A massive molecular gas reservoir in the z = 2.221 type-2 quasar host galaxy SMM J0939+8315 lensed by the radio galaxy 3C220.3

Journal Article · Sat Feb 20 04:00:00 EST 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/818/2/196· OSTI ID:22886997

Leung, T. K. Daisy

We report the detection of CO(J = 3 → 2) line emission in the strongly lensed submillimeter galaxy (SMG) SMM J0939+8315 at z = 2.221, using the Combined Array for Research in Millimeter-wave Astronomy. SMM J0939+8315 hosts a type-2 quasar, and is gravitationally lensed by the radio galaxy 3C220.3 and its companion galaxy at z = 0.685. The 104 GHz continuum emission underlying the CO line is detected toward 3C220.3 with an integrated flux density of S{sub cont} = 7.4 ± 1.4 mJy. Using the CO(J = 3 → 2) line intensity of I{sub CO(3-2)} = (12.6 ± 2.0) Jy km s{sup −1}, we derive a lensing- and excitation-corrected CO line luminosity of L{sub CO(1−0)}{sup ′} = (3.4 ± 0.7) × 10{sup 10} (10.1/μ{sub L}) K km s{sup −1} pc{sup 2} for the SMG, where μ{sub L} is the lensing magnification factor inferred from our lens modeling. This translates to a molecular gas mass of M{sub gas} = (2.7 ± 0.6) × 10{sup 10} (10.1/μ{sub L}) M{sub ⊙}. Fitting spectral energy distribution models to the (sub)-millimeter data of this SMG yields a dust temperature of T = 63.1{sub −1.3}{sup +1.1} K, a dust mass of M{sub dust} = (5.2 ± 2.1) × 10{sup 8} (10.1/μ{sub L}) M{sub ⊙}, and a total infrared luminosity of L{sub IR} = (9.1 ± 1.2) ×10{sup 12} (10.1/μ{sub L}) L{sub ⊙}. We find that the properties of the interstellar medium of SMM J0939+8315 overlap with both SMGs and type-2 quasars. Hence, SMM J0939+8315 may be transitioning from a starbursting phase to an unobscured quasar phase as described by the “evolutionary link” model, according to which this system may represent an intermediate stage in the evolution of present-day galaxies at an earlier epoch.

• OSTI ID: 22886997
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 818; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United Kingdom
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTRONOMY
CARBON MONOXIDE
COMPUTERIZED SIMULATION
COSMIC DUST
COSMOLOGY
DETECTION
EMISSION
ENERGY SPECTRA
EXCITATION
FLUX DENSITY
GALACTIC EVOLUTION
GRAVITATIONAL LENSES
LUMINOSITY
MASS
QUASARS
RADIO GALAXIES
RED SHIFT