HD 100453: An Evolutionary Link Between Protoplanetary Disks and Debris Disks
Abstract
We present a multi-wavelength examination of the disk and environment of the near-ZAMS Herbig Ae star HD 100453 A. Chandra ACIS-S imagery shows that the Herbig Ae star has Lx/Lbol and a pulse height spectrum similar to β Pic Moving Group early F stars, suggesting a similar magnetic field configuration and X-ray production in winds. The disk lacks the conspicuous Fe II emission and continuum seen in FUV spectra of actively accreting Herbig Ae stars, and FUSE, HST ACS FUV, and FEROS data suggest a 3σ upper limit on accretion rate of 4.0×10-10 Msolar yr-1. Weak, variable Hα and Brγ emission suggest low levels of intermittent accretion or contamination by stellar activity. We confirm that HD 100453 B is a common proper motion companion to HD 100453 A, with a spectral type of M4.0V-M4.5V, and derive an age of 14+/-4 Myr. It is likely the companion has truncated the circumprimary disk radius at less than ~50 AU, and we estimate the dust mass to be ~0.1 MJ. A sensitive upper limit to the CO J = 3-2 intensity indicates that the gas in the outer disk is likely optically thin. Assuming a [CO]/[H2] abundance of 1×10-4 and a depletion factor of 103, we find that the mass of cold molecular gas is less than ~0.33 MJ and that the gas-to-dust ratio is no more than ~4:1 in the outer disk.
- Publication:
-
15th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun
- Pub Date:
- February 2009
- DOI:
- 10.1063/1.3099134
- Bibcode:
- 2009AIPC.1094..409C
- Keywords:
-
- 97.10.Fy;
- 97.10.-q;
- 97.10.Gz;
- Circumstellar shells clouds and expanding envelopes;
- circumstellar masers;
- Stellar characteristics and properties;
- Accretion and accretion disks;
- circumstellar matter;
- stars;
- accretion disks