Buscar

Estamos realizando la búsqueda. Por favor, espere...

 Detalle_Publicacion

The XMM deep survey in the CDF-S: IV. Compton-thick AGN candidates

Abstract: The Chandra Deep Field is the region of the sky with the highest concentration of X-ray data available: 4 Ms of Chandra and 3 Ms of XMM-Newton data, allowing excellent quality spectra to be extracted even for faint sources. We took advantage of this to compile a sample of heavily obscured active galactic nuclei (AGN) using X-ray spectroscopy. We selected our sample among the 176 brightest XMM-Newton sources, searching for either flat X-ray spectra (? < 1.4 at the 90% confidence level) suggestive of a reflection dominated continuum or an absorption turn-over suggestive of a column density higher than ? 1024 cm-2. We found a sample of nine heavily-obscured sources satisfying the above criteria. Four of these show statistically significant FeK? lines with large equivalent widths (three out of four have equivalent widths consistent with 1 keV) suggesting that these are the most certain Compton-thick AGN candidates. Two of these sources are transmission dominated while the other two are most probably reflection dominated Compton-thick AGN. Although this sample of four sources is by no means statistically complete, it represents the best example of Compton-thick sources found at moderate-to-high redshift with three sources at z = 1.2-1.5 and one source at z = 3.7. Using Spitzer and Herschel observations, we estimate with good accuracy the X-ray to mid-IR (12 ?m) luminosity ratio of our sources. These are well below the average AGN relation, independently suggesting that these four sources are heavily obscured.

Otras publicaciones de la misma revista o congreso con autores/as de la Universidad de Cantabria

 Autoría: Georgantopoulos I., Comastri A., Vignali C., Ranalli P., Rovilos E., Iwasawa K., Gilli R., Cappelluti N., Carrera F., Fritz J., Brusa M., Elbaz D., Mullaney R.J., Castello-Mor N., Barcons X., Tozzi P., Balestra I., Falocco S.,

 Fuente: Astronomy and Astrophysics, 2013, 555, A43

Editorial: EDP Sciences

 Fecha de publicación: 01/07/2013

Nº de páginas: 13

Tipo de publicación: Artículo de Revista

 DOI: 10.1051/0004-6361/201220828

ISSN: 0004-6361,1432-0746

Proyecto español: AYA2010-21490-C02-01

Url de la publicación: https://doi.org/10.1051/0004-6361/201220828

Autores/as

GEORGANTOPOULOS, IOANNIS

COMASTRI, ANDREA

VIGNALI, CRISTIAN

RANALLI, PIERO

ROVILOS, EMMANOUEL

IWASAWA, KAZUSHI

GILLI, ROBERTO

CAPPELLUTI, NICO

BRUSA, MARCELLA

ELBAZ, DAVID

MULLANEY, JAMES R.

NURIA CASTELLÓ MOR

BALESTRA, ITALO

SERENA FALOCCO