http://hdl.handle.net/2289/101 Search the Channel search http://dspace.rri.res.in:8080/jspui/simple-search http://hdl.handle.net/2289/4239 Title: Twenty-Five Years of Radio Astronomy at TIFR<br/><br/>Authors: Swarup, G.; Kapahi, V.K.; Velusamy, T.; Ananthakrishnan, S.; Balasubramanian, V.; Gopal-Krishna; Pramesh-Rao, A.; Subrahmanya, C.R.; Kulkarni, V.K.<br/><br/>Description: Restricted Access. http://hdl.handle.net/2289/4238 Title: Low frequency imaging and the non-isoplanatic atmosphere<br/><br/>Authors: Subrahmanya, C.R.<br/><br/>Abstract: A method for image reconstruction in radio telescopes using self-calibration is presented for the case of a nonisoplanatic atmosphere. While computation intensive, most of the computations consist of calculating the model visibilities and the solution of nonlinear equations, and the method is suitable for implementation on parallel processors.<br/><br/>Description: Restricted Access. http://hdl.handle.net/2289/4237 Title: High-redshift radio galaxies from the Molonglo Catalogue<br/><br/>Authors: McCarthy, P.J.; Kapahi, V.K.; Van Breugel, W.; Subrahmanya, C.R.<br/><br/>Abstract: Radio and optical observations of a sample of southern hemisphere radio galaxies, selected from the 408 MHz Molonglo Reference Catalogue, are discussed. The sample is defined by means of two criteria: flux densities greater than 0.9 Jy and low-frequency spectral indices steeper than -0.9. From the initial sample of 700 sources, 150 combine the best characteristics of the 1 Jy and ultrasteep samples. It is suggested that these sources can be used to find galaxies at large redshift and explore the properties of galaxies at extreme luminosities and early epochs. VLA 6 cm maps and optical identifications of 13 sources are presented. Eleven of the sources have extended optical structures with morphologies characteristic of high-redshift (z greater than 0.8) radio galaxies.<br/><br/>Description: Restricted Access. http://hdl.handle.net/2289/4236 Title: Low-frequency radio spectra of SCO X-1<br/><br/>Authors: Velusamy, T.; Subrahmanya, C.R.<br/><br/>Abstract: New observations of Sco X-1 at 327 and 843 MHz with the Ooty Synthesis Radio Telescope and the Molonglo Observatory Synthesis Telescope are presented. The northeastern component in Sco X-1 shows a spectral turnover at about 1.5 GHz. The central component was not detected at these frequencies. The southwestern component shows a power-law spectrum with alpha of about -0.75 between 0.3 and 5 GHz. The radio structure and spectra of Sco X-1 resemble those of extragalactic compact doubles.<br/><br/>Description: Restricted Access.