J/ApJ/887/105 Herschel/SPIRE FTS [CI] lines in KINGFISH gal. (Crocker+, 2019)
[C I](1-0) and [C I](2-1) in resolved local galaxies.
Crocker A.F., Pellegrini E., Smith J.-D.T., Draine B.T., Wilson C.D.,
Wolfire M., Armus L., Brinks E., Dale D.A., Groves B., Herrera-Camus R.,
Hunt L.K., Kennicutt R.C., Murphy E.J., Sandstrom K., Schinnerer E.,
Rigopoulou D., Rosolowsky E., van der Werf P.
<Astrophys. J., 887, 105-105 (2019)>
=2019ApJ...887..105C 2019ApJ...887..105C (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby; Spectra, infrared
Keywords: Interstellar atomic gas; Disk galaxies
Abstract:
We present resolved [CI] line intensities of 18 nearby galaxies
observed with the SPIRE FTS spectrometer on the Herschel Space
Observatory. We use these data along with resolved CO line intensities
from Jup=1 to 7 to interpret what phase of the interstellar medium
the [CI] lines trace within typical local galaxies. A tight, linear
relation is found between the intensities of the CO(4-3) and [CI](2-1)
lines; we hypothesize this is due to the similar upper level
temperature of these two lines. We modeled the [CI] and CO line
emission using large-velocity gradient models combined with an
empirical template. According to this modeling, the [CI](1-0) line is
clearly dominated by the low-excitation component. We determine [CI]
to molecular mass conversion factors for both the [CI](1-0) and
[CI](2-1) lines, with mean values of
α[CI](1-0)=7.3M☉/K/km.s/pc2 and
α[CI](2-1)=34M☉/K/km.s/pc2 with logarithmic
root-mean-square spreads of 0.20 and 0.32dex, respectively. The
similar spread of α[CI](1-0) to αCO (derived using the
CO(2-1) line) suggests that [CI](1-0) may be just as good a tracer of
cold molecular gas as CO(2-1) in galaxies of this type. On the other
hand, the wider spread of α[CI](2-1) and the tight relation
found between [CI](2-1) and CO(4-3) suggest that much of the [CI](2-1)
emission may originate in warmer molecular gas.
Description:
The Beyond the Peak (BtP) project used the SPIRE spectrometer on the
Herschel Space Observatory to target 22 local star-forming galaxies
taken from the KINGFISH project sample (see Table 1).
The Herschel SPIRE FTS spectrometer data were obtained and reduced as
explained in detail in Pellegrini+ (2013ApJ...779L..19P 2013ApJ...779L..19P).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 31 22 Beyond the Peak (BtP) sample galaxies:
basic parameters and coverage
table2.dat 73 252 [CI](1-0) and [CI](2-1) line intensities
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See also:
J/ApJS/190/233 : Spectroscopy & abundances of SINGS galaxies (Moustakas+, 2010)
J/ApJ/745/95 : Herschel FIR & submm phot. of KINGFISH sample (Dale+, 2012)
J/A+A/576/A33 : KINGFISH galaxy sample radial profile SED (Hunt+, 2015)
J/ApJ/829/93 : CO, [CI] & [NII] lines from Herschel (Kamenetzky+, 2016)
J/ApJS/230/1 : Herschel SPIRE/FTS 194-671um survey of GOALS LIRGs (Lu+, 2017)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- n_Gal Note on Gal (1)
4- 10 A7 --- Gal Galaxy name
12- 15 F4.2 kpc Res [0.69/5.9] 40" diameter aperture
physical resolution
17- 18 I2 K Tdc [21/30] Modified blackbody derived temperature
for the center of the BtP galaxy
20- 21 I2 K Tdd [21/26]? Average dust temperature of region
detected in [CI] for the disk
23- 26 F4.2 --- 70um [0.05/0.95] 70um emission enclosed (2)
28- 31 F4.2 --- R25 [0.05/0.45] Fraction of the R25 galactic
radius (2)
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Note (1): Note as follows:
nd = Not detected in [CI] (below a S/N of 3)
c = Central [CI]
r = Resolved [CI]
Note (2): The proportion of 70um emission enclosed and the fraction of the R25
galactic radius covered by the regions detected in [CI] (or the
central aperture for non-detections) rounded to nearest 5% to indicate
rough level of precision.
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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- 7 A7 --- Gal Galaxy name
9- 11 A3 --- Reg Region name (1)
13- 21 F9.5 deg RAdeg [41.57/339.28] Right Ascension (J2000)
23- 31 F9.5 deg DEdeg [-30.3/68.8] Declination (J2000)
33- 42 E10.3 W/sr/m2 ICI(1-0) [-2.7e-10/1.3e-9]? Line intensity
for [CI](1-0)
44- 52 E9.3 W/sr/m2 e_ICI(1-0) [4.5e-11/3.3e-10]? Uncertainty in ICI(1-0)
54- 62 E9.3 W/sr/m2 ICI(2-1) [2.9e-11/2.1e-9] Line intensity
for [CI](2-1)
65- 73 E9.3 W/sr/m2 e_ICI(2-1) [1.6e-11/2.6e-10] Uncertainty in ICI(2-1)
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Note (1): The region name for the Beyond the Peak survey allows for easy
cross-referencing to the CO line intensities. The regions are enumerated
as 'x_y' in a coordinate grid, with '2_2' the central region.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 27-May-2021