J/MNRAS/508/5425 Study of NGC 300 objects with dendogram (McLeod+, 2021)
The impact of pre-supernova feedback and its dependence on environment.
Mcleod A.F., Ali A.A., Chevance M., Della Bruna L., Schruba A.,
Stevance H.F., Adamo A., Kruijssen J.M.D., Longmore S.N., Weisz D.R.,
Zeidler P.
<Mon. Not. R. Astron. Soc. 508, 5425-5448>
=2021MNRAS.508.5425M 2021MNRAS.508.5425M (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; H II regions ; Supernova remnants ; Nebulae ;
Optical ; Spectrophotometry ; Line Profiles ; Galaxies, radius ;
Abundances ; Balmer lines ; Positional data
Keywords: stars: massive - H II regions - galaxies: star formation
Abstract:
Integral field units enable resolved studies of a large number of
star-forming regions across entire nearby galaxies, providing insight
on the conversion of gas into stars and the feedback from the emerging
stellar populations over unprecedented dynamic ranges in terms of
spatial scale, star-forming region properties, and environments. We
use the Very Large Telescope (VLT) MUSE (Multi Unit Spectroscopic
Explorer) legacy data set covering the central 35 arcmin2 (∼12
kpc2) of the nearby galaxy NGC 300 to quantify the effect of stellar
feedback as a function of the local galactic environment. We extract
spectra from emission line regions identified within dendrograms,
combine emission line ratios and line widths to distinguish between H
II regions, planetary nebulae, and supernova remnants, and compute
their ionized gas properties, gas-phase oxygen abundances, and
feedback-related pressure terms. For the H II regions, we find that
the direct radiation pressure (Pdir) and the pressure of the ionized
gas (PHII) weakly increase towards larger galactocentric radii, i.e.
along the galaxy's (negative) abundance and (positive) extinction
gradients. While the increase of PHII with galactocentric radius is
likely due to higher photon fluxes from lower-metallicity stellar
populations, we find that the increase of Pdir is likely driven by
the combination of higher photon fluxes and enhanced dust content at
larger galactocentric radii. In light of the above, we investigate the
effect of increased pre-supernova feedback at larger galactocentric
distances (lower metallicities and increased dust mass surface
density) on the ISM, finding that supernovae at lower metallicities
expand into lower-density environments, thereby enhancing the impact
of supernova feedback.
Description:
In this study, we based our observations on the VLT/MUSE data set of
NGC 300 first presented in McLeod te al. (M20, 2020ApJ...891...25M 2020ApJ...891...25M).
The data were taken in the nominal wavelength range of the MUSE
instrument (from 475 nm to 935 nm) and using its wide-field mode
(∼ 1arcmin * 1 arcmin per pointing). As opposed to M20, where only 2 of
the NGC 300 MUSE data cubes are analysed, here we exploit the full
coverage of the in total 35 individual mosaic pointings which cover a
7 arcmin * 5 arcmin contiguous mosaic of the central star-forming disc
of NGC 300. We proceed to data reduction with the MUSE pipeline
(Weilbacher et al. 2012) in the ESOREX environment with the standard
static calibration files. Giving birth to spectra of regions of
interest extracted from each one of the large data cubes spanning
about 62.5 nm each, and combined to cover the entire wavelength range.
Emission line maps are obtained by collapsing the cubes over ± 0.3 nm
(about ±140 km/s at Hα) around the lines of interest,
(i.e see section 2 Observations).
Next, the analysis described in the section 3 Region identification
and classification is based on a continuum-subtracted Hα map,
we proceed in a similar fashion to Della Bruna et al.
(2020A&A...635A.134D 2020A&A...635A.134D), we used the Python package ASTRODENDRO to
identify bright regions in a MUSE Hα map we add an extra
spectral clustering step to the classical dendrogram hierarchy of
'trunks', 'branches', and 'leaves' which, as described in the section
3.1 Emission line region identification, is not ideal at the high
spatial resolution achieved with MUSE in NGC 300. Hereafter, the
SCIMES package is used to obtain coherent and relevant regions based
on a spectral clustering paradigm. We obtain an initial catalogue of
204 emission line regions and we extract integrated spectra for all of
these based on the identified region contours.
After isolating only H II regions, SNRs and PNes, the remaining 188
spectra are passed to the Gaussian fitting routine and subsequent
classification described firstly for SNR selection criteria on
properties showed in the tableb1.dat regrouping the 11 SNR candidate,
(see the section 3.2 Emission line fitting and region classification
and the section 3.2.1 Supernova remnants). Secondly, we extract 19 PNe
structures (i.e see the section 3.2.2 Planetary nebulae) throughout
selection criteria on property values exhibited in the tableb2.dat.
Finally, we obtained 103 spatially resolved H II region sources (i.e
see the section 3.2.3 H II regions) by putting constrains on size
regions and line ratios. More, as explained in the section 4
Feedback-driven gas in H II regions, we characterize measurable
consequences on feedback by computing gas and H II regions pressures
also available with properties in the tableb3.dat.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tableb1.dat 119 11 Our sample of SNR properties
tableb2.dat 74 19 Our sample of PNe properties
tableb3.dat 117 103 Our sample of H II region properties
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See also:
J/other/Ser/184.19 : NGC 300 candidate supernova remnants (Millar+, 2012)
J/A+A/552/A12 : Abundances of PNe in NGC 300 (Stasisnka+, 2013)
Byte-by-byte Description of file: tableb1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- MillarID SNR number ID (Millar12id) (1)
5- 7 I3 --- ID ?=- Dendogram identifier number
(Dendrogramid) (2)
9- 16 F8.5 deg RAdeg Right Ascension (J2000)
18- 26 F9.5 deg DEdeg Declination (J2000)
28- 32 F5.2 [-] log([NII/Ha]) ?=- [N II/Hα] line ratio of
[N II] at 658.4 nm and Hα
at 656.28 nm ([N II/Hα])
34- 37 F4.2 [-] e_log([NII/Ha]) ?=- Mean error on [N II/Hα]
39- 43 F5.2 [-] log([SII/Ha]) ?=- [S II/Hα] line ratio of
[S II] at 671.7 nm and Hα
at 656.28 nm ([S II/Hα])
45- 48 F4.2 [-] e_log([SII/Ha]) ?=- Mean error on [S II/Hα]
50- 53 F4.2 0.1nm FWHMSII ?=- The full width at half-maximum of
[S II] at 671.7 nm line (FWHM_[S II]_)
55- 58 F4.2 0.1nm e_FWHMSII ?=- Mean error on FWHM of [S II]
60-119 A60 --- Notes Notes on object characteristics (Notes)
--------------------------------------------------------------------------------
Note (1): NGC 300 candidate supernova remnants from
Millar et al. 2012SerAJ.184...19M 2012SerAJ.184...19M, Cat. J/other/Ser/184.19 .
Note (2): Identifier number for objects analysed by the dendogram method
described in the section 3 Region identification and classification.
Dendrograms are tree diagrams representing hierarchical structures
in astronomical images. Structures are divided into branches
(structures that can be further divided into smaller sub-structures)
and leaves (the smallest structures that cannot be divided anymore).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tableb2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- StasinskaID ?=- PNe number ID (Stasinska13id) (1)
5- 7 I3 --- ID ?=- Dendogram identifier number
(Dendrogramid) (2)
9- 16 F8.5 deg RAdeg Right Ascension (J2000)
18- 26 F9.5 deg DEdeg Declination (J2000)
28- 32 F5.2 [-] log([NII/Ha]) ?=- [N II/Hα] line ratio of
[N II] at 658.4 nm and Hα
at 656.28 nm ([N II/Hα])
34- 37 F4.2 [-] e_log([NII/Ha]) ?=- Mean error on [N II/Hα]
39- 43 F5.2 [-] log([OIII/Hb]) ?=- [O III/Hβ] line ratio of
[O III] at 500.7 nm and Hβ
at 486.13 nm ([O III/Hβ])
45- 48 F4.2 [-] e_log([OIII/Hb]) ?=- Mean error on [O III/Hβ]
50- 74 A25 --- Notes Notes on object characteristics (Notes)
--------------------------------------------------------------------------------
Note (1): NGC 300 PNe candidate from
Stasisnka et al. (2013A&A...552A..12S 2013A&A...552A..12S, Cat. J/A+A/552/A12).
Note (2): Identifier number for objects analysed by the dendogram method
described in the section 3 Region identification and classification.
Dendrograms are tree diagrams representing hierarchical structures
in astronomical images. Structures are divided into branches
(structures that can be further divided into smaller sub-structures)
and leaves (the smallest structures that cannot be divided anymore).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tableb3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- ID Dendogram identifier number
(Dendrogramid) (1)
5- 12 F8.5 deg RAdeg Right Ascension (J2000)
14- 22 F9.5 deg DEdeg Declination (J2000)
24- 27 F4.2 --- R Galactocentric radius in R25 unit (R)
(2)
29- 33 F5.2 pc r Radius of the observed H II region (r)
(3)
35- 38 F4.2 [-] 12+[O/H] Logarithm of oxygen abundance 12+log(O/H)
(12+logO/H)
40- 43 F4.2 [-] e_12+[O/H] Mean error of 12+log(O/H) (e_12+logO/H)
45- 49 F5.2 [-] log([NII/Ha]) Logarithm of [N II/Hα] line
ratio of [N II] at 658.4 nm
and Hα at 656.28 nm
([N II/Hα])
51- 54 F4.2 [-] e_log([NII/Ha]) Mean error on [N II/Hα]
56- 60 F5.2 [-] log([OIII/Hb]) Logarithm of [O III/Hβ] line
ratio of [O III] at 500.7 nm
and Hβ at 486.13 nm
([O III/Hβ])
62- 65 F4.2 [-] e_log([OIII/Hb]) Mean error on [O III/Hβ]
67- 71 F5.2 [-] log([SII/Ha]) Logarithm of [S II/Hα] line
ratio of [S II] at 671.7 nm
and Hα at 656.28 nm
([S II/Hα])
73- 76 F4.2 [-] e_log([SII/Ha]) Mean error on [S II/Hα]
78- 81 F4.2 K/cm3 log(Pdir/kb) Direct radiation pressure Pdir divided
by the Boltzmann's constant kb
(logPdir/kb) (4)
83- 86 F4.2 K/cm3 e_log(Pdir/kb) Mean error on log(Pdir/kb)
(elogPdir/kb_)
88- 91 F4.2 K/cm3 log(PHII/kb) ?=- Pressure of the ionized gas PHII
divided by the Boltzmann's constant kb
(logPHII/kb) (4)
93- 96 F4.2 K/cm3 e_log(PHII/kb) ?=- Mean error on log(PHII/kb)
98-101 F4.2 --- EtaNII The radiation softness parameter
ηNII as 'ratio of ratios'
(ηNII) (5)
103-106 F4.2 --- e_EtaNII Mean error on ηNII
108-112 F5.2 [-] S32 Logarithm of ratio between [S III]
at 906.8nm and [S II] at 671.7nm
and at 673.1nm (S32)
114-117 F4.2 [-] e_S32 Mean error on S32 (e_S32)
--------------------------------------------------------------------------------
Note (1): Identifier number for objects analysed by the dendogram method
described in the section 3 Region identification and classification.
Dendrograms are tree diagrams representing hierarchical structures
in astronomical images. Structures are divided into branches
(structures that can be further divided into smaller sub-structures)
and leaves (the smallest structures that cannot be divided anymore).
Note (2): In this paper, we use a legacy value data set covering the inner
star-forming disc of NGC 300 taken with the VLT/MUSE instrument
(Bacon et al. 2010SPIE.7735E..08B 2010SPIE.7735E..08B), consisting of a contiguous
7 arcmin * 5 arcmin mosaic (∼4 kpc * 3 kpc) and covering the galaxy
out to galactocentric radii of about 0.45*R25, (with R25 ∼ 5.33 kpc
being the optical radius; Paturel et al. 2003A&A...412...45P 2003A&A...412...45P,
Cat. VII/237).
As in the RC2 system (Second Reference Catalogue of Bright Galaxies)
R25 refers to the isophotal radius at which the surface brightness
of a galaxy reaches 25 B-magnitudes per square arcsecond in blue
light. This parameter is often used to standardize the measurement
of galaxy sizes based on their apparent surface brightness in the
B-band. It serves as a reference point to compare the physical
properties of galaxies in a consistent way across different
observations, (i.e see section 1 Introduction).
Note (3): Derived from ASTRODENDRO (http://www.dendrograms.org/) as the
geometric mean of the major and minor axes of the projection on
to the position-position plane, (i.e. of an ellipse that describes
the identified region, and for which we assume a measurement
uncertainty of 20 per cent, please see the section 3 Region
identification and classification and the section 4.2 Feedback-related
pressure terms).
Note (4): As explained in the section 4.2 Feedback-related pressure terms,
question of whether H II radiation fields has measurable consequences
on the impact of stellar feedback in these regions. As in Lopez et al.
(2014ApJ...795..121L 2014ApJ...795..121L) and Olivier et al. (2021ApJ...908...68O 2021ApJ...908...68O), we
focus here on the pressure of the ionized gas PHII (computed with
the equation 3 in the same section) and the direct radiation pressure
Pdir (computed with the equation 4 in the same section) but do not
quantify the effect of stellar winds.
Note (5): We further explore the ionization properties of H II regions within
the covered portion of NGC 300 in terms of the radiation hardness.
Similar to Perez-Montero & Vilchez (2009MNRAS.400.1721P 2009MNRAS.400.1721P) and based on
Vilchez & Pagel (1988MNRAS.231..257V 1988MNRAS.231..257V) , we use a 'ratio of ratios' to
evaluate the radiation softness parameter ηNII as
[N II 658.4 nm]/[O III 500.7nm] (use to compute N+/O2+) divide by
[S II 671.7nm, 673.1nm]/[S III 906.8nm] (use to compute S+/S2+
ratio), (i.e see the section 4.1 Gas-phase abundances and ionization
properties).
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History:
From electronic version of the journal
(End) Luc Trabelsi [CDS] 04-Sep-2024