TY - JOUR
T1 - Galaxy Structure in the Ultraviolet
T2 - The Dependence of Morphological Parameters on Rest-frame Wavelength
AU - Mager, Violet A.
AU - Conselice, Christopher J.
AU - Seibert, Mark
AU - Gusbar, Courtney
AU - Katona, Anthony P.
AU - Villari, Joseph M.
AU - Madore, Barry F.
AU - Windhorst, Rogier A.
N1 - Funding Information:
7 galex.stsci.edu/GR6 8 IRAF is distributed by the National Optical Astronomy Observatories, which are operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation.
Funding Information:
This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This research has also made use of NASA's Astrophysics Data System. The research was funded by NASA grant NNX09AF83G. R.A.W. is supported by NASA JWST Interdisciplinary Scientist grants NAG5-12460, NNX14AN10G, and 80NSSC18K0200 from GSFC.
Funding Information:
We thank the peer reviewer for the careful review of our paper. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This research has also made use of NASA’s Astrophysics Data System. The research was funded by NASA grant NNX09AF83G. R.A.W. is supported by NASA JWST Interdisciplinary Scientist grants NAG5-12460, NNX14AN10G, and 80NSSC18K0200 from GSFC. Facilities: GALEX, HST.
Publisher Copyright:
© 2018. The American Astronomical Society. All rights reserved.
PY - 2018/9/10
Y1 - 2018/9/10
N2 - Evolutionary studies that compare galaxy structure as a function of redshift are complicated by the fact that any particular galaxy's appearance depends in part on the rest-frame wavelength of the observation. This leads to the necessity for a "morphological k-correction" between different passbands, especially when comparing the rest-frame optical or infrared (IR) to the ultraviolet (UV). This is of particular concern for high-redshift studies that are conducted in the rest-frame UV. We investigate the effects of this "bandpass shifting" out of the UV by quantifying nearby galaxy structure via concentration, asymmetry, and clumpiness (CAS) parameters. For this study we combine panchromatic data from the UV through the near-IR with Galaxy Evolution Explorer (GALEX) data of 2073 nearby galaxies in the "near-UV" (NUV; ∼230 nm) and 1127 in the "far-UV" (FUV; ∼150 nm), providing the largest study of this kind in the mid- to far-UV. We find a relationship between the CAS parameters and observed rest-frame wavelength that make galaxies appear more late-type at shorter wavelengths, particularly in the UV. The effect is strongest for E/S0 galaxies in the far-UV, which have concentrations and asymmetries that more closely resemble those of spiral and peculiar/merging galaxies in the optical. This may be explained by extended disks containing recent star formation. Here, we also release the CAS values of the galaxies imaged in GALEX NUV and FUV for use in comparisons with deep Hubble Space Telescope imaging and the James Webb Space Telescope in the future.
AB - Evolutionary studies that compare galaxy structure as a function of redshift are complicated by the fact that any particular galaxy's appearance depends in part on the rest-frame wavelength of the observation. This leads to the necessity for a "morphological k-correction" between different passbands, especially when comparing the rest-frame optical or infrared (IR) to the ultraviolet (UV). This is of particular concern for high-redshift studies that are conducted in the rest-frame UV. We investigate the effects of this "bandpass shifting" out of the UV by quantifying nearby galaxy structure via concentration, asymmetry, and clumpiness (CAS) parameters. For this study we combine panchromatic data from the UV through the near-IR with Galaxy Evolution Explorer (GALEX) data of 2073 nearby galaxies in the "near-UV" (NUV; ∼230 nm) and 1127 in the "far-UV" (FUV; ∼150 nm), providing the largest study of this kind in the mid- to far-UV. We find a relationship between the CAS parameters and observed rest-frame wavelength that make galaxies appear more late-type at shorter wavelengths, particularly in the UV. The effect is strongest for E/S0 galaxies in the far-UV, which have concentrations and asymmetries that more closely resemble those of spiral and peculiar/merging galaxies in the optical. This may be explained by extended disks containing recent star formation. Here, we also release the CAS values of the galaxies imaged in GALEX NUV and FUV for use in comparisons with deep Hubble Space Telescope imaging and the James Webb Space Telescope in the future.
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U2 - 10.3847/1538-4357/aad59e
DO - 10.3847/1538-4357/aad59e
M3 - Article
AN - SCOPUS:85053458584
SN - 0004-637X
VL - 864
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 123
ER -