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Title: (Almost) Dark Galaxies in the ALFALFA Survey: Isolated H i-bearing Ultra-diffuse Galaxies

Abstract

We present a sample of 115 very low optical surface brightness, highly extended, H i-rich galaxies carefully selected from the ALFALFA survey that have similar optical absolute magnitudes, surface brightnesses, and radii to recently discovered “ultra-diffuse” galaxies (UDGs). However, these systems are bluer and have more irregular morphologies than other UDGs, are isolated, and contain significant reservoirs of H i. We find that while these sources have normal star formation rates for H i-selected galaxies of similar stellar mass, they have very low star formation efficiencies. We further present deep optical and H i-synthesis follow-up imaging of three of these H i-bearing ultra-diffuse sources. We measure H i diameters extending to ∼40 kpc, but note that while all three sources have large H i diameters for their stellar mass, they are consistent with the H i mass–H i radius relation. We further analyze the H i velocity widths and rotation velocities for the unresolved and resolved sources, respectively, and find that the sources appear to inhabit halos of dwarf galaxies. We estimate spin parameters, and suggest that these sources may exist in high spin parameter halos, and as such may be potential H i-rich progenitors to the ultra-diffuse galaxies observedmore » in cluster environments.« less

Authors:
; ;  [1];  [2];  [3];  [4];  [5];  [6];  [7]; ; ;  [8]
  1. Cornell Center for Astrophysics and Planetary Science, Space Sciences Building, Cornell University, Ithaca, NY 14853 (United States)
  2. International Centre for Radio Astronomy Research (ICRAR), University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia)
  3. Department of Physics and Astronomy, Union College, Schenectady, NY 12308 (United States)
  4. SKA South Africa Radio Astronomy Research Group, 3rd Floor, The Park, Park Road, Pinelands 7405 (South Africa)
  5. ASTRON, the Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA, Dwingeloo (Netherlands)
  6. Departamento de Física, Universidad de los Andes, Cra. 1 No. 18A-10, Edificio Ip, Bogotá (Colombia)
  7. Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States)
  8. Department of Astronomy, Indiana University, 727 East Third Street, Bloomington, IN 47405 (United States)
Publication Date:
OSTI Identifier:
22663465
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 842; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BEARINGS; BRIGHTNESS; EFFICIENCY; EVOLUTION; GALAXIES; MASS; ROTATION; SPIN; STARS; SURFACES; SYNTHESIS; VELOCITY

Citation Formats

Leisman, Lukas, Haynes, Martha P., Giovanelli, Riccardo, Janowiecki, Steven, Hallenbeck, Gregory, Józsa, Gyula, Adams, Elizabeth A. K., Neira, David Bernal, Cannon, John M., Janesh, William F., Rhode, Katherine L., and Salzer, John J.. (Almost) Dark Galaxies in the ALFALFA Survey: Isolated H i-bearing Ultra-diffuse Galaxies. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA7575.
Leisman, Lukas, Haynes, Martha P., Giovanelli, Riccardo, Janowiecki, Steven, Hallenbeck, Gregory, Józsa, Gyula, Adams, Elizabeth A. K., Neira, David Bernal, Cannon, John M., Janesh, William F., Rhode, Katherine L., & Salzer, John J.. (Almost) Dark Galaxies in the ALFALFA Survey: Isolated H i-bearing Ultra-diffuse Galaxies. United States. doi:10.3847/1538-4357/AA7575.
Leisman, Lukas, Haynes, Martha P., Giovanelli, Riccardo, Janowiecki, Steven, Hallenbeck, Gregory, Józsa, Gyula, Adams, Elizabeth A. K., Neira, David Bernal, Cannon, John M., Janesh, William F., Rhode, Katherine L., and Salzer, John J.. Tue . "(Almost) Dark Galaxies in the ALFALFA Survey: Isolated H i-bearing Ultra-diffuse Galaxies". United States. doi:10.3847/1538-4357/AA7575.
@article{osti_22663465,
title = {(Almost) Dark Galaxies in the ALFALFA Survey: Isolated H i-bearing Ultra-diffuse Galaxies},
author = {Leisman, Lukas and Haynes, Martha P. and Giovanelli, Riccardo and Janowiecki, Steven and Hallenbeck, Gregory and Józsa, Gyula and Adams, Elizabeth A. K. and Neira, David Bernal and Cannon, John M. and Janesh, William F. and Rhode, Katherine L. and Salzer, John J.},
abstractNote = {We present a sample of 115 very low optical surface brightness, highly extended, H i-rich galaxies carefully selected from the ALFALFA survey that have similar optical absolute magnitudes, surface brightnesses, and radii to recently discovered “ultra-diffuse” galaxies (UDGs). However, these systems are bluer and have more irregular morphologies than other UDGs, are isolated, and contain significant reservoirs of H i. We find that while these sources have normal star formation rates for H i-selected galaxies of similar stellar mass, they have very low star formation efficiencies. We further present deep optical and H i-synthesis follow-up imaging of three of these H i-bearing ultra-diffuse sources. We measure H i diameters extending to ∼40 kpc, but note that while all three sources have large H i diameters for their stellar mass, they are consistent with the H i mass–H i radius relation. We further analyze the H i velocity widths and rotation velocities for the unresolved and resolved sources, respectively, and find that the sources appear to inhabit halos of dwarf galaxies. We estimate spin parameters, and suggest that these sources may exist in high spin parameter halos, and as such may be potential H i-rich progenitors to the ultra-diffuse galaxies observed in cluster environments.},
doi = {10.3847/1538-4357/AA7575},
journal = {Astrophysical Journal},
number = 2,
volume = 842,
place = {United States},
year = {Tue Jun 20 00:00:00 EDT 2017},
month = {Tue Jun 20 00:00:00 EDT 2017}
}