J/MNRAS/405/436 LBDS-Lynx region GMRT 150-MHz obs. (Ishwara-Chandra+, 2010)
Deep GMRT 150-MHz observations of the LBDS-Lynx region:
ultrasteep spectrum radio sources.
Ishwara-Chandra C.H., Sirothia S.K., Wadadekar Y., Pal S., Windhorst R.
<Mon. Not. R. Astron. Soc., 405, 436-446 (2010)>
=2010MNRAS.405..436I 2010MNRAS.405..436I
ADC_Keywords: Galaxies, radio
Keywords: galaxies: active - galaxies: high-redshift - radio continuum: galaxies
Abstract:
It has been known for nearly three decades that high-redshift radio
galaxies exhibit steep radio spectra, and hence ultrasteep spectrum
radio sources provide candidates for high-redshift radio galaxies.
Nearly all radio galaxies with z>3 have been found using this
redshift-spectral index correlation. We have started a programme with
the Giant Metrewave Radio Telescope (GMRT) to exploit this correlation
at flux density levels about 10 to 100 times deeper than the known
high-redshift radio galaxies which were identified primarily using the
already available radio catalogues. In our programme, we have obtained
deep, high-resolution radio observations at 150MHz with GMRT for
several "deep" fields which are well studied at higher radio
frequencies and in other bands of the electromagnetic spectrum, with
an aim to detect candidate high-redshift radio galaxies. In this paper
we present results from the deep 150-MHz observations of the LBDS-Lynx
field (Leiden-Berkeley Deep Survey), which has been already imaged at
327, 610 and 1412MHz with the Westerbork Synthesis Radio Telescope and
at 1400 and 4860MHz with the Very Large Array.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 115 765 GMRT 150-MHz sources
table4.dat 54 98 Steep spectrum sources which do not have
counterparts in the SDSS
--------------------------------------------------------------------------------
See also:
VIII/62 : The Westerbork Northern Sky Survey (Leiden, 1998)
VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)
VIII/71 : The FIRST Survey Catalog, Version 03Apr11 (Becker+ 2003)
J/A+AS/58/1 : 1412 MHz catalogue of Westerbork survey. I. (Windhorst+, 1984)
J/A+AS/71/221 : The 65W part of the WSRT 21 cm survey in Lynx (Oort, 1987)
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [GMRT]
5- 18 A14 --- GMRT GMRT designation (JHHMMSS+DDMMSS) (G1)
20- 21 I2 h RAh Right ascension (J2000)
23- 24 I2 min RAm Right ascension (J2000)
26- 29 F4.1 s RAs Right ascension (J2000)
31 A1 --- DE- Declination sign (J2000)
32- 33 I2 deg DEd Declination (J2000)
35- 36 I2 arcmin DEm Declination (J2000)
38- 41 F4.1 arcsec DEs Declination (J2000)
43- 49 F7.1 mJy S150 ?=- GMRT flux density at 150MHz
51- 56 F6.1 mJy S327 ?=- WSRT flux density at 327MHz
58- 63 F6.1 mJy S327w ?=- WENSS flux density at 327MHz (VIII/62)
65- 70 F6.1 mJy S610 ?=- WSRT flux density at 610MHz
72- 77 F6.1 mJy S1412a ?=- WSRT flux density at 1412MHz from
Windhorst et al., 1984, Cat. J/A+AS/58/1
79- 84 F6.1 mJy S1412b ?=- WSRT flux density at 1412MHz from
Oort, 1987, Cat. J/A+AS/71/221
86- 91 F6.1 mJy S1400n ?=- NVSS flux density at 1400MHz (VIII/65)
93- 98 F6.1 mJy S1400f ?=- FIRST flux density at 1400MHz (VIII/71)
100-104 F5.1 mJy S1462 ?=- VLA flux density at 1462MHz
106-109 F4.2 mJy S4860 ?=- VLA flux density at 4860MHz
111-115 F5.2 --- alpha ?=- Spectral index from the fit
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- --- [GMRT]
5- 18 A14 --- GMRT GMRT designation (JHHMMSS+DDMMSS) (G1)
20- 21 I2 h RAh Right ascension (J2000)
23- 24 I2 min RAm Right ascension (J2000)
26- 29 F4.1 s RAs Right ascension (J2000)
31 A1 --- DE- Declination sign (J2000)
32- 33 I2 deg DEd Declination (J2000)
35- 36 I2 arcmin DEm Declination (J2000)
38- 41 F4.1 arcsec DEs Declination (J2000)
43- 48 F6.1 mJy S150 ?=- GMRT flux density at 150MHz
51- 54 F4.2 --- alpha ?=- Spectral index from the fit
--------------------------------------------------------------------------------
Global notes:
Note (G1): Sources identified as <[ISW2010] GMRT JHHMMSS+DDMMSS> in Simbad.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 13-Aug-2011