Publication: The XMM deep survey in the CDF-S. VI. Obscured AGN selected as infrared power-law galaxies
Loading...
Official URL
Full text at PDC
Publication Date
2013-08
Authors
Castelló Mor, N.
Carrera, F. J.
Alonso Herrero, A.
Mateos, S.
Barcons, X.
Ranalli, P.
Comastri, A.
Vignali, C.
Georgantopoulos, I.
Advisors (or tutors)
Editors
Journal Title
Journal ISSN
Volume Title
Publisher
EDP Sciencies
Abstract
Context. Accretion onto supermassive black holes is believed to occur mostly in obscured active galactic nuclei (AGN). Such objects are proving rather elusive in surveys of distant galaxies, including those at X-ray energies. Aims. Our main goal is to determine whether the revised IRAC criteria of Donley et al. (2012, ApJ, 748, 142; objects with an infrared (IR) power-law spectral shape), are effective at selecting X-ray type-2 AGN (i.e., absorbed N_H > 10^22 cm^-2). Methods. We present the results from the X-ray spectral analysis of 147 AGN selected by cross-correlating the highest spectral quality ultra-deep XMM-Newton and the Spitzer/IRAC catalogues in the Chandra Deep Field South. Consequently it is biased towards sources with high S/N X-ray spectra. In order to measure the amount of intrinsic absorption in these sources, we adopt a simple X-ray spectral model that includes a power-law modified by intrinsic absorption at the redshift of each source and a possible soft X-ray component. Results. We find 21/147 sources to be heavily absorbed but the uncertainties in their obscuring column densities do not allow us to confirm their Compton-Thick nature without resorting to additional criteria. Although IR power-law galaxies are less numerous in our sample than IR non-power-law galaxies (60 versus 87 respectively), we find that the fraction of absorbed (N_H^intr > 10^22 cm^-2) AGN is significantly higher (at about 3 sigma level) for IR-power-law sources (similar to 2/3) than for those sources that do not meet this IR selection criteria (~1/2). This behaviour is particularly notable at low luminosities, but it appears to be present, although with a marginal significance, at all luminosities. Conclusions. We therefore conclude that the IR power-law method is efficient in finding X-ray-absorbed sources. We would then expect that the long-sought dominant population of absorbed AGN is abundant among IR power-law spectral shape sources not detected in X-rays.
Description
© ESO, 2013.
We are grateful to the referee for comments that helped improve the paper. This work is based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA. N.C.-M., F.J.C., S.M. and X.B. acknowledge financial support provided by the Spanish Ministry of Economy and Competitiveness through grant AYA2010-21490-C02-01. S.M., F.J.C. and A.A.-H. acknowledge financial support by the Spanish Ministry of Economy and Competitiveness through grants AYA2010-21490-C02-01 and AYA2012-31447. SM acknowledges financial support from the JAE-Doc program (Consejo Superior de Investigaciones Científicas, cofunded by FSE). A.A.-H. acknowledges support from the Universidad de Cantabria through the Augusto G. Linares program. P.G.P.-G. acknowledges support from the Spanish Programa Nacional de Astronomía y Astrofísica under grants AYA2009-07723-E and AYA2009-10368. This work has made use of the Rainbow Cosmological Surveys Database, which is operated by the Universidad Complutense de Madrid (UCM). We acknowledge financial contribution from the agreement ASI-INAF I/009/10/0 and from the INAF-PRIN-2011.
UCM subjects
Unesco subjects
Keywords
Citation
Alonso Herrero, A., Ward, M. J., & Kotilainen, J. K. 1996, MNRAS, 278, 902
Alonso Herrero, A., Pérez González, P. G., Alexander, D. M., et al. 2006, ApJ, 640, 167
Antonucci, R. 1993, ARA&A, 31, 473
Arnaud, K. A. 1996, in Astronomical Data Analysis Software and Systems V, eds. G. H. Jacoby, & J. Barnes, ASP Conf. Ser., 101, 17
Assef, R. J., Stern, D., Kochanek, C. S., et al. 2013, ApJ, 772, 26
Avni, Y. 1976, ApJ, 210, 642
Barger, A. J., Cowie, L. L., Mushotzky, R. F., et al. 2005, AJ, 129, 578
Barvainis, R. 1987, ApJ, 320, 537
Bauer, F. E., Alexander, D. M., Brandt, W. N., et al. 2004, AJ, 128, 2048
Brandt, W. N., & Hasinger, G. 2005, ARA&A, 43, 827
Brightman, M., & Ueda, Y. 2012, MNRAS, 423, 702
Caccianiga, A., Severgnini, P., Braito, V., et al. 2004, A&A, 416, 901
Comastri, A., & the XMM-CDFS team 2013 [arXiv:1304.3664]
Comastri, A., Fiore, F., Vignali, C., et al. 2001, MNRAS, 327, 781
Comastri, A., Ranalli, P., Iwasawa, K., et al. 2011, A&A, 526, L9
Della Ceca, R., Caccianiga, A., Severgnini, P., & et al. 2008, A&A, 487, 119
Dickey, J. M., & Lockman, F. J. 1990, ARA&A, 28, 215
Donley, J. L., Rieke, G. H., Pérez González, P. G., et al. 2007, ApJ, 660, 167
Donley, J. L., Rieke, G. H., Pérez González, P. G., et al. 2008, ApJ, 687, 111
Donley, J. L., Koekemoer, A. M., Brusa, M., et al. 2012, ApJ, 748, 142
Edelson, R. A., & Malkan, M. A. 1986, ApJ, 308, 59
Elvis, M., Wilkes, B. J., McDowell, J. C., et al. 1994, ApJS, 95, 1
Fabian, A. C. 1999, MNRAS, 308, L39
Fazio, G. G., Hora, J. L., Allen, et al. 2004, ApJS, 154, 10
Feruglio, C., Daddi, E., Fiore, F., et al. 2011, ApJ, 729, L4
Franceschini, A., Manners, J., Polletta, M. d. C., et al. 2005, AJ, 129, 2074
Galbiati, E., Caccianiga, A., Maccacaro, T., el al. 2005, A&A, 430, 927
Georgantopoulos, I., Georgakakis, A., & Akylas, A. 2007, A&A, 466, 823
Georgantopoulos, I., Akylas, A., Georgakakis, A., et al. 2009, A&A, 507, 747
Georgantopoulos, I., Comastri, A., Vignali, C., et al. 2013, A&A, 555, A43
Gilli, R., Salvati, M., & Hasinger, G. 2001, A&A, 366, 407
Gilli, R., Comastri, A., & Hasinger, G. 2007, A&A, 463, 79
Granato, G. L., & Danese, L. 1994, MNRAS, 268, 235
Helou, G., Roussel, H., Appleton, P., et al. 2004, ApJS, 154, 253
Hickox, R. C., & Markevitch, M. 2006, ApJ, 645, 95
Iwasawa, K., Gilli, R., Vignali, C., et al. 2012, A&A, 546, A84
King, A. 2005, ApJ, 635, L121
Komatsu, E., Dunkley, J., Nolta, M. R., et al. 2009, ApJS, 180, 330
Kotilainen, J. K., Ward, M. J., Boisson, C., et al. 1992, MNRAS, 256, 125
Lacy, M., Storrie-Lombardi, L. J., Sajina, A., et al. 2004, ApJS, 154, 166
Lehmer, B. D., Brandt, W. N., Alexander, D. M., et al. 2005, ApJS, 161, 21
Lu, N., Helou, G., Werner, M. W., et al. 2003, ApJ, 588, 199
Luo, B., Brandt, W. N., Xue, Y. Q., et al. 2011, ApJ, 740, 37
Magnelli, B., Chary, R. R., Pope, A., et al. 2008, ApJ, 681, 258
Maiolino, R., & Rieke, G. H. 1995, ApJ, 454, 95
Mateos, S., Barcons, X., Carrera, F. J., et al. 2005, A&A, 444, 79
Mateos, S., Saxton, R. D., Read, A. M., et al. 2009, A&A, 496, 879
Mateos, S., Carrera, F. J., Page, M. J., et al. 2010, A&A, 510, A35
Mateos, S., Alonso Herrero, A., Carrera, F. J., et al. 2012, MNRAS, 426, 3271
Mushotzky, R. 2004, in Supermassive Black Holes in the Distant Universe, ed. A. J. Barger, Astrophys. Space Sci. Lib., 308, 53
Nenkova, M., Ivezić, Ž., & Elitzur, M. 2002, ApJ, 570, L9
Nenkova, M., Sirocky, M. M., Nikutta, R., Ivezić, Ž., & Elitzur, M. 2008, ApJ, 685, 160
Neugebauer, G., Oke, J. B., Becklin, E. E., et al. 1979, ApJ, 230, 79
Page, M. J., McHardy, I. M., Gunn, K. F., et al. 2003, Astron. Nachr., 324, 101
Pérez García, A. M., Rodríguez Espinosa, J. M., & Santolaya Rey, A. E. 1998, ApJ, 500, 685
Pérez González, P. G., Rieke, G. H., Villar, V., et al. 2008, ApJ, 675, 234
Perola, G. C., Puccetti, S., Fiore, F., et al. 2004, A&A, 421, 491
Pineau, F.-X., Motch, C., Carrera, F., et al. 2011, A&A, 527, A126
Ramos Almeida, C., Levenson, N. A., Alonso Herrero, A., et al. 2011, ApJ, 731, 92
Ranalli, P., Comastri, A., Vignali, C., et al. 2013, A&A, 555, A42
Rieke, G. H., & Lebofsky, M. J. 1981, ApJ, 250, 87
Rieke, G. H., Young, E. T., Engelbracht, C. W., et al. 2004, ApJS, 154, 25
Schurch, N. J., Roberts, T. P., & Warwick, R. S. 2002, MNRAS, 335, 241
Steidel, C. C., Hunt, M. P., Shapley, A. E., & et al. 2002, ApJ, 576, 653
Stern, D., Eisenhardt, P., Gorjian, V., et al. 2005, ApJ, 631, 163
Stern, D., Assef, R. J., Benford, D. J., et al. 2012, ApJ, 753, 30
Stevens, J. A., Page, M. J., Ivison, R. J., et al. 2005, MNRAS, 360, 610
Szokoly, G. P., Bergeron, J., Hasinger, G., et al. 2004, ApJS, 155, 271
Tozzi, P., Gilli, R., Mainieri, V., et al. 2006, A&A, 451, 457
Treister, E., & Urry, C. M. 2005, ApJ, 630, 115
Treister, E., Urry, C. M., & Virani, S. 2009, ApJ, 696, 110
Ueda, Y., Akiyama, M., Ohta, K., & Miyaji, T. 2003, ApJ, 598, 886
Urry, C. M., & Padovani, P. 1995, PASP, 107, 803
Wall, J. V., & Jenkins, C. R. 2008, Practical Statistics for Astronomers, 21
Werner, M. W., Roellig, T. L., Low, F. J., et al. 2004, ApJS, 154, 1
Worsley, M. A., Fabian, A. C., Barcons, X., et al. 2004, MNRAS, 352, L28
Worsley, M. A., Fabian, A. C., Bauer, F. E., et al. 2005, MNRAS, 357, 1281
Xue, Y. Q., Luo, B., Brandt, W. N., et al. 2011, ApJS, 195, 10
Xue, Y. Q., Wang, S. X., Brandt, W. N., et al. 2012, ApJ, 758, 129
Yan, L., Donoso, E., Tsai, C.-W., et al. 2013, AJ, 145, 55
Yaqoob, T. 1997, ApJ, 479, 184