The Shape of LITTLE THINGS Dwarf Galaxies DDO 46 and DDO 168: Understanding the stellar and gas kinematics
Megan C. Johnson, Deidre A. Hunter, Sarah Wood, Se-Heon Oh, Hong-Xin, Zhang, Kimberly A. Herrmann, and Stephen E. Levine

TL;DR
This study measures the stellar and gas kinematics of two dwarf galaxies, DDO 46 and DDO 168, revealing their thin disk structures through velocity dispersion and rotation speed analysis.
Contribution
It provides new kinematic measurements of DDO 46 and DDO 168, demonstrating their thin disk nature using detailed spectroscopic and HI data analysis.
Findings
Both galaxies have Vmax/sigma_z,0 values indicating thin disks.
DDO 46 has a Vmax of 77.4 km/s; DDO 168 has 67.4 km/s.
Results contrast with previous minor-to-major axis ratio studies.
Abstract
We present the stellar and gas kinematics of DDO 46 and DDO 168 from the LITTLE THINGS survey and determine their respective Vmax/sigma_z,0 values. We used the KPNO's 4-meter telescope with the Echelle spectrograph as a long-slit spectrograph. We acquired spectra of DDO 168 along four position angles by placing the slit over the morphological major and minor axes and two intermediate position angles. However, due to poor weather conditions during our observing run for DDO 46, we were able to extract only one useful data point from the morphological major axis. We determined a central stellar velocity dispersion perpendicular to the disk, sigma_z,0, of 13.5+/-8 km/s for DDO 46 and <sigma_z,0> of 10.7+/-2.9 km/s for DDO 168. We then derived the maximum rotation speed in both galaxies using the LITTLE THINGS HI data. We separated bulk motions from non-circular motions using a double…
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
Taxonomy
TopicsAstronomy and Astrophysical Research · Astronomical Observations and Instrumentation · Stellar, planetary, and galactic studies
