The Vertical Structure of the Outer Milky Way HI Disk

Abstract

We examine the outer Galactic HI disk for deviations from the b=0 plane by constructing maps of disk surface density, mean height, and thickness. We find that the Galactic warp is well described by a vertical offset plus two Fourier modes of frequency 1 and 2, all of which grow with Galactocentric radius. Adding the m=2 mode accounts for the large asymmetry between the northern and southern warps. We use a Morlet wavelet transform to investigate the spatial and frequency localization of higher frequency modes; these modes are often referred to as "scalloping." We find that the m=10 and 15 scalloping modes are well above the noise, but localized; this suggests that the scalloping does not pervade the whole disk, but only local regions.

Accepted by ApJ. 17 pages, 18 figures. Color maps are available at http://astron.berkeley.edu/~elevine

References in corpus (9)

• The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI: Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections
• The Distribution of Nearby Stars in Velocity Space Inferred from Hipparcos Data
• Neutral Hydrogen and Optical Observations of Edge-on Galaxies: Hunting for Warps
• Warps and Cosmic Infall
• A high sensitivity HI survey of the sky at delta < -25 deg Final data release
• A Magellanic Origin for the Warp of the Galaxy
• Generation of galactic disc warps due to intergalactic accretion flows onto the disc
• The Persistence of Warps in Spiral Galaxies with Massive Halos
• On the origin of warps and the role of the intergalactic medium

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