J/A+A/676/A67 Molecular Superbubbles in nearby galaxies (Watkins+, 2023)
Quantifying the energetics of molecular superbubbles in PHANGS galaxies.
Watkins E.J., Kreckel K., Groves B., Glover S.C.O., Whitmore B.C.,
Leroy A.K., Schinnerer E., Meidt S.E., Egorov O.V., Barnes A.T., Lee J.C.,
Boquien M., Chandar R., Chevance M., Dale D.A., Grasha K., Klessen R.S.,
Kruijssen J.M.D., Larson K.L., Li J., Mendez-Delgado J.E., Pessa I.,
Saito T., Sanchez-Blazquez P., Sarbadhicary S.K., Scheuermann F.,
Thilker D.A., Williams T.G.
<Astron. Astrophys. 676, A67 (2023)>
=2023A&A...676A..67W 2023A&A...676A..67W (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies ; Molecular data ; Carbon monoxide ; Radio sources
Keywords: ISM: bubbles - galaxies: star formation - stars: massive -
molecular data - methods: observational
Abstract:
Star formation and stellar feedback are interlinked processes that
redistribute energy, turbulence, and material throughout galaxies.
Because young and massive stars form in spatially clustered
environments, they create pockets of expanding gas termed
superbubbles, which retain information about the physical processes
that drive them. As these processes play a critical role in shaping
galaxy discs and regulating the baryon cycle, measuring the properties
of superbubbles provides important input for galaxy evolution models.
With the wide coverage and high angular resolution (∼50-150pc) of the
PHANGS-ALMA CO (J=2-1) survey, we can now resolve, identify and
characterise a statistically representative number of superbubbles
using molecular gas in nearby galaxies. We identify superbubbles by
requiring spatial correspondence between shells in CO with stellar
populations identified in PHANGS-HST. Then, by combining the
properties of the stellar populations with the CO, we quantify the
energetics of the stars and constrain feedback models. We visually
find 325 cavities across 18 PHANGS--ALMA galaxies, 88 of which have
clear superbubble signatures (unbroken shells, central clusters,
kinematic signatures of expansion). We measure their radii and
expansion velocities using CO (2-1) to dynamically derive their ages
and the mechanical power driving the bubbles, which we use to compute
the expected properties of the parent stellar populations driving the
bubbles. We find consistency between the predicted and derived stellar
ages and masses of the stellar populations if we use a supernova (SN)
model that injects energy with a coupling efficiency of ∼10%. Not only
does this confirm that molecular gas accurately traces superbubble
properties, but it also provides key observational constraints for
superbubble models. We also find evidence that the bubbles are
sweeping up gas as they expand, and speculate that these sites have
the potential to host new generations of stars. This work demonstrates
that molecular superbubbles provide novel quantitative constraints on
SNe feedback efficiencies and gas clearing times, and represent a
promising environment to search for the propagation of star formation,
all of which are needed to understand what sets the observed star
formation rates in galaxies.
Description:
Provided here is the full version of Table 2 & 3 found in the paper.
Table 2 provides the properties the molecular superbubbles
found in 18 nearby PHANGS galaxies while Table 3 contains the average
properties of HST stellar associations found within the superbubbles.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 91 88 Superbubble properties ordered by RA
derived using CO
table3.dat 98 88 Mass averaged weighted ages, total mass, and
number of clusters found for the multi-scale
association catalogues found inside the
superbubbles
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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- 2 I2 --- ID [1/88] Bubble ID number
4- 10 A7 --- Galaxy Which galaxy the bubble is located in
12- 14 I3 deg RAd Right ascension (J2000) (RA_D)
16- 17 I2 arcmin RAm Right ascension (J2000) (RA_M)
19- 22 F4.1 arcsec RAs [0/60] Right ascension (J2000) (RA_S)
24 A1 --- DE- Declination sign (J2000) (DEC_-)
25- 26 I2 deg DEd Declination (J2000) (DEC_D)
28- 29 I2 arcmin DEm Declination (J2000) (DEC_M)
31- 34 F4.1 arcsec DEs Declination (J2000) (DEC_S)
36- 38 I3 pc Rad Bubble Radius (RAD_PC)
40- 43 F4.1 km/s Vexp Expansion velocity (VEXPKMS)
45- 47 F3.1 Myr Age Dynamical age assuming eta=1/4 (AGE_MYR)
49- 56 E8.3 Msun Mshell Molecular mass of the bubble (MSHELLMSUN)
58- 66 E9.3 10-7J KE Kinetic energy of the shell (in erg) (KE_ERG)
67- 74 E8.3 Msun Mcluster Mass of the cluster with injected energy with
a coupling efficiency of ∼10% (MCLSTMSUN)
76- 91 A16 --- Notes Location of the bubble using
Querejeta et al., 2021A&A...656A.133Q 2021A&A...656A.133Q (NOTES)
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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- 2 I2 --- ID [1/88] Bubble ID number (ID)
5- 7 F3.1 Myr Age16 ?=- Mass-weighted avg age of 16pc
stellar populations (AGE16MYR)
9- 12 F4.1 Myr e_Age16 ? Mass-weighted avg age of 16pc
stellar populations error (AGE16MYR_ERR)
14- 21 E8.5 Msun Mass16 ?=- Total mass of 16pc stellar populations
(MASS16MSUN)
23- 30 E8.5 Msun e_Mass16 ? Total mass of 16pc stellar populations
(MASS16MSUN_ERR)
32- 33 I2 --- N16 Number of 16pc stellar populations
found/used (NUM_16)
35- 38 F4.1 Myr Age32 ?=- Mass-weighted avg age of 32pc
stellar populations (AGE32MYR)
40- 43 F4.1 Myr e_Age32 ? Mass-weighted avg age of 32pc
stellar populations (AGE32MYR_ERR)
45- 53 E9.5 Msun Mass32 ?=- Total mass of 32pc stellar populations
(MASS32MSUN)
55- 62 E8.5 Msun e_Mass32 ? Total mass of 32pc stellar populations
(MASS32MSUN_ERR)
64- 65 I2 --- N32 Number of 32pc stellar populations
found/used (NUM_32)
67- 70 F4.1 Myr Age64 ?=- Mass-weighted avg age of 64pc
stellar populations (AGE64MYR)
72- 75 F4.1 Myr e_Age64 ? Mass-weighted avg age of 64pc
stellar populations (AGE64MYR_ERR)
77- 86 E10.4 Msun Mass64 ?=- Total mass of 64pc stellar populations
(MASS64MSUN)
88- 96 E9.4 Msun e_Mass64 ? Total mass of 64pc stellar populations
(MASS64MSUN_ERR)
98 I1 --- N64 Number of 64pc stellar populations
found/used (NUM_64)
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Acknowledgements:
Elizabeth Watkins, elizabeth.watkins(at)uni-heidelberg.de
(End) Patricia Vannier [CDS] 28-Jul-2023