UNVEILING THE MASK ON THE ULIRG-TO-QSO TRANSITION OBJECT [H89]1821+643 AT z = 0.3: A GAS-POOR/GAS-RICH GALAXY MERGER AND THE IMPLICATIONS FOR CO-BASED DYNAMICAL MASS ESTIMATES
- National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States)
- European Southern Observatory, Alonso de Cordoba 3107, Vitacura, Casilla 19001, Santiago 19 (Chile)
- Argelander Institute for Astronomy, Auf dem Huegel 71, Bonn D-53121 (Germany)
We report the detection of the {sup 12}CO J = 1-0 emission line in [H89]1821+643, one of the most optically luminous quasi-stellar objects (QSOs) in the local universe, and a template ULIRG-to-QSO transition object, located in a rich, cool-core cluster at z = 0.297. The CO emission is likely to be extended, highly asymmetric with respect to the center of the host elliptical where the QSO resides, and correspond with a molecular gas mass of {approx}8.0 x 10{sup 9} M{sub sun}. The dynamical mass enclosed by the CO emission-line region could amount to {approx}1.7 x 10{sup 12} M{sub sun} (80% of the total mass of the elliptical host). The bulk of the CO emission is located at {approx}9 kpc southeast from the nuclei position, close to a faint optical structure, suggesting that the CO emission could either represent a gas-rich companion galaxy merging with the elliptical host or a tail-like structure reminiscent of a previous interaction. We argue that the first scenario is more likely given the large masses implied by the CO source, which would imply a highly asymmetric elliptical host. The close alignment between the CO emission's major axis and the radio plume suggests a possible role in the excitation of the ambient gas reservoir by the latter. The stacking technique was used to search for CO emission and 3-mm continuum emission from galaxies in the surrounding cluster. However, no detection was found toward individual galaxies or the stacked ensemble of galaxies, with a 3{sigma} limit of <1.1 x 10{sup 9} M{sub sun} for the molecular gas.
- OSTI ID:
- 21579946
- Journal Information:
- Astrophysical Journal, Vol. 737, Issue 2; Other Information: DOI: 10.1088/0004-637X/737/2/64; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
Similar Records
THE QSO HE 0450-2958: SCANTILY DRESSED OR HEAVILY ROBED? A NORMAL QUASAR AS PART OF AN UNUSUAL ULIRG
A DEEP HUBBLE SPACE TELESCOPE H-BAND IMAGING SURVEY OF MASSIVE GAS-RICH MERGERS. II. THE QUEST QSOs