MASSIVE GALAXIES IN COSMOS: EVOLUTION OF BLACK HOLE VERSUS BULGE MASS BUT NOT VERSUS TOTAL STELLAR MASS OVER THE LAST 9 Gyr?

Journal Article · Tue Dec 01 00:00:00 EST 2009 · Astrophysical Journal (Online)

DOI:https://doi.org/10.1088/0004-637X/706/2/L215· OSTI ID:21385100

Jahnke, Knud; Cisternas, Mauricio; Inskip, Katherine ^[1]; Bongiorno, Angela; Brusa, Marcella; Cappelluti, Nico; Merloni, Andrea ^[2]; Capak, Peter; Colbert, James; Riechers, Dominik; Salvato, Mara ^[3]; Civano, Francesca; Elvis, Martin ^[4]; Comastri, Andrea ^[5]; Hasinger, Guenther ^[6]; Ilbert, Olivier ^[7]; Impey, Chris ^[8]; Koekemoer, Anton M ^[9]; Lilly, Simon; Maier, Christian ^[10]

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1. Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany)
2. Max-Planck-Institut fuer Extraterrestrische Physik, Giessenbachstrasse, D-85741 Garching b. Muenchen (Germany)
3. California Institute of Technology, 1200 East California Boulevard, MC 249-17, Pasadena, CA 91125 (United States)
4. Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
5. INAF-Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy)
6. Max-Planck-Institut fuer Plasmaphysik, Boltzmanstrasse 2, D-85741 Garching (Germany)
7. Institute for Astronomy, 2680 Woodlawn Drive, University of Hawaii, Honolulu, HI 96822 (United States)
8. Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)
9. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
10. Department of Physics, ETH Zuerich, CH-8093 Zuerich (Switzerland)

We constrain the ratio of black hole (BH) mass to total stellar mass of type-1 active galactic nuclei (AGNs) in the COSMOS survey at 1 < z < 2. For 10 AGNs at mean redshift z approx 1.4 with both Hubble Space Telescope (HST)/ACS and HST/NICMOS imaging data, we are able to compute the total stellar mass M {sub *,total}, based on rest-frame UV-to-optical host galaxy colors which constrain mass-to-light ratios. All objects have virial M {sub BH} estimates available from the COSMOS Magellan/IMACS and zCOSMOS surveys. We find within errors zero difference between the M {sub BH}-M {sub *,total} relation at z approx 1.4 and the M {sub BH}-M {sub *,bulge} relation in the local universe. Our interpretation is (1) if our objects were purely bulge-dominated, the M {sub BH}-M {sub *,bulge} relation has not evolved since z approx 1.4. However, (2) since we have evidence for substantial disk components, the bulges of massive galaxies (M {sub *,total} = 11.1 +- 0.3 or log M {sub BH} approx 8.3 +- 0.2) must have grown over the last 9 Gyr predominantly by redistribution of the disk into the bulge mass. Since all necessary stellar mass exists in galaxies at z = 1.4, no star formation or addition of external stellar material is required, but only a redistribution, e.g., induced by minor and major merging or through disk instabilities. Merging, in addition to redistributing mass in the galaxy, will add both BH and stellar/bulge mass, but does not change the overall final M {sub BH}/M {sub *,bulge} ratio. Since the overall cosmic stellar and BH mass buildup trace each other tightly over time, our scenario of bulge formation in massive galaxies is independent of any strong BH feedback and means that the mechanism coupling BH and bulge mass until the present is very indirect.

• OSTI ID: 21385100
• Journal Information: Astrophysical Journal (Online), Vol. 706, Issue 2; Other Information: DOI: 10.1088/0004-637X/706/2/L215; ISSN 1538-4357
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
BLACK HOLES
GALACTIC EVOLUTION
GALAXIES
GALAXY NUCLEI
MASS
RED SHIFT
STARS
TELESCOPES
UNIVERSE
VISIBLE RADIATION
ELECTROMAGNETIC RADIATION
EVOLUTION
RADIATIONS