J/A+A/589/A110 SN II in host HII regions (Anderson+, 2016)
Type II supernovae as probes of environment metallicity:
observations of host H II regions.
Anderson J.P., Gutierrez C.P., Dessart L., Hamuy M., Galbany L.,
Morrell N.I., Stritzinger M.D., Phillips M.M., Folatelli G., Boffin H.M.J.,
De Jaeger T., Kuncarayakti H., Prieto J.L.
<Astron. Astrophys., 589, A110 (2016)>
=2016A&A...589A.110A 2016A&A...589A.110A (SIMBAD/NED BibCode)
ADC_Keywords: H II regions ; Supernovae
Keywords: supernovae: general - HII regions - galaxies: abundances
Abstract:
Spectral modelling of typeII supernova atmospheres indicates a clear
dependence of metal line strengths on progenitor metallicity. This
dependence motivates further work to evaluate the accuracy with which
these supernovae can be used as environment metallicity indicators.
To assess this accuracy we present a sample of type II supernova host
HII-region spectroscopy, from which environment oxygen abundances have
been derived. These environment abundances are compared to the
observed strength of metal lines in supernova spectra.
Combining our sample with measurements from the literature, we present
oxygen abundances of 119 host HII regions by extracting emission line
fluxes and using abundance diagnostics. These abundances are then
compared to equivalent widths of FeII 5018Å at various time and
colour epochs.
Our distribution of inferred type II supernova host HII-region
abundances has a range of ∼0.6dex. We confirm the dearth of type II
supernovae exploding at metallicities lower than those found (on
average) in the Large Magellanic Cloud. The equivalent width of FeII
5018Å at 50 days post-explosion shows a statistically significant
correlation with host HII-region oxygen abundance. The strength of
this correlation increases if one excludes abundance measurements
derived far from supernova explosion sites. The correlation
significance also increases if we only analyse a "gold" IIP
sample, and if a colour epoch is used in place of time. In addition,
no evidence is found of a correlation between progenitor metallicity
and supernova light-curve or spectral properties - except for that
stated above with respect to FeII 5018Å equivalent widths -
suggesting progenitor metallicity is not a driving factor in producing
the diversity that is observed in our sample.
This study provides observational evidence of the usefulness of typeII
supernovae as metallicity indicators. We finish with a discussion of
the methodology needed to use supernova spectra as independent
metallicity diagnostics throughout the Universe.
Description:
The data analysed in this publication comprise two distinct types of
observations. The first is of SN II optical spectroscopy obtained
during their photospheric phases, i.e. from discovery to at most ∼100
days post explosion. These data are used to extract absorption line
pEW measurements. The second data set is emission line spectral
observations of host HII regions of SNe II. These are used to
estimate SN II environment oxygen abundances, which can be used as
metallicity proxies. In the course of this work we compare our
observational results with the predictions from the spectral models of
Dessart et al. (2014MNRAS.440.1856D 2014MNRAS.440.1856D).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablea1.dat 67 119 SN and host galaxy data
tableb1.dat 84 119 HII region abundances and SN pEWs
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- SN SN name
7- 8 A2 --- n_SN [* ] Note on SN (1)
10- 25 A16 --- Host Host galaxy name
27- 31 I5 km/s Vr ?=- Host galaxy recession velocity (2)
33- 37 F5.1 mag BMAGH ?=- Host absolute B magnitude (3)
39- 43 F5.2 10-2mag/d s2 ?=- "plateau" decline rate, in mag/100d (4)
45- 50 F6.2 mag Mmax ?=- Absolute magnitude at maximum light (4)
52- 57 F6.2 d OPTd ?=- Optically thick phase duration (4)
59- 62 F4.2 --- a/e ?=- Ratio of pEWs of Hα absorption
to emission (4)
64- 67 I4 km/s VHa ?=- FWHM velocity of Hα (with the
latter two measured at a common epoch) (4)
--------------------------------------------------------------------------------
Note (1): Notes as follows:
* = SNe IIn
** = SNe IIb
Note (2): taken from NED: http://ned.ipac.caltech.edu/
Note (3): taken from HyperLeda: http://leda.univ-lyon1.fr/
Note (4): SN V-band photometric and spectroscopic Hα parameters
The reader is referred to Anderson et al. (2014ApJ...786...67A 2014ApJ...786...67A) and
Gutierrez et al. (2014ApJ...786L..15G 2014ApJ...786L..15G) for more details of those measurements.
(It is important to note that the SN magnitudes we use within this analysis
have not been corrected for host galaxy extinction.)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tableb1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- SN SN name
7 A1 --- f_SN [*] Note on SN (5)
9- 13 F5.2 kpc Dist HII distance of the spectral extraction
region from the explosion site
15- 18 F4.2 --- M13-N2 ?=- Oxygen abundances as calculated by the
M13 N2 diagnostic
20- 23 F4.2 --- E_M13-N2 ? Error on M13-N2 (upper value)
25- 28 F4.2 --- e_M13-N2 ? Error on M13-N2 (lower value)
30- 33 F4.2 --- M13-O3N2 ?=- Oxygen abundances as calculated by the
M13 O3N2 diagnostic
35- 38 F4.2 --- E_M13-O3N2 ? Error on M13-O3N2 (upper value)
40- 43 F4.2 --- e_M13-O3N2 ? Error on M13-O3N2 (lower value)
45- 48 F4.2 --- PP04-N2 ?=- Oxygen abundances as calculated by the
Pettini & Pagel (2004MNRAS.348L..59P 2004MNRAS.348L..59P)
N2 diagnostic
50- 53 F4.2 --- E_PP04-N2 ?=- Error on PP04-N2 (upper value)
55- 58 F4.2 --- e_PP04-N2 ?=- Error on PP04-N2 (lower value)
60- 63 F4.2 --- PP04-O3N2 ?=- Oxygen abundances as calculated by the
Pettini & Pagel (2004MNRAS.348L..59P 2004MNRAS.348L..59P)
O3N2 diagnostic
65- 68 F4.2 --- E_PP04-O3N2 ?=- Error on PP04-O3N2 (upper value)
70- 73 F4.2 --- e_PP04-O3N2 ?=- Error on PP04-O3N2 (lower value)
75- 79 F5.2 0.1nm pEW ?=- FeII 5018Å pseudo equivalent width as
estimated at 50days
81- 84 F4.2 0.1nm e_pEW ? rms uncertainty on pEW (6)
--------------------------------------------------------------------------------
Note (5): * when abundance measurements are taken from Anderson et al.
(2010MNRAS.407.2660A 2010MNRAS.407.2660A).
Note (6): Errors on pEWs are those obtained from the fitting process to the
sample of pEWs for each SN. In the case of a straight-line fit to two data
points we set the minimum error to 0.5Å. The inferred abundances of
SN 2005dn are upper limits as [NII] was not detected in the spectra.
To estimate abundances a 3σ [NII] flux upper limit was calculated using
an estimation of the rms noise in the spectrum close in wavelength to the
spectral line. Removing this SN from our correlations has a negligible effect
on our results and conclusions.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 25-Jul-2016