skip to main content

Title: VARIABILITY OF DISK EMISSION IN PRE-MAIN SEQUENCE AND RELATED STARS. III. EXPLORING STRUCTURAL CHANGES IN THE PRE-TRANSITIONAL DISK IN HD 169142

We present near-IR (NIR) and far-UV observations of the pre-transitional (gapped) disk in HD 169142 using NASA's Infrared Telescope Facility and Hubble Space Telescope. The combination of our data along with existing data sets into the broadband spectral energy distribution reveals variability of up to 45% between ∼1.5-10 μm over a maximum timescale of 10 yr. All observations known to us separate into two distinct states corresponding to a high near-IR state in the pre-2000 epoch and a low state in the post-2000 epoch, indicating activity within the ≲1 AU region of the disk. Through analysis of the Pa β and Br γ lines in our data we derive a mass accretion rate in 2013 May of M-dot ≈ (1.5-2.7) × 10{sup –9} M {sub ☉} yr{sup –1}. We present a theoretical modeling analysis of the disk in HD 169142 using Monte-Carlo radiative transfer simulation software to explore the conditions and perhaps signs of planetary formation in our collection of 24 yr of observations. We find that shifting the outer edge (r ≈ 0.3 AU) of the inner disk by 0.05 AU toward the star (in simulation of accretion and/or sculpting by forming planets) successfully reproduces the shift in NIR flux. We establish thatmore » the ∼40-70 AU dark ring imaged in the NIR by Quanz et al. and Momose et al. and at 7 mm by Osorio et al. may be reproduced with a 30% scaled density profile throughout the region, strengthening the link to this structure being dynamically cleared by one or more planetary mass bodies.« less
Authors:
; ; ; ; ;  [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [7] ;  [8] ; ;  [9] ;  [10] ;  [11] ;  [12] ;  [13] ;  [14]
  1. Department of Physics, University of Cincinnati, Cincinnati, OH 45221 (United States)
  2. Eureka Scientific, 2452 Delmer, Suite 100, Oakland, CA 96002 (United States)
  3. Department of Astronomy, University of Wisconsin, 475 North CharterStreet, Madison, WI 53706-1582 (United States)
  4. The Aerospace Corporation, Los Angeles, CA 90009 (United States)
  5. Steward Observatory, 933 North Cherry Avenue, University of Arizona, Tucson, AZ 85721 (United States)
  6. Ibaraki University, 310-0056 Ibaraki, Mito, Bunkyo, 11 (Japan)
  7. Kogakuin University, 1-24-2 Nishishinjuku, Shinjuku, Tokyo 163-8677 (Japan)
  8. Osaka Sangyo University, College of General Education, 3-1-1 Nakagaito, Daito, Osaka 574-8530 (Japan)
  9. University of Louisville Research Foundation, Inc., 2301 South 3rd Street, Louisville, KY 40292 (United States)
  10. Center for Astrophysics and Space Astronomy, Astrophysics Research Laboratory, 593 UCB, University of Colorado, Boulder, CO 80309-0593 (United States)
  11. Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1, Machikaneyama, Toyonaka, Osaka 560-0043 (Japan)
  12. Oak Ridge Associated Universities, 100 ORAU Way, Oak Ridge, TN 37830-6218 (United States)
  13. University of Oklahoma, 660 Parrington Oval, Norman, OK 73019 (United States)
  14. NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States)
Publication Date:
OSTI Identifier:
22364646
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 798; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPUTER CODES; DENSITY; ENERGY SPECTRA; FAR ULTRAVIOLET RADIATION; IMAGES; MASS; MONTE CARLO METHOD; NEAR INFRARED RADIATION; PLANETS; PROTOPLANETS; PROTOSTARS; RADIANT HEAT TRANSFER; STAR ACCRETION; STAR EVOLUTION; TELESCOPES