J/ApJS/173/538 XUV-Disk galaxies in the Local Universe (Thilker+, 2007)
A search for extended ultraviolet disk (XUV-disk) galaxies in the Local
Universe.
Thilker D.A., Bianchi L., Meurer G., Gil De Paz A., Boissier S.,
Madore B.F., Boselli A., Ferguson A.M.N., Munoz-Mateos J.C., Madsen G.J.,
Hameed S., Overzier R.A., Forster K., Friedman P.G., Martin D.C.,
Morrissey P., Neff S.G., Schiminovich D., Seibert M., Small T., Wyder T.K.,
Donas J., Heckman T.M., Lee Y.-W., Milliard B., Rich R.M., Szalay A.S.,
Welsh B.Y., Yi S.K.
<Astrophys. J. Suppl. Ser., 173, 538-571 (2007)>
=2007ApJS..173..538T 2007ApJS..173..538T
ADC_Keywords: Galaxies, nearby ; Ultraviolet
Keywords: galaxies: evolution - ultraviolet: galaxies
Abstract:
We have initiated a search for extended ultraviolet disk (XUV-disk)
galaxies in the local universe. Here we compare GALEX UV and
visible-NIR images of 189 nearby (D<40Mpc) S0-Sm galaxies included in
the GALEX Atlas of Nearby Galaxies (Gil de Paz et al. 2007, Cat.
J/ApJS/173/185) and present the first catalog of XUV-disk galaxies.
We find that XUV-disk galaxies are surprisingly common but have varied
relative (UV/optical) extent and morphology. Type 1 objects (≳20%
incidence) have structured, UV-bright/optically faint emission
features in the outer disk, beyond the traditional star formation
threshold. Type 2 XUV-disk galaxies (∼10% incidence) exhibit an
exceptionally large, UV-bright/optically low surface brightness (LSB)
zone having blue UV-Ks outside the effective extent of the inner,
older stellar population, but not reaching extreme galactocentric
distance.
Description:
GALEX obtained FUV and NUV direct imaging observations of our sample
targets during primary mission surveys, principally the Nearby
Galaxy Survey (NGS; Bianchi et al. 2003, in The Local Group as an
Astrophysical Laboratory, ed. M. Livio & T. Brown (Baltimore: STScI),
10) and Medium Imaging Survey (MIS; Martin et al., 2005ApJ...619L...1M 2005ApJ...619L...1M).
Second-generation Digitial Sky Survey (DSS-II) imaging data were used
for compared GALEX imagery to the visible morphology of targets.
We obtained Sloan Digital Sky Survey (SDSS) DR5 ugriz imagery of
confirmed XUV-disk objects whenever possible. 2MASS Large Galaxy Atlas
(LGA; Jarrett et al., 2003AJ....125..525J 2003AJ....125..525J) was our preferred source
for Ks data.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 88 189 40Mpc Disk Galaxy Sample
table2.dat 89 54 XUV-Disk Classification Results
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See also:
J/AJ/106/530 : Low surface brightness disk galaxies (Bothun+, 1993)
J/ApJS/173/185 : GALEX ultraviolet atlas of nearby galaxies (Gil de Paz+, 2007)
J/ApJS/173/441 : UV-Luminous galaxies discovered by GALEX (Hoopes+, 2007)
J/A+A/478/353 : Structural properties of disk galaxies (Mendez-Abreu+, 2008)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Object name (NGC, UGC, IC or ESO)
14 A1 --- n_Name [*] Different name used (1)
16- 19 F4.1 --- T Morphology
21- 23 F3.1 --- e_T Uncertainty in T
25- 28 F4.1 Mpc Dist Distance (2)
30- 33 F4.1 arcmin D25 Diameter at 25mag/arcsec2
35- 40 F6.3 [solMass/yr] logSFR Log of star formation rate (3)
42- 47 F6.2 [yr-1] logsSFR Log of specific star formation rate
49- 53 F5.2 [solMass/yr/kpc2] logSig Log star formation surface density
55- 59 F5.2 [solMass] logMHI ? Log of the HI mass
61- 65 F5.2 [Sun] logM/L ? Log of HI mass to B band luminosity
67- 69 I3 --- Ngrp ? Number of galaxies in associated
NOG group (from Giuricin et al. 2000,
Cat. J/ApJ/543/178)
71- 82 A12 --- NOG Brightest galaxy in associated NOG
group, or group name (when available)
84- 88 F5.2 --- f ? Tidal perturbation parameter (4)
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Note (1): the asterisk (*) indicates a different name in Gil de Paz et al.
(2007, Cat. J/ApJS/173/185)
Note (2): From the Virgo-infall corrected radial velocity adopting
H0=70km/s/Mpc, except as noted in Gil de Paz et al.
(2007, Cat. J/ApJS/173/185).
Note (3): SFR estimates are derived jointly from TIR and UV luminosities,
adopting the calibration of Kennicutt (1998ARA&A..36..189K 1998ARA&A..36..189K) without
any correction for the fractional contribution of diffuse IR emission
unrelated to present star formation.
Note (4): parameter computed following Varela et al. 2004A&A...420..873V 2004A&A...420..873V:
galaxies with f←4.5 may be considered as "isolated" (tidally
unaffected in the recent past); galaxies with f>-2.0 are "perturbed".
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Name Object name (NGC, UGC, IC or ESO)
14 A1 --- T1 [YN] Type 1 XUV-disks assessment (2)
16- 18 A3 --- n_T1 [FUV NUV] In which band Type 1 XUV-disk
20- 25 F6.1 kpc2 S(K80) ?=- Area enclosed by Ks contour
27- 32 F6.1 kpc2 S(UV) ?=- Area enclosed by UV contour
34- 38 F5.2 --- S(LSB)/S(K80) ?=- Distribution of relative size
40- 43 F4.1 mag UV-Ks ?=- UV(AB)-Ks(AB) color index (1)
45 A1 --- T2 [YN] Type 2 XUV-disks assessment (2)
47- 89 A43 --- Comm Interaction comment
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Note (1): Colors measured within the low surface brightness (LSB) zone,
UV(AB)-Ks(AB), have been corrected for Galactic extinction.
Note (2): XUV-disk galaxies are classified as:
* Type 1: show structured, UV-bright emission complexes beyond
the anticipated location of the star formation threshold;
* Type 2: have blue (FUV-NIR) color withing an exceptionally large,
outer and optically-LSB portion of the disk.
Mixed-type XUV-disks have a "Y" in the Assessment column
for both criteria.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 27-May-2009