J/ApJ/757/52 UV and IR observations for SINGS galaxies. I. (Mao+, 2012)
Characterizing ultraviolet and infrared observational properties for galaxies.
I. Influences of dust attenuation and stellar population age.
Mao Y.-W., Kennicutt R.C. Jr, Hao C.-N., Kong X., Zhou X.
<Astrophys. J., 757, 52 (2012)>
=2012ApJ...757...52M 2012ApJ...757...52M
ADC_Keywords: Galaxies, nearby ; Photometry, ultraviolet ; Photometry, infrared
Keywords: dust, extinction; galaxies: individual; galaxies: spiral;
infrared: galaxies; ultraviolet: galaxies
Abstract:
The correlation between infrared-to-ultraviolet luminosity ratio and
ultraviolet color (or ultraviolet spectral slope), i.e., the IRX-UV
(or IRX-β) relation, found in studies of starburst galaxies is a
prevalent recipe for correcting extragalactic dust attenuation.
Considerable dispersion in this relation discovered for normal
galaxies, however, complicates its usability. In order to investigate
the cause of the dispersion and to have a better understanding of the
nature of the IRX-UV relation, in this paper, we select five nearby
spiral galaxies, and perform spatially resolved studies on each of the
galaxies, with a combination of ultraviolet and infrared imaging data.
We measure all positions within each galaxy and divide the extracted
regions into young and evolved stellar populations. By means of this
approach, we attempt to discover separate effects of dust attenuation
and stellar population age on the IRX-UV relation for individual
galaxies. In this work, in addition to dust attenuation, stellar
population age is interpreted to be another parameter in the IRX-UV
function, and the diversity of star formation histories is suggested
to disperse the age effects. At the same time, strong evidence shows
the need for more parameters in the interpretation of observational
data, such as variations in attenuation/extinction law. Fractional
contributions of different components to the integrated luminosities
of the galaxies suggest that the integrated measurements of these
galaxies, which comprise different populations, would weaken the
effect of the age parameter on IRX-UV diagrams. The dependence of the
IRX-UV relation on luminosity and radial distance in galaxies presents
weak trends, which offers an implication of selective effects. The
two-dimensional maps of the UV color and the infrared-to-ultraviolet
ratio are displayed and show a disparity in the spatial distributions
between the two galaxy parameters, which offers a spatial
interpretation of the scatter in the IRX-UV relation.
Description:
The sample of galaxies in this work is compiled from the Spitzer
Infrared Nearby Galaxies Survey (SINGS; Kennicutt et al.
2003PASP..115..928K 2003PASP..115..928K). The SINGS project has observed images of IR
emission components for a sample of 75 nearby galaxies in the
wavelength range of 3.6um to 160um. The UV imaging data of the SINGS
galaxies have been obtained as a part of the Ultraviolet Atlas of
GALEX Nearby Galaxies Survey (Gil de Paz et al. 2007,
Cat. J/ApJS/173/185).
GALEX observation works at two ultraviolet wavelength bands: the
far-ultraviolet (FUV, λeff=1516Å) and the near-ultraviolet
(NUV, λeff=2267Å). The GALEX data can be retrieved on the
GALEX data release Web site.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 102 635 Aperture photometry of the UV clusters
table3.dat 102 2043 Aperture photometry of the local background regions
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See also:
II/312 : GALEX-DR5 (GR5) sources from AIS and MIS (Bianchi+ 2011)
J/ApJ/741/79 : The Spitzer-SDSS-GALEX Spectroscopic Survey (O'Dowd+, 2011)
J/AJ/141/205 : UVOT imaging of M81 and Holmberg IX (Hoversten+, 2011)
J/ApJS/190/233 : Spectro. and abundances of SINGS galaxies (Moustakas+, 2010)
J/ApJ/715/572 : GOALS UV and FIR properties (Howell+, 2010)
J/ApJ/706/599 : Hα and UV SFR in the local volume (Lee+, 2009)
J/ApJ/706/553 : Fluxes in nearby star-forming galaxies (Boquien+, 2009)
J/ApJ/703/1672 : Far-IR and Hα fluxes in galaxies (Kennicutt+, 2009)
J/ApJ/703/1569 : Radial distribution in SINGS gal. I. (Munoz-Mateos+, 2009)
J/ApJ/703/517 : The Spitzer Local Volume Legacy: IR photometry (Dale+, 2009)
J/ApJ/701/1965 : Radial dust properties of SINGS galaxies (Munoz-Mateos+, 2009)
J/ApJS/173/572 : GALEX/Spitzer photometry in NGC 7331 (Thilker+, 2007)
J/ApJS/173/185 : GALEX ultraviolet atlas of nearby galaxies (Gil de Paz+, 2007)
J/ApJ/671/333 : Aperture photometry in NGC 5194 (Kennicutt+, 2007)
J/ApJ/648/987 : UV through far-IR analysis of M81 (Perez-Gonzalez+, 2006)
J/ApJ/633/871 : Positions and photometry of HII knots in M51 (Calzetti+, 2005)
http://galex.stsci.edu/GR6/ : GALEX data access
http://ssc.spitzer.caltech.edu/ : Spitzer Science Center home page
http://irsa.ipac.caltech.edu/data/SPITZER/SINGS/ : SINGS Spitzer data access
Byte-by-byte Description of file: table[23].dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- ID Source identifier (1)
17- 23 F7.3 deg RAdeg Right Ascension in decimal degrees (J2000) (2)
25- 30 F6.3 deg DEdeg Declination in decimal degrees (J2000) (2)
32- 39 E8.3 10-7W LFUV GALEX/FUV (1516Å) luminosity (3)
41- 48 E8.3 10-7W e_LFUV Uncertainty in LFUV
50- 57 E8.3 10-7W LNUV GALEX/NUV (2267Å) luminosity (3)
59- 66 E8.3 10-7W e_LNUV Uncertainty in LNUV
68- 75 E8.3 10-7W L8 Spitzer/IRAC 8um luminosity (4)
77- 84 E8.3 10-7W e_L8 Uncertainty in L8
86- 93 E8.3 10-7W L24 Spitzer/MIPS 24um luminosity (4)
95-102 E8.3 10-7W e_L24 Uncertainty in L24
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Note (1): Where the ID format is NGC NNNN-CLUNNN for Cluster Number (table2)
or NGC NNNN-BKGNNN for Region Number (table3). The aperture radius is
8.5" for NGC 3031 (M81) and NGC 6946, and 6.8" for NGC 4536, NGC 5194
(M51a), and NGC 7331.
Note (2): Position of the apertures on the sky.
Note (3): After local (or global for table 3) background subtraction and
corrected for Galactic foreground extinction. In units of erg/s.
Note (4): After local (or global for table 3) background subtraction and
corrected for aperture effects. In units of erg/s.
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Nomenclature note:
In table 2, clusters are <[MKH2012] NGCNNNN-CLUNNN> in Simbad.
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 21-May-2014