J/A+A/668/A74 NGC 300 catalog of HII and DIG regions (Micheva+, 2022)
MUSE crowded field 3D spectroscopy in NGC 300.
III. Characterizing extremly faint HII regions and diffuse ionized gas.
Micheva G., Roth M.M., Weilbacher P.M., Morisset C., Castro N.,
Monreal Ibero A., Soemitro A.A., Maseda M.V., Steinmetz M., Brinchmann J.
<Astron. Astrophys. 668, A74 (2022)>
=2022A&A...668A..74M 2022A&A...668A..74M (SIMBAD/NED BibCode)
ADC_Keywords: H II regions ; Abundances ; Extinction ; Rotational velocities ;
Velocity dispersion ; Spectroscopy
Keywords: HII regions - galaxies: ISM - ISM: general - ISM: lines and bands -
ISM: kinematics and dynamics - galaxies: individual: NGC 300
Abstract:
There are known differences between the physical properties of HII
and diffuse ionized gas (DIG). However, most of the studied regions in
the literature are relatively bright, with log10
L(Hα)[erg/s]≳37.
We compiled an extremely faint sample of 390 HII regions with a
median Hα luminosity of 34.7 in the flocculent spiral galaxy NGC
300, derived their physical properties in terms of metallicity,
density, extinction, and kinematics, and performed a comparative
analysis of the properties of the DIG.
We used MUSE data of nine fields in NGC 300, covering a galactocentric
distance of zero to ∼450 arcsec (∼4 projected kpc), including spiral
arm and inter-arm regions. We binned the data in dendrogram leaves and
extracted all strong nebular emission lines. We identified HII and
DIG regions and compared their electron densities, metallicity,
extinction, and kinematic properties. We also tested the effectiveness
of unsupervised machine-learning algorithms in distinguishing between
the HII and DIG regions.
The gas density in the HII and DIG regions is close to the
low-density limit in all fields. The average velocity dispersion in
the DIG is higher than in the HII regions, which can be explained
by the DIG being 1.8kK hotter than HII gas. The DIG manifests a
lower ionization parameter than HII gas, and the DIG fractions vary
between 15-77%, with strong evidence of a contribution by hot
low-mass evolved stars and shocks to the DIG ionization. Most of the
DIG is consistent with no extinction and an oxygen metallicity that is
indistinguishable from that of the HII gas. We observe a flat
metallicity profile in the central region of NGC 300, without a sign
of a gradient.
The differences between extremely faint HII and DIG regions follow
the same trends and correlations as their much brighter cousins. Both
types of objects are so heterogeneous, however, that the differences
within each class are larger than the differences between the two
classes.
Description:
A catalog of extremely faint HII and diffuse ionized gas (DIG) regions
from MUSE data of nine fields in NGC 300, covering a galactocentric
distance of 0 to 450 arcsec. The catalog provides emission line
fluxes, kinematics, sizes, extinction, and metallicities for each
region. All regions are constructed via the dendrogram method. For
more details, see the associated paper. DIG regions are dialated ring
masks around HII regions, which is why their peak x, y coordinates are
the same as for the HII region they were created from, but their
number of pixels is different.
The data are taken in 2014, 2016, and 2018. All observations used the
wide- field mode, and individual exposures of 900s were made, with
90 deg rotations in between exposures and with an offset sky exposure
taken after two science exposures. Fields A, B, and C were carried out
with AO support in WFM-AO-E and WFM-AO-N. Fields D, E, I, J, P, and Q
were carried out without AO support in WFM-NOAO-E.
Objects:
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RA (2000) DE Designation(s)
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00 54 53.48 -37 41 03.9 NGC 300 = LEDA 3238
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
ngc300.dat 912 1290 Extremely faint HII and diffuse ionized gas
(DIG) regions from MUSE data of nine fields
in NGC 300
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See also:
J/A+A/618/A3 : NGC 300 MUSE spectroscopy for central fields (Roth+, 2018)
J/ApJ/789/81 : Multiwavelength survey of HII regions in NGC 300 (Faesi+, 2014)
Byte-by-byte Description of file: ngc300.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- Type [HII DIG] Classification into HII or DIG
5 A1 --- Field Field identifier, one of A,B,C,D,E,I,J,P,Q
7- 11 I5 --- Npix [10/36108] Number of pixels inside of the
dendrogram leaf and ring mask for HII and
DIG, respectively.
13- 17 F5.1 pix Xpeak [1.0/915.0] X pixel coordinate of the peak
flux pixel inside of the HII region
19- 23 F5.1 pix Ypeak [3.0/323.0] Y pixel coordinate of the peak
flux pixel inside of the HII region
25- 46 E22.17 mW/m2 Fpeak ?=0 Flux inside of the brightest pixel of
the dendrogram or ring mask
48- 65 F18.15 deg RAdeg [13.58/13.74] Right Ascension (J2000)
of the peak pixel
67- 85 F19.15 deg DEdeg [-37.72/-37.59] Declination (J2000)
of the peak pixel
87-106 F20.16 arcsec galdist [3.05/486.77] Galactocentric distance to the
Xpeak,Ypeak coordinates
108-125 F18.14 km/s gasV [111.92/237.43] Gas velocity from pPXF
127-146 F20.17 km/s e_gasV [0.05/11.19] Error in Gas velocity from pPXF
148-166 F19.16 km/s gasSigma [0.99/64.44] Gas velocity dispersion
from pPXF
168-188 F21.17 km/s e_gasSigma [0.12/156.96] Error in Gas velocity
dispersion from pPXF
190-210 F21.19 mag gasE(B-V) E(B-V) of the gas
212-233 E22.17 mag e_gasE(B-V) Error in E(B-V) of the gas
235-256 E22.17 mW/m2 Halpha ?=0 Hα (6562.791Å) line flux
258-279 E22.17 mW/m2 e_Halpha ?=0 Error in Halpha (6562.791Å) line flux
281-302 E22.17 mW/m2 Hbeta ?=0 Hβ (4861.32Å) line flux
304-325 E22.17 mW/m2 e_Hbeta ?=0 Error in Hbeta (4861.32Å) line flux
327-348 E22.17 mW/m2 SII6716 ?=0 [SII]6716.44Å line flux
350-371 E22.17 mW/m2 e_SII6716 ?=0 Error in [SII]6716.44Å line flux
373-394 E22.17 mW/m2 SII6731 ?=0 [SII]6730.816Å line flux
396-417 E22.17 mW/m2 e_SII6731 ?=0 Error in [SII]6730.816Å line flux
419-440 E22.17 mW/m2 OII7320 ?=0 [OII]7319.99Å line flux
442-463 E22.17 mW/m2 e_OII7320 ?=0 Error in [OII]7319.99Å line flux
465-486 E22.17 mW/m2 OII7330 ?=0 [OII]7330.73Å line flux
488-509 E22.17 mW/m2 e_OII7330 ?=0 Error in [OII]7330.73Å line flux
511-532 E22.17 mW/m2 SIII6312 ?=0 [SIII]6312.06Å line flux
534-555 E22.17 mW/m2 e_SIII6312 ?=0 Error in [SIII]6312.06Å line flux
557-578 E22.17 mW/m2 SIII9068 ?=0 [ArIII]7135.79Å line flux
580-601 E22.17 mW/m2 e_SIII9068 ?=0 Error in [ArIII]7135.79Å line flux
603-624 E22.17 mW/m2 ArIII7136 ?=0 [SIII]9068Å line flux
626-647 E22.17 mW/m2 e_ArIII7136 ?=0 Error in [SIII]9068Å line flux
649-670 E22.17 mW/m2 OIII5007 ?=0 [OIII]5006.843Å line flux
672-693 E22.17 mW/m2 e_OIII5007 ?=0 Error in [OIII]5006.843Å line flux
695-716 E22.17 mW/m2 NII6583 ?=0 [NII]6583.45Å line flux
718-739 E22.17 mW/m2 e_NII6583 ?=0 Error in [NII]6583.45Å line flux
741-758 F18.15 --- M13-12logOH [8.24/8.77]? 12+logO/H metallicity with the
Marino et al. (2013, Cat. J/A+A/559/A114)
calibration of the O3N2 strong-line method
760-781 F22.19 --- e_M13-12logOH [0.0/8.77]? Non-symmetric lower error in the
12+logO/H metallicity with the Marino et
al. (2013, Cat. J/A+A/559/A114) calibration
of the O3N2 strong-line method
783-804 F22.19 --- E_M13-12logOH [0.0/0.62]? Non-symmetric upper error in the
12+logO/H metallicity with the Marino et
al. (2013, Cat. J/A+A/559/A114) calibration
of the O3N2 strong-line method
806-824 F19.16 --- P16-12logOH [7.74/9.4]? 12+logO/H metallicity with the
Pilyugin & Grebel (2016MNRAS.457.3678P 2016MNRAS.457.3678P)
S-calibration
826-847 F22.19 --- e_P16-12logOH [0.0/2.18]? Non-symmetric lower error in the
12+logO/H metallicity with the Pilyugin &
Grebel (2016MNRAS.457.3678P 2016MNRAS.457.3678P) S-calibration
849-870 F22.19 --- E_P16-12logOH [0.0/0.49]? Non-symmetric upper error in the
12+logO/H metallicity with the Pilyugin &
Grebel (2016MNRAS.457.3678P 2016MNRAS.457.3678P) S-calibration
872-890 F19.15 10-7W LumHa [33.16/37.27]? Log10 of the Luminosity of
Halpha [erg/s] line flux
892-912 F21.18 10-7W e_LumHa [0.0/0.77]? Error in Log10 of the Luminosity
of Halpha [erg/s] line flux
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Acknowledgements:
Genoveva Micheva, gmicheva(at)aip.de
(End) Patricia Vannier [CDS] 10-Oct-2022