J/AJ/123/637 Ultra-steep-spectrum radio sources (De Breuck +, 2002)
Optical and near-infrared imaging of ultra-steep-spectrum radio sources:
the K-z diagram of radio-selected and optically selected galaxies.
De Breuck C., van Breugel W., Stanford S.A., Rottgering H., Miley G.,
Stern D.
<Astron. J. 123, 637 (2002)>
=2002AJ....123..637D 2002AJ....123..637D
ADC_Keywords: Radio sources ; Redshifts ; Galaxies, photometry
Keywords: galaxies: active - galaxies: formation - galaxies: photometry -
galaxies: structure - pulsars: general - radio continuum - surveys
Abstract:
We present optical and/or near-IR images of 128 ultra-steep-spectrum
radio sources. Roughly half of the objects are identified in the
optical images (R≲24), while in the near-IR images, more than 94% are
detected at K≲22. The mean K magnitude is 19.26 within a 2" diameter
aperture. The distribution of R-K colors indicates that at least
one-third of the objects observed have very red colors (R-K>5). The
major axes of the identifications in the K band are preferentially
oriented along the radio axes, with half of them having compact
morphologies. The 22 sources with spectroscopic redshifts and K-band
magnitudes follow the K-z relation found from previous radio samples,
but with a larger scatter.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table5.dat 44 83 Optical Photometry of USS Sources
table6.dat 47 365 Astrometric Data
table7.dat 109 87 K-band Photometry and Morphology
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See also:
J/A+AS/93/399 : Optical id. of steep spectrum radio sources (Wieringa+ 1992)
J/A+AS/108/79 : Ultra-steep spectrum radiosources (Roettgering+, 1994)
J/A+AS/143/303 : Ultra steep spectrum radio sources catalog (De Breuck+ 2000)
Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- [DVR2000] Source name
15- 19 F5.3 --- z ? Redshift
21- 23 A3 --- Run Observation run number
25- 28 A4 --- Filt [I R rS] Filter (1)
30 A1 --- l_Mag Limit flag on Mag
31- 34 F4.1 mag Mag ? Magnitude within 4'' diameter aperture
35 A1 --- u_Mag [:] Uncertainty flag in Mag
37 A1 --- f_Mag [ad] Flag on Mag (2)
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Note (1): Filters:
rS: "Spinrad night-sky" filter, λeff=6890Å, EW=1370Å
Transformation from Spinrad night-sky rS into Johnson VR:
(rS - R) = -0.004 - 0.072(V-R) + 0.073(V-R)2
Note (2): Flag on Mag:
d = Estimated from non-photometric conditions
a = Nearby bright star prohibits measurement
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- [DVR2000] Source name (1)
15- 22 A8 --- Pos Source position (2)
24- 25 I2 h RAh Hour of Right Ascension (J2000)
27- 28 I2 min RAm Minute of Right Ascension (J2000)
30- 34 F5.2 s RAs Second of Right Ascension (J2000)
36 A1 --- DE- Sign of the Declination (J2000)
37- 38 I2 deg DEd Degree of Declination (J2000)
40- 41 I2 arcmin DEm Arcminute of Declination (J2000)
43- 46 F4.1 arcsec DEs Arcsecond of Declination (J2000)
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Note (1): Simbad designation:
The name is [DVR2000] AA JHHMM+DDMM for the source position
(i.e. Pos = Radio, IR or Opt)
The name is [DVS2002] AA JHHMM+DDMM AAAAA for the offset stars
where AAAAA = A(opt), A(IR) or B(IR)
(i.e. Pos = A(opt), A(IR) or B(IR))
Note (2): Source position:
Radio = radio source position
Opt = optical identification
IR = near-IR identification
A(opt) = offset star within optical image
A(IR) = offset star within near-IR image
B(IR) = second offset star within near-IR image
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- [DVR2000] Source name
15- 19 F5.3 --- z ? Redshift
20 A1 --- u_z [:] Uncertainty flag on z
22- 24 A3 --- Run Observation run number
26- 29 A4 --- Filt [K k' KS Ks] Filter (1)
31- 35 F5.3 mag K(A) K-band extinction from H I column density
37 A1 --- l_2mag Limit flag on 2mag
38- 42 F5.2 mag 2mag Magnitude within 2'' diameter aperture
44- 47 F4.2 mag e_2mag ? Error in 2mag (2)
49 A1 --- f_2mag [d] Flag on 2mag (3)
51- 55 F5.2 mag 4mag ? Magnitude within 4'' diameter aperture
57- 60 F4.2 mag e_4mag ? Error in 4mag (2)
62 A1 --- f_4mag [d] Flag on 4mag (3)
64- 68 F5.2 mag 8mag ? Magnitude within 8'' diameter aperture
70- 73 F4.2 mag e_8mag ? Error in 8mag (2)
75 A1 --- f_8mag [d] Flag on 8mag (3)
77 A1 --- l_HLRad Limit flag on Rad
78- 80 F3.1 arcsec HLRad ? The half-light radius
82- 85 F4.2 --- Ellipt ? Ellipticity
87- 89 I3 deg PA ? Position angle
91-108 A18 --- Morph Morphology information
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Note (1): Keck and CTIO filter passbands:
K: 2.000um-2.427um
k': 1.955um-2.292um
KS: 1.990um-2.320um
Ks: 1.990um-2.300um
Note (2): Includes both the zero-point uncertainty and the aperture
centering and sky fitting uncertainties.
Note (3): Flag on magnitudes:
d: Estimated from non-photometric conditions.
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History:
From electronic version of the journal
* 24-Apr-2003: Source named "WN J0837-1053" corrected into "TN J0837-1053"
* 10-Jul-2003: Source named "TN J0859-1510" corrected into "TN J0856-1510"
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 25-Apr-2002