J/ApJ/871/17 HI and CO observations of M33 interstellar medium (Utomo+, 2019)
The origin of interstellar turbulence in M33.
Utomo D., Blitz L., Falgarone E.
<Astrophys. J. Ser., 871, 17 (2019)>
=2019ApJ...871...17U 2019ApJ...871...17U
ADC_Keywords: Galaxies, nearby; Molecular clouds; Interstellar medium;
Carbon monoxide; H I data; Velocity dispersion
Keywords: galaxies: individual (M33) ; ISM: kinematics and dynamics ;
ISM: structure
Abstract:
We utilize the multi-wavelength data of M33 to study the origin of
turbulence in its interstellar medium. We find that the HI turbulent
energy surface density inside 8kpc is ∼1-3x1046erg/pc2, and has no
strong dependence on galactocentric radius because of the lack of
variation in HI surface density and HI velocity dispersion. Then, we
consider the energies injected by supernovae (SNe), the
magneto-rotational instability (MRI), and the gravity-driven
turbulence from accreted materials as the sources of turbulent energy.
For a constant dissipation time of turbulence, the SNe energy can
maintain turbulence inside ∼4kpc radius (equivalent to ∼0.5R25),
while the MRI energy is always smaller than the turbulent energy
within 8kpc radius. However, when we let the dissipation time to be
equal to the crossing time of turbulence across the HI scale height,
the SNe energy is enough to maintain turbulence out to 7kpc radius,
and the sum of SNe and MRI energies is able to maintain turbulence out
to 8kpc radius. Due to lack of constraint in the mass accretion rate
through the disk of M33, we cannot rule out the accretion driven
turbulence as a possible source of energy. Furthermore, by resolving
individual giant molecular clouds in M33, we also show that the SNe
energy can maintain turbulence within individual molecular clouds with
∼1% of coupling efficiency. This result strengthens the proposition
that stellar feedback is an important source of energy to maintain
turbulence in nearby galaxies.
Description:
The data cube of HI emission (spectral resolution of 0.2km/s) is
retrieved from Koch+ (2018MNRAS.479.2505K 2018MNRAS.479.2505K). This data cube is a
combination of new interferometric observations from the Karl G.
Jansky Very Large Array (Project ID 14B-088) and archival single dish
observations from the Robert C. Byrd Green Bank Telescope (2002 October).
As part of the M33 CO Large Program (Gratier+ 2010, J/A+A/522/A3;
Druard+ 2014A&A...567A.118D 2014A&A...567A.118D), the CO(2-1) line has been observed
over the whole disk of M33 down to a noise level of 20mK per channel.
The on-the-fly mapping technique was done with the Heterodyne Receiver
Array (HERA) multibeam dual-polarization receiver on the Institut
Radioastronomie Millimetrique (IRAM) 30m telescope on Pico Veleta,
Spain. We adopt a line ratio CO(2-1)/CO(1-0) of 0.7. The data have
a spatial resolution of 12" and a spectral resolution of 2.6km/s.
Objects:
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RA (ICRS) DE Designation(s)
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01 33 50.90 +30 39 35.8 M33 = NAME Triangulum Galaxy
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 136 80 The radial profile of energy per unit area
table2.dat 114 80 The radial profile of surface densities,
velocity dispersion, and scale-height
table3.dat 78 124 The properties of molecular clouds in M33
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See also:
J/ApJS/149/343 : Giant molecular clouds in M33 (Engargiola+, 2003)
J/A+A/417/421 : WSRT wide-field HI survey. II. (Braun+, 2004)
J/ApJS/173/185 : GALEX UV atlas of nearby galaxies (Gil de Paz+, 2007)
J/ApJ/658/1006 : Radial profiles for face-on spirals (Munoz-Mateos+, 2007)
J/ApJ/661/830 : Giant molecular clouds of M33 (Rosolowsky+, 2007)
J/AJ/136/2782 : Star formation efficiency in nearby galaxies (Leroy+, 2008)
J/ApJ/675/1213 : Abundances in M33 HII regions (Rosolowsky+, 2008)
J/AJ/136/2563 : HI Nearby Galaxy Survey, THINGS (Walter+, 2008)
J/ApJ/703/517 : The Spitzer Local Volume Legacy: IR photometry (Dale+, 2009)
J/ApJ/699/1092 : Giant molecular clouds (SRBY) (Heyer+, 2009)
J/A+A/522/A3 : M33 CO(2-1) & HI integrated intensity maps (Gratier+, 2010)
J/A+A/542/A108 : Giant molecular clouds in M33 (Gratier+, 2012)
J/A+A/548/A52 : Molecular cloud formation in M33 (Braine+, 2012)
J/ApJ/761/37 : CO obs. in giant molecular clouds of M33 (Miura+, 2012)
J/A+A/549/A17 : IRAM spectra toward M33 Molecular Clouds (Buchbender+, 2013)
J/ApJ/803/16 : Giant molecular clouds in NGC4526 from 12CO (Utomo+, 2015)
J/A+A/601/A146 : M33 molecular clouds & stellar clusters (Corbelli+, 2017)
J/MNRAS/468/3965 : SAMI Galaxy Survey. Gas surface densities (Federrath+, 2017)
J/ApJ/846/71 : M51 ISM structures from the CO maps of PAWS (Leroy+, 2017)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 F4.2 kpc Rad [0.05/8] Radius
6- 9 F4.2 kpc e_Rad [0.05] Error in Rad
11- 14 F4.2 10+39J/pc2 Kin [1.7/4.4] Kinetic energy surface density
16- 19 F4.2 10+39J/pc2 e_Kin [0.3/1.8] Lower limit in Kin
21- 24 F4.2 10+39J/pc2 E_Kin [0.3/1.8] Upper limit in Kin
26- 29 F4.2 10+39J/pc2 Therm [0.4/0.9] Thermal energy surface density
31- 34 F4.2 10+39J/pc2 e_Therm [0.1/0.4] Lower limit in Therm
36- 39 F4.2 10+39J/pc2 E_Therm [0.05/0.3] Upper limit in Therm
41- 44 F4.2 10+39J/pc2 Turb [1.3/3.7] Turbulent energy surface density
46- 49 F4.2 10+39J/pc2 e_Turb [0.4/2] Lower limit in Turb
51- 54 F4.2 10+39J/pc2 E_Turb [0.5/2] Upper limit in Turb
56- 59 F4.2 10+39J/pc2 MRI [0.07/1.1] The magneto-rotational
instability (MRI) energy surface density
61- 64 F4.2 10+39J/pc2 e_MRI [0.04/1] Lower limit in MRI
66- 69 F4.2 10+39J/pc2 E_MRI [0.06/2.3] Upper limit in MRI
71- 75 F5.2 10+39J/pc2 SNeC [0.1/26.7] Supernovae energy
surface density with constant dissipation
time of 9.8Myr
77- 81 F5.2 10+39J/pc2 e_SNeC [0.08/9.7] Lower limit in SNeC
83- 87 F5.2 10+39J/pc2 E_SNeC [0.2/51.2] Upper limit in SNeC
89- 93 F5.2 10+39J/pc2 SNeV [1.1/34.8] Supernovae energy surface
density with variable dissipation time
95- 99 F5.2 10+39J/pc2 e_SNeV [0.8/22.3] Lower limit in SNeC
101-106 F6.2 10+39J/pc2 E_SNeV [2.4/193] Upper limit in SNeC
108-111 F4.2 --- EffC [0.1/3.3] Total coupling efficiency;
Turb/(MRI+SNeC)
113-116 F4.2 --- e_EffC [0.02/2.1] Lower limit in EffC
118-121 F4.2 --- E_EffC [0.03/9.2] Upper limit in EffC
123-126 F4.2 --- EffV [0.08/0.9] Total coupling efficiency;
Turb/(MRI+SNeV)
128-131 F4.2 --- e_EffV [0.02/0.6] Lower limit in EffV
133-136 F4.2 --- E_EffV [0.02/2.1] Upper limit in EffV
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 F4.2 kpc Rad [0.05/8] Radius
6- 9 F4.2 kpc e_Rad [0.05] Error in Rad
11- 14 F4.2 Msun/pc2 AtomSB [4.5/9.8] Atomic gas mass surface density
16- 19 F4.2 Msun/pc2 e_AtomSB [0.5/3.7] Lower limit in AtomSB
21- 24 F4.2 Msun/pc2 E_AtomSB [0.5/4.3] Upper limit in AtomSB
26- 29 F4.2 Msun/pc2 MolSB [0.2/6] Molecular gas mass surface
density
31- 34 F4.2 Msun/pc2 e_MolSB [0.2/3.1] Lower limit in MolSB
36- 39 F4.2 Msun/pc2 E_MolSB [0.8/5.2] Upper limit in MolSB
41- 47 F7.2 Msun/pc2 StarSB [3.8/1019] Stellar mass surface density
49- 53 F5.2 Msun/pc2 e_StarSB [0.04/19]? Lower limit in StarSB (1)
55- 59 F5.2 Msun/pc2 E_StarSB [0.1/19]? Upper limit in StarSB (1)
61- 65 F5.2 Msun/pc2/Gyr SFRSB [0.05/13.4] Star formation rate
surface density
67- 71 F5.2 Msun/pc2/Gyr e_SFRSB [0.04/5] Lower limit in SFRSB
73- 77 F5.2 Msun/pc2/Gyr E_SFRSB [0.1/26] Upper limit in SFRSB
79- 83 F5.2 km/s VDisp [9.9/13.7] Atomic gas velocity dispersion
85- 88 F4.2 km/s e_VDisp [0.2/1.2] Lower limit in VDisp
90- 93 F4.2 km/s E_VDisp [0/2.3] Upper limit in VDisp
95-100 F6.2 pc Height [72/628] Scale-height of the atomic gas
102-107 F6.2 pc e_Height [19/416] Lower limit in Height
109-114 F6.2 pc E_Height [20/929] Upper limit in Height
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Note (1): Blanks indicate nan values.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/124] Cloud number, ordered
from center of M33
5- 8 F4.2 kpc Rad [0.2/6.7] Cloud distance from M33 center
10- 13 F4.2 kpc e_Rad [0.02/0.2] Uncertainty in Rad
15- 20 F6.2 pc Size [36/140] Effective cloud radius
defined as (area/π)^0.5
22- 26 F5.2 pc e_Size [16.66] Uncertainty in Size (1)
28- 31 F4.2 10+5Msun Mass [0.1/6.8] Cloud mass derived using
a variable α_CO
33- 36 F4.2 10+5Msun e_Mass [0.01/0.4] Uncertainty in Mass (2)
38- 41 F4.2 km/s VDisp [1/5.4]? Mean cloud velocity
dispersion
43- 46 F4.2 km/s e_VDisp [0/9.4]? Uncertainty in VDisp (3)
48- 52 F5.2 [10+44J/pc2] logTEng [-4.3/-0.4]? Log cloud turbulent energy
surface density
in units of 1051erg/pc2
54- 57 F4.2 [10+44J/pc2] e_logTEng [0.04/1.2]? Lower limit in logTEng
59- 62 F4.2 [10+44J/pc2] E_logTEng [0.04/0.5]? Upper limit in logTEng
64- 68 F5.2 [10+44J/pc2] logSNe [-1.5/1.71] Log cloud supernovae energy
surface density
in units of 1051erg/pc2
70- 73 F4.2 [10+44J/pc2] e_logSNe [0.01/0.2] Lower limit in logSNe
75- 78 F4.2 [10+44J/pc2] E_logSNe [0.01/0.2] Upper limit in logSNe
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Note (1): The uncertainty is the physical size of one pixel.
Note (2): The uncertainty is calculated using bootstrap resampling
with 1000 iterations.
Note (3): The uncertainty is standard deviation of velocity dispersion
within a cloud.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 24-Jul-2020