arXiv subjects

Matthew J. Holman

Publications and source records attributed to Matthew J. Holman.

167 records · Page 10Linked to original sources

arXiv2004

The Dynamical Influence of a Planet at Semimajor Axis 3.4 AU on the Dust Around Epsilon Eridani

Precise-Doppler experiments suggest that a massive (m sin i=0.86 M_J) planet orbits at semimajor axis a=3.4 AU around Epsilon Eridani, a nearby star with a massive debris disk. The dynamical perturbations from such a planet would mold the distribution of dust around this star. We numerically integrated the orbits of dust grains in this system to predict the central dust cloud structure. For a supply of grains that begin in low-inclination, low-eccentricity orbits at 15 AU, the primary feature of the dust distribution is a pair of dense clumps, containing dust particles trapped in mean-motion resonances of the form n:1. These clumps appear to revolve around the star once every two planet revolutions. Future observations with the IRAM Plateau de Bure Interferometer, the SMA, or ALMA could detect these clumps, confirming the existence of the planet and revealing its location.

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arXiv2004

Near-Infrared Photometry of Irregular Satellites of Jupiter and Saturn

We present JHKs photometry of 10 Jovian and 4 Saturnian irregular satellites, taken with the Near-InfraRed Imager (NIRI) at the 8-m Gemini North Observatory on Mauna Kea, Hawaii. The observed objects have near-infrared colors consistent with C, P and D-type asteroids, although J XII Ananke and S IX Phoebe show weak indications of possible water features in the H filter. The four members of the Himalia-family have similar near-infrared colors, as do the two members of the Gallic family, S XX Paaliaq and S XXIX Siarnaq. From low resolution normalized reflectance spectra based on the broadband colors and covering 0.4 to 2.2 microns, the irregular satellites are identified as C-type (J VII Pasiphae, J VI Himalia and S IX Phoebe), P-type (J XII Ananke and J XVIII Themisto) and D-type (J IX Carme and J X Sinope), showing a diversity of origins of these objects.

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arXiv2004

KH 15D: Gradual Occultation of a Pre-Main-Sequence Binary

We propose that the extraordinary ``winking star'' KH 15D is an eccentric pre-main-sequence binary that is gradually being occulted by an opaque screen. This model accounts for the periodicity, depth, duration, and rate of growth of the modern eclipses; the historical light curve from photographic plates; and the existing radial velocity measurements. It also explains the re-brightening events that were previously observed during eclipses, and the subsequent disappearance of these events. We predict the future evolution of the system and its full radial velocity curve. Given the small velocity of the occulting screen relative to the center of mass of the binary, the screen is probably associated with the binary, and may be the edge of a precessing circumbinary disk.

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arXiv2003

The Geometry of Resonant Signatures in Debris Disks with Planets

Using simple geometrical arguments, we paint an overview of the variety of resonant structures a single planet with moderate eccentricity (e < ~0.6) can create in a dynamically cold, optically thin dust disk. This overview may serve as a key for interpreting images of perturbed debris disks and inferring the dynamical properties of the planets responsible for the perturbations. We compare the resonant geometries found in the solar system dust cloud with observations of dust clouds around Vega and other stars and we discuss a new model for the asymmetries in the Epsilon Eridani cloud.

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arXiv2003

Photometric Survey of the Irregular Satellites

We present BVRI colors of 13 Jovian and 8 Saturnian irregular satellites obtained with the 2.56m Nordic Optical Telescope on La Palma, the 6.5m Magellan Baade Telescope on La Campanas, and the 6m MMT on Mt. Hopkins. The observations were performed between December 2001 to March 2002. Nearly all of the known irregular satellites can be divided into two distinct classes based on their colors. One, the grey color class, has the similar colors to the C-type asteroid, and the other, the light red color class, has colors similar to P/D-type asteroids. We also find at least one object, the Jovian irregular J XXIII Kalyke, that has colors similar to the red colored Centaurs/TNOs, although its classification is unsecure. We also find that there is a correlation between the physical properties and dynamical properties of the irregular satellites. Most of the dynamical clusters have homogeneous colors, which points to single homogeneous progenitors being cratered or fragmented as the source of each individual cluster. The heterogeneous colored clusters are most easily explained by assuming that there are several dynamical clusters in the area, rather than just one.

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