J/MNRAS/429/189 SNRs in six nearby galaxies (Leonidaki+, 2013)
A multiwavelength study of supernova remnants in six nearby galaxies.
II. New optically selected supernova remnants.
Leonidaki I., Boumis P., Zezas A.
<Mon. Not. R. Astron. Soc., 429, 189-220 (2013)>
=2013MNRAS.429..189L 2013MNRAS.429..189L
ADC_Keywords: Galaxies, nearby ; Supernova remnants
Keywords: ISM: supernova remnants - galaxies: star formation
Abstract:
We present results from a study of optically emitting supernova
remnants (SNRs) in six nearby galaxies (NGC 2403, 3077, 4214, 4395,
4449 and 5204) based on deep narrow-band Hα and [SII] images as
well as spectroscopic observations. The SNR classification was based
on the detected sources that fulfil the well-established emission-line
flux criterion of [SII]/Hα>0.4. This study revealed ∼400
photometric SNRs down to a limiting Hα flux of
10-15erg/s/cm2. Spectroscopic observations confirmed the
shock-excited nature of 56 out of the 96 sources with
([SII]/Hα)phot>0.3 (our limit for an SNR classification) for
which we obtained spectra. 11 more sources were spectroscopically
identified as SNRs although their photometric [SII]/Hα ratio was
below 0.3. We discuss the properties of the optically detected SNRs in
our sample for different types of galaxies and hence different
environments, in order to address their connection with the
surrounding interstellar medium. We find that there is a difference in
[NII]/Hα line ratios of the SNR populations between different
types of galaxies which indicates that this happens due to
metallicity. We cross-correlate parameters of the optically detected
SNRs ([SII]/Hα ratio, luminosity) with parameters of coincident
X-ray-emitting SNRs, resulted from our previous studies on the same
sample of galaxies, in order to understand their evolution and
investigate possible selection effects. We do not find a correlation
between their Hα and X-ray luminosities, which we attribute to
the presence of material in a wide range of temperatures. We also find
evidence for a linear relation between the number of luminous optical
SNRs (1037erg/s) and star formation rate in our sample of galaxies.
Description:
Optical images were obtained with the 1.3m (f/7.7) Ritchey-Chretien
telescope at the Skinakas Observatory on 2008 June 6-12 and 2009
November 16-18. A 2048x2048 ANDOR Tech CCD was used which has a
9.6x9.6arcmin2 field of view and an image scale of 0.28arcsec/pix.
Apart from 2009 November 18, all the other observing nights were
photometric with seeing conditions ranging from 1.3 to 2.5arcsec. The
observations were performed with the narrow-band Hα+[NII], [SII]
and [OIII] filters. Broad-band continuum filters in red and blue were
used to subtract the continuum from the Hα+[NII], [SII] and
[OIII] images, respectively. The continuum filters used for the
observations are centred on line-free regions of the spectra in order
to avoid strong SNR emission lines to pass.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
snr.dat 116 419 *Properties of photometric SNRs in NGC 2403, NGC 3077,
NGC 4214, NGC 4395, NGC 4449 and NGC 5204
(tables 3-8 of the paper)
table9.dat 82 61 Photometric properties of spectroscopically-verified
non-SNRs in our sample of galaxies
table11.dat 63 204 Emission line fluxes of spectroscopically observed
SNRs in our sample of galaxies
table12.dat 95 68 Emission-line parameters of spectroscopically observed
SNRs in our sample of galaxies
table13.dat 95 61 Emission line parameters of spectroscopically-verified
non-SNRs in our sample of galaxies
notes.dat 80 102 Individual notes
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Note on snr.dat: SNR of NGC 2403 forgotten added on 10-Oct-2016 (No. 28 to 149).
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See also:
J/A+AS/114/215 : New SNR candidates in M31 (Magnier+, 1995)
J/ApJS/120/247 : Supernova remnants in M33 (Gordon+, 1999)
J/A+A/435/437 : Extragalactic SNRs brightness and diameters (Urosevic+, 2006)
J/AJ/137/3869 : Radio SNRs in 4 irregular galaxies (Chomiuk+, 2009)
J/ApJ/703/370 : Radio SNRs in nearby galaxies (Chomiuk+, 2009)
J/ApJS/187/495 : SNRs in M33 from optical and X-ray (Long+, 2010)
Byte-by-byte Description of file: snr.dat table9.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Gal Galaxy name, NGCNNNN
9- 16 A8 --- Source Source ID, LBZNNN or LBZNN-N
18- 19 I2 h RAh Right ascension (J2000)
21- 22 I2 min RAm Right ascension (J2000)
24- 27 F4.1 s RAs Right ascension (J2000)
29 A1 --- DE- Declination sign (J2000)
30- 31 I2 deg DEd Declination (J2000)
33- 34 I2 arcmin DEm Declination (J2000)
36- 39 F4.1 arcsec DEs Declination (J2000)
41- 42 I2 pix Rad Radius in pixel
44- 45 I2 pix An ? Inner radius of the annulus used for
background subtraction
46 A1 --- n_An [e] e for sources for which the background
was measured from a nearby region
48- 49 I2 pix Dan ? Outer radius of the annulus used for
background subtraction
50 A1 --- n_Dan [e] e for sources for which the background
was measured from a nearby region
52- 57 F6.2 aW/m2 F(Ha) Flux in Hα (10-15erg/cm2/s)
59- 62 F4.2 aW/m2 e_F(Ha) rms uncertainty on F(Ha)
63- 67 F5.1 aW/m2 F(SII) Flux in [SII] (10-15erg/cm2/s)
69- 72 F4.2 aW/m2 e_F(SII) rms uncertainty on F([SII])
74- 77 F4.2 --- [SII]a Photometric line ratio ([SII]/Hα
79- 82 F4.2 --- e_[SII]a rms uncertainty on [SII]a
84- 86 A3 --- Sp [Yes/No ] Spectra is available ?
88- 90 A3 --- Tel [(MS) ] Telescope: M=Mayall, S=Skinakas
92-113 A22 --- Class Classification (SNR, candidate SNR or
probable candidate SNR)
115-116 I2 --- Note ? Note, in notes.dat file
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Byte-by-byte Description of file: table11.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Gal Galaxy name, NGCNNNN
9- 13 A5 --- Source Source ID, LBZNNN
15- 17 A3 --- Param [F I S/N] Parameter measured (1)
19- 20 I2 --- Hb ?=- Hβ (4861Å) parameter value
22- 23 I2 --- 4959 ?=- [OIII] (4959Å) parameter value
25- 27 I3 --- 5007 ?=- [OIII] (5007Å) parameter value
29- 30 I2 --- 5577 ?=- [OI] (5577Å) parameter value
32- 33 I2 --- 5876 ?=- [HeI] (5876Å) parameter value
35- 36 I2 --- 6234 ?=- [HeII] (6234Å) parameter value
38- 39 I2 --- 6300 ?=- [OI] (6300Å) parameter value
41- 42 I2 --- 6364 ?=- [OI] (6364Å) parameter value
44- 45 I2 --- 6548 ?=- [NII] (6548Å) parameter value
47- 49 I3 --- Ha ?=- Hα (6563Å) parameter value
51- 52 I2 --- 6584 ?=- [NII] (6584Å) parameter value
54 I1 --- 6678 ?=- [HeI] (6678Å) parameter value
56- 57 I2 --- 6716 ?=- [SII] (6716Å) parameter value
59- 60 I2 --- 6731 ?=- [SII] (6731Å) parameter value
62- 63 I2 --- 7136 ?=- [ArIII] (7136Å) parameter value
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Note (1): Parameters as follows:
F = Observed emission line fluxes normalized to F(Hα)=100,
not corrected for interstellar extinction
I = Extinction corrected emission line fluxes, normalized to
I(Hα)=100
S/N = Signal-to-noise ratios of the quoted fluxes
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Byte-by-byte Description of file: table12.dat table13.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Gal Galaxy name, NGCNNNN
9- 16 A8 --- Source Source ID, LBZNNNN
17- 21 F5.2 10-17W/m2 F(Ha)c Absolute Hα flux, extinction corrected
(10-14erg/cm2/s)
23- 26 F4.2 --- c(Hb) ?=- Extinction (1)
28- 31 F4.2 --- e_c(Hb) ?=- rms uncertainty on c(Hb) (4)
33- 36 F4.2 mag E(B-V) ? Redenning
38- 41 F4.2 mag e_E(B-V) ? rms uncertainty on E(B-V) (4)
43- 47 F5.2 --- Ha/Hb ?=- Line ratio Hα/Hβ (2)
49- 52 F4.2 --- e_Ha/Hb ?=- rms uncertainty on Hα/Hβ (4)
54- 57 F4.2 --- [SII]c Line ratio [SII](6716+6731)/Hα
59- 62 F4.2 --- e_[SII]c rms uncertainty on [SII]/Ha (4)
64- 67 F4.2 --- [NII]c ?=- Line ratio [NII](6548+6584)/Hα (3)
69- 72 F4.2 --- e_[NII]c ?=- rms uncertainty on [NII]/Ha (4)
73 A1 --- n_[NII]c [*] one [NII] line detected (5)
75- 78 F4.2 --- [SII]r Line ratio [SII](6716)/[SII](6731) (3)
80- 83 F4.2 --- e_[SII]r rms uncertainty on [SII]1/2 (4)
85- 89 F5.2 --- [OIII]c ?=- Line ratio [OIII](4959+5007)/Hβ (3)
91- 94 F4.2 --- e_[OIII]c ?=- rms uncertainty on [OIII]/Hb (4)
95 A1 --- n_[OIII]c [*] one [OIII] line detected (5)
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Note (1): The extinction c(Hb) is derived from the relation
c=1/(0.346xlog[(Ha/Hb)spec/2.87]), using the absorbed Ha and Hb fluxes.
Note (2): For the calculation of the Ha/Hb ratios, the absorbed
measured fluxes were used.
Note (3): The rest of the ratios, and when the Hb emission line was available,
were measured from the extinction-corrected emission-line fluxes.
Note (4): All errors were calculated through standard error propagation.
Note (5): The asterisk symbol denotes that one of the two lines of [NII] or
[OIII] was detected and thus used.
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Byte-by-byte Description of file: notes.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Note Note number
4- 80 A77 --- Text Text of the note
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History:
* 23-Apr-2014: From electronic version of the journal
* 10-Oct-2016: Forgotten SNR of NGC 2403 added in snr.dat
(End) Patricia Vannier [CDS] 14-Mar-2014