Radio-optical analysis of extended radio sources in the first look survey field
Hons, Claudio Moises Paulo
MetadataShow full item record
I combine 610 MHz Giant Metrewave Radio Telescope (GMRT) data, 1.4 GHz Very Large Array (VLA) data and 1.4 GHz Westerbork Synthesis Radio Telescope (WSRT) observations, encompassing a ∼ 4 square degree field (sq. deg. field) centred on the verification strip of the Spitzer First Look Survey (FLS) field (RA = 17h18m00s, Dec = 59◦30′30′′), to study radio sources down to fluxes of about 0.1 mJy. The results of an analysis of a sample of 107 multi-component radio sources obtained by cross-correlating the VLA and GMRT catalogues are shown. The spectral index analysis shows that the majority of multi-component sources are steep-spectrum sources. Nevertheless the spread in the spectral distribution is wide, with a significant number of ultrasteep,flat or inverted sources. By cross-correlating 107 multi-component radio sources with the optical catalogues of Marleau et al. (2007) and Papovich et al. (2006), 23 objects were identified and spectroscopically classified as galaxies. Some of them are classified as star-forming or star-burst galaxies, perhaps indicating that AGN and starformation activity are ongoing in the same galaxy. The measured redshifts span the range 0 < z < 1.8 and peak at z ∼ 0.2. According to their radio power (P), 6 of the identified objects are in the range of FR II sources (P1.4GHz > 1024.5W/Hz) while 17 are in the range of FR I sources (P1.4GHz < 1024.5W/Hz). Most of the sources having P1.4GHz < 1024.5W/Hz are compact and few are extended and peculiar, while all sources in the range of P1.4GHz > 1024.5W/Hz are extended. Further optical followup is recommended to allow a more complete census of the sub-mJy population and more information on AGN feedback from such sources.
Showing items related by title, author, creator and subject.
Ratsimbazafy, Ando Lalaina (2010)There have been a number of attempts to measure the expansion rate of the Universe using age-dating of Luminous Red Galaxies (LRGs).Assuming stars in LRGs form at the same time, age-dating of two populations of LRGs at ...
The curious case of offset bars : markers for a baby galaxy disk or signposts of an interaction with dark matter sub halos? Fortune, Marc Harris Yao (University of the Western Cape, 2016)We have used the Spitzer Survey of Stellar Structure in Galaxies (S⁴G) as a representative sample of the local universe (total of 2352 galaxies in S⁴G) to make a catalog of offset disk barred galaxies. Using the combined ...
Ocran Emmanuel Francis (University of the Western Cape, 2015)The study of the faint radio universe and of its properties has recently become a very active field of research not only because of the much improved capabilities of the SKA pathfinders but also because of the need to ...