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Title: A Complete ALMA Map of the Fomalhaut Debris Disk

Abstract

We present ALMA mosaic observations at 1.3 mm (223 GHz) of the Fomalhaut system with a sensitivity of 14 μ Jy/beam. These observations provide the first millimeter map of the continuum dust emission from the complete outer debris disk with uniform sensitivity, enabling the first conclusive detection of apocenter glow. We adopt an MCMC modeling approach that accounts for the eccentric orbital parameters of a collection of particles within the disk. The outer belt is radially confined with an inner edge of 136.3 ± 0.9 au and width of 13.5 ± 1.8 au. We determine a best-fit eccentricity of 0.12 ± 0.01. Assuming a size distribution power-law index of q = 3.46 ± 0.09, we constrain the dust absorptivity power-law index β to be 0.9 < β < 1.5. The geometry of the disk is robustly constrained with inclination 65.°6 ± 0.°3, position angle 337.°9 ± 0.°3, and argument of periastron 22.°5 ± 4.°3. Our observations do not confirm any of the azimuthal features found in previous imaging studies of the disk with Hubble Space Telescope , SCUBA, and ALMA. However, we cannot rule out structures ≤10 au in size or that only affect smaller grains. The central star ismore » clearly detected with a flux density of 0.75 ± 0.02 mJy, significantly lower than predicted by current photospheric models. We discuss the implications of these observations for the directly imaged Fomalhaut b and the inner dust belt detected at infrared wavelengths.« less

Authors:
;  [1]; ; ; ;  [2]; ; ;  [3];  [4];  [5]; ;  [6];  [7];  [8];  [9];  [10];  [11]
  1. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
  2. Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom)
  3. Astronomy Department, University of California, Berkeley CA 94720-3411 (United States)
  4. MIT Department of Earth, Atmospheric, and Planetary Sciences, Cambridge, MA 02139 (United States)
  5. Department of Astronomy, Van Vleck Observatory, Wesleyan University, Middletown, CT 06459 (United States)
  6. Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States)
  7. NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)
  8. Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095 (United States)
  9. UK Astronomy Technology Centre, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom)
  10. (United Kingdom)
  11. School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT (United Kingdom)
Publication Date:
OSTI Identifier:
22663249
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 842; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTIVITY; BEAMS; DETECTION; DISTRIBUTION; DUSTS; EMISSION; FLUX DENSITY; GHZ RANGE; INCLINATION; SENSITIVITY; SIMULATION; SPACE; STARS; TELESCOPES; WAVELENGTHS

Citation Formats

MacGregor, Meredith A., Wilner, David J., Matrà, Luca, Kennedy, Grant M., Wyatt, Mark C., Shannon, Andrew, Kalas, Paul, Duchene, Gaspard, Graham, James R., Pan, Margaret, Hughes, A. Meredith, Rieke, George H., Su, Kate, Clampin, Mark, Fitzgerald, Michael P., Holland, Wayne S., Institute for Astronomy, Royal Observatory, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, and Panić, Olja. A Complete ALMA Map of the Fomalhaut Debris Disk. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA71AE.
MacGregor, Meredith A., Wilner, David J., Matrà, Luca, Kennedy, Grant M., Wyatt, Mark C., Shannon, Andrew, Kalas, Paul, Duchene, Gaspard, Graham, James R., Pan, Margaret, Hughes, A. Meredith, Rieke, George H., Su, Kate, Clampin, Mark, Fitzgerald, Michael P., Holland, Wayne S., Institute for Astronomy, Royal Observatory, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, & Panić, Olja. A Complete ALMA Map of the Fomalhaut Debris Disk. United States. doi:10.3847/1538-4357/AA71AE.
MacGregor, Meredith A., Wilner, David J., Matrà, Luca, Kennedy, Grant M., Wyatt, Mark C., Shannon, Andrew, Kalas, Paul, Duchene, Gaspard, Graham, James R., Pan, Margaret, Hughes, A. Meredith, Rieke, George H., Su, Kate, Clampin, Mark, Fitzgerald, Michael P., Holland, Wayne S., Institute for Astronomy, Royal Observatory, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, and Panić, Olja. Sat . "A Complete ALMA Map of the Fomalhaut Debris Disk". United States. doi:10.3847/1538-4357/AA71AE.
@article{osti_22663249,
title = {A Complete ALMA Map of the Fomalhaut Debris Disk},
author = {MacGregor, Meredith A. and Wilner, David J. and Matrà, Luca and Kennedy, Grant M. and Wyatt, Mark C. and Shannon, Andrew and Kalas, Paul and Duchene, Gaspard and Graham, James R. and Pan, Margaret and Hughes, A. Meredith and Rieke, George H. and Su, Kate and Clampin, Mark and Fitzgerald, Michael P. and Holland, Wayne S. and Institute for Astronomy, Royal Observatory, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ and Panić, Olja},
abstractNote = {We present ALMA mosaic observations at 1.3 mm (223 GHz) of the Fomalhaut system with a sensitivity of 14 μ Jy/beam. These observations provide the first millimeter map of the continuum dust emission from the complete outer debris disk with uniform sensitivity, enabling the first conclusive detection of apocenter glow. We adopt an MCMC modeling approach that accounts for the eccentric orbital parameters of a collection of particles within the disk. The outer belt is radially confined with an inner edge of 136.3 ± 0.9 au and width of 13.5 ± 1.8 au. We determine a best-fit eccentricity of 0.12 ± 0.01. Assuming a size distribution power-law index of q = 3.46 ± 0.09, we constrain the dust absorptivity power-law index β to be 0.9 < β < 1.5. The geometry of the disk is robustly constrained with inclination 65.°6 ± 0.°3, position angle 337.°9 ± 0.°3, and argument of periastron 22.°5 ± 4.°3. Our observations do not confirm any of the azimuthal features found in previous imaging studies of the disk with Hubble Space Telescope , SCUBA, and ALMA. However, we cannot rule out structures ≤10 au in size or that only affect smaller grains. The central star is clearly detected with a flux density of 0.75 ± 0.02 mJy, significantly lower than predicted by current photospheric models. We discuss the implications of these observations for the directly imaged Fomalhaut b and the inner dust belt detected at infrared wavelengths.},
doi = {10.3847/1538-4357/AA71AE},
journal = {Astrophysical Journal},
number = 1,
volume = 842,
place = {United States},
year = {Sat Jun 10 00:00:00 EDT 2017},
month = {Sat Jun 10 00:00:00 EDT 2017}
}