ALMA Observations of the Debris Disk around the Young Solar Analog HD 107146
Abstract
We present the Atacama Large Millimeter/submillimeter Array (ALMA) continuum observations at a wavelength of 1.25 mm of the debris disk surrounding the ~100 Myr old solar analog HD 107146. The continuum emission extends from about 30 to 150 AU from the central star with a decrease in the surface brightness at intermediate radii. We analyze the ALMA interferometric visibilities using debris disk models with radial profiles for the dust surface density parameterized as (1) a single power law, (2) a single power law with a gap, and (3) a double power law. We find that models with a gap of radial width ~8 AU at a distance of ~80 AU from the central star, as well as double power-law models with a dip in the dust surface density at ~70 AU provide significantly better fits to the ALMA data than single power-law models. We discuss possible scenarios for the origin of the HD 107146 debris disk using models of planetesimal belts in which the formation of Pluto-sized objects trigger disruptive collisions of large bodies, as well as models that consider the interaction of a planetary system with a planetesimal belt and spatial variation of the dust opacity across the disk. If future observations with higher angular resolution and sensitivity confirm the fully depleted gap structure discussed here, a planet with a mass of approximately a few Earth masses in a nearly circular orbit at ~80 AU from the central star would be a possible explanation for the presence of the gap.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 2015
- DOI:
- 10.1088/0004-637X/798/2/124
- arXiv:
- arXiv:1410.8265
- Bibcode:
- 2015ApJ...798..124R
- Keywords:
-
- circumstellar matter;
- planets and satellites: formation;
- stars: individual: HD 107146;
- submillimeter: stars;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- (38 pages, 7 figures, accepted for publication in ApJ)