luminosity function of a given population is sampled in a flux-limited survey like the CDF-N. Overall, we find excellent agreement between our simulations and the observed distribution of FX/Foptratios for absorbed AGNs in the CDF-N. Our analysis has thus failed to reveal any physical differences between the local population of Seyfert 2s and CDF-N sources with similar X-ray properties. These results support the hypothesis that the nuclear emission lines of many distant hard X-ray galaxies are hidden in ground-based spectra due to a combination of observational effects: signal-to-noise ratio, wavelength coverage, and dilution by host-galaxy light.

Abstract Copyright: ∼

Journal keyword(s): Galaxies: Seyfert - X-Rays: Diffuse Background - X-Rays: Galaxies

Simbad objects: 40

goto Full paper

goto View the references in ADS

Number of rows : 40
N Identifier Otype ICRS (J2000)
RA 		ICRS (J2000)
DEC 		Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026 		#notes
1 NGC 262 Bla 00 48 47.14147900 +31 57 25.0845702 14.04 13.90 13.06 8.53   ~ 778 2
2 LEDA 212600 G 00 48 52.8394597320 +31 57 30.996910152           ~ 8 0
3 NGC 788 Sy2 02 01 06.4628889816 -06 48 57.149808084   13.71 12.76 11.79   ~ 291 0
4 M 77 Sy2 02 42 40.7091669408 -00 00 47.859690204 9.70 9.61 8.87 10.1 9.9 ~ 4897 2
5 Z 524-40 Sy2 02 59 58.5970307633 +36 49 13.808979663   14.89 13.96     ~ 369 1
6 NAME Chandra Deep Field-South reg 03 32 28.0 -27 48 30           ~ 2282 1
7 NGC 1358 Sy2 03 33 39.6807616872 -05 05 22.213915692   14.10 13.05 11.76   ~ 220 1
8 NGC 1386 Sy1 03 36 46.238 -35 59 57.39 12.42 12.16 11.23 10.76   ~ 553 1
9 NGC 1667 Sy2 04 48 37.1804579280 -06 19 11.824427712   13.66 12.86 11.72   ~ 384 2
10 NGC 1685 Sy2 04 52 34.2987606264 -02 56 57.337701864   16.21 15.18     ~ 72 0
11 NGC 2110 Sy2 05 52 11.3768668776 -07 27 22.507465392   14.77 13.51 11.86   ~ 712 1
12 Z 329-24 Sy2 06 15 36.2812259376 +71 02 14.837219808 14.21 14.03 12.97     ~ 960 2
13 NGC 2273 Sy1 06 50 08.6691789600 +60 50 44.864645136   14.50 13.54     ~ 566 2
14 MCG-05-18-002 Sy2 07 16 31.2062162520 -29 19 28.882826364   13.28 13.52 11.61   ~ 288 4
15 NGC 2992 Sy2 09 45 42.045 -14 19 34.90 13.54 13.14 12.18 12.6 12.2 ~ 951 3
16 MCG-05-23-016 Sy2 09 47 40.1332188528 -30 56 55.960779696   14.10 13.69 12.44   ~ 611 0
17 NGC 3081 Sy2 09 59 29.5437024336 -22 49 34.747341960   13.06 13.55 11.67 12.1 ~ 509 0
18 NGC 3281 Sy2 10 31 52.086 -34 51 13.40   12.62 14.02 11.17   ~ 392 1
19 Z 37-92 Sy2 10 36 35.7949609728 +05 54 38.079944820   14.7       ~ 46 0
20 NGC 3982 Sy2 11 56 28.1445516072 +55 07 30.859586652   12.20 11.70 11.18   ~ 588 1
21 NGC 4117 Sy2 12 07 46.1195809200 +43 07 34.818483864   14.04       ~ 178 1
22 NGC 4388 Sy2 12 25 46.820 +12 39 43.45 11.91 11.76 11.02     ~ 1433 2
23 NGC 4507 Sy2 12 35 36.6338976888 -39 54 33.710416272   12.95 13.54 11.70 12.4 ~ 532 1
24 NAME Chandra Deep Field-North reg 12 36.8 +62 13           ~ 686 0
25 IC 3639 Sy1 12 40 52.8344884344 -36 45 21.057011172   13.01 13.50 11.87 12.7 ~ 262 1
26 NGC 4941 Sy2 13 04 13.1036380320 -05 33 05.752803672   13.18 12.23 10.74   ~ 410 0
27 NGC 5135 Sy2 13 25 44.059 -29 50 01.24   12.58 13.35 11.53 12.2 ~ 500 1
28 NGC 5283 Sy2 13 41 05.7499712616 +67 40 19.967186280   14.97 14.05     ~ 269 0
29 NGC 5347 Sy2 13 53 17.7984934128 +33 29 27.011618196   13.46 12.70     ~ 373 1
30 NGC 5506 Bla 14 13 14.8761010056 -03 12 27.556909272   15.25 14.38     ~ 1173 1
31 NGC 5643 Sy2 14 32 40.778 -44 10 28.60   11.03 13.60 9.92 10.6 ~ 652 1
32 NGC 5695 Sy2 14 37 22.1349838776 +36 34 04.201272336   14.55 13.60     ~ 215 0
33 NGC 5728 Sy2 14 42 23.8918506576 -17 15 11.240783784   14.34 13.40     ~ 679 1
34 NGC 5929 Sy1 15 26 06.1564333536 +41 40 14.384294616   13.0 14.00     ~ 450 0
35 NGC 5930 AGN 15 26 07.9964334517 +41 40 33.691556640   13.0       ~ 441 0
36 NGC 6890 Sy2 20 18 18.1057797216 -44 48 24.750633168   13.06 14.02 11.57   ~ 171 0
37 NGC 7172 Sy2 22 02 01.897 -31 52 11.60   12.72 13.61 11.15 25.10 ~ 572 2
38 NGC 7314 Sy2 22 35 46.1985355872 -26 03 01.564993476   11.62 13.11 10.61 11.4 ~ 601 0
39 NGC 7582 Sy2 23 18 23.60 -42 22 13.3 11.62 10.92 10.62     ~ 978 3
40 NGC 7672 Sy2 23 27 31.4358992112 +12 23 06.832583628   15.05 14.21     ~ 95 0

To bookmark this query, right click on this link: simbad:objects in 2007AJ....134.1263C and select 'bookmark this link' or equivalent in the popup menu