The Arecibo Pisces Perseus Supercluster Survey (APPSS) is an HI survey measuring galaxy infall into the filament and clusters. Galaxies were selected for HI observations based on their location within the Pisces Perseus supercluster and SDSS and GALEX colors predictive of cold gas content. Most of the HI observations were conducted at Arecibo using the L Band Wide receiver, with some high-declination coverage provided by Green Bank. The observations provide increased sensitivity compared to ALFALFA blind survey data. For this project, we investigated a subset of 132 APPSS galaxies with declinations near 27 degrees. Using custom data reduction and analysis tools developed for the Undergraduate ALFALFA Team, we determined the following information for galaxies in our subset: systemic velocity, line width, integrated flux density, HI mass, and gas fraction (or corresponding limits for non-detections). We calculate our HI detection fraction and mean gas fraction as a function of stellar mass and compare to previous results. We investigate the distribution of systemic velocities for our galaxies with their location on the sky. Finally, we discuss several interesting sources from our subset of APPSS galaxies. This work has been supported by NSF grants AST-1211005, AST-1637299, and AST-1637339
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Is Cold Gas Removed from Galaxies in Filaments and Tendrils?
We present results from an ALFALFA HI study to examine whether the cold gas reservoirs of galaxies are inhibited or enhanced in large-scale filaments, and we discuss implications for follow-up work using the new Arecibo Pisces-Perseus Supercluster survey (APPSS). From the ALFALFA survey, we find that the HI deficiency for galaxies in the range 10^8.5-10^10.5 solar masses decreases with distance from the filament spine, suggesting that galaxies are cut off from cold gas, possibly by heating or by dynamical detachment from the smaller-scale cosmic web. This contrasts with previous results for larger galaxies in the HI Parkes All-Sky Survey. We discuss the prospects for elucidating this apparent dependence on galaxy mass with data from the APPSS, which will extend to smaller masses. We also find that the most gas-rich galaxies at fixed local density and stellar mass are those in small, correlated ``tendril” structures within voids: although galaxies in tendrils are in significantly denser environments, on average, than galaxies in voids, they are not redder or more HI deficient. This work has been supported by NSF grants AST-1211005 and AST-1637339.
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- PAR ID:
- 10059752
- Date Published:
- Journal Name:
- American Astronomical Society, AAS Meeting
- Volume:
- 231
- Page Range / eLocation ID:
- 351.13
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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