J/MNRAS/444/3258 Velocities and EW of PTF SNe Ia (Maguire+, 2014)
Exploring the spectral diversity of low-redshift Type Ia supernovae using the
Palomar Transient Factory.
Maguire K., Sullivan M., Pan Y.-C., Gal-Yam A., Hook I.M., Howell D.A.,
Nugent P.E., Mazzali P., Chotard N., Clubb K.I., Filippenko A.V.,
Kasliwal M.M., Kandrashoff M.T., Poznanski D., Saunders C.M.,
Silverman J.M., Walker E., Xu D.
<Mon. Not. R. Astron. Soc., 444, 3258-3274 (2014)>
=2014MNRAS.444.3258M 2014MNRAS.444.3258M
ADC_Keywords: Supernovae ; Equivalent widths ; Spectroscopy
Keywords: supernovae: general - galaxies: general - distance scale
Abstract:
We present an investigation of the optical spectra of 264 low-redshift
(z<0.2) Type Ia supernovae (SNe Ia) discovered by the Palomar
Transient Factory, an untargeted transient survey. We focus on
velocity and pseudo-equivalent width measurements of the SiII 4130,
5972, and 6355Å lines, as well those of the CaII near-infrared
(NIR) triplet, up to +5days relative to the SN B-band maximum
light. We find that a high-velocity component of the CaII NIR triplet
is needed to explain the spectrum in ∼95% of SNe Ia observed
before -5days, decreasing to ∼80% at maximum. The average
velocity of the CaII high-velocity component is ∼8500km/s higher
than the photospheric component. We confirm previous results that SNe
Ia around maximum light with a larger contribution from the
high-velocity component relative to the photospheric component in
their CaII NIR feature have, on average, broader light curves and
lower CaII NIR photospheric velocities. We find that these relations
are driven by both a stronger high-velocity component and a weaker
contribution from the photospheric CaII NIR component in broader light
curve SNe Ia. We identify the presence of CII in very-early-time SN Ia
spectra (before -10days), finding that >40% of SNe Ia observed
at these phases show signs of unburnt material in their spectra, and
that CII features are more likely to be found in SNe Ia having
narrower light curves.
Description:
We present spectroscopic classification and follow-up data for SNe Ia
obtained as part of the PTF collaboration. SN candidates were
discovered in P48 g- and R-band images using image-subtraction
techniques. Photometry was obtained at the P48, as well as the 2-m
robotic Liverpool Telescope (LT) and the Las Cumbres Observatory
Global Telescope (LCOGT) Faulkes Telescope North (FTN). In this paper,
we focus on the spectroscopic sample analysis and use only derived
quantities from the light curves (light-curve width, time of B-band
maximum light).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 49 359 Light-curve information and heliocentric redshift
for each SN Ia in the sample
table5.dat 124 359 Spectral measurement information for each spectrum
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See also:
II/313 : PTF photometric catalog 1.0 (Ofek+, 2012)
J/AJ/142/60 : Palomar Transient Factory Orion Project (Van Eyken+, 2011)
J/ApJ/736/159 : Photometry monitoring of the SN PTF10vdl (Gal-Yam+, 2011)
J/MNRAS/438/1391 : Host galaxies of Type Ia SN from PTF (Pan+, 2014)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- SN Supernova designation
11- 18 F8.6 --- z [0/0.2] Heliocentric redshift
20- 27 F8.6 --- e_z [0.000005/0.002] rms uncertainty on z
29- 32 F4.2 --- S [0.6/1.7] Stretch parameter
34- 37 F4.2 --- e_S [0.01/0.14] rms uncertainty on Stretch
39- 45 F7.1 d MJDmax Maximum light MJD
47- 49 F3.1 d e_MJDmax [0/1.3] rms uncertainty on MJDmax
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- SN Supernova designation
11- 15 F5.1 d Phase [-18/5] Phase (days after maximum)
17- 19 F3.1 d e_Phase [0/1.3] rms uncertainty on phase
21- 25 I5 km/s V4130 [7699/13958]?=- SiII 4130 line velocity
27- 30 I4 km/s e_V4130 [25/2222]?=- rms uncertainty on V4130 (1)
32- 35 F4.1 0.1nm W4130 [1/38]?=- SiII 4130 pseudo-equivalent width
37- 39 F3.1 0.1nm e_W4130 [0.1/4]?=- rms uncertainty on W4130 (1)
41- 45 I5 km/s V5972 [8000/19000]?=- SiII 5972 line velocity
47- 50 I4 km/s e_V5972 [15/5352]?=- rms uncertainty on V5972 (1)
52- 55 F4.1 0.1nm W5972 [3/58]?=- SiII 5972 pseudo-equivalent width
57- 59 F3.1 0.1nm e_W5972 [0.2/3.5]?=- rms uncertainty on W5972 (1)
61- 65 I5 km/s V5355 [8400/21300]?=- SiII 5355 line velocity
67- 70 I4 km/s e_V5355 [3/600]?=- rms uncertainty on V5355 (1)
72- 76 F5.1 0.1nm W5355 [9/227]?=- SiII 5355 pseudo-equivalent width
78- 80 F3.1 0.1nm e_W5355 [0.1/7.6]?=- rms uncertainty on W5355 (1)
82- 86 I5 km/s V-PVF [8220/25150]?=- - PVF line velocity (2)
88- 91 I4 km/s e_V-PVF [6/3741]?=- rms uncertainty on V-PVF (1)
93- 97 F5.1 0.1nm W-PVF [17/343]?=- - PVF pseudo-equivalent width (2)
99-102 F4.1 0.1nm e_W-PVF [0.1/59]?=- rms uncertainty on W-PVF (1)
104-108 I5 km/s V-HVF [14789/38210]?=- - HVF line velocity (2)
110-113 I4 km/s e_V-HVF [6/3741]?=- rms uncertainty on V-HVF (1)
115-119 F5.1 0.1nm W-HVF [0/426]?=- - HVF pseudo-equivalent width (2)
121-124 F4.1 0.1nm e_W-HVF [0/57]?=- rms uncertainty on W-HVF (1)
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Note (1): The uncertainties are only the uncertainties on the fitting routine.
Note (2): Near-IR CaII line: PVF for photospheric-velocity features and
HVF for high-velocity features of the CaII lines.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 29-Apr-2015