Detected Galaxies and Large Scale Structure in the Arecibo L-band Feed Array Zone of Avoidance Survey (ALFAZOA) - Observatoire de Paris Access content directly
Conference Papers Year : 2017

Detected Galaxies and Large Scale Structure in the Arecibo L-band Feed Array Zone of Avoidance Survey (ALFAZOA)

Patricia A. Henning
  • Function : Author
Monica Sanchez-Barrantes
  • Function : Author
Travis Mcintyre
  • Function : Author
Robert F. Minchin
  • Function : Author
Emmanuel Momjian
  • Function : Author
Zhon Butcher
  • Function : Author
Jessica L. Rosenberg
  • Function : Author
Stephen E. Schneider
  • Function : Author
Lister Staveley-Smith
  • Function : Author
Mpati Ramatsoku
  • Function : Author
Baerbel Koribalski
  • Function : Author
Brady Spears
  • Function : Author

Abstract

While large, systematic redshift surveys of galaxies have been conducted for decades, lack of information behind the Milky Way (the Zone of Avoidance) contributes uncertainty to our picture of dynamics in the local universe. Controversy persists for the dipole calculated from galaxy and redshift surveys compared to the CMB. Depth in redshift space is an issue, as is incomplete sky mapping, even of supposed all sky redshifts surveys. For instance, the wide-angle 2MASS Redshift Survey retains a gap of 5-8 deg around the Galactic plane. Fortunately, there is no ZOA at 21cm, except for velocities occupied by the Galaxy. This long-wavelength spectral line passes unimpeded through dust, and is unaffected by stellar confusion. With immediate redshift determination, a 21-cm survey produces a 3-dimensional map of the distribution of obscured galaxies which contain HI. It traces large-scale structure right across the Galactic Plane, and identifies obscured mass overdensities relevant to flow-field studies.ALFAZOA is a blind HI survey for galaxies behind the Milky Way covering more than 1000 square degrees of the Arecibo sky. It proceeds in two phases: shallow (completed) and deep (ongoing). The shallow survey (rms ~5-7 mJy) mapped the region within Galactic longitude l = 30 - 75 deg, and latitude b = -10 to +10 deg, detecting several hundred galaxies to about 12,000 km/s, tracing large-scale structure across the plane. The deep survey (rms ~1 mJy), in both the inner (Galactic longitude 30 - 75 deg and latitude plus/minus 2 deg) and outer (longitude 175 - 207 deg and latitude = +1 to -2 deg) Galaxy is ongoing, with detections reaching to 18,000 km/s. Analysis of detections to date, and large-scale structure mapped, will be presented.
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Dates and versions

obspm-04009816 , version 1 (01-03-2023)

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Patricia A. Henning, Monica Sanchez-Barrantes, Travis Mcintyre, Robert F. Minchin, Emmanuel Momjian, et al.. Detected Galaxies and Large Scale Structure in the Arecibo L-band Feed Array Zone of Avoidance Survey (ALFAZOA). American Astronomical Society, 2017, à renseigner, Unknown Region. ⟨obspm-04009816⟩
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