The evolution of X-ray-selected narrow-emission-line galaxies

We examine the cosmological evolution of X-ray-selected narrow-emission-line galaxies (NELGs), using a sample of 35 such objects identified in the combined ROSAT UK Deep Survey and RIXOS. This sample is entirely independent of those previously used to investigate the X-ray evolution of NELGs. We det...

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Detalles Bibliográficos
Autores: Page, Matt, Mason, Keith O., McHardy, I. M., Jones, L. R., Carrera, Francisco J.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:1997
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:dnet:digitalcsic_::21d945395379decff51798f1da06ab13
Acceso en línea:http://hdl.handle.net/10261/170129
Access Level:acceso abierto
Palabra clave:Galaxies: active
X-ray galaxies
Cosmology: observations
Quasars: general
Galaxies: evolution
Surveys
Descripción
Sumario:We examine the cosmological evolution of X-ray-selected narrow-emission-line galaxies (NELGs), using a sample of 35 such objects identified in the combined ROSAT UK Deep Survey and RIXOS. This sample is entirely independent of those previously used to investigate the X-ray evolution of NELGs. We detect evolution which is at a similar rate to the evolution found in the optical luminosity function of blue galaxies. The lack of high-redshift (z > 0.6) NELGs detected in X-ray surveys, and the small, well-defined number of X-ray sources which are not optically identified indicate that the evolution of NELGs is probably not the same as the X-ray evolution of QSOs: NELG evolution is slower than the evolution of QSOs and/or ends at a lower redshift.