Search for Ultra Steep Spectrum Radio Sources Using GMRT 150 MHz Band
The Giant Metrewave Radio Telescope (GMRT) in India which operates at five frequency bands from 150 MHz to 1450 MHz is currently the largest radio telescope in the world at metre wavelength. We have carried out deep radio imaging of selected regions of the sky at 150 MHz using the GMRT to detect ultra-steep spectrum radio sources. It has been known that the high redshift radio sources exhibit steep radio spectra and hence ultra-steep spectrum radio sources are used as tracers of high-redshift radio galaxies. The GMRT 150 MHz images with a resolution of about 20 and rms noise of about 1 to 1.5 mjy/beam is ideally placed for detecting ultra steep spectrum radio sources. In this paper we report the discovery of several ultra steep spectrum radio sources which has no counterparts in SDSS and are likely to be candidate high-redshift radio galaxies. These sources needs to be followed up with multi-wavelength observations, particularly at optical and infra-red bands.
radio continuum galaxies - galaxies active
C. H. Ishwara-Chandra S. K. Sirothia N. G. Kantharia
National Centre for Radio Astrophysics, TIFR, Post Bag 3, Ganeshkhind, Pune University Campus, Pune - 411 007, Inctia
国际会议
The 10th Asian-Pacific Regional International Astronomical Union Meeting(第十届亚洲及太平洋地区天文学大会 APRIM)
昆明
英文
223-225
2008-08-03（万方平台首次上网日期，不代表论文的发表时间）