J/A+A/587/L7 Metallicity from Type II SN from (i)PTF (Taddia+, 2016)
Metallicity from Type II supernovae from the (i)PTF.
Taddia F., Moquist P., Sollerman J., Rubin A., Leloudas G., Gal-Yam A.,
Arcavi I., Cao Y., Filippenko A.V., Graham M.L., Mazzali P.A., Nugent P.E.,
Pan Y.-C., Silverman J.M., Xu D., Yaron O.
<Astron. Astrophys., 587, L7-7 (2016)>
=2016A&A...587L...7T 2016A&A...587L...7T (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Supernovae ; Abundances
Keywords: supernovae: general - Galaxy: abundances
Abstract:
Type IIP supernovae (SNe IIP) have recently been proposed as
metallicity (Z) probes. The spectral models of Dessart et al.
(2014MNRAS.440.1856D 2014MNRAS.440.1856D) showed that the pseudo-equivalent width of FeII
λ5018 (pEW5018) during the plateau phase depends on the
primordial Z, but there was a paucity of SNe IIP exhibiting pEW5018
that were compatible with Z<0.4Z☉. This lack might be due to
some physical property of the SN II population or to the fact that
those SNe have been discovered in luminous, metal-rich targeted
galaxies. Here we use SN II observations from the untargeted
(intermediate) Palomar Transient Factory [(i)PTF] survey, aiming to
investigate the pEW5018 distribution of this SN population and, in
particular, to look for the presence of SNe II at lower Z. We perform
pEW5018 measurements on the spectra of a sample of 39 (i)PTF SNe II,
selected to have well-constrained explosion epochs and light-curve
properties. Based on the comparison with the pEW5018 spectral
models, we subgrouped our SNe into four Z bins from Z≃0.1 Z☉ up
to Z≃2 Z☉. We also independently investigated the Z of the
hosts by using their absolute magnitudes and colors and, in a few
cases, using strong-line diagnostics from spectra. We searched for
possible correlations between SN observables, such as their peak
magnitudes and the Z inferred from pEW5018. We found 11 events with
pEW5018 that were small enough to indicate Z≃0.1 Z☉. The
trend of pEW5018 with Z matches the Z estimates obtained from the
host-galaxy photometry, although the significance of the correlation
is weak. We also found that SNe with brighter peak magnitudes have
smaller pEW5018 and occur at lower Z.
Description:
We collected the optical spectra of the 57 SNe II presented by R15, as
obtained by the (i)PTF collaboration.
The selected spectra were obtained with many different telescopes and
instruments, as summarized in Table A.1.
For each spectrum where FeIIλ5018 was identified, we
established the phase, based on the explosion date reported by Rubin
et al. (2016ApJ...820...33R 2016ApJ...820...33R).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 56 39 Log of spectral observations and pEW measurements
tablea2.dat 109 39 Log of metallicity estimates and galaxy properties
for our sample of (i)PTF SNe II
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- SN (i)PTF SN designation (YYaaa)
6 A1 --- n_SN [*] Note on SN (G1)
8- 13 F6.2 d Phase Phase, from explosion date, and corrected for
time dilation
15- 18 F4.2 d e_Phase rms uncertainty on Phase
20- 24 F5.2 0.1nm mpEW5018 Opposite of the pseudo equivalent width
of FeII 5018Å, -pEW5018
26- 29 F4.2 0.1nm e_mpEW5018 rms uncertainty on mpEW5018
31- 44 A14 --- Tel Telescope+Instrument
47- 56 A10 "date" Obs.date Observation date
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- SN (i)PTF SN designation (YYaaa)
6 A1 --- n_SN [*] Note on SN (G1)
8- 35 A28 --- Host Host-galaxy name
37- 38 I2 h RAh ? Host-galaxy right ascension (J2000)
40- 41 I2 min RAm ? Host-galaxy right ascension (J2000)
43- 48 F6.3 s RAs ? Host-galaxy right ascension (J2000)
50 A1 --- DE- Host-galaxy declination sign (J2000)
51- 52 I2 deg DEd ? Host-galaxy declination (J2000)
54- 55 I2 arcmin DEm ? Host-galaxy declination (J2000)
57- 61 F5.2 arcsec DEs ? Host-galaxy declination (J2000)
63- 66 F4.2 --- dSN/Rg ?=- Deprojected distance of each SN from its
host-galaxy center (normalized by the
De Vaucouleurs g-band radius of the host)
68- 73 F6.2 mag rMAG ?=- Absolute r-band magnitude of the host
galaxy
75- 79 F5.2 mag g-r ?=- g-r color index of the host galaxy
81- 84 F4.2 Sun Zhost1 ?=- Host Z position as measured from the
luminosity-metallicity relation (LZ) (2)
86- 89 F4.2 Sun Zhost2 ?=- Host Z position as measured from the
luminosity-color-metallicity relation
(LCZ) (2)
91- 94 F4.2 Sun Zhost3 ?=- Host Z position as measured from the
strong-line diagnostic (O3N2;
Pettini & Pagel, 2004MNRAS.348L..59P 2004MNRAS.348L..59P) (2)
96- 99 F4.2 Sun ZSN1 ?=- SN Z position as measured from the
luminosity-metallicity relation (LZ) (2)
101-104 F4.2 Sun ZSN2 ?=- SN Z position as measured from the
luminosity-color-metallicity relation
(LCZ) (2)
106-109 F4.2 Sun ZSN3 ?=- Host Z position as measured from the
strong-line diagnostic (O3N2;
Pettini & Pagel, 2004MNRAS.348L..59P 2004MNRAS.348L..59P) (2)
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Note (2): When computing the metallicity at the SN distance from the
host-galaxy center, we converted the average Z gradient in units of
DeVRad_g-1 by multiplying the metallicity gradient by 0.3, which is the
typical ratio between DeVRad_g-1 and the isophotal radius in the g-band.
The isophotal radius, isoA_g, is available only for the SDSS galaxies in
the DR7.
The host of PTF10vdl is not detected, those of PTF09fma, PTF11hsj, and
PTF11hzt are not in the SDSS footprint. We exclude these hosts from the
analysis presented in Fig. 3. The vast majority of our SN hosts are in the
optimal Mg-(g-r) range where the LCZ relation was calibrated. The adoption of
a standard gradient for all the host galaxies is a strong assumption and
could lead to erroneous local metallicity estimates for some of the SNe if
their actual gradient is significantly different from ours, as it could be
for dwarf galaxies.
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Glonal notes:
Note (G1): *: SN IIL. The other objects are SNe IIP.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 09-Jun-2016