The gas-rich disk of HR 4049: A study of the infrared spectrum

Journal Article · Fri May 02 04:00:00 EDT 2014 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.4874061· OSTI ID:22280452

Malek, Sarah E. ^[1]; Cami, Jan ^[2]

---

1. Department of Physics and Astronomy, University of Western Ontario, London, ON N6A 3K7 (Canada)
2. Department of Physics and Astronomy, University of Western Ontario, London, ON N6A 3K7 Canada and SETI Institute, 189 Bernardo Avenue, Suite 100, Mountain View, CA 94034 (United States)

Here, we present a summary of our analyses of the mid-and near-infrared spectrum of the unusual evolved binary HR 4049. We f nd that the disk is massive (M > 8 × 10{sup −3} M{sub ⊙}), warm and radially extended. We also report some enrichment in {sup 17}O and {sup 18}O and a comparison of observations from Spitzer-IRS to those obtained by ISO-SWS 10 years earlier reveals that the CO{sub 2} f ux has more than doubled in this time, indicating active and ongoing chemical evolution in the circumbinary disk. Given the high column densities of the gas in the disk, we expect that the molecular gas plays a crucial role in the thermal properties of the circumbinary disk by allowing visible light to heat the dust and then trapping the IR photons emitted by the dust. This will result in higher temperatures and a more homogeneous temperature structure in the disk. Finally, we estimate a mass for the primary in HR 4049 which is too low for the star to have experienced a typical evolutionary path.

• OSTI ID: 22280452
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 1594; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTROPHYSICS
BINARY STARS
CARBON DIOXIDE
COMPARATIVE EVALUATIONS
COSMIC DUST
COSMIC PHOTONS
COSMOLOGY
DENSITY
INFRARED SPECTRA
MASS
OXYGEN 17
OXYGEN 18
STAR EVOLUTION
THERMODYNAMIC PROPERTIES
VISIBLE RADIATION