The suppression of star formation by powerful active galactic nuclei

• Published in: Nature (London) 2012-05, Vol.485 (7397), p.213-216
• Main Authors: Page, M. J., Symeonidis, M., Vieira, J. D., Altieri, B., Amblard, A., Arumugam, V., Aussel, H., Babbedge, T., Blain, A., Bock, J., Boselli, A., Buat, V., Castro-Rodríguez, N., Cava, A., Chanial, P., Clements, D. L., Conley, A., Conversi, L., Cooray, A., Dowell, C. D., Dubois, E. N., Dunlop, J. S., Dwek, E., Dye, S., Eales, S., Elbaz, D., Farrah, D., Fox, M., Franceschini, A., Gear, W., Glenn, J., Griffin, M., Halpern, M., Hatziminaoglou, E., Ibar, E., Isaak, K., Ivison, R. J., Lagache, G., Levenson, L., Lu, N., Madden, S., Maffei, B., Mainetti, G., Marchetti, L., Nguyen, H. T., O’Halloran, B., Oliver, S. J., Omont, A., Panuzzo, P., Papageorgiou, A., Pearson, C. P., Pérez-Fournon, I., Pohlen, M., Rawlings, J. I., Rigopoulou, D., Riguccini, L., Rizzo, D., Rodighiero, G., Roseboom, I. G., Rowan-Robinson, M., Portal, M. Sánchez, Schulz, B., Scott, D., Seymour, N., Shupe, D. L., Smith, A. J., Stevens, J. A., Trichas, M., Tugwell, K. E., Vaccari, M., Valtchanov, I., Viero, M., Vigroux, L., Wang, L., Ward, R., Wright, G., Xu, C. K., Zemcov, M.
• Format: Article
• Language: English
• Subjects: 639/33/34; Accretion; Active and peculiar galaxies (including bl lacertae objects, blazars, seyfert galaxies, markarian galaxies, active galactic nuclei); Active galactic nuclei; Active galaxies; Astronomy; Astrophysics; Black holes (astronomy); Bulging; Cosmology and Extra-Galactic Astrophysics; Earth, ocean, space; Exact sciences and technology; Galaxies; Humanities and Social Sciences; letter; Luminosity; multidisciplinary; Observations; Quasars. Active or peculiar galaxies, objects, and systems; Science; Science (multidisciplinary); Sciences of the Universe; Star & galaxy formation; Star formation; Stars; Stars & galaxies; Stellar systems. Galactic and extragalactic objects and systems. The universe; Wavelengths; X-rays
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/nature11096

Observations at submillimetre and X-ray wavelengths show that rapid star formation was common in the host galaxies of active galactic nuclei when the Universe was 2–6 Gyr old, but that the most vigorous star formation is not observed around powerful black holes, thereby confirming a key prediction of models in which an active galactic nucleus expels the interstellar medium of its host galaxy. Star formation blocked by powerful black holes Radiation from active galactic nuclei (AGNs) outshines that produced by star formation at most wavelengths, but in the far-infrared to millimetre waveband AGNs emit comparatively little radiation in comparison with strongly star-forming galaxies. A combination of deep X-ray observations from the Chandra catalogue and submillimetre observations from the SPIRE instrument on the Herschel Space Observatory shows that rapid star formation was common in the host galaxies of AGNs when the Universe was between two billion and six billion years old, but that vigorous star formation is not seen around the more luminous black holes. This suppression of star formation in galaxies that host a powerful AGN is a key prediction of models in which the AGN expels the interstellar medium of its host galaxy when it becomes sufficiently powerful. The old, red stars that constitute the bulges of galaxies, and the massive black holes at their centres, are the relics of a period in cosmic history when galaxies formed stars at remarkable rates and active galactic nuclei (AGN) shone brightly as a result of accretion onto black holes. It is widely suspected, but unproved, that the tight correlation between the mass of the black hole and the mass of the stellar bulge 1 results from the AGN quenching the surrounding star formation as it approaches its peak luminosity 2 , 3 , 4 . X-rays trace emission from AGN unambiguously 5 , whereas powerful star-forming galaxies are usually dust-obscured and are brightest at infrared and submillimetre wavelengths 6 . Here we report submillimetre and X-ray observations that show that rapid star formation was common in the host galaxies of AGN when the Universe was 2–6 billion years old, but that the most vigorous star formation is not observed around black holes above an X-ray luminosity of 10 44 ergs per second. This suppression of star formation in the host galaxy of a powerful AGN is a key prediction of models in which the AGN drives an outflow 7 , 8 , 9 , expelling the interstellar medium of its host and transf