Chasing highly obscured QSOs in the cosmos field
— University of Arizona Skip to main navigation Skip to search Skip to main content University of Arizona Home Home Profiles Departments and Centers Scholarly Works Activities Grants Datasets Prizes Search by expertise, name or affiliation Chasing highly obscured QSOs in the cosmos field F. Fiore, S. Puccetti, M. Brusa, M. Salvato, G. Zamorani, T. Aldcroft, H. Aussel, H. Brunner, P. Capak, N. Cappelluti, F. Civano, A. Comastri, M. Elvis, C. Feruglio, A. Finoguenov, A. Fruscione, R. Gilli, G. Hasinger, A. Koekemoer, J. KartaltepeShow 24 othersShow lessO. Ilbert, C. Impey, E. Le Floc'H, S. Lilly, V. Mainieri, A. Martinez-Sansigre, H. J. McCracken, N. Menci, A. Merloni, T. Miyaji, D. B. Sanders, M. Sargent, E. Schinnerer, N. Scoville, J. Silverman, V. Smolcic, A. Steffen, P. Santini, Y. Taniguchi, D. Thompson, J. R. Trump, C. Vignali, M. Urry, L. Yan Astronomy Research output: Contribution to journal › Article › peer-review 182 Scopus citations Overview Fingerprint Abstract A large population of heavily obscured, Compton-thick active galactic nuclei (AGNs) is predicted by AGN synthesis models for the cosmic X-ray background and by the "relic" supermassive black hole mass function measured from local bulges. However, even the deepest X-ray surveys are inefficient to search for these elusive AGNs. Alternative selection criteria, combining mid-infrared with near-infrared, and optical photometry, have instead been successful in pinpointing a large population of Compton-thick AGNs. We take advantage of the deep Chandra and Spitzer coverage of a large area (more than 10 times the area covered by the Chandra deep fields, CDFs) in the Cosmic Evolution Survey (COSMOS) field to extend the search of highly obscured, Compton-thick active nuclei to higher luminosity. These sources have low surface density, and therefore large samples can be provided only through large area surveys, like the COSMOS survey. We analyze the X-ray properties of COSMOS MIPS sources with 24 μm fluxes higher than 550 μJy. For the MIPS sources not directly detected in the Chandra images, we produce stacked images in soft and hard X-rays bands. To estimate the fraction of Compton-thick AGN in the MIPS source population, we compare the observed stacked count rates and hardness ratios to those predicted by detailed Monte Carlo simulations, including both obscured AGN and star-forming galaxies. The volume density of Compton-thick QSOs (log L(2-10 keV) = 44-45 erg s-1, or logλL λ(5.8 μm) = 44.79-46.18 erg s-1 for a typical infrared to X-ray luminosity ratio) evaluated in this way is (4.8 ± 1.1) × 10-6 Mpc-3 in the redshift bin 1.2-2.2. This density is ∼44% of all X-ray-selected QSOs in the same redshift and luminosity bin, and it is consistent with the expectation of the most up-to-date AGN synthesis models for the cosmic X-ray background (Gilli et al. 2007). The density of lower luminosity Compton-thick AGNs (log L(2-10 keV) = 43.5-44) at z = 0.7-1.2 is (3.7 ± 1.1) × 10-5 Mpc-3, corresponding to ∼67% of X-ray-selected AGNs. The comparison between the fraction of infrared-selected, Compton-thick AGNs to the X-ray selected, unobscured, and moderately obscured AGNs at high and low luminosity suggests that Compton-thick AGNs follow a luminosity dependence similar to that discovered for Compton-thin AGNs, becoming relatively rarer at high luminosities. We estimate that the fraction of AGNs (unobscured, moderately obscured, and Compton thick) to the total MIPS source population is 49 ± 10%, a value significantly higher than that previously estimated at similar 24 μm fluxes. We discuss how our findings can constrain AGN feedback models. Original language English (US) Pages (from-to) 447-462 Number of pages 16 Journal Astrophysical Journal Volume 693 Issue number 1 DOIs https://doi.org/10.1088/0004-637X/693/1/447 State Published - Mar 1 2009 Keywords X-rays: diffuse background galaxies: active galaxies: high-redshift ASJC Scopus subject areas Astronomy and Astrophysics Space and Planetary Science Access to Document 10.1088/0004-637X/693/1/447 Other files and links Link to publication in Scopus Fingerprint Dive into the research topics of 'Chasing highly obscured QSOs in the cosmos field'. Together they form a unique fingerprint. cosmos Physics & Astronomy 100% active galactic nuclei Physics & Astronomy 72% quasars Physics & Astronomy 71% luminosity Earth & Environmental Sciences 66% erg Earth & Environmental Sciences 21% x rays Physics & Astronomy 19% field survey Earth & Environmental Sciences 7% near infrared Earth & Environmental Sciences 7% View full fingerprint Cite this APA Standard Harvard Vancouver Author BIBTEX RIS Fiore, F., Puccetti, S., Brusa, M., Salvato, M., Zamorani, G., Aldcroft, T., Aussel, H., Brunner, H., Capak, P., Cappelluti, N., Civano, F., Comastri, A., Elvis, M., Feruglio, C., Finoguenov, A., Fruscione, A., Gilli, R., Hasinger, G., Koekemoer, A., ... Yan, L. (2009). Chasing highly obscured QSOs in the cosmos field. Astrophysical Journal, 693(1), 447-462. https://doi.org/10.1088/0004-637X/693/1/447 Chasing highly obscured QSOs in the cosmos field. / Fiore, F.; Puccetti, S.; Brusa, M.; Salvato, M.; Zamorani, G.; Aldcroft, T.; Aussel, H.; Brunner, H.; Capak, P.; Cappelluti, N.; Civano, F.; Comastri, A.; Elvis, M.; Feruglio, C.; Finoguenov, A.; Fruscione, A.; Gilli, R.; Hasinger, G.; Koekemoer, A.; Kartaltepe, J.; Ilbert, O.; Impey, C.; Le Floc'H, E.; Lilly, S.; Mainieri, V.; Martinez-Sansigre, A.; McCracken, H. J.; Menci, N.; Merloni, A.; Miyaji, T.; Sanders, D. B.; Sargent, M.; Schinnerer, E.; Scoville, N.; Silverman, J.; Smolcic, V.; Steffen, A.; Santini, P.; Taniguchi, Y.; Thompson, D.; Trump, J. R.; Vignali, C.; Urry, M.; Yan, L. In: Astrophysical Journal, Vol. 693, No. 1, 01.03.2009, p. 447-462. Research output: Contribution to journal › Article › peer-review Fiore, F, Puccetti, S, Brusa, M, Salvato, M, Zamorani, G, Aldcroft, T, Aussel, H, Brunner, H, Capak, P, Cappelluti, N, Civano, F, Comastri, A, Elvis, M, Feruglio, C, Finoguenov, A, Fruscione, A, Gilli, R, Hasinger, G, Koekemoer, A, Kartaltepe, J, Ilbert, O, Impey, C, Le Floc'H, E, Lilly, S, Mainieri, V, Martinez-Sansigre, A, McCracken, HJ, Menci, N, Merloni, A, Miyaji, T, Sanders, DB, Sargent, M, Schinnerer, E, Scoville, N, Silverman, J, Smolcic, V, Steffen, A, Santini, P, Taniguchi, Y, Thompson, D, Trump, JR, Vignali, C, Urry, M & Yan, L 2009, 'Chasing highly obscured QSOs in the cosmos field', Astrophysical Journal, vol. 693, no. 1, pp. 447-462. https://doi.org/10.1088/0004-637X/693/1/447 Fiore F, Puccetti S, Brusa M, Salvato M, Zamorani G, Aldcroft T et al. Chasing highly obscured QSOs in the cosmos field. Astrophysical Journal. 2009 Mar 1;693(1):447-462. https://doi.org/10.1088/0004-637X/693/1/447 Fiore, F. ; Puccetti, S. ; Brusa, M. ; Salvato, M. ; Zamorani, G. ; Aldcroft, T. ; Aussel, H. ; Brunner, H. ; Capak, P. ; Cappelluti, N. ; Civano, F. ; Comastri, A. ; Elvis, M. ; Feruglio, C. ; Finoguenov, A. ; Fruscione, A. ; Gilli, R. ; Hasinger, G. ; Koekemoer, A. ; Kartaltepe, J. ; Ilbert, O. ; Impey, C. ; Le Floc'H, E. ; Lilly, S. ; Mainieri, V. ; Martinez-Sansigre, A. ; McCracken, H. J. ; Menci, N. ; Merloni, A. ; Miyaji, T. ; Sanders, D. B. ; Sargent, M. ; Schinnerer, E. ; Scoville, N. ; Silverman, J. ; Smolcic, V. ; Steffen, A. ; Santini, P. ; Taniguchi, Y. ; Thompson, D. ; Trump, J. R. ; Vignali, C. ; Urry, M. ; Yan, L. / Chasing highly obscured QSOs in the cosmos field. In: Astrophysical Journal. 2009 ; Vol. 693, No. 1. pp. 447-462. @article{86f3fb03d5e14d98b10b2406cf4cd2f5, title = "Chasing highly obscured QSOs in the cosmos field", abstract = "A large population of heavily obscured, Compton-thick active galactic nuclei (AGNs) is predicted by AGN synthesis models for the cosmic X-ray background and by the {"}relic{"} supermassive black hole mass function measured from local bulges. However, even the deepest X-ray surveys are inefficient to search for these elusive AGNs. Alternative selection criteria, combining mid-infrared with near-infrared, and optical photometry, have instead been successful in pinpointing a large population of Compton-thick AGNs. We take advantage of the deep Chandra and Spitzer coverage of a large area (more than 10 times the area covered by the Chandra deep fields, CDFs) in the Cosmic Evolution Survey (COSMOS) field to extend the search of highly obscured, Compton-thick active nuclei to higher luminosity. These sources have low surface density, and therefore large samples can be provided only through large area surveys, like the COSMOS survey. We analyze the X-ray properties of COSMOS MIPS sources with 24 μm fluxes higher than 550 μJy. For the MIPS sources not directly detected in the Chandra images, we produce stacked images in soft and hard X-rays bands. To estimate the fraction of Compton-thick AGN in the MIPS source population, we compare the observed stacked count rates and hardness ratios to those predicted by detailed Monte Carlo simulations, including both obscured AGN and star-forming galaxies. The volume density of Compton-thick QSOs (log L(2-10 keV) = 44-45 erg s-1, or logλL λ(5.8 μm) = 44.79-46.18 erg s-1 for a typical infrared to X-ray luminosity ratio) evaluated in this way is (4.8 ± 1.1) × 10-6 Mpc-3 in the redshift bin 1.2-2.2. This density is ∼44% of all X-ray-selected QSOs in the same redshift and luminosity bin, and it is consistent with the expectation of the most up-to-date AGN synthesis models for the cosmic X-ray background (Gilli et al. 2007). The density of lower luminosity Compton-thick AGNs (log L(2-10 keV) = 43.5-44) at z = 0.7-1.2 is (3.7 ± 1.1) × 10-5 Mpc-3, corresponding to ∼67% of X-ray-selected AGNs. The comparison between the fraction of infrared-selected, Compton-thick AGNs to the X-ray selected, unobscured, and moderately obscured AGNs at high and low luminosity suggests that Compton-thick AGNs follow a luminosity dependence similar to that discovered for Compton-thin AGNs, becoming relatively rarer at high luminosities. We estimate that the fraction of AGNs (unobscured, moderately obscured, and Compton thick) to the total MIPS source population is 49 ± 10%, a value significantly higher than that previously estimated at similar 24 μm fluxes. We discuss how our findings can constrain AGN feedback models.", keywords = "X-rays: diffuse background, galaxies: active, galaxies: high-redshift", author = "F. Fiore and S. Puccetti and M. Brusa and M. Salvato and G. Zamorani and T. Aldcroft and H. Aussel and H. Brunner and P. Capak and N. Cappelluti and F. Civano and A. Comastri and M. Elvis and C. Feruglio and A. Finoguenov and A. Fruscione and R. Gilli and G. Hasinger and A. Koekemoer and J. Kartaltepe and O. Ilbert and C. Impey and {Le Floc'H}, E. and S. Lilly and V. Mainieri and A. Martinez-Sansigre and McCracken, {H. J.} and N. Menci and A. Merloni and T. Miyaji and Sanders, {D. B.} and M. Sargent and E. Schinnerer and N. Scoville and J. Silverman and V. Smolcic and A. Steffen and P. Santini and Y. Taniguchi and D. Thompson and Trump, {J. R.} and C. Vignali and M. Urry and L. Yan", year = "2009", month = mar, day = "1", doi = "10.1088/0004-637X/693/1/447", language = "English (US)", volume = "693", pages = "447--462", journal = "Astrophysical Journal", issn = "0004-637X", publisher = "IOP Publishing Ltd.", number = "1", } TY - JOUR T1 - Chasing highly obscured QSOs in the cosmos field AU - Fiore, F. AU - Puccetti, S. AU - Brusa, M. AU - Salvato, M. AU - Zamorani, G. AU - Aldcroft, T. AU - Aussel, H. AU - Brunner, H. AU - Capak, P. AU - Cappelluti, N. AU - Civano, F. AU - Comastri, A. AU - Elvis, M. AU - Feruglio, C. AU - Finoguenov, A. AU - Fruscione, A. AU - Gilli, R. AU - Hasinger, G. AU - Koekemoer, A. AU - Kartaltepe, J. AU - Ilbert, O. AU - Impey, C. AU - Le Floc'H, E. AU - Lilly, S. AU - Mainieri, V. AU - Martinez-Sansigre, A. AU - McCracken, H. J. AU - Menci, N. AU - Merloni, A. AU - Miyaji, T. AU - Sanders, D. B. AU - Sargent, M. AU - Schinnerer, E. AU - Scoville, N. AU - Silverman, J. AU - Smolcic, V. AU - Steffen, A. AU - Santini, P. AU - Taniguchi, Y. AU - Thompson, D. AU - Trump, J. R. AU - Vignali, C. AU - Urry, M. AU - Yan, L. PY - 2009/3/1 Y1 - 2009/3/1 N2 - A large population of heavily obscured, Compton-thick active galactic nuclei (AGNs) is predicted by AGN synthesis models for the cosmic X-ray background and by the "relic" supermassive black hole mass function measured from local bulges. However, even the deepest X-ray surveys are inefficient to search for these elusive AGNs. Alternative selection criteria, combining mid-infrared with near-infrared, and optical photometry, have instead been successful in pinpointing a large population of Compton-thick AGNs. We take advantage of the deep Chandra and Spitzer coverage of a large area (more than 10 times the area covered by the Chandra deep fields, CDFs) in the Cosmic Evolution Survey (COSMOS) field to extend the search of highly obscured, Compton-thick active nuclei to higher luminosity. These sources have low surface density, and therefore large samples can be provided only through large area surveys, like the COSMOS survey. We analyze the X-ray properties of COSMOS MIPS sources with 24 μm fluxes higher than 550 μJy. For the MIPS sources not directly detected in the Chandra images, we produce stacked images in soft and hard X-rays bands. To estimate the fraction of Compton-thick AGN in the MIPS source population, we compare the observed stacked count rates and hardness ratios to those predicted by detailed Monte Carlo simulations, including both obscured AGN and star-forming galaxies. The volume density of Compton-thick QSOs (log L(2-10 keV) = 44-45 erg s-1, or logλL λ(5.8 μm) = 44.79-46.18 erg s-1 for a typical infrared to X-ray luminosity ratio) evaluated in this way is (4.8 ± 1.1) × 10-6 Mpc-3 in the redshift bin 1.2-2.2. This density is ∼44% of all X-ray-selected QSOs in the same redshift and luminosity bin, and it is consistent with the expectation of the most up-to-date AGN synthesis models for the cosmic X-ray background (Gilli et al. 2007). The density of lower luminosity Compton-thick AGNs (log L(2-10 keV) = 43.5-44) at z = 0.7-1.2 is (3.7 ± 1.1) × 10-5 Mpc-3, corresponding to ∼67% of X-ray-selected AGNs. The comparison between the fraction of infrared-selected, Compton-thick AGNs to the X-ray selected, unobscured, and moderately obscured AGNs at high and low luminosity suggests that Compton-thick AGNs follow a luminosity dependence similar to that discovered for Compton-thin AGNs, becoming relatively rarer at high luminosities. We estimate that the fraction of AGNs (unobscured, moderately obscured, and Compton thick) to the total MIPS source population is 49 ± 10%, a value significantly higher than that previously estimated at similar 24 μm fluxes. We discuss how our findings can constrain AGN feedback models. AB - A large population of heavily obscured, Compton-thick active galactic nuclei (AGNs) is predicted by AGN synthesis models for the cosmic X-ray background and by the "relic" supermassive black hole mass function measured from local bulges. However, even the deepest X-ray surveys are inefficient to search for these elusive AGNs. Alternative selection criteria, combining mid-infrared with near-infrared, and optical photometry, have instead been successful in pinpointing a large population of Compton-thick AGNs. We take advantage of the deep Chandra and Spitzer coverage of a large area (more than 10 times the area covered by the Chandra deep fields, CDFs) in the Cosmic Evolution Survey (COSMOS) field to extend the search of highly obscured, Compton-thick active nuclei to higher luminosity. These sources have low surface density, and therefore large samples can be provided only through large area surveys, like the COSMOS survey. We analyze the X-ray properties of COSMOS MIPS sources with 24 μm fluxes higher than 550 μJy. For the MIPS sources not directly detected in the Chandra images, we produce stacked images in soft and hard X-rays bands. To estimate the fraction of Compton-thick AGN in the MIPS source population, we compare the observed stacked count rates and hardness ratios to those predicted by detailed Monte Carlo simulations, including both obscured AGN and star-forming galaxies. The volume density of Compton-thick QSOs (log L(2-10 keV) = 44-45 erg s-1, or logλL λ(5.8 μm) = 44.79-46.18 erg s-1 for a typical infrared to X-ray luminosity ratio) evaluated in this way is (4.8 ± 1.1) × 10-6 Mpc-3 in the redshift bin 1.2-2.2. This density is ∼44% of all X-ray-selected QSOs in the same redshift and luminosity bin, and it is consistent with the expectation of the most up-to-date AGN synthesis models for the cosmic X-ray background (Gilli et al. 2007). The density of lower luminosity Compton-thick AGNs (log L(2-10 keV) = 43.5-44) at z = 0.7-1.2 is (3.7 ± 1.1) × 10-5 Mpc-3, corresponding to ∼67% of X-ray-selected AGNs. The comparison between the fraction of infrared-selected, Compton-thick AGNs to the X-ray selected, unobscured, and moderately obscured AGNs at high and low luminosity suggests that Compton-thick AGNs follow a luminosity dependence similar to that discovered for Compton-thin AGNs, becoming relatively rarer at high luminosities. We estimate that the fraction of AGNs (unobscured, moderately obscured, and Compton thick) to the total MIPS source population is 49 ± 10%, a value significantly higher than that previously estimated at similar 24 μm fluxes. We discuss how our findings can constrain AGN feedback models. KW - X-rays: diffuse background KW - galaxies: active KW - galaxies: high-redshift UR - http://www.scopus.com/inward/record.url?scp=66149186353&partnerID=8YFLogxK UR - http://www.scopus.com/inward/citedby.url?scp=66149186353&partnerID=8YFLogxK U2 - 10.1088/0004-637X/693/1/447 DO - 10.1088/0004-637X/693/1/447 M3 - Article AN - SCOPUS:66149186353 VL - 693 SP - 447 EP - 462 JO - Astrophysical Journal JF - Astrophysical Journal SN - 0004-637X IS - 1 ER - Powered by Pure, Scopus & Elsevier Fingerprint Engine™ © 2022 Elsevier B.V We use cookies to help provide and enhance our service and tailor content. By continuing you agree to the use of cookies Log in to Pure About web accessibility Contact us
