The suppression of star formation by powerful active galactic nuclei.

Average star formation rates, (SFR), derived from averaged far-infrared luminosities of 1<z<3 AGNs, as a function of suLX.
Average star formation rates, (SFR), derived from averaged far-infrared luminosities of 1<z<3 AGNs, as a function of suLX.
Advertised on
References
2012, Natur.,485,213

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 results from the AGN quenching the surrounding star formation as it approaches its peak luminosity. X-rays trace emission from AGN unambiguously, whereas powerful star-forming galaxies are usually dust-obscured and are brightest at infrared and submillimetre wavelengths. 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 1044 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, expelling the interstellar medium of its host and transforming the galaxy's properties in a brief period of cosmic time.

News type
Research news

It may interest you

  • Spectra obtained with ESPRESSO, corresponding to three different transitions in an absorbing system at z=1.15 towards the quasar HE0515-4414, compared with previous spectra on the same object obtained with the UVES and HARPS spectrographs, at lower spectral resolution.
    Research news
    Testing fundamental physics with ESPRESSO

    Many of the most basic and important physical phenomena are determined by a set of “fundamental constants”, whose values are experimentally known to high accuracy. A key aspect is to know whether they are “universal constants”, i.e., whether they have always had the same value across the Universe and throughout its history. Here we made use of data from the ESPRESSO spectrograph on the Very Large Telescope (VLT) in order to determine the value of the fine structure constant 8 thousand million years ago (when the Universe was just 40% its current age) by measuring spectral transitions in a

    Advertised on
  • Background is a Hubble Space Telescope image of the relic galaxy, NGC 1277 (Credits: NASA, ESA, M. Beasley, and P. Kehusmaa). Bottom-left shows the H-band spectrum of the relic galaxy, NGC 1277, obtained with the EMIR spectrograph (middle) at Gran Telescopio Canarias (left) (Credits: pictures of GTC and EMIR are from GTC website).
    Research news
    New insights into the puzzle of strong CO absorptions in massive early-type galaxies

    Puzzling properties of massive early-type galaxies (ETGs) emerge when studying their spectra at near-infrared (NIR) wavelengths. Massive ETGs show strong CO absorption features in their H and K band spectra that cannot be explained by state-of-the-art stellar population models. For many years, the disagreement has been attributed to the presence of intermediate-age (0.1-2 Gyr) stellar populations in these galaxies, as the NIR light of intermediate-age stellar populations is dominated by cool stars (e.g. asymptotic giant branch (AGB) stars) that show strong CO absorptions in their spectrum

    Advertised on
  • Artistic impression of the BL Lac nucleus. The particle jet emerging from the black-hole follows the spiral structure of the magnetic field. In the inset the brightness variations are shown as observed in red light (2020, August).
    Research news
    Rapid quasi-periodic oscillations in a relativistic jet

    Active galactic nuclei (AGN) consist of a supermassive black hole fed by the circumnuclear material close to the galaxy center. Around 10% of the AGNs develop a pair of jets that are launched to the interstellar medium at speed close to velocity of light. Blazars are observed when one of the jets points very close to our line of sight, which produce an extraordinary boosting of the emission by relativistic effects. Jets produce electromagnetic emission that varies rapidly and covers from radio waves to gamma rays. The observed light is mostly random without an apparent pattern. The source BL

    Advertised on