Chandra counterparts of candels goods-s sources

Nico Cappelluti, A. Comastri, A. Fontana, G. Zamorani, R. Amorin, M. Castellano, E. Merlin, P. Santini, D. Elbaz, C. Schreiber, X. Shu, T. Wang, J. S. Dunlop, N. Bourne, V. A. Bruce, F. Buitrago, Michał J. Michałowski, S. Derriere, H. C. Ferguson, S. M. FaberF. Vito

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

Improving the capabilities of detecting faint X-ray sources is fundamental for increasing the statistics on faint high-z active galactic nuclei (AGNs) and star-forming galaxies (SFGs). We performed a simultaneous maximum likelihood point-spread function fit in the [0.5-2] keV and [2-7] keV energy bands of the 4 Ms Chandra Deep Field South (CDFS) data at the position of the 34,930 CANDELS H-band selected galaxies. For each detected source we provide X-ray photometry and optical counterpart validation. We validated this technique by means of a ray-tracing simulation. We detected a total of 698 X-ray point sources with a likelihood (i.e., >2.7σ). We show that prior knowledge of a deep sample of optical-NIR galaxies leads to a significant increase in the detection of faint (i.e., ∼10-17 cgs in the [0.5-2] keV band) sources with respect to "blind" X-ray detections. By including previous X-ray catalogs, this work increases the total number of X-ray sources detected in the 4 Ms CDFS, CANDELS area to 793, which represents the largest sample of extremely faint X-ray sources assembled to date. Our results suggest that a large fraction of the optical counterparts of our X-ray sources determined by likelihood ratio actually coincides with the priors used for the source detection. Most of the new detected sources are likely SFGs or faint, absorbed AGNs. We identified a few sources with putative photometric redshift z > 4. Despite the low number statistics and the uncertainties on the photo z, this sample significantly increases the number of X-ray-selected candidate high-z AGNs.

Original languageEnglish (US)
Article number95
JournalAstrophysical Journal
Volume823
Issue number2
DOIs
StatePublished - Jun 1 2016
Externally publishedYes

Fingerprint

x rays
active galactic nuclei
galaxies
statistics
goods
stars
likelihood ratio
ray tracing
point spread functions
point sources
catalogs
energy bands
point source
photometry
simulation
energy
detection

Keywords

  • galaxies: active
  • galaxies: high-redshift
  • quasars: supermassive black holes

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Cappelluti, N., Comastri, A., Fontana, A., Zamorani, G., Amorin, R., Castellano, M., ... Vito, F. (2016). Chandra counterparts of candels goods-s sources. Astrophysical Journal, 823(2), [95]. https://doi.org/10.3847/0004-637X/823/2/95

Chandra counterparts of candels goods-s sources. / Cappelluti, Nico; Comastri, A.; Fontana, A.; Zamorani, G.; Amorin, R.; Castellano, M.; Merlin, E.; Santini, P.; Elbaz, D.; Schreiber, C.; Shu, X.; Wang, T.; Dunlop, J. S.; Bourne, N.; Bruce, V. A.; Buitrago, F.; Michałowski, Michał J.; Derriere, S.; Ferguson, H. C.; Faber, S. M.; Vito, F.

In: Astrophysical Journal, Vol. 823, No. 2, 95, 01.06.2016.

Research output: Contribution to journalArticle

Cappelluti, N, Comastri, A, Fontana, A, Zamorani, G, Amorin, R, Castellano, M, Merlin, E, Santini, P, Elbaz, D, Schreiber, C, Shu, X, Wang, T, Dunlop, JS, Bourne, N, Bruce, VA, Buitrago, F, Michałowski, MJ, Derriere, S, Ferguson, HC, Faber, SM & Vito, F 2016, 'Chandra counterparts of candels goods-s sources', Astrophysical Journal, vol. 823, no. 2, 95. https://doi.org/10.3847/0004-637X/823/2/95
Cappelluti N, Comastri A, Fontana A, Zamorani G, Amorin R, Castellano M et al. Chandra counterparts of candels goods-s sources. Astrophysical Journal. 2016 Jun 1;823(2). 95. https://doi.org/10.3847/0004-637X/823/2/95
Cappelluti, Nico ; Comastri, A. ; Fontana, A. ; Zamorani, G. ; Amorin, R. ; Castellano, M. ; Merlin, E. ; Santini, P. ; Elbaz, D. ; Schreiber, C. ; Shu, X. ; Wang, T. ; Dunlop, J. S. ; Bourne, N. ; Bruce, V. A. ; Buitrago, F. ; Michałowski, Michał J. ; Derriere, S. ; Ferguson, H. C. ; Faber, S. M. ; Vito, F. / Chandra counterparts of candels goods-s sources. In: Astrophysical Journal. 2016 ; Vol. 823, No. 2.
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