CO LINE EMISSION FROM COMPACT NUCLEAR STARBURST DISKS AROUND ACTIVE GALACTIC NUCLEI

Journal Article · Wed Jun 20 04:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/752/2/87· OSTI ID:22037044

Armour, J N

There is substantial evidence for a connection between star formation in the nuclear region of a galaxy and growth of the central supermassive black hole. Furthermore, starburst activity in the region around an active galactic nucleus (AGN) may provide the obscuration required by the unified model of AGNs. Molecular line emission is one of the best observational avenues to detect and characterize dense, star-forming gas in galactic nuclei over a range of redshift. This paper presents predictions for the carbon monoxide (CO) line features from models of nuclear starburst disks around AGNs. These small-scale ({approx}< 100 pc), dense and hot starbursts have CO luminosities similar to scaled-down ultra-luminous infrared galaxies and quasar host galaxies. Nuclear starburst disks that exhibit a pc-scale starburst and could potentially act as the obscuring torus show more efficient CO excitation and higher brightness temperature ratios than those without such a compact starburst. In addition, the compact starburst models predict strong absorption when J{sub Upper} {approx}> 10, a unique observational signature of these objects. These findings allow for the possibility that CO spectral line energy distributions (SLEDs) could be used to determine if starburst disks are responsible for the obscuration in z {approx}< 1 AGNs. Directly isolating the nuclear CO line emission of such compact regions around AGNs from galactic-scale emission will require high-resolution imaging or selecting AGN host galaxies with weak galactic-scale star formation. Stacking individual CO SLEDs will also be useful in detecting the predicted high-J features.

• OSTI ID: 22037044
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 752; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABSORPTION
ACCRETION DISKS
ASTRONOMY
ASTROPHYSICS
BLACK HOLES
BRIGHTNESS
CARBON MONOXIDE
ENERGY SPECTRA
EXCITATION
GALAXIES
GALAXY NUCLEI
LUMINOSITY
PHOTON EMISSION
QUASARS
RED SHIFT
STARS
UNIFIED MODEL