MAPPING H-BAND SCATTERED LIGHT EMISSION IN THE MYSTERIOUS SR21 TRANSITIONAL DISK

Journal Article · Wed Apr 10 04:00:00 EDT 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/767/1/10· OSTI ID:22167456

Follette, Katherine B.; Close, Laird ^[1]; Tamura, Motohide; Hashimoto, Jun; Kwon, Jungmi; Kandori, Ryo ^[2]; Whitney, Barbara ^[3]; Grady, Carol ^[4]; Andrews, Sean M. ^[5]; Wisniewski, John ^[6]; Brandt, Timothy D.; Dong, Ruobing ^[7]; Mayama, Satoshi ^[8]; Abe, Lyu ^[9]; Brandner, Wolfgang; Feldt, Markus ^[10]; Carson, Joseph ^[11]; Currie, Thayne ^[12]; Egner, Sebastian E. ^[13]; Goto, Miwa ^[14] ; others, and

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1. Steward Observatory, The University of Arizona, 933 N Cherry Ave, Tucson, AZ 85721 (United States)
2. National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)
3. Astronomy Department, University of Wisconsin-Madison, 475 N. Charter Street, Madison, WI 53706 (United States)
4. Eureka Scientific, 2452 Delmer, Suite 100, Oakland, CA 96002 (United States)
5. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
6. H.L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W Brooks St Norman, OK 73019 (United States)
7. Department of Astrophysical Sciences, Princeton University, NJ 08544 (United States)
8. The Center for the Promotion of Integrated Sciences, The Graduate University for Advanced Studies (Sokendai), Shonan International Village, Hayama-cho, Miura-gun, Kanagawa 240-0193 (Japan)
9. Laboratoire Lagrange, UMR7293, Universite de Nice-Sophia Antipolis, CNRS, Observatoire de la Cote d'Azur, F-06300 Nice (France)
10. Max Planck Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg (Germany)
11. Department of Physics and Astronomy, College of Charleston, 58 Coming St., Charleston, SC 29424 (United States)
12. Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street M5S 3H4, Toronto Ontario (Canada)
13. Subaru Telescope, 650 North Aohoku Place, Hilo, HI 96720 (United States)
14. Universitats-Sternwarte Munchen, Ludwig-Maximilians-Universitat, Scheinerstr. 1, D-81679 Munchen (Germany)

We present the first near infrared (NIR) spatially resolved images of the circumstellar transitional disk around SR21. These images were obtained with the Subaru HiCIAO camera, adaptive optics, and the polarized differential imaging technique. We resolve the disk in scattered light at H-band for stellocentric 0.''1 {<=} r {<=} 0.''6 (12 {approx}< r {approx}< 75 AU). We compare our results with previously published spatially resolved 880 {mu}m continuum Submillimeter Array images that show an inner r {approx}< 36 AU cavity in SR21. Radiative transfer models reveal that the large disk depletion factor invoked to explain SR21's sub-mm cavity cannot be 'universal' for all grain sizes. Even significantly more moderate depletions ({delta} = 0.1, 0.01 relative to an undepleted disk) than those that reproduce the sub-mm cavity ({delta} {approx} 10{sup -6}) are inconsistent with our H-band images when they are assumed to carry over to small grains, suggesting that surface grains scattering in the NIR either survive or are generated by whatever mechanism is clearing the disk midplane. In fact, the radial polarized intensity profile of our H-band observations is smooth and steeply inwardly-increasing (r {sup -3}), with no evidence of a break at the 36 AU sub-mm cavity wall. We hypothesize that this profile is dominated by an optically thin disk envelope or atmosphere component. We also discuss the compatibility of our data with the previously postulated existence of a sub-stellar companion to SR21 at r {approx} 10-20 AU, and find that we can neither exclude nor verify this scenario. This study demonstrates the power of multiwavelength imaging of transitional disks to inform modeling efforts, including the debate over precisely what physical mechanism is responsible for clearing these disks of their large midplane grains.

• OSTI ID: 22167456
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 767; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CAMERAS
CAVITIES
EMISSION
GRAIN SIZE
IMAGES
MAPPING
OPTICS
PROTOPLANETS
RADIANT HEAT TRANSFER
SCATTERING
SIMULATION
VISIBLE RADIATION
WALLS