Flat-spectrum symmetric objects with similar to 1 kpc sizes - I. The candidates

• Tipo: Outra Publicação em Revista Científica Internacional
• Data: 2006

Autores

Augusto, P (Autor) Outra; Gonzalez Serrano, JI (Autor) Outra; Perez Fournon, I (Autor) Outra; Wilkinson, PN (Autor) Outra

Revista

Título: Monthly Notices of the Royal Astronomical Society

Vol. 368

Páginas: 1411-1428

ISSN: 0035-8711

Editora: Oxford University Press

Indexação

ISI Web of Knowledge - 23 Citações

Scopus - 22 Citações

Outras Informações

ID Authenticus: P-004-KQY

DOI: 10.1111/j.1365-2966.2006.10227.x

Abstract (EN): In order to understand the origin and evolution of radio galaxies, searches for the youngest such sources have been conducted. Compact symmetric objects (CSOs)/medium symmetric objects (MSOs) are thought to be the earliest stages of radio sources, with possible ages of less than or similar to 10(3) yr for CSOs ( < 1 kpc in size) and 10(4) - 10(5) yr for MSOs (1-15 kpc). From a literature selection in heterogeneous surveys, we have established a sample of 37 confirmed CSOs. In addition, we only found three confirmed flat-spectrum MSOs in the literature. The typical CSO resides on a z less than or similar to 0.5 galaxy, has a flat radio spectrum (alpha(thin) < 0.5; S-v proportional to v(-alpha)), is < 0.3 kpc in size, has an arm length ratio <= 2, and well- aligned (theta <= 20 degrees) opposite lobes with a flux density ratio <= 10. In order to populate the 0.3-1 kpc size range (large CSOs) and also in order to find more flat-spectrum MSOs, we have built a sample of 157 radio sources with alpha(4.85)(1.40) < 0.5 that were resolved with the Very Large Array A configuration (VLA-A) 8.4 GHz. As first results, we have 'rediscovered' nine of the known CSO/MSOs while identifying two new similar to 14 kpc MSOs and two candidate CSO/MSOs (which only lack redshifts for final classification). We were able to reject 61 of the remaining 144 objects from literature information alone. In the series of papers that starts with this one we plan to classify the remaining 83 CSO/MSO candidates (thanks to radio and optical observations) as well as characterize the physical properties of the (likely) many 0.3 - 15 kpc flat-spectrum CSO/MSOs to be found.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 18