ALMA Detection of Extended Millimeter Halos in the HD 32297 and HD 61005 Debris Disks

Meredith A. Macgregor, Alycia J. Weinberger, A. Meredith Hughes, D. J. Wilner, Thayne Currie, John H. Debes, Jessica K. Donaldson, Seth Redfield, Aki Roberge, Glenn Schneider

Research output: Contribution to journalArticlepeer-review

37 Scopus citations


We present Atacama Large Millimeter/submillimeter Array (ALMA) 1.3 mm (230 GHz) observations of the HD 32297 and HD 61005 debris disks, two of the most iconic debris disks because of their dramatic swept-back wings seen in scattered light images. These observations achieve sensitivities of 14 and 13 μJy beam-1 for HD 32297 and HD 61005, respectively, and provide the highest resolution images of these two systems at millimeter wavelengths to date. By adopting a Markov Chain Monte Carlo modeling approach, we determine that both disks are best described by a two-component model consisting of a broad (ΔR/R > 0.4) planetesimal belt with a rising surface density gradient and a steeply falling outer halo aligned with the scattered light disk. The inner and outer edges of the planetesimal belt are located at 78.5 ± 8.1 au and 122 ± 3 au for HD 32297, and 41.9 ± 0.9 au and 67.0 ± 0.5 au for HD 61005. The halos extend to 440 ± 32 au and 188 ± 8 au, respectively. We also detect 12CO J = 2-1 gas emission from HD 32297 co-located with the dust continuum. These new ALMA images provide observational evidence that larger, millimeter-sized grains may also populate the extended halos of these two disks previously thought to only be composed of small, micron-sized grains. We discuss the implications of these results for potential shaping and sculpting mechanisms of asymmetric debris disks.

Original languageEnglish (US)
Article number75
JournalAstrophysical Journal
Issue number1
StatePublished - Dec 10 2018


  • circumstellar matter
  • stars: individual (HD 32297, HD 61005)
  • submillimeter: planetary systems

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'ALMA Detection of Extended Millimeter Halos in the HD 32297 and HD 61005 Debris Disks'. Together they form a unique fingerprint.

Cite this