J/MNRAS/444/757 HII complexes optical and IR emissions (Khramtsova+, 2014)
Optical and infrared emission of HII complexes as a clue to the PAH life cycle.
Khramtsova M.S., Wiebe D.S., Lozinskaya T.A., Egorov O.V.
<Mon. Not. R. Astron. Soc., 444, 757-775 (2014)>
=2014MNRAS.444..757K 2014MNRAS.444..757K
ADC_Keywords: Galaxies, nearby ; H II regions ; Interstellar medium ;
Photometry, infrared ; Spectroscopy
Keywords: galaxies: ISM - infrared: galaxies - infrared: ISM
Abstract:
We present an analysis of optical spectroscopy and infrared aperture
photometry of more than 100 HII complexes in nine galaxies. Spectra
obtained with the 6-m telescope of Special Astrophysical Observatory
of the Russian Academy of Sciences are used along with archival data
from Spitzer and several ground-based telescopes to infer a
strength of polycyclic aromatic hydrocarbon (PAH) emission, age,
properties of the UV radiation field, and metallicity of studied HII
complexes. Physical properties (age, radiation field parameters,
metallicity) are related to the F8/F24 ratio used as a
proxy for the PAH abundance in order to reveal factors that may
influence the PAH evolution in HII complexes. The well-known
correlation between the F8/F24 ratio and metallicity is
confirmed in the studied complexes. The infrared flux ratio also
correlates with the [Oiii]λ5007/Hβ ratio which is often
considered as an indicator of the radiation field hardness, but this
correlation seems to be a mere reflection of a correlation between
[Oiii]λ5007/Hβ and metallicity. In separate metallicity
bins, the F8/F24 ratio is found to correlate with an age
of an Hii complex, which is estimated from the equivalent width of
Hβ line. The correlation is positive for low-metallicity
complexes and negative for high-metallicity complexes. Analysing
various mechanisms of PAH formation and destruction in the context of
found correlations, we suggest that PAH abundance is likely altered by
the UV radiation within HII complexes, but this is not necessarily due
to their destruction. If PAHs can also form in Hii complexes due to
some processes like aromatization, photodestruction, shattering and
sputtering of very small grains, the net F8/F24 ratio is
determined by a balance between all these processes that can be
different at different metallicities.
Description:
Spectroscopic observations of HII complexes in IC 1727 and NGC 7741
galaxies were performed with the 6-m telescope of the Special
Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS)
using the multi-mode SCORPIO focal reducer in the long-slit
spectroscopy mode on 22-23 of October, 2011.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 44 9 Summary of galaxies included in the work
table2.dat 129 21 List of studied HII complexes in galaxies IC 1727
and NGC 7741 and results of spectroscopy of
HII complexes
table3.dat 147 110 Results of aperture infrared photometry of
HII complexes
table4.dat 53 109 Parameters of HII complexes
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Galaxy Galaxy name
13- 14 I2 --- N [6/21] Number of studied HII complexes
16 A1 --- --- [(]
17- 18 I2 --- N2 [10/11]? Number of HII complexes in table2
19 A1 --- --- [)]
21- 24 F4.1 Mpc Dist [3.4/15.1] Adopted distance
26 I1 --- r_Dist Distance reference (1)
28- 34 A7 --- MType Morphological type
36- 44 A9 --- r_MType Morphological type reference (1)
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Note (1): References as follows:
1 = Tully et al. (2009AJ....138..323T 2009AJ....138..323T)
2 = Karachentsev et al. (2004, Cat. J/AJ/127/2031)
3 = Jacobs et al. (2009, Cat. J/AJ/138/332)
4 = Dalcanton et al. (2009ApJS..183...67D 2009ApJS..183...67D)
5 = Leonard et al. (2002AJ....124.2506L 2002AJ....124.2506L)
6 = Egorov, Lozinskaya & Moiseev (2013MNRAS.429.1450E 2013MNRAS.429.1450E)
7 = Croxall et al. (2009ApJ...705..723C 2009ApJ...705..723C)
8 = Gusev et al. (2012MNRAS.424.1930G 2012MNRAS.424.1930G)
9 = van Zee et al. (1998, Cat. J/AJ/116/2805)
10 = Ryder (1995ApJ...444..610R 1995ApJ...444..610R)
11 = Gusev, Sakhibov & Dodonov (2013AstBu..68...40G 2013AstBu..68...40G)
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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- 8 A8 --- Galaxy Galaxy name
10- 20 A11 --- Complex Designation of complex
22- 26 F5.2 arcsec oRA Offset in right ascension (from the galaxy)
28- 34 F7.2 arcsec oDE Offset in declination (from the galaxy)
36- 39 F4.2 --- I(3728) [2.2/5.2] Bright line intensity of [OII]
λ3727+3729 normalized to Hβ
41- 44 F4.2 --- e_I(3728) [0.1/1.2] rms uncertainty on I(3728)
46- 49 F4.2 --- I(4959) [0.1/1.5] Bright line intensity of
[OIII] λ4959 normalized to Hβ
51- 54 F4.2 --- e_I(4959) [0.01/0.12] rms uncertainty on I([OIII])1
56- 59 F4.2 --- I(5007) [0.19/4.20] Bright line intensity of
[OIII] λ5007 normalized to Hβ
61- 64 F4.2 --- e_I(5007) [0.01/0.11] rms uncertainty on I([OIII])2
66- 69 F4.2 --- I(Ha) [2.7/3.1] Bright line intensities of Hα
normalized to Hβ
71- 74 F4.2 --- e_I(Ha) [0.02/0.15] rms uncertainty on I(Ha)
76- 79 F4.2 --- I([NII]) [0.17/0.82] Bright line intensity of
[NII]λ6548+6584 normalized to Hβ
81- 84 F4.2 --- e_I([NII]) [0.02/0.22] rms uncertainty on I([NII])
86- 89 F4.2 --- I([SII]) [0.42/1.14] Bright line intensity or
[SII] λ6717+6731 normalized to Hβ
91- 94 F4.2 --- e_I([SII]) [0.03/0.37] rms uncertainty on I([SII])
96-100 F5.1 0.1nm EWHb [4/130] Hβ equivalent width
102-104 F3.1 0.1nm e_EWHb [0.1/2.5] rms uncertainty on EWHb
106-109 F4.2 mag E(B-V) [0.04/0.39] Redenning
111-114 F4.2 mag e_E(B-V) [0.01/0.19] rms uncertainty on E(B-V)
116-119 F4.2 [-] Ab(O) [7.9/8.5] Abundance 12+log(O/H), estimated by
the ONS method (G1)
121-124 F4.2 [-] e_Ab(O) [0.03/0.13] rms uncertainty on Ab(O)
126-129 F4.2 --- r/R25 [0.1/0.8] Radial distance from the centre
of a galaxy normalized to a R25
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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- 11 A11 --- Galaxy Galaxy name
14- 24 A11 --- Complex Designation of complex
26- 27 I2 h RAh Rigth ascension (J2000)
29- 30 I2 min RAm Rigth ascension (J2000)
32- 37 F6.3 s RAs Rigth ascension (J2000)
39 A1 --- DE- Declination sign (J2000)
40- 41 I2 deg DEd Declination (J2000)
43- 44 I2 arcmin DEm Declination (J2000)
46- 50 F5.2 arcsec DEs Declination (J2000)
52- 55 F4.1 arcsec Ap [4/14] Aperture radius
57- 62 F6.4 mJy F3.6 Spitzer/IRAC flux at 3.6um
64- 68 F5.3 mJy e_F3.6 rms uncertainty on F3.6um
71- 75 F5.3 mJy F4.5 Spitzer/IRAC flux at 4.5um
77- 81 F5.3 mJy e_F4.5 rms uncertainty on F4.5um
84- 88 F5.3 mJy F5.8 Spitzer/IRAC flux at 5.8um
90- 94 F5.3 mJy e_F5.8 rms uncertainty on F5.8um
96-101 F6.3 mJy F8.0 Spitzer/IRAC flux at 8.0um
103-107 F5.3 mJy e_F8.0 rms uncertainty on F8.0um
109-114 F6.3 mJy F8.0e PAH emission at 8.0um (1)
116-120 F5.3 mJy e_F8.0e rms uncertainty on F24e
122-127 F6.3 mJy F24 Spitzer/MIPS flux at 24um
129-133 F5.3 mJy e_F24 rms uncertainty on F24um
135-141 F7.4 mJy F24e PAH emission at 24um
143-147 F5.3 mJy e_F24e rms uncertainty on F24e
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Note (1): also designated as 'afe' flux (Aromatic Feature Emission)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Galaxy Galaxy name
13- 23 A11 --- Complex Designation of complex
25- 28 F4.2 Myr Age [0.1/8.6] Age
30- 33 F4.2 Myr e_Age [0.01/1.1] rms uncertainty on Age
35- 38 F4.2 [-] Ab(O) [7.4/9] Abundance 12+log(O/H) (G1)
40- 43 F4.2 [-] e_Ab(O) [0.01/0.15] rms uncertainty on Ab(O)
45- 48 F4.2 --- I(5007) [0/5] Ratio [OIII]λ5007/Hβ
considered as a potential indicator of the
radiation field hardness
50- 53 F4.2 --- e_I(5007) rms uncertainty on I(5007)
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Global Notes:
Note (G1): the 2 methods used to derive the metallicities are:
ONS: based on the measurements of bright oxygen [OII]λ3727+3729,
[OIII]λ4959,5007, Nitrogen [NII]λ6548+6584, and
[SII]λ6717+6731 (Pilyugin et al. 2010ApJ...720.1738P 2010ApJ...720.1738P)
NS: for HolmbergII, where [OII]λ3727+3729 is missing;
see Pilyugin & Mattsson, 2011MNRAS.412.1145P 2011MNRAS.412.1145P.
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 23-Apr-2015