J/ApJ/864/123 Morphological parameters of galaxies with GALEX (Mager+, 2018)
Galaxy structure in the ultraviolet: the dependence of morphological parameters
on rest-frame wavelength.
Mager V.A., Conselice C.J., Seibert M., Gusbar C., Katona A.P.,
Villari J.M., Madore B.F., Windhorst R.A.
<Astrophys. J., 864, 123 (2018)>
=2018ApJ...864..123M 2018ApJ...864..123M
ADC_Keywords: Galaxies, nearby; Morphology; Ultraviolet
Keywords: galaxies: evolution ; galaxies: structure
Abstract:
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; ∼230nm) and 1127 in the "far-UV" (FUV; ∼150nm),
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.
Description:
Our resolution-limited sample contains 2967 galaxies in the GALEX GR6
data release that have images in at least the NUV filter. Applying the
S/N cut (see section 2) reduced the sample to 2073 galaxies in NUV and
1127 galaxies in FUV.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 142 2073 High S/N measured concentration, asymmetry, and
clumpiness (CAS) parameters
table2.dat 142 1854 Low S/N measured CAS parameters
--------------------------------------------------------------------------------
See also:
II/312 : GALEX-DR5 (GR5) sources from AIS and MIS (Bianchi+ 2011)
II/335 : Revised catalog of GALEX UV sources (GUVcat_AIS GR6+7) (Bianchi+ 2017)
J/ApJS/147/1 : Classification of nearby galaxies (Conselice+, 2003)
J/ApJ/659/162 : CAS parameters of 199 nearby galaxies (Taylor-Mager+, 2007)
J/MNRAS/427/3159 : Quantified HI morphology. VI. NUV/FUV (Holwerda+, 2012)
J/MNRAS/435/623 : Multiwavelength measurement of galaxy structure (Vika, 2013)
J/MNRAS/436/34 : GALEX Arecibo SDSS survey. Final release (Catinella+, 2013)
J/MNRAS/464/3920 : GALEX/WISE early-type galaxies sample (Simonian+, 2017)
J/ApJS/234/18 : GALEX/S4G surface brightness profiles. I. (Bouquin+, 2018)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 23 A23 --- ID Galaxy identifier (1)
25- 36 F12.8 deg RAdeg Right Ascension in decimal degrees (J2000)
38- 49 F12.8 deg DEdeg Declination in decimal degrees (J2000)
51 I1 --- TType [1/5] Galaxy type (G1)
53- 57 F5.3 --- CNUV [0/5.4] GALEX NUV light concentration
59- 63 F5.3 --- e_CNUV [0/0.5] Uncertainty in CNUV
65- 70 F6.3 --- ANUV [-0.6/1.5] GALEX NUV deviation from
perfect symmetry
72- 76 F5.3 --- e_ANUV [0/0.3] Uncertainty in ANUV
78- 83 F6.3 --- SNUV [-0.8/1.4] GALEX NUV deviation from a
perfectly smooth light distribution
85- 89 F5.3 --- e_SNUV [0/0.05] Uncertainty in SNUV
91- 95 F5.3 --- CFUV [0/5.3]?=9.999 GALEX FUV light concentration
97-101 F5.3 --- e_CFUV [0.02/0.5]?=9.999 Uncertainty in CFUV
103-108 F6.3 --- AFUV [-4.5/1.6]?=9.999 GALEX FUV deviation from
perfect symmetry
110-114 F5.3 --- e_AFUV [0/0.6]?=9.999 Uncertainty in AFUV
116-121 F6.3 --- SFUV [-7.7/1.1]?=9.999 GALEX FUV deviation from
a perfectly smooth light distribution
123-127 F5.3 --- e_SFUV [0/0.09]?=9.999 Uncertainty in SFUV
129-135 F7.1 --- SNR-NUV [75/18230] Signal-to-Noise in NUV image
137-142 F6.1 --- SNR-FUV [0/8785] Signal-to-Noise in FUV image
--------------------------------------------------------------------------------
Note (1): All sources have signal-to-noise ratio S/NNUV≥75.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 23 A23 --- ID Galaxy identifier (1)
25- 36 F12.8 deg RAdeg Right Ascension in decimal degrees (J2000)
38- 49 F12.8 deg DEdeg Declination in decimal degrees (J2000)
51 I1 --- TType [1/5] Galaxy type (G1)
53- 57 F5.3 --- CNUV [0/5.5] GALEX NUV light concentration
59- 63 F5.3 --- e_CNUV [0/0.4] Uncertainty in CNUV
65- 70 F6.3 --- ANUV [-1.1/1.4] GALEX NUV deviation from
perfect symmetry
72- 76 F5.3 --- e_ANUV [0/0.4] Uncertainty in ANUV
78- 83 F6.3 --- SNUV [-1.4/1.4] GALEX NUV deviation from a
perfectly smooth light distribution
85- 89 F5.3 --- e_SNUV [0/0.05] Uncertainty in SNUV
91- 96 F6.3 --- CFUV [-0.2/7.1]?=9.999 GALEX FUV light concentration
98-102 F5.3 --- e_CFUV [0.02/0.5]?=9.999 Uncertainty in CFUV
104-109 F6.3 --- AFUV [-6/1.7]?=9.999 GALEX FUV deviation from
perfect symmetry
111-115 F5.3 --- e_AFUV [0/4]?=9.999 Uncertainty in AFUV
117-122 F6.3 --- SFUV [-3.7/2]?=9.999 GALEX FUV deviation from a
perfectly smooth light distribution
124-128 F5.3 --- e_SFUV [0/0.2]?=9.999 Uncertainty in SFUV
130-136 F7.1 --- SNR-NUV [6/12396] Signal-to-Noise in NUV image
138-142 F5.1 --- SNR-FUV [0/397] Signal-to-Noise in FUV image
--------------------------------------------------------------------------------
Note (1): All sources have signal-to-noise ratio S/N<75 in one or both
filters, which were rejected in our analysis. We advise against
using data with S/N<30 in structure and morphology studies.
--------------------------------------------------------------------------------
Global notes:
Note (G1): Type as follows:
1 = E-S0 (elliptical and lenticular);
2 = Sa-Sc ("early-type" spirals);
3 = Sd-Im ("late-type" spirals and irregulars);
4 = peculiar or merging. All galaxies that had a peculiar (pec) designation
in their classification were placed in this 4th type bin.
5 = Galaxies that could not be placed into any of these categories were
given no type (such as those without any classification listed in NED,
or non-specific classifications such as S?).
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 19-Aug-2019