Probing the Uniformity of the Local Sheet Environment (PULSE)

Fingerhut, Robin L.; McCall, Marshall L.; Vaduvescu, Ovidiu
Bibliographical reference

NOAO Proposal ID #2006A-0528

Advertised on:
2
2006
Number of authors
3
IAC number of authors
0
Citations
0
Refereed citations
0
Description
Essentially all galaxies within roughly 4 Mpc of the Milky Way are confined to a thin sheet-like structure, here referred to as the ``Local Sheet''. Our perspective from within a structure like those seen on much larger scales provides us with unique opportunities to search for environmental imprints on constituent galaxies. Clues about the nature of the Sheet environment may come from the systematics of dwarf irregular galaxies as a function of height above or below the Sheet's midplane, where the galaxy density is highest. Of particular interest are the baryonic masses, gas fractions, optical-NIR colours and the relationship between the metallicity and the gas fraction. All of these diagnostics require photometry in the near-infrared, where light is most sensitive to the old stellar populations dominating the luminous mass. We are therefore conducting an imaging survey of dwarf irregular galaxies in the Sheet in K'. We are requesting 1 full night and 2 half nights with CTIO ISPI to complete the Southern portion of our survey.