J/MNRAS/492/4325 BSNIP Spectroscopy of 247 type Ia supernovae (Stahl+, 2020)
Berkeley supernova Ia program: data release of 637 spectra from 247 Type Ia
supernovae.
Stahl B.E., Zheng W., de Jaeger T., Brink T.G., Filippenko A.V.,
Silverman J.M., Cenko S.B., Clubb K.I., Graham M.L., Halevi G., Kelly P.L.,
Kleiser I., Shivvers I., Yuk H., Cobb B.E., Fox O.D., Kandrashoff M.T.,
Kong J.J., Mauerhan J.C., Wang X., Wang X.
<Mon. Not. R. Astron. Soc., 492, 4325-4343 (2020)>
=2020MNRAS.492.4325S 2020MNRAS.492.4325S (SIMBAD/NED BibCode)
ADC_Keywords: Supernovae ; Redshifts ; Spectra, optical
Keywords: techniques: spectroscopic - surveys - supernovae: general
distance scale - cosmology: observations
Abstract:
We present 637 low-redshift optical spectra collected by the Berkeley
Supernova Ia Program (BSNIP) between 2009 and 2018, almost entirely
with the Kast double spectrograph on the Shane 3 m telescope at Lick
Observatory. We describe our automated spectral classification scheme
and arrive at a final set of 626 spectra (of 242 objects) that are
unambiguously classified as belonging to Type Ia supernovae (SNe Ia).
Of these, 70 spectra of 30 objects are classified as spectroscopically
peculiar (i.e. not matching the spectral signatures of 'normal' SNe
Ia) and 79 SNe Ia (covered by 328 spectra) have complementary
photometric coverage. The median SN in our final set has one epoch of
spectroscopy, has a redshift of 0.0208 (with a low of 0.0007 and high
of 0.1921), and is first observed spectroscopically 1.1d after maximum
light. The constituent spectra are of high quality, with a median
signal-to-noise ratio of 31.8pixel-1, and have broad wavelength
coverage, with ∼95 per cent covering at least 3700-9800Å. We
analyse our data set, focusing on quantitative measurements (e.g.
velocities, pseudo-equivalent widths) of the evolution of prominent
spectral features in the available early-time and late-time spectra.
The data are available to the community, and we encourage future
studies to incorporate our spectra in their analyses.
Description:
All Berkeley Supernova Ia Program (BSNIP) spectroscopy, along with
useful metadata for those observations and the SNe in them (e.g.
observer, reducer, host galaxy, redshift), are catalogued in our UC
Berkeley SuperNova DataBase (SNDB; Silverman et al.
2012MNRAS.425.1789S 2012MNRAS.425.1789S, Cat. J/MNRAS/425/1789, Shivvers et al.
2016MNRAS.461.3057S 2016MNRAS.461.3057S) after the data are processed and reduced.
Therefore, to collect the data set presented herein, we simply query
the private (pre-publication) portion of our SNDB for all spectra
observed between 2009 January 1 and 2018 December 31 for objects
spectroscopically classified as SNe Ia.
This results in 744 matches, which we then filter by (i) selecting
only those spectra with an average signal-to-noise ratio (SNR) greater
than 5/pixel and (ii) retaining only those with a wavelength coverage
of at least 3700-7000Å. Finally, we remove several of the remaining
spectra, including any that are from SNe discovered earlier than 2008
January 1, to obtain a set of 637 spectra.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 93 247 SN Ia information
tables1.dat 92 637 SN Ia spectral information
tables2.dat 97 608 SNID classification results
table3.dat 51 9 Spectral features
tables4.dat 89 1154 SN Ia spectral feature measurements near
maximum brightness
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 23 A23 --- Name Supernova name
25- 34 I10 "Y:M:D" Discov Discovery date (UT)
36- 43 F8.4 deg RAdeg Right ascension (J2000)
45- 52 F8.4 deg DEdeg Declination (J2000)
54- 59 F6.4 --- z ? Heliocentric redshift mostly from NED
61 A1 --- r_z Reference for z (1)
63- 67 F5.3 mag E(B-V) Extinction calculated at the supernova
position (2)
69- 75 A7 --- Subtype Supernova subtype (3)
77- 78 I2 --- Nsp Number of spectra
80- 84 F5.1 d fepoch ? First observation epoch (4)
86- 90 F5.1 d lepoch ? Last observation epoch (4)
92- 93 I2 --- Ref ? Reference for the light-curve-determined
MJD corresponding to B-band maximum
brightness (5)
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Note (1): Flag as follows:
c = Supernova catalogue of Lennarz, Altmann & Wiebusch (2012A&A...538A.120L 2012A&A...538A.120L,
Cat. J/A+A/538/A120)
p = Spectroscopic host-galaxy observations of PTF SNe Ia described by
Pan et al. (2014MNRAS.438.1391P 2014MNRAS.438.1391P, Cat. J/MNRAS/438/1391)
t = Transient Name Server (TNS)
w = Weizmann Interactive Supernova Data Repository Yaron & Gal-Yam
(WISeREP 2012PASP..124..668Y 2012PASP..124..668Y)
d = Appropriate discovery or classification announcement (e.g. CBET or IAUC)
Note (2): Extinction calculated using the dust maps of Schlegel, Finkbeiner &
Davis (1998ApJ...500..525S 1998ApJ...500..525S) subject to the recalibration of
Schlafly & Finkbeiner (2011ApJ...737..103S 2011ApJ...737..103S)
Note (3): SN classifications are derived from our SNID classification scheme,
as described in Section 3. Based on the arguments made by Foley et al.
(2013ApJ...767...57F 2013ApJ...767...57F), we have relabelled all SNe Ia with a 'Ia-02cx'
subtype as 'Iax'
Note (4): First and last observation epochs are in rest-frame days relative to
the time of B-band maximum brightness and are computed using
information from the table
Note (5): References as follows:
1 = Stahl et al. (2019MNRAS.490.3882S 2019MNRAS.490.3882S) (S19)
2 = Friedman et al. (2015ApJS..220....9F 2015ApJS..220....9F, Cat. J/ApJS/220/9) and references
therein
3 = Foley et al. (2018MNRAS.475..193F 2018MNRAS.475..193F, Cat. J/MNRAS/475/193)
4 = Krisciunas et al. (2017AJ....154..211K 2017AJ....154..211K, Cat. J/AJ/154/211)
5 = Maguire et al. (2014MNRAS.444.3258M 2014MNRAS.444.3258M, Cat. J/MNRAS/444/3258)
6 = Khan et al. (2011ApJ...726..106K 2011ApJ...726..106K)
7 = Zhang et al. (2014AJ....148....1Z 2014AJ....148....1Z, Cat. J/AJ/148/1)
8 = Yamanaka et al. (2014ApJ...782L..35Y 2014ApJ...782L..35Y)
9 = Shappee et al. (2016ApJ...826..144S 2016ApJ...826..144S, Cat. J/ApJ/826/144)
10 = Srivastav et al. (2017MNRAS.466.2436S 2017MNRAS.466.2436S)
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Byte-by-byte Description of file: tables1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 23 A23 --- Name Supernova name
25- 38 F14.3 "Y:M:D" UTDate UT date for the temporal midpoint of the
associated observation
40- 44 F5.1 d tLC ? Phase in rest-frame days as computed from
the appropriate redshift and photometry
from Table A1
46 I1 --- Inst [1/2] Instrument used for observation (1)
48- 51 I4 0.1nm lambdamin Wavelength range (minimum value)
53- 57 I5 0.1nm lambdamax Wavelenght range (maximum value)
59- 62 F4.1 0.1nm Resb ? Spectral resolution for the blue component
64- 67 F4.1 0.1nm Resr ? Spectral resolution for the red component
69- 73 F5.1 deg PA []? Observed slit position angle
75- 78 F4.2 --- Airmass ? Airmass for the temporal midpoint of the
associated observation
80- 83 I4 s ExpTime ? Exposure time
85- 89 F5.1 --- S/N Signal to noise ratio
91- 92 I2 --- Ref ? References (2)
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Note (1): Instrument as follows:
1 = Kast (Shane 3 m)
2 = LRIS (Keck-I 10 m)
Note (2): References as follows:
1 = Silverman et al. (2011MNRAS.410..585S 2011MNRAS.410..585S, Cat. J/MNRAS/410/585)
2 = Foley et al. (2012ApJ...744...38F 2012ApJ...744...38F)
3 = Foley et al. (2013ApJ...767...57F 2013ApJ...767...57F)
4 = Silverman et al. (2013MNRAS.430.1030S 2013MNRAS.430.1030S)
5 = Mazzali et al. (2015MNRAS.450.2631M 2015MNRAS.450.2631M)
6 = Silverman et al. (2012ApJ...756L...7S 2012ApJ...756L...7S)
7 = Childress et al. (2013ApJ...770...29C 2013ApJ...770...29C)
8 = Zheng et al. (2013ApJ...778L..15Z 2013ApJ...778L..15Z)
9 = Pan et al. (2015MNRAS.452.4307P 2015MNRAS.452.4307P, Cat. J/MNRAS/452/4307)
10 = Foley et al. (2015ApJ...798L..37F 2015ApJ...798L..37F)
11 = Foley et al. (2016MNRAS.461..433F 2016MNRAS.461..433F)
12 = Zheng et al. (2017ApJ...841...64Z 2017ApJ...841...64Z)
13 = Xuhui et al. (2019, in prep.)
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Byte-by-byte Description of file: tables2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 23 A23 --- Name Supernova name
25- 26 A2 --- Type Supernova type
28- 35 A8 --- Subtype Supernova subtype
37- 42 F6.4 --- zSNID ? SNID redshift
44- 49 F6.4 --- e_zSNID ? Error on zSNID
51- 55 F5.1 d tSNID ? SNID spectral age in rest-frame days
relative to the time of the associated SN's
maximum brightness
57- 60 F4.1 d e_tSNID ? Error on tSNID
62- 69 A8 --- SName Name of the best-matching SNID template
71- 78 A8 --- SSubtype Subtype of the best-matching SNID template
80- 83 F4.1 --- rlap Measure of quality used by SNID (1)
85- 91 F7.4 --- z Redshift of the best-matching SNID template
93- 97 F5.1 d t Spectral age of the best-matching SNID
template
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Note (1): Higher values of rlap correspond to classifications that are more
trustworthy
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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- 21 A21 --- Feature Spectral feature
23- 29 F7.2 0.1nm restwvl ? Rest wavelength
31 A1 --- f_restwvl [a] Flag on restwvl (1)
33- 41 A9 0.1nm bboundary Blue boundary of the absorption feature
43- 51 A9 0.1nm rboundary Red boundary of the absorption feature
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Note (1): Flag as follows:
a = A single reference wavelength is not useful for this feature because it
is a blend of too many spectral lines. Hence, we do not compute
expansion velocities for this feature.
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Byte-by-byte Description of file: tables4.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Supernova name
13- 33 A21 --- Feature Spectral feature
35- 40 F6.2 d tLC Phases in rest-frame days
42- 47 F6.2 10-2W/m2/nm Fb Flux within the blue edge boundary
49- 53 F5.2 10-2W/m2/nm e_Fb Error on Fb
55- 60 F6.2 10-2W/m2/nm Fr Flux within the red edge boundary
62- 66 F5.2 10-2W/m2/nm e_Fr Error on Fr
68- 72 F5.1 0.1nm pEW Pseudo-equivalent width
74- 77 F4.1 0.1nm e_pEW Error on pEW
79- 84 F6.2 10+3km/s v ? Expansion velocity (blueshift)
86- 89 F4.2 10+3km/s e_v ? Error on v
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 28-Mar-2023