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J/A+A/436/457       Ultra-steep spectrum radio sources    (Gopal-Krishna+, 2005)

Optical and radio observations of a sample of 52 powerful ultra-steep spectrum radio sources. Gopal-Krishna, Ledoux C., Melnick J., Giraud E., Kulkarni V., Altieri B. <Astron. Astrophys., 436, 457-464 (2005)> =2005A&A...436..457G
ADC_Keywords: Galaxies, radio ; Morphology ; Photometry, UBVRI Keywords: cosmology: observations - galaxies: active - cooling flows - galaxies: clusters: general - quasars: general - radio continuum: galaxies Abstract: We present the results of radio (VLA) and optical (ESO/La Silla) imaging of a sample of 52 radio sources having an ultra-steep radio spectrum with α mostly steeper than -1.1 at decimetre wavelengths (median α=-1.22). Radio-optical overlays are presented to an astrometric accuracy of ∼1". For 41 of the sources, radio spectral indices are newly determined using unpublished observations made with the 100-m Effelsberg radio telescope. For 14 of the sources identified with relatively brighter optical counterparts, spectroscopic observations were also carried out at La Silla and their redshifts are found to lie in the range 0.4 to 2.6. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 89 52 Overall properties of the sample galaxies notes.dat 80 252 Individual notes
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) J/AJ/123/637 : Ultra-steep-spectrum radio sources (De Breuck +, 2002) J/MNRAS/355/20 : K magnitudes of 74MHz radio sources (Jarvis+, 2004) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 8 A8 --- Name IAU name (HHMM+DDd, B1950) 10- 11 A2 --- n_Name Origin of the object (1) 13- 14 I2 h RAh Right ascension (J2000) (2) 16- 17 I2 min RAm Right ascension (J2000) (2) 19- 23 F5.2 s RAs Right ascension (J2000) (2) 25 A1 --- DE- Declination sign (J2000) 26- 27 I2 deg DEd Declination (J2000) (2) 29- 30 I2 arcmin DEm Declination (J2000) (2) 32- 35 F4.1 arcsec DEs Declination (J2000) (2) 37- 39 A3 --- RMorph Radio morphology (3) 41 A1 --- l_RSize [~<] Limit flag on RSize 42- 44 I3 arcsec RSize ? Radio size 45 A1 --- n_RSize [s] s: see text 47- 51 F5.2 --- alpha Radio spectral index 53- 56 F4.2 Jy RFlux Radio flux at 408MHz (or 327MHz if n_RFlux=")") 57 A1 --- n_RFlux [)] ): indicates RFlux at 327MHz 59 A1 --- Filter [BVRI] Photometric filter 60 A1 --- l_mag [≃>] Limit flag on mag 61- 64 F4.1 mag mag ? Magnitude in "Filter" 66- 68 F3.1 mag e_mag ? rms uncertainty on mag 69 A1 --- n_mag [s] s: see text of the article 71- 74 F4.2 --- z ?=- Redshift 77- 89 A13 --- Obs Details of observations (4)
Note (1): Radio survey from where the object was selected as follows: oo = Ooty lunar occultation survey at 327MHz ml = Molonglo surveys (MC1 and MC2) at 408MHz mg = MIT (365MHz) - Green-Bank (4.8GHz) survey gb = Green-Bank (1.4GHz) - Molonglo (408MHz) survey Note (2): The positions refer to the radio peak for unresolved sources and to the central radio component if detected. For the remaining sources, the mid-point between the lobes is adopted. Note (3): Radio morphology as follows: D = Double T = Triple SR = Slightly Resolved R = Resolved U = Unresolved Note (4): The codes for the optical observations (I,S) are as defined in Tables 2 and 3 (see "Table 2" and "Table 3" sections below). Exposure times for imaging ranged between ten and 30min at the ESO 3.6m/NTT 3.5m telescopes, and 20 and 60min at the ESO 2.2m/Danish 1.5m telescopes. Exposure times for spectroscopy are given together with the comments for each source. The letters "a", "b" and "c" refer to the quality of the astrometry as follows: a = astrometric accuracy is ∼1" b = astrometric accuracy is ∼1.5" c = astrometric accuracy is ∼2" Asterisks refer to the sources for which our spectroscopic data did not yield redshift.
Table 2: Optical imaging observations ------------------------------------------------------------------------------ Run Telescope Instrument Time span CCD Pixel size No. of pixels ------------------------------------------------------------------------------ I1 NTT 3.5m EFOSC2 1989 #05 0.2578 512 x 320 I2 ESO 3.6m EFOSC1 1989-1991 #08 0.3375 1024 x 640 I3 ESO 3.6m EFOSC1 1991-1993 #26 0.6094 512 x 512 I4 ESO/MPI 2.2m EFOSC2 1991 #05 0.3500 512 x 320 I5 ESO/MPI 2.2m EFOSC2 1991 #19 0.3340 1024 x 1024 I6 Danish 1.5m DFOSC 1996 Loral 0.3800 2052 x 2052 Table 3: Optical spectroscopy observations ------------------------------------------------------------------------------- Run Telescope Instrument CCD Grism Pixel size Wavelength range (nm) (nm) ------------------------------------------------------------------------------- S1 ESO 3.6m EFOSC1 #08 B300 0.48 350- 700 S2 ESO 3.6m EFOSC1 #08 R300 0.52 500- 900 S3 ESO 3.6m EFOSC1 #08 B1000 1.3 350-1050 S4 ESO 3.6m EFOSC1 #26 B300 0.96 350- 700 S5 ESO 3.6m EFOSC1 #26 R300 1.04 500- 900 S6 NTT 3.5m EMMI #18 #2 0.44 400- 700 S7 ESO/MPI 2.2m EFOSC2 #19 #1 1.0 400- 920 Byte-by-byte Description of file: notes.dat
Bytes Format Units Label Explanations
1- 8 A8 --- Name IAU name (HHMM+DDd, B1950) 10- 80 A71 --- Note Text of the note
Nomenclature note: Objects identified as [GLM2005] JHHMMSS.ss+DDMMSS.s in Simbad History: From electronic version of the journal
(End) Patricia Vannier [CDS] 29-Sep-2006
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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