HIGH-RESOLUTION NEAR-INFRARED SPECTROSCOPY OF HD 100546. II. ANALYSIS OF VARIABLE ROVIBRATIONAL CO EMISSION LINES

Journal Article · Sat Apr 20 04:00:00 EDT 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/767/2/159· OSTI ID:22126876

Brittain, Sean D.; Liskowsky, Joseph ^[1]; Najita, Joan R. ^[2]; Carr, John S. ^[3]; Troutman, Matthew R. ^[4]

---

1. Department of Physics and Astronomy, 118 Kinard Laboratory, Clemson University, Clemson, SC 29634 (United States)
2. National Optical Astronomy Observatory, 950 N. Cherry Ave., Tucson, AZ 85719 (United States)
3. Naval Research Laboratory, Code 7211, Washington, DC 20375 (United States)
4. Department of Physics and Astronomy, University of Missouri - St. Louis, St. Louis, MO 63121 (United States)

We present observations of rovibrational CO in HD 100546 from four epochs spanning 2003 January through 2010 December. We show that the equivalent widths of the CO lines vary during this time period with the v = 1-0 CO lines brightening more than the UV fluoresced lines from the higher vibrational states. While the spectroastrometric signal of the hot band lines remains constant during this period, the spectroastrometric signal of the v = 1-0 lines varies substantially. At all epochs, the spectroastrometric signals of the UV fluoresced lines are consistent with the signal one would expect from gas in an axisymmetric disk. In 2003, the spectroastrometric signal of the v = 1-0 P26 line was symmetric and consistent with emission from an axisymmetric disk. However, in 2006 there was no spatial offset of the signal detected on the red side of the profile, and in 2010 the spectroastrometric offset was yet more strongly reduced toward zero velocity. A model is presented that can explain the evolution of the equivalent width of the v = 1-0 P26 line and its spectroastrometric signal by adding to the system a compact source of CO emission that orbits the star near the inner edge of the disk. We hypothesize that such emission may arise from a circumplanetary disk orbiting a gas giant planet near the inner edge of the circumstellar disk. We discuss how this idea can be tested observationally and be distinguished from an alternative interpretation of random fluctuations in the disk emission.

• OSTI ID: 22126876
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 767; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABSORPTION SPECTROSCOPY
AXIAL SYMMETRY
CARBON MONOXIDE
EMISSION
INFRARED SPECTRA
ORBITS
PROTOPLANETS
SIGNALS
VIBRATIONAL STATES