Infrared Excess in the Be Star Delta Scorpii

Abstract

We present infrared photometric observations of the Be binary system delta Scorpii obtained in 2006. The J,H and K magnitudes are the same within the errors compared to observations taken 10 months earlier. We derive the infrared excess from the observation and compare this to the color excess predicted by a radiative equilibrium model of the primary star and its circumstellar disk. We use a non-LTE computational code to model the gaseous envelope concentrated in the star's equatorial plane and calculate the expected spectral energy distribution and Halpha emission profile of the star with its circumstellar disk. Using the observed infrared excess of delta Sco, as well as Halpha spectroscopy bracketing the IR observations in time, we place constraints on the radial density distribution in the circumstellar disk. Because the disk exhibits variability in its density distribution, this work will be helpful in understanding its dynamics.

12 pages, 14 figures, to be published in PASP May 2008

References in corpus (8)

• Be-star rotation: how close to critical?
• Remarks on statistical errors in equivalent widths
• The Thermal Structure of the Circumstellar Disk Surrounding the Classical Be Star gamma Cassiopeia
• Properties of the $\delta$ Scorpii Circumstellar Disk from Continuum Modeling
• Spectroscopic Observations of the Delta Scorpii Binary during Its Recent Periastron Passage
• Achernar: Rapid Polarization Variability as Evidence of Photospheric and Circumstellar Activity
• The Orbit of the Binary Star Delta Scorpii
• Be stars: one ring to rule them all?

Cited by in corpus (4)

• The Revised Orbit of the Delta Sco System
• Spectro-interferometry of the Be star delta Sco: Near-Infrared Continuum and Gas Emission Region Sizes in 2007
• Photoionization Models for the Inner Gaseous Disks of Herbig Be Stars: Evidence Against Magnetospheric Accretion?
• Photoionization Models of the Inner Gaseous Disk of the Herbig Be Star BD+65 1637