J/ApJ/660/167 Spitzer AGN candidates in CDFN (Donley+, 2007)
Spitzer power-law active galactic nucleus candidates in the
Chandra Deep Field-North.
Donley J.L., Rieke G.H., Perez-Gonzalez P.G., Rigby J.R., Alonso-Herrero A.
<Astrophys. J., 660, 167-190 (2007)>
=2007ApJ...660..167D 2007ApJ...660..167D
ADC_Keywords: Active gal. nuclei ; X-ray sources ; Radio sources ;
Millimetric/submm sources
Keywords: galaxies: active - infrared: galaxies - X-rays: galaxies
Abstract:
We define a sample of 62 galaxies in the Chandra Deep Field-North
whose Spitzer IRAC SEDs exhibit the characteristic power-law emission
expected of luminous AGNs. We study the multi-wavelength properties of
this sample and compare the AGNs selected in this way to those
selected via other Spitzer color-color criteria. Only 55% of the
power-law galaxies are detected in the X-ray catalog at exposures of
>0.5Ms, although a search for faint emission results in the detection
of 85% of the power-law galaxies at the ≥2.5sigma detection level.
Most of the remaining galaxies are likely to host AGNs that are
heavily obscured in the X-ray. Because the power-law selection
requires the AGNs to be energetically dominant in the near- and
mid-infrared, the power-law galaxies comprise a significant fraction
of the Spitzer-detected AGN population at high luminosities and
redshifts. The high 24um detection fraction also points to a luminous
population. The power-law galaxies comprise a subset of color-selected
AGN candidates.
Description:
Spitzer was used to obtain MIPS and IRAC MIR observations of the
CDF-N, with 1400 and 500s exposures, respectively. We use these MIPS
GTO images in place of the GOODS Spitzer data because the former cover
the full CDF-N, whereas the latter cover a field approximately 2 times
smaller.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 109 62 Power-law galaxy sample
table5.dat 65 603 Templates
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Objects:
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RA (2000) DE Designation(s)
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15 34 57.2 +23 30 10 Arp 220 = IC 1127
17 23 21.9 -00 17 00 IRAS 17208-0014 = PMN J1723-0016
13 44 42.1 +55 53 11 Mrk 273 = UGC 8696
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See also:
J/AJ/122/2810 : Chandra Deep Field North Survey. V. (Brandt+, 2001)
J/AJ/124/2351 : Chandra Deep Field North survey. XII (Bauer+, 2002)
J/AJ/126/539 : The Chandra Deep Fields North and South (Alexander+, 2003)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- --- [CDFN]
6- 10 I5 --- CDFN CDFN number, [DRP2007] NNNNN in Simbad
12- 13 I2 h RAh Right ascension (J2000)
15- 16 I2 min RAm Right ascension (J2000)
18- 22 F5.2 s RAs Right ascension (J2000)
24 A1 --- DE- Declination sign (J2000)
25- 26 I2 deg DEd Declination (J2000)
28- 29 I2 arcmin DEm Declination (J2000)
31- 35 F5.2 arcsec DEs Declination (J2000)
37- 40 F4.2 --- Pchi χ2 probability for power-law fit
(see section 3 of paper)
42- 46 F5.2 --- alpha IRAC spectral index (f(ν)∝νalpha)
48- 51 F4.2 --- z ?=- Redshift
53- 56 F4.2 --- e_z ? rms uncertainty on z
58 A1 --- l_F24um Limit flag on F24um
59- 64 F6.1 uJy F24um ? 24um flux density
66 A1 --- l_F1.4G Limit flag on F1.4G
67- 72 F6.1 uJy F1.4G 1.4GHz flux density
74 A1 --- l_FX Limit flag on FX
75- 82 E8.3 mW/m2 FX 0.5-8keV X-ray flux
84 A1 --- l_logLX Limit flag on logLX
85- 88 F4.1 [10-7W] logLX ?=- X-ray luminosity in 0.5-8keV
90- 97 E8.3 s Exp X-ray exposure time
99-102 F4.1 arcmin theta X-ray off-axis angle
104 A1 --- l_q Limit flag on q
105-109 F5.2 [-] q ?=- Flux ratio, log(F24um/F1.4G)
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 10 E10.4 um Arp.w The Arp 220 template wavelength
12- 21 E10.4 Jy Arp.F The Arp 220 template flux density
23- 32 E10.4 um IRAS.w ? The IRAS 17208-0014 template wavelength
34- 43 E10.4 Jy IRAS.F ? The IRAS 17208-0014 template flux density
45- 54 E10.4 um Mrk.w ? The Mrk 273 template wavelength
56- 65 E10.4 Jy Mrk.F ? The Mrk 273 template flux density
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 04-Mar-2009