The mean star formation rate of X-ray selected active galaxies and its evolution from z ∼ 2.5

Results from PEP-Herschel

D. J. Rosario, P. Santini, D. Lutz, L. Shao, R. Maiolino, D. M. Alexander, B. Altieri, P. Andreani, H. Aussel, F. E. Bauer, S. Berta, A. Bongiovanni, William Nielsen Brandt, M. Brusa, J. Cepa, A. Cimatti, T. J. Cox, E. Daddi, D. Elbaz, A. Fontana & 20 others N. M. Förster Schreiber, R. Genzel, A. Grazian, E. Le Floch, B. Magnelli, V. Mainieri, H. Netzer, R. Nordon, I. Pérez Garcia, A. Poglitsch, P. Popesso, F. Pozzi, L. Riguccini, G. Rodighiero, M. Salvato, M. Sanchez-Portal, E. Sturm, L. J. Tacconi, I. Valtchanov, S. Wuyts

Research output: Contribution to journalArticle

173 Citations (Scopus)

Abstract

We study relationships between star-formation rate (SFR) and the accretion luminosity and nuclear obscuration of X-ray selected active galactic nuclei (AGNs) using a combination of deep far-infrared (FIR) and X-ray data in three key extragalactic survey fields (GOODS-South, GOODS-North and COSMOS), as part of the PACS Evolutionary Probe (PEP) program. The use of three fields with differing areas and depths enables us to explore trends between the global FIR luminosity of the AGN hosts and the luminosity of the active nucleus across 4.5 orders of magnitude in AGN luminosity (L AGN) and spanning redshifts from the Local Universe to z = 2.5. Using imaging from the Herschel/PACS instrument in 2-3 bands, we combine FIR detections and stacks of undetected objects to arrive at mean fluxes for subsamples in bins of redshift and X-ray luminosity. We constrain the importance of AGN-heated dust emission in the FIR and confirm that the majority of the FIR emission of AGNs is produced by cold dust heated by star-formation in their host galaxies. We uncover characteristic trends between the mean FIR luminosity (L 60) and accretion luminosity of AGNs, which depend both on L AGN and redshift. At low AGN luminosities, accretion and SFR are uncorrelated at all redshifts, consistent with a scenario where most low-luminosity AGNs are primarily fueled by secular processes in their host galaxies. At high AGN luminosities, a significant correlation is observed between L 60 and L AGN, but only among AGNs at low and moderate redshifts (z < 1). We interpret this observation as a sign of the increasing importance of major-mergers in driving both the growth of super-massive black holes (SMBHs) and global star-formation in their hosts at high AGN luminosities. We also find evidence that the enhancement of SFR in luminous AGNs weakens or disappears at high redshifts (z > 1) suggesting that the role of mergers is less important at these epochs. At all redshifts, we find essentially no relationship between L 60 and nuclear obscuration across five orders of magnitude in obscuring Hydrogen column density (N H), suggesting that various mechanisms are likely to be responsible for obscuring X-rays in active galaxies. We discuss a broad scenario which can account for these trends: one in which two different modes of AGN fueling operate in the low-and high-luminosity regimes of SMBH accretion. We postulate that the dominant mode of accretion among high-luminosity AGNs evolves with redshift. Our study, as well as a body of evidence from the literature and emerging knowledge about the properties of high redshift galaxies, supports this scenario.

Original languageEnglish (US)
Article numberA45
JournalAstronomy and Astrophysics
Volume545
DOIs
StatePublished - Sep 10 2012

Fingerprint

active galaxies
star formation rate
active galactic nuclei
probe
luminosity
probes
x rays
accretion
rate
occultation
galaxies
trends
dust
refueling
merger
field survey
axioms

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Rosario, D. J. ; Santini, P. ; Lutz, D. ; Shao, L. ; Maiolino, R. ; Alexander, D. M. ; Altieri, B. ; Andreani, P. ; Aussel, H. ; Bauer, F. E. ; Berta, S. ; Bongiovanni, A. ; Brandt, William Nielsen ; Brusa, M. ; Cepa, J. ; Cimatti, A. ; Cox, T. J. ; Daddi, E. ; Elbaz, D. ; Fontana, A. ; Förster Schreiber, N. M. ; Genzel, R. ; Grazian, A. ; Le Floch, E. ; Magnelli, B. ; Mainieri, V. ; Netzer, H. ; Nordon, R. ; Pérez Garcia, I. ; Poglitsch, A. ; Popesso, P. ; Pozzi, F. ; Riguccini, L. ; Rodighiero, G. ; Salvato, M. ; Sanchez-Portal, M. ; Sturm, E. ; Tacconi, L. J. ; Valtchanov, I. ; Wuyts, S. / The mean star formation rate of X-ray selected active galaxies and its evolution from z ∼ 2.5 : Results from PEP-Herschel. In: Astronomy and Astrophysics. 2012 ; Vol. 545.
@article{1ef70f4c91014fd9b48d9ffc08ac801c,
title = "The mean star formation rate of X-ray selected active galaxies and its evolution from z ∼ 2.5: Results from PEP-Herschel",
abstract = "We study relationships between star-formation rate (SFR) and the accretion luminosity and nuclear obscuration of X-ray selected active galactic nuclei (AGNs) using a combination of deep far-infrared (FIR) and X-ray data in three key extragalactic survey fields (GOODS-South, GOODS-North and COSMOS), as part of the PACS Evolutionary Probe (PEP) program. The use of three fields with differing areas and depths enables us to explore trends between the global FIR luminosity of the AGN hosts and the luminosity of the active nucleus across 4.5 orders of magnitude in AGN luminosity (L AGN) and spanning redshifts from the Local Universe to z = 2.5. Using imaging from the Herschel/PACS instrument in 2-3 bands, we combine FIR detections and stacks of undetected objects to arrive at mean fluxes for subsamples in bins of redshift and X-ray luminosity. We constrain the importance of AGN-heated dust emission in the FIR and confirm that the majority of the FIR emission of AGNs is produced by cold dust heated by star-formation in their host galaxies. We uncover characteristic trends between the mean FIR luminosity (L 60) and accretion luminosity of AGNs, which depend both on L AGN and redshift. At low AGN luminosities, accretion and SFR are uncorrelated at all redshifts, consistent with a scenario where most low-luminosity AGNs are primarily fueled by secular processes in their host galaxies. At high AGN luminosities, a significant correlation is observed between L 60 and L AGN, but only among AGNs at low and moderate redshifts (z < 1). We interpret this observation as a sign of the increasing importance of major-mergers in driving both the growth of super-massive black holes (SMBHs) and global star-formation in their hosts at high AGN luminosities. We also find evidence that the enhancement of SFR in luminous AGNs weakens or disappears at high redshifts (z > 1) suggesting that the role of mergers is less important at these epochs. At all redshifts, we find essentially no relationship between L 60 and nuclear obscuration across five orders of magnitude in obscuring Hydrogen column density (N H), suggesting that various mechanisms are likely to be responsible for obscuring X-rays in active galaxies. We discuss a broad scenario which can account for these trends: one in which two different modes of AGN fueling operate in the low-and high-luminosity regimes of SMBH accretion. We postulate that the dominant mode of accretion among high-luminosity AGNs evolves with redshift. Our study, as well as a body of evidence from the literature and emerging knowledge about the properties of high redshift galaxies, supports this scenario.",
author = "Rosario, {D. J.} and P. Santini and D. Lutz and L. Shao and R. Maiolino and Alexander, {D. M.} and B. Altieri and P. Andreani and H. Aussel and Bauer, {F. E.} and S. Berta and A. Bongiovanni and Brandt, {William Nielsen} and M. Brusa and J. Cepa and A. Cimatti and Cox, {T. J.} and E. Daddi and D. Elbaz and A. Fontana and {F{\"o}rster Schreiber}, {N. M.} and R. Genzel and A. Grazian and {Le Floch}, E. and B. Magnelli and V. Mainieri and H. Netzer and R. Nordon and {P{\'e}rez Garcia}, I. and A. Poglitsch and P. Popesso and F. Pozzi and L. Riguccini and G. Rodighiero and M. Salvato and M. Sanchez-Portal and E. Sturm and Tacconi, {L. J.} and I. Valtchanov and S. Wuyts",
year = "2012",
month = "9",
day = "10",
doi = "10.1051/0004-6361/201219258",
language = "English (US)",
volume = "545",
journal = "Astronomy and Astrophysics",
issn = "0004-6361",
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Rosario, DJ, Santini, P, Lutz, D, Shao, L, Maiolino, R, Alexander, DM, Altieri, B, Andreani, P, Aussel, H, Bauer, FE, Berta, S, Bongiovanni, A, Brandt, WN, Brusa, M, Cepa, J, Cimatti, A, Cox, TJ, Daddi, E, Elbaz, D, Fontana, A, Förster Schreiber, NM, Genzel, R, Grazian, A, Le Floch, E, Magnelli, B, Mainieri, V, Netzer, H, Nordon, R, Pérez Garcia, I, Poglitsch, A, Popesso, P, Pozzi, F, Riguccini, L, Rodighiero, G, Salvato, M, Sanchez-Portal, M, Sturm, E, Tacconi, LJ, Valtchanov, I & Wuyts, S 2012, 'The mean star formation rate of X-ray selected active galaxies and its evolution from z ∼ 2.5: Results from PEP-Herschel', Astronomy and Astrophysics, vol. 545, A45. https://doi.org/10.1051/0004-6361/201219258

The mean star formation rate of X-ray selected active galaxies and its evolution from z ∼ 2.5 : Results from PEP-Herschel. / Rosario, D. J.; Santini, P.; Lutz, D.; Shao, L.; Maiolino, R.; Alexander, D. M.; Altieri, B.; Andreani, P.; Aussel, H.; Bauer, F. E.; Berta, S.; Bongiovanni, A.; Brandt, William Nielsen; Brusa, M.; Cepa, J.; Cimatti, A.; Cox, T. J.; Daddi, E.; Elbaz, D.; Fontana, A.; Förster Schreiber, N. M.; Genzel, R.; Grazian, A.; Le Floch, E.; Magnelli, B.; Mainieri, V.; Netzer, H.; Nordon, R.; Pérez Garcia, I.; Poglitsch, A.; Popesso, P.; Pozzi, F.; Riguccini, L.; Rodighiero, G.; Salvato, M.; Sanchez-Portal, M.; Sturm, E.; Tacconi, L. J.; Valtchanov, I.; Wuyts, S.

In: Astronomy and Astrophysics, Vol. 545, A45, 10.09.2012.

Research output: Contribution to journalArticle

TY - JOUR

T1 - The mean star formation rate of X-ray selected active galaxies and its evolution from z ∼ 2.5

T2 - Results from PEP-Herschel

AU - Rosario, D. J.

AU - Santini, P.

AU - Lutz, D.

AU - Shao, L.

AU - Maiolino, R.

AU - Alexander, D. M.

AU - Altieri, B.

AU - Andreani, P.

AU - Aussel, H.

AU - Bauer, F. E.

AU - Berta, S.

AU - Bongiovanni, A.

AU - Brandt, William Nielsen

AU - Brusa, M.

AU - Cepa, J.

AU - Cimatti, A.

AU - Cox, T. J.

AU - Daddi, E.

AU - Elbaz, D.

AU - Fontana, A.

AU - Förster Schreiber, N. M.

AU - Genzel, R.

AU - Grazian, A.

AU - Le Floch, E.

AU - Magnelli, B.

AU - Mainieri, V.

AU - Netzer, H.

AU - Nordon, R.

AU - Pérez Garcia, I.

AU - Poglitsch, A.

AU - Popesso, P.

AU - Pozzi, F.

AU - Riguccini, L.

AU - Rodighiero, G.

AU - Salvato, M.

AU - Sanchez-Portal, M.

AU - Sturm, E.

AU - Tacconi, L. J.

AU - Valtchanov, I.

AU - Wuyts, S.

PY - 2012/9/10

Y1 - 2012/9/10

N2 - We study relationships between star-formation rate (SFR) and the accretion luminosity and nuclear obscuration of X-ray selected active galactic nuclei (AGNs) using a combination of deep far-infrared (FIR) and X-ray data in three key extragalactic survey fields (GOODS-South, GOODS-North and COSMOS), as part of the PACS Evolutionary Probe (PEP) program. The use of three fields with differing areas and depths enables us to explore trends between the global FIR luminosity of the AGN hosts and the luminosity of the active nucleus across 4.5 orders of magnitude in AGN luminosity (L AGN) and spanning redshifts from the Local Universe to z = 2.5. Using imaging from the Herschel/PACS instrument in 2-3 bands, we combine FIR detections and stacks of undetected objects to arrive at mean fluxes for subsamples in bins of redshift and X-ray luminosity. We constrain the importance of AGN-heated dust emission in the FIR and confirm that the majority of the FIR emission of AGNs is produced by cold dust heated by star-formation in their host galaxies. We uncover characteristic trends between the mean FIR luminosity (L 60) and accretion luminosity of AGNs, which depend both on L AGN and redshift. At low AGN luminosities, accretion and SFR are uncorrelated at all redshifts, consistent with a scenario where most low-luminosity AGNs are primarily fueled by secular processes in their host galaxies. At high AGN luminosities, a significant correlation is observed between L 60 and L AGN, but only among AGNs at low and moderate redshifts (z < 1). We interpret this observation as a sign of the increasing importance of major-mergers in driving both the growth of super-massive black holes (SMBHs) and global star-formation in their hosts at high AGN luminosities. We also find evidence that the enhancement of SFR in luminous AGNs weakens or disappears at high redshifts (z > 1) suggesting that the role of mergers is less important at these epochs. At all redshifts, we find essentially no relationship between L 60 and nuclear obscuration across five orders of magnitude in obscuring Hydrogen column density (N H), suggesting that various mechanisms are likely to be responsible for obscuring X-rays in active galaxies. We discuss a broad scenario which can account for these trends: one in which two different modes of AGN fueling operate in the low-and high-luminosity regimes of SMBH accretion. We postulate that the dominant mode of accretion among high-luminosity AGNs evolves with redshift. Our study, as well as a body of evidence from the literature and emerging knowledge about the properties of high redshift galaxies, supports this scenario.

AB - We study relationships between star-formation rate (SFR) and the accretion luminosity and nuclear obscuration of X-ray selected active galactic nuclei (AGNs) using a combination of deep far-infrared (FIR) and X-ray data in three key extragalactic survey fields (GOODS-South, GOODS-North and COSMOS), as part of the PACS Evolutionary Probe (PEP) program. The use of three fields with differing areas and depths enables us to explore trends between the global FIR luminosity of the AGN hosts and the luminosity of the active nucleus across 4.5 orders of magnitude in AGN luminosity (L AGN) and spanning redshifts from the Local Universe to z = 2.5. Using imaging from the Herschel/PACS instrument in 2-3 bands, we combine FIR detections and stacks of undetected objects to arrive at mean fluxes for subsamples in bins of redshift and X-ray luminosity. We constrain the importance of AGN-heated dust emission in the FIR and confirm that the majority of the FIR emission of AGNs is produced by cold dust heated by star-formation in their host galaxies. We uncover characteristic trends between the mean FIR luminosity (L 60) and accretion luminosity of AGNs, which depend both on L AGN and redshift. At low AGN luminosities, accretion and SFR are uncorrelated at all redshifts, consistent with a scenario where most low-luminosity AGNs are primarily fueled by secular processes in their host galaxies. At high AGN luminosities, a significant correlation is observed between L 60 and L AGN, but only among AGNs at low and moderate redshifts (z < 1). We interpret this observation as a sign of the increasing importance of major-mergers in driving both the growth of super-massive black holes (SMBHs) and global star-formation in their hosts at high AGN luminosities. We also find evidence that the enhancement of SFR in luminous AGNs weakens or disappears at high redshifts (z > 1) suggesting that the role of mergers is less important at these epochs. At all redshifts, we find essentially no relationship between L 60 and nuclear obscuration across five orders of magnitude in obscuring Hydrogen column density (N H), suggesting that various mechanisms are likely to be responsible for obscuring X-rays in active galaxies. We discuss a broad scenario which can account for these trends: one in which two different modes of AGN fueling operate in the low-and high-luminosity regimes of SMBH accretion. We postulate that the dominant mode of accretion among high-luminosity AGNs evolves with redshift. Our study, as well as a body of evidence from the literature and emerging knowledge about the properties of high redshift galaxies, supports this scenario.

UR - http://www.scopus.com/inward/record.url?scp=84865733603&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84865733603&partnerID=8YFLogxK

U2 - 10.1051/0004-6361/201219258

DO - 10.1051/0004-6361/201219258

M3 - Article

VL - 545

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

SN - 0004-6361

M1 - A45

ER -