J/A+A/576/A33 KINGFISH galaxy sample radial profile SED (Hunt+, 2015)
Cool dust heating and temperature mixing in nearby star-forming galaxies.
Hunt L.K., Draine B.T., Bianchi S., Gordon K.D., Aniano G., Calzetti D.,
Dale D.A., Helou G., Hinz J.L., Kennicutt R.C., Roussel H., Wilson C.D.,
Bolatto A., Boquien M., Croxall K.V., Galametz M., Gil de Paz A., Koda J.,
Munoz-Mateos J.C., Sandstrom K.M., Sauvage M., Vigroux L., Zibett S.
<Astron. Astrophys. 576, A33 (2015)>
=2015A&A...576A..33H 2015A&A...576A..33H
ADC_Keywords: Galaxies, nearby ; Energy distributions
Keywords: galaxies: ISM - dust, extinction - galaxies: star formation
Abstract:
Physical conditions of the interstellar medium in galaxies are closely
linked to the ambient radiation field and the heating of dust grains.
In order to characterize dust properties in galaxies over a wide range
of physical conditions, we present here the radial surface brightness
profiles of the entire sample of 61 galaxies from Key Insights into
Nearby Galaxies: Far-Infrared Survey with Herschel (KINGFISH). The
main goal of our work is the characterization of the grain
emissivities, dust temperatures, and interstellar radiation fields
responsible for heating the dust. After fitting the dust and stellar
radial profiles with exponential functions, we fit the far-infrared
spectral energy distribution (SED) in each annular region with
single-temperature modified black bodies using both variable (MBBV)
and fixed (MBBF) emissivity indices β, as well as with physically
motivated dust models. Results show that while most SED parameters
decrease with radius, the emissivity index β also decreases with
radius in some galaxies, but in others is increasing, or rising in the
inner regions and falling in the outer ones. Despite the fixed grain
emissivity (average β∼2.1) of the physically-motivated models,
they are well able to accommodate flat spectral slopes with β≤1.
We find that flatter slopes (β≤1.5) are associated with cooler
temperatures, contrary to what would be expected from the usual
Tdust-β degeneracy. This trend is related to variations in Umin
since β and Umin are very closely linked over the entire range
in Umin sampled by the KINGFISH galaxies: low Umin is associated
with flat β≤1. Both these results strongly suggest that the low
apparent β values (flat slopes) in MBBV fits are caused by
temperature mixing along the line-of-sight, rather than by intrinsic
variations in grain properties.
Description:
Radial profile spectral energy distributions (SEDs) for the KINGFISH
galaxies. The profiles are extracted from the convolved and
sky-subtracted images, and all have the same spatial resolution,
roughly 39-arcsec. The annular fluxes were extracted along fixed-shape
ellipses with radial bins of 18-arcsec. A masking technique was
applied to galaxies more inclined than 60°. Uncertainties were
calculated as the quadrature sum of calibration uncertainty and the
mean error of the standard deviation of the surface brightness
distribution along the elliptical isophote circumference. The
uncertainties for PACS and MIPS data were adjusted when necessary for
discrepancies larger than the nominal uncertainties.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 88 61 KINGFISH galaxy sample
prosed.dat 54 15158 Radial profile SED surface brightness
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See also:
J/ApJ/715/506 : Aromatic inventory of the local volume (Marble+, 2010)
J/ApJS/190/233 : Spectroscopy + abundances of SINGS galaxies (Moustakas+ 2010)
J/ApJ/703/1569 : Radial distribution in SINGS galaxies (Munoz-Mateos+, 2009)
J/ApJ/757/52 : UV and IR observations for SINGS galaxies. I. (Mao+, 2012)
J/ApJ/774/136 : X-ray observations of SINGS galaxies (Tzanavaris+, 2013)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- Name Name
9- 14 A6 --- MType Hubble morphological type
16- 17 I2 --- TT [-5/10] T-type
19- 23 F5.2 Mpc Dist [3/31] Distance (1)
25- 28 F4.2 [-] Abund [7.5/8.8] 12+log(O/H) abundance
29 A1 --- r_Abund [d] Reference for Abund (3)
31- 34 F4.2 [-] e_Abund rms uncertainty on Abund
36- 37 I2 h RAh Right ascension (J2000)
39- 40 I2 min RAm Right ascension (J2000)
42- 45 F4.1 s RAs Right ascension (J2000)
47 A1 --- DE- Declination sign (J2000)
48- 49 I2 deg DEd Declination (J2000)
51- 52 I2 arcmin DEm Declination (J2000)
54- 55 I2 arcsec DEs Declination (J2000)
57- 60 F4.1 arcmin amaj [0.9/29] Major axis diameter (2)
62- 65 F4.1 arcmin bmin [0.6/27] Minor axis diameter (2)
67- 69 I3 deg PA [0/180] Position angle (E from N)
71- 74 A4 --- r_PA Reference for PA (4)
76- 77 I2 --- i [0/90] Inclination angle
79- 88 A10 --- r_i Reference for i (4)
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Note (1): The method of distance determination is given by
Kennicutt et al. (2011PASP..123.1347K 2011PASP..123.1347K).
Note (2): Galaxy sizes are taken from NED=NASA/IPAC Extragalactic Database;
Note (3): d: Metallicity gradient from Moustakas et al. 2010 (J/ApJS/190/233),
except for:
* NGC5457 (M101) from Li et al. (2013ApJ...766...17L 2013ApJ...766...17L) and
* IC 342 from Pilyugin et al. (2007MNRAS.376..353P 2007MNRAS.376..353P).
The latter has been adjusted to the mean slope ratio between
Moustakas et al. 2010 and Pilyugin & Thuan (2005ApJ...631..231P 2005ApJ...631..231P),
namely ΔO/H=-0.49.
Note (4): References for PAs and inclination angles as follows:
B06 = Begum et al. (2006MNRAS.365.1220B 2006MNRAS.365.1220B)
B81 = Bosma (1981AJ.....86.1791B 1981AJ.....86.1791B)
C00 = Crosthwaite et al. (2000AJ....119.1720C 2000AJ....119.1720C)
D06 = Daigle et al. (2006MNRAS.367..469D 2006MNRAS.367..469D)
D09 = Davies et al. (2009ApJ...702..114D 2009ApJ...702..114D)
dB08 = de Blok et al. (2008AJ....136.2648D 2008AJ....136.2648D)
NED = NED (http://ned.ipac.caltech.edu)
O08 = Oh et al. (2008AJ....136.2761O 2008AJ....136.2761O)
T08 = Tamburro et al. (2008AJ....136.2872T 2008AJ....136.2872T)
W08 = Walter et al. (2008AJ....136.2563W 2008AJ....136.2563W, Cat. J/AJ/136/2563)
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Byte-by-byte Description of file: prosed.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Name Galaxy designation
11- 13 I3 --- Row [1/72] Row number in a given galaxy
(index of r-value)
15- 22 F8.1 arcsec r [18/1296] Galactocentric radius of row center
25- 31 F7.2 um lambda [3.5/504] Central wavelength of filter for SED
35- 44 E10.3 MJy/sr SuBr Radial brightness level
46- 54 E9.3 MJy/sr e_SuBr Radial brightness uncertainty
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Acknowledgements:
Leslie Hunt, hunt(at)arcetri.astro.it
History:
* 17-Oct-2014: Original version
* 08-Aug-2015: in table1, value of the arror on the O/h abundance for
NGC 3077, originally identical to its value (8.64), was fixed into
0.20, following the SINGS inventory (Marble et al. 2010, J/ApJ/715/506)
(End) L. Hunt [INAF, Oss. di Arcetri, Firenze], P. Vannier [CDS] 17-Oct-2014