John Carpenter

Executive Director, Owens Valley Radio Observatory
Department of Astronomy
California Institute of Technology
MC 249-17
Pasadena, CA 91125

Phone: (626)-395-4024
Office: 226 Cahill

  1. List of publications (pdf)
  2. Curriculum Vitae (pdf)
  3. CARMA

Recent Research

The Debris Disk Around HD 107146

My collaborators and I used ALMA to image the 1.3mm continuum emission around the star HD 107146. This star is only about 80-200 Myr old, and has a G2 V spectral type, and therefore is young solar type star. Confirming previous results with CARMA and the SMA, ALMA detected a broad disk that extends from approximately 30 to 150 . However, ALMA also revealed for the first time a local minimum in the dust surface density at a semimajor axis of 80 AU. If this is caused by a planet, it would require a planet with a few Earth masses. [paper]  [ADS]

Asymmetries in Transition Disks

We used ALMA to iamge the dust and molecular gas toward a sample of transition disks surrounding the stars SAO 206462 and SR 21. These ALMA observations resolve the dust-depleted disk cavities and extended gaseous disks, revealing large-scale asymmetries in the dust emission of both disks that may be caused by planetary systems. [paper]  [ADS]

Evolution of Primordial Disks

We used to ALMA to image the 880 micron continuum of 20 K- and M-type stars in the Upper Scorpius OB association (Upper Sco) that are surrounded by protoplanetary disks. These data were used to measure the dust content in disks around low-mass stars (0.1-1.6 Msun) at a stellar age of 5-11 Myr. Thirteen sources were detected in the dust continuum at > 3 sigma, with inferred dust masses between 0.3 and 52 Earth masses. The observations suggest the dust masses around solar type stars are about a factor of two lower in Upper Sco compared to 1-2&nbps;Myr regions (Taurus), and observations are underway to further determine the significance of this result. [paper]  [ADS]

Structure of the Orion Molecular Cloud

I am leading a collaboration to mosaic with CARMA the molecular clouds found in Orion and the North American Nebula. By combining the data with single dish images, we can recover both the large and small scale cloud structure. A preliminary image for a small portion of the Orion mosaic when combined with data from the Nobeyama Radio observatory is shown on the left.