Timothy Rodigas Published a Paper on Debris Disks in The Astrophysical Journal This Month
Timothy J Rodigas, a DTM postdoctoral fellow, published a paper titled, "On the Morphology and Chemical Composition of the HR 4796A Debris Disk," in The Astrophysical Journal this month. The team of authors on the paper also included DTM Staff Scientist Alycia Weinberger.
|A ring of dusty debris around the star, using Carnegie’s Magellan Clay telescope. (Rodigas, DTM, 2014)
Abstract: We present the first resolved near infrared imagery of the transition disk Oph IRS 48 (WLY 2-48), which was recently observed with ALMA to have a strongly asymmetric sub-millimeter flux distribution. H-band polarized intensity images show a ∼60AU radius scattered light cavity with two pronounced arcs of emission, one from Northeast to Southeast and one smaller, fainter and more distant arc in the Northwest. K-band scattered light imagery reveals a similar morphology, but with a clear third arc along the Southwestern rim of the disk cavity. This arc meets the Northwestern arc at nearly a right angle, revealing the presence of a spiral arm or local surface brightness deficit in the disk, and explaining the East-West brightness asymmetry in the H-band data. We also present 0.8-5.4μm IRTF SpeX spectra of this object, which allow us to constrain the spectral class to A0±1 and measure a low mass accretion rate of 10−8.5M⊙/yr, both consistent with previous estimates. We investigate a variety of reddening laws in order to fit the mutliwavelength SED of Oph IRS 48 and find a best fit consistent with a younger, higher luminosity star than previous estimates.