J/ApJ/899/158 Gas structure comparison; NGC 253 and Milky Way (Krieger+, 2020)
The Turbulent Gas Structure in the Centers of NGC 253 and the Milky Way.
Krieger N., Bolatto A.D., Koch E.W., Leroy A.K., Rosolowsky E., Walter F.,
Weiss A., Eden D.J., Levy R.C., Meier D.S., Mills E.A.C., Moore T., Ott J.,
Su Y., Veilleux S.
<Astrophys. J., 899, 158 (2020)>
=2020ApJ...899..158K 2020ApJ...899..158K
ADC_Keywords: Interstellar medium; Molecular clouds; Milky Way; Galactic center;
Galaxies; Spectra, millimetric/submm
Keywords: Interstellar medium ; Interstellar dynamics ; Molecular clouds ;
Starburst galaxies ; Galactic center ; Stellar feedback
Abstract:
We compare molecular gas properties in the starbursting center of
NGC253 and the Milky Way Galactic center (GC) on scales of ∼1-100pc
using dendrograms and resolution-, area-, and noise-matched data sets
in CO(1-0) and CO(3-2). We find that the size-line width relations in
NGC253 and the GC have similar slope, but NGC253 has larger line
widths by factors of ∼2-3. The σ2/R dependency on column density
shows that, in the GC, on scales of 10-100pc the kinematics of gas
over N>3x1021/cm2 are compatible with gravitationally bound
structures. In NGC253 this is only the case for column densities
N>3x1022/cm2. The increased line widths in NGC253 originate in the
lower column density gas. This high velocity dispersion, not
gravitationally self-bound gas, is likely in transient structures
created by the combination of high average densities and feedback in
the starburst. The high densities turn the gas molecular throughout
the volume of the starburst, and the injection of energy and momentum
by feedback significantly increases the velocity dispersion at a given
spatial scale over what is observed in the GC.
Description:
For NGC253 the interferometric CO(1-0) observations were carried out
in Atacama Large Millimeter/submillimeter Array (ALMA) cycle 2 and
then combined with Mopra single-dish observations. The final
zero-spacing corrected data cube has 1.6" angular and 5.0km/s spectral
resolution. The CO(3-2) data were obtained with ALMA during cycle 4
and include total power observations. The resulting zero-spacing
corrected data cube has 0.15" angular and 2.5km/s spectral resolution.
We draw CO(1-0) observations of the Galactic Center (GC) from the
COGAL survey. These data have angular resolution 7.5" and spectral
resolution 1.3km/s.
Objects:
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RA (2000) DE Designation(s)
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00 47 33.13 -25 17 19.7 NGC 253 = NGC 253
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig1.dat 44 50 Binned Size-Linewidth relation or CO(3-2) and CO(1-0)
fig2.dat 53 50 Relation between dendrogram structure size and
luminosity for CO(3-2) and CO(1-0)
fig3.dat 51 44 Size-line width coefficient as a function of column
density
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See also:
J/ApJ/551/852 : FCRAO CO survey of the outer Galaxy (Heyer+, 2001)
J/ApJ/699/1092 : Giant molecular clouds (SRBY) (Heyer+, 2009)
J/AJ/142/35 : The VLBA Galactic Plane Survey (VGaPS) (Petrov+, 2011)
J/A+A/555/L4 : Inner rings in disc galaxies from UV + Hα (Comeron, 2013)
J/ApJ/784/3 : The PAWS catalogs of GMCs and islands in M51 (Colombo+, 2014)
J/A+A/586/A50 : Central Molecular Zone H2CO temperature maps (Ginsburg+, 2016)
J/MNRAS/471/4027 : CVRHS classifications for the GZ2 Ring Sample (Buta, 2017)
J/AJ/156/18 : APOGEE DR14:Binary comp. of evolved stars (Price-Whelan+, 2018)
J/ApJ/857/19 : ALMA view of GMCs in NGC 300 (Faesi+, 2018)
J/ApJ/860/172 : Cloud-scale molecular gas properties in 15 galaxies (Sun+,2018)
Byte-by-byte Description of file: fig1.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- Galaxy Source identifier; Galactic Center or NGC253
8- 14 A7 --- CO CO transition; (1-0) or (3-2)
16- 20 F5.2 pc Rmin [0.49/60.7] Lower edge of R bin
22- 26 F5.2 pc Rmax [0.62/76.4] Upper edge of R bin
28- 32 F5.2 km/s b_sigma [1/41.8] Lower 16th percentile bound in sigma
34- 38 F5.2 km/s sigma [1.56/47.8] Median sigma distrib. 50th percentile
40- 44 F5.2 km/s B_sigma [3.08/53.7] Upper 84th percentile bound in sigma
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Byte-by-byte Description of file: fig2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- Galaxy Source identifier; Galactic Center or NGC253
8- 14 A7 --- CO CO transition; (1-0) or (3-2)
16- 20 F5.2 pc Rmin [0.49/60.7] Lower edge of R bin
22- 26 F5.2 pc Rmax [0.62/76.4] Upper edge of R bin
28- 35 E8.2 K.km/s/pc2 b_Lum Lower 16th percentile bound in Lum
37- 44 E8.2 K.km/s/pc2 Lum Median of luminosity distribution;
50th percentile
46- 53 E8.2 K.km/s/pc2 B_Lum Upper 84th percentile bound in Lum
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Byte-by-byte Description of file: fig3.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- Galaxy Source identifier; Galactic Center or NGC253
8- 14 A7 --- CO CO transition; (1-0) or (3-2)
16- 23 E8.2 /cm2 Nmin Lower edge of N bin
25- 32 E8.2 /cm2 Nmax Upper edge of N bin
34- 38 F5.2 km2/s2/pc b_sigma2R Lower 16th percentile bound in sigma2/R
40- 44 F5.2 km2/s2/pc sigma2R Median of σ2/R distribution;
50th percentile
46- 51 F6.2 km2/s2/pc B_sigma2R Upper 84th percentile bound in sigma2/R
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 22-Oct-2021