J/MNRAS/427/3159 Quantified HI morphology. VI. NUV/FUV (Holwerda+, 2012)
Quantified HI morphology. VI. The morphology of extended discs in UV and HI.
Holwerda B.W., Pirzkal N., Heiner J.S.
<Mon. Not. R. Astron. Soc., 427, 3159-3175 (2012)>
=2012MNRAS.427.3159H 2012MNRAS.427.3159H
ADC_Keywords: Galaxies, nearby; H I data; Morphology
Keywords: galaxies: interactions - galaxies: ISM - galaxies: spiral -
galaxies: star formation - galaxies: statistics - galaxies: structure
Abstract:
Extended ultraviolet (XUV) discs have been found in a substantial
fraction of late-type - S0, spiral and irregular - galaxies.
Similarly, most late-type spirals have an extended gas disc,
observable in the 21-cm radio line (HI). The morphology of galaxies
can be quantified well using a series of scale-invariant parameters;
concentration-asymmetry-smoothness (CAS), Gini, M20, and GM
parameters. In this series of papers, we apply these to HI column
density maps to identify mergers and interactions, lopsidedness and
now XUV discs.
In this paper, we compare the quantified morphology and effective
radius (R50) of the Westerbork observations of neutral Hydrogen in
Irregular and SPiral galaxies Project (WHISP) HI maps to those of
far- and near-ultraviolet images obtained with GALEX, to explore how
close the morphology and scales of HI and UV in these discs correlate.
We find that XUV discs do not stand out by their effective radii in UV
or HI. However, the concentration index in far-ultraviolet (FUV)
appears to select some XUV discs. And known XUV discs can be
identified via a criterion using asymmetry and M20; 80 per cent of
XUV discs are included but with 55 per cent contamination. This
translates into 61 candidate XUV disc out of our 266 galaxies, 23 per
cent consistent with previous findings. Otherwise, the UV and HI
morphology parameters do not appear closely related.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 9 109 The WHISP galaxies identified by their
FUV M20-A relation
tablec1.dat 98 339 Values of morphological parameters in the HI
maps, regridded and scaled to GALEX pixel scale
tablec2.dat 98 339 Values of morphological parameters in the NUV
images, smoothed to the WHISP resolution
tablec3.dat 98 298 Values of morphological parameters in the FUV
images, smoothed to the WHISP resolution
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See also:
J/AJ/136/2563 : HI Nearby Galaxy Survey, THINGS (Walter+, 2008)
J/A+A/442/137 : HI observations of WHISP disk galaxies (Noordermeer+, 2005)
J/MNRAS/416/2401 : Quantified H I morphology. I (Holwerda+, 2011)
J/MNRAS/416/2415 : Quantified H I morphology. II (Holwerda+, 2011)
J/MNRAS/416/2437 : Quantified H I morphology. IV (Holwerda+, 2011)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- UGC [79/12754] UGC number
7- 9 A3 --- Class [01/2 -] Thilker et al. XUV classification
(2007, J/ApJS/173/538) (1)
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Note (1): XUV classification:
1 = show structured, UV-bright emission complexes beyond
the anticipated location of the star formation threshold
2 = have blue (FUV-NIR) color within an exceptionally large,
outer and optically-LSB portion of the disk
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Byte-by-byte Description of file: tablec1.dat tablec2.dat tablec3.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- UGC [79/12754] Galaxy UGC number
7- 11 F5.3 --- Gini [0/1]?=- Gini parameter
13- 17 F5.3 --- e_Gini ?=- rms uncertainty on Gini
19- 24 F6.3 --- M20 [-5/0]?=- Moment of light parameter
26- 30 F5.3 --- e_M20 ?=- rms uncertainty on M20
32- 36 F5.3 --- C [0/9]?=- Concentration parameter, C=5log(r80/r20)
38- 42 F5.3 --- e_C ?=- rms uncertainty on C
44- 48 F5.3 --- A [0/2]?=- Asymmetry parameter
50- 54 F5.3 --- e_A ?=- rms uncertainty on A
56- 60 F5.3 --- S [0/0.4]?=- Smoothness parameter
62- 66 F5.3 --- e_S ?=- rms uncertainty on S
68- 72 F5.3 --- E [0/1]?=- Ellipticity
74- 78 F5.3 --- e_E ?=- rms uncertainty on E
80- 84 F5.3 --- GM [0/1]?=- Gini of the second-order moment parameter
86- 90 F5.3 --- e_GM ?=- rms uncertainty on GM
92- 98 F7.3 arcsec R50 ? Half-light radius
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History:
From electronic version of the journal
References:
Holwerda et al., Paper I 2011MNRAS.416.2401H 2011MNRAS.416.2401H, Cat. J/MNRAS/416/2401
Holwerda et al., Paper II 2011MNRAS.416.2415H 2011MNRAS.416.2415H, Cat. J/MNRAS/416/2415
Holwerda et al., Paper III 2011MNRAS.416.2426H 2011MNRAS.416.2426H
Holwerda et al., Paper IV 2011MNRAS.416.2437H 2011MNRAS.416.2437H, Cat. J/MNRAS/416/2437
Holwerda et al., Paper V 2011MNRAS.416.2447H 2011MNRAS.416.2447H
(End) Patricia Vannier [CDS] 06-Sep-2013