Panchromatic Imaging of a Transitional Disk: The Disk of GM Aur in Optical and FUV Scattered Light

We have imaged GM Aur with HST, detected its disk in scattered light at 1400A and 1650A, and compared these with observations at 3300A, 5550A, 1.1 microns, and 1.6 microns. The scattered light increases at shorter wavelengths. The radial surface brightness profile at 3300A shows no evidence of the 24AU radius cavity that has been previously observed in sub-mm observations. Comparison with dust grain opacity models indicates the surface of the entire disk is populated with sub-micron grains. We have compiled an SED from 0.1 microns to 1 mm, and used it to constrain a model of the star+disk system that includes the sub-mm cavity using the Monte Carlo Radiative Transfer code by Barbara Whitney. The best-fit model image indicates that the cavity should be detectable in the F330W bandpass if the cavity has been cleared of both large and small dust grains, but we do not detect it. The lack of an observed cavity can be explained by the presence of sub-microns grains interior to the sub-mm cavity wall. We suggest one explanation for this which could be due to a planet of mass <9 Jupiter masses interior to 24 AU. A unique cylindrical structure is detected in the FUV data from the Advanced Camera for Surveys/Solar Blind Channel. It is aligned along the system semi-minor axis, but does not resemble an accretion-driven jet. The structure is limb-brightened and extends 190 +/- 35 AU above the disk midplane. The inner radius of the limb-brightening is 40 +/- 10 AU, just beyond the sub-millimeter cavity wall.Comment: 40 pages, 11 figures, 4 tables, accepted to Ap

Resolving the gap and AU-scale asymmetries in the pre-transitional disk of V1247 Orionis

Pre-transitional disks are protoplanetary disks with a gapped disk structure, potentially indicating the presence of young planets in these systems. In order to explore the structure of these objects and their gap-opening mechanism, we observed the pre-transitional disk V1247 Orionis using the Very Large Telescope Interferometer, the Keck Interferometer, Keck-II, Gemini South, and IRTF. This allows us spatially resolve the AU-scale disk structure from near- to mid-infrared wavelengths (1.5 to 13 {\mu}m), tracing material at different temperatures and over a wide range of stellocentric radii. Our observations reveal a narrow, optically-thick inner-disk component (located at 0.18 AU from the star) that is separated from the optically thick outer disk (radii >46 AU), providing unambiguous evidence for the existence of a gap in this pre-transitional disk. Surprisingly, we find that the gap region is filled with significant amounts of optically thin material with a carbon-dominated dust mineralogy. The presence of this optically thin gap material cannot be deduced solely from the spectral energy distribution, yet it is the dominant contributor at mid-infrared wavelengths. Furthermore, using Keck/NIRC2 aperture masking observations in the H, K', and L' band, we detect asymmetries in the brightness distribution on scales of about 15-40 AU, i.e. within the gap region. The detected asymmetries are highly significant, yet their amplitude and direction changes with wavelength, which is not consistent with a companion interpretation but indicates an inhomogeneous distribution of the gap material. We interpret this as strong evidence for the presence of complex density structures, possibly reflecting the dynamical interaction of the disk material with sub-stellar mass bodies that are responsible for the gap clearing.Comment: 16 pages, 17 Figures, accepted by Astrophysical Journa

Exile Vol. XL No. 1

38th Year Title Page by Carrie Horner \u2797 i Epigraph by Ezra Pound ii Table of Contents iii-iv Vertigo by Lisa Stillman \u2795 1 Departing Flight by Morgan Roper \u2794 2 Untitled by Lizzie Loud \u2795 3 Marietta by Craig McDonough \u2794 4 Interlaken by Kira A . Pollack \u2794 5 Why Nature Surprises Us by Josh Endicott \u2796 6-7 Untitled by Colin Mack \u2794 7 My Father by Matt Wanat \u2795 8 Legs In The Dust by Alison Stevens \u2795 9-11 Untitled by Lilly Streett \u2794 12 of cigarettes, saltwater and death... by Tricia B. Swearingen \u2794 13 Serendipity by Lizzie Lout \u2795 14 Untitled by Lilly Streett \u2794 15 Summer by Allison Lemieux \u2795 16 And the Rain Fell by Jeremy Aufrance \u2795 17-18 Main Street by Elise Gargarella \u2795 19 Füssen by Morgan Roper \u2794 20 Lightning on the Snow by Matt Wanat \u2795 21 A discussion of 12 year-old murders, of course by Jeremy Aufrance \u2795 22 Get your hands off my hat by Jamie Oliver \u2794 23 The Hero by Sara Sterling Ely \u2796 24-26 Punker Dave by Trevett Allen \u2795 27 still looking for the perfect line by ryan shafer \u2794 28-29 Untitled by Lizzie Loud \u2795 30 Civil War by Katherine Anne Campo \u2794 31 Disposable belief by ryan shafer \u2794 32-33 Schizophrenic Sylvia by Maria Mohiuddin \u2795 34 Excerpts from Revolutions, a novel by Marcu McLaughlin \u2794 35-36 Untitled by Keith Chapman \u2795 37 The Survivors by Kira A. Pollack \u2794 38 Days of Prophecy by Trey Dunham \u2794 39 Untitled by Carrie Horner \u2797 40 What to do by Christopher Harnish \u2794 41 Familiar Stranger by Lisa Stillman \u2795 42-46 Untitled by John Salter \u2797 47 On Meeting Emma by Allison Lemieux \u2795 48 Nude Figure by James Oliver \u2794 49 Tathagata by Leslie Dana Wells \u2794 50 On Fences and My Dogs by Christopher Harnish \u2794 51 Editorial Board 52 Cover, Kira Pollack \u2794 -iv Editorial decision is shared equally among the Editorial Board. -5

Extreme Asymmetry in the Disk of V1247 Ori

We present the first near-infrared scattered-light detection of the transitional disk around V1247 Ori, which was obtained using high-resolution polarimetric differential imaging observations with Subaru/HiCIAO. Our imaging in the H band reveals the disk morphology at separations of ~0.14"-0.86" (54-330 au) from the central star. The polarized intensity (PI) image shows a remarkable arc-like structure toward the southeast of the star, whereas the fainter northwest region does not exhibit any notable features. The shape of the arm is consistent with an arc of 0.28" $\pm$ 0.09" in radius (108 au from the star), although the possibility of a spiral arm with a small pitch angle cannot be excluded. V1247 Ori features an exceptionally large azimuthal contrast in scattered, polarized light; the radial peak of the southeastern arc is about three times brighter than the northwestern disk measured at the same distance from the star. Combined with the previous indication of an inhomogeneous density distribution in the gap at $\lesssim$46 au, the notable asymmetry in the outer disk suggests the presence of unseen companions and/or planet-forming processes ongoing in the arc.Comment: 21 pages, 5 figures, accepted for publication in PAS

Exile Vol. XL No. 2

38th Year Title Page by Carrie Horner \u2797 i Epigraph by Ezra Pound ii Table of Contents iii-iv Remembering Sundays by Allison Lemieux \u2795 1 Untitled by James Oliver \u2794 2 \u2778 Beige Chevy Malibu by Craig J. McDonough \u2794 3-4 Brushtown Road by Lelei Jennings \u2795 5 In Memoriam: River Phoenix, 1970-93 by Kirstin Rogers \u2794 6 Untitled by Kira Pollack \u2794 7 Checkmate by Kevin Nix \u2794 8 Anywhere in Ohio by Jen Hanysh \u2795 9 Untitled by Nicky Taylor \u2794 10 Under Your Influence by Katherine Anne Campo \u2794 11 Tulips by Tricia B. Swearingen \u2794 12 Untitled by Keith Chapman \u2795 12 December Storm by Erin Lott \u2796 13-19 On Meeting Phil Levine After a Reading at Denison University April 6, 1993 by Christopher Harnish \u2794 20 The 422 Bypass by Joel Husenits \u2795 21 Untitled by Ken Tyburski \u2794 22 Shakespeare\u27s Foreskin by Carey Christie \u2795 23 The Thaw by Chris Iven \u2794 24 The Rockbridge County Fair by Morgan Roper \u2794 25 Let it Drop Through by Carey Christie \u2795 26-27 Aladdin\u27s by Paul Rinkes \u2794 28-29 Untitled by Aileen Jones \u2794 30 The Tango by Hope Layne Morgan \u2794 31 Icarus by Carey Christine \u2795 32-33 fad by Jeremy Aufrance \u2795 34 Untitled by James Oliver \u2794 35 Desert Villanelle by Christopher Harnish \u2794 36 The Skull by Nicky Taylor \u2794 37 Rodeo Bar by Carl Jeffrey Boon \u2796 38 I, Mordred by Carey Christie \u2795 39-43 Between Centuries by Leslie Dana Wells \u2794 44-45 Untitled by Carrie Horner \u2797 45 Untitled by Alex Emmons \u2796 46 Coleridge\u27s Curse by Allison Lemieux \u2795 47 Untitled by Jenny Baker \u2794 48 five by Jeremy Aufrance \u2795 49 Untitled by James Oliver \u2794 50 Lobster Boy by Kirstin Rogers \u2794 51 Fire on the Mountain by Christopher Harnish \u2794 52-53 Yosemite by Morgan Roper \u2794 54 Untitled by Carrie Horner \u2797 54 Untitled by Ken Tyburski \u2794 55 Sleepless Nights Fades to Credits by Allison Lemieux \u2794 56 Dancing Days by Julie McDonald \u2794 57 Immobile by Adrienne Fair \u2796 58-59 Untitled by Kira Pollack \u2794 60 Dorm Fire by Lisa Marie Antonille \u2795 Untitled by Carrie Horner \u2797 61 The Book by Matt Wanat \u2795 62-63 Distance by Carl Jeffrey Boon \u2796 64 Untitled by Jenny Baker \u2794 65 Cover by Ken Tyburski \u2794 Editorial decision is shared equally among the Editorial Board. -6

Extreme Asymmetry in the Polarized Disk of V1247 Orionis *

We present the first near-infrared scattered-light detection of the transitional disk around V1247 Ori, which was obtained using high-resolution polarimetric differential imaging observations with Subaru/HiCIAO. Our imaging in the H band reveals the disk morphology at separations of 0.′′14–0.′′86 (54–330 au) from the central star. The polarized intensity (PI) image shows a remarkable arc-like structure toward the southeast of the star, whereas the fainter northwest region does not exhibit any notable features. The shape of the arm is consistent with an arc of 0.′′28 0.′′09 in radius (108 au from the star), although the possibility of a spiral arm with a small pitch angle cannot be excluded. V1247 Ori features an exceptionally large azimuthal contrast in scattered, polarized light; the radial peak of the southeastern arc is about three times brighter than the northwestern disk measured at the same distance from the star. Combined with the previous indication of an inhomogeneous density distribution in the gap at < 46 au, the notable asymmetry in the outer disk suggests the presence of unseen companions and/or planet-forming processes ongoing in the arc.This work is supported by MEXT KAKENHI Nos. 23103005. S.K. acknowledges support from an STFC Ernest Rutherford Fellowship (ST/J004030/1) and Marie Curie CIG grant (SH-06192)