| Title: |
The XMM-Newton serendipitous survey - IV. Optical identification of the XMM-Newton medium sensitivity survey (XMS) |
| Authors: |
Barcons, X; Carrera, FJ; Ceballos, MT; Page, MJ; Bussons-Gordo, J; Corral, A; Ebrero, J; Mateos, S; Tedds, JA; Watson, MG; Baskill, D; Birkinshaw, M; Boller, T; Borisov, N; Bremer, M; Bromage, GE; Brunner, H; Caccianiga, A; Crawford, CS; Cropper, MS; Della Ceca, R; Derry, P; Fabian, AC; Guillout, P; Hashimoto, Y; Hasinger, G; Hassall, BJM; Lamer, G; Loaring, NS; Maccacaro, T; Mason, KO; McMahon, RG; Mirioni, L; Mittaz, JPD; Motch, C; Negueruela, I; Osborne, JP; Panessa, F; Perez-Fournon, I; Pye, JP; Roberts, TP; Rosen, S; Schartel, N; Schurch, N; Schwope, A; Severgnini, P; Sharp, R; Stewart, GC; Szokoly, G; Ullan, A; Ward, MJ; Warwick, RS; Wheatley, PJ; Webb, NA; Worrall, D; Yuan WM(袁为民); Ziaeepour, H; Barcons, X (reprint author), CSIC UC, Inst Fis Cantabria, Santander 39005, Spain. |
| Publication Year: |
2007 |
| Collection: |
Yunnan Observatories: YNAO OpenIR (Chinese Academy of Sciences, CAS) / 中国科学院云南天文台机构知识库 |
| Subject Terms: |
X-rays : General; X-rays : Galaxies; X-rays : Stars; Galaxies : Active; Astronomy & Astrophysics; ACTIVE GALACTIC NUCLEI; CHANDRA MULTIWAVELENGTH PROJECT; X-RAY SOURCES; DEEP ROSAT SURVEY; LOG S-RELATION; HELLAS2XMM SURVEY; SOURCE CATALOG; LOCKMAN HOLE; FOLLOW-UP; FIELD; Science & Technology; Physical Sciences |
| Description: |
Aims. X-ray sources at intermediate fluxes (a few x 10(-14) erg cm(-2) s(-1)) with a sky density of similar to 100 deg(-2) are responsible for a significant fraction of the cosmic X-ray background at various energies below 10 keV. The aim of this paper is to provide an unbiased and quantitative description of the X-ray source population at these fluxes and in various X-ray energy bands. Methods. We present the XMM-Newton Medium sensitivity Survey (XMS), including a total of 318 X-ray sources found among the serendipitous content of 25 XMM-Newton target fields. The XMS comprises four largely overlapping source samples selected at soft (0.5-2 keV), intermediate (0.5-4.5 keV), hard (2-10 keV) and ultra-hard (4.5-7.5 keV) bands, the first three of them being flux-limited. Results. We report on the optical identification of the XMS samples, complete to 85-95%. At the flux levels sampled by the XMS we find that the X-ray sky is largely dominated by Active Galactic Nuclei. The fraction of stars in soft X-ray selected samples is below 10%, and only a few per cent for hard selected samples. We find that the fraction of optically obscured objects in the AGN population stays constant at around 15-20% for soft and intermediate band selected X-ray sources, over 2 decades of flux. The fraction of obscured objects amongst the AGN population is larger (similar to 35-45%) in the hard or ultra-hard selected samples, and constant across a similarly wide flux range. The distribution in X-ray-to-optical flux ratio is a strong function of the selection band, with a larger fraction of sources with high values in hard selected samples. Sources with X-ray-to-optical flux ratios in excess of 10 are dominated by obscured AGN, but with a significant contribution from unobscured AGN. |
| Document Type: |
article in journal/newspaper; report |
| Language: |
English |
| Relation: |
ASTRONOMY & ASTROPHYSICS; Barcons, X,Carrera, FJ,Ceballos, MT,et al. The XMM-Newton serendipitous survey - IV. Optical identification of the XMM-Newton medium sensitivity survey (XMS)[J]. ASTRONOMY & ASTROPHYSICS,2007,476(3):1191-U35.; http://ir.ynao.ac.cn/handle/114a53/4953 |
| DOI: |
10.1051/0004-6361:20077606 |
| Availability: |
http://ir.ynao.ac.cn/handle/114a53/4953; http://www.aanda.org/articles/aa/abs/2007/48/aa7606-07/aa7606-07.html; https://doi.org/10.1051/0004-6361:20077606 |
| Rights: |
cn.org.cspace.api.content.CopyrightPolicy@1a5fc2f |
| Accession Number: |
edsbas.7DF80243 |
| Database: |
BASE |