Mapping Mass in the Local Universe

TL;DR

This paper discusses the 2MASS Tully-Fisher survey's efforts to map the distribution of matter in the local universe using peculiar velocities, aiming to improve sky coverage and understand the 'great attractor' region.

Contribution

The paper introduces the 2MTF survey, which enhances peculiar velocity measurements with better sky coverage and data quality, especially near the Galactic plane.

Findings

Initial data from over 300 hours of HI observations at GBT.

Progress on southern hemisphere observations with Parkes Telescope.

Preliminary results from the SFI++ peculiar velocity sample.

Abstract

We only see a small fraction of the matter in the universe, but the rest gives itself away by the impact of its gravity. Peculiar velocities have the potential to be a powerful tool to trace this matter however previous peculiar velocity surveys have struggled to meet their potential because of the large errors on individual measurements, poor statistics and uneven sky coverage. The 2MASS Tully-Fisher (2MTF) survey will make use of existing high quality rotations widths, new HI widths and 2MASS (2 Micron All-Sky Survey) photometry to measure Tully-Fisher distances/peculiar velocities for all bright inclined spirals in the 2MASS redshift survey (2MRS). This survey based on the 2MASS galaxy catalog will provide a qualitatively better sample. It will provide significant improvements in sky coverage especially near the plane of our Galaxy which crosses the poorly understood "great attractor" region. I will give a progress report on the 2MTF survey including a look at over 300 hours of HI observations from the Green Bank Telescope (GBT) and a report on ongoing southern hemisphere observations with the Parke s Radio Telescope. The new spiral I-band field (SFI++) sample is currently the best available peculiar velocity survey for use in the local universe. I will also report on some preliminary results from this sample.