J/A+A/592/A40 Photometry of SN 2013gh and iPTF13dge (Ferretti+, 2016)
Time-varying sodium absorption in the type Ia supernova 2013gh.
Ferretti R., Amanullah R., Goobar A., Johansson J., Vreeswijk P.,
Butler R.P., Cao Y., Cenko S.B., Doran G., Filippenko A.V., Freeland E.,
Hosseinzadeh G., Howell D.A., Lundqvist P., Mattila S., Nordin J.,
Nugent P.E., Petrushevska T., Valenti S., Vogt S., Wozniak P.
<Astron. Astrophys. 592, A40 (2016)>
=2016A&A...592A..40F 2016A&A...592A..40F (SIMBAD/NED BibCode)
ADC_Keywords: Supernovae ; Photometry, UBV ; Photometry, ugriz ;
Photometry, ultraviolet
Keywords: supernovae: general - supernovae: individual: SN2013gh -
circumstellar matter - dust, extinction -
supernovae: individual: iPTF13dge
Abstract:
Temporal variability of narrow absorption lines in high-resolution
spectra of Type Ia supernovae (SNe Ia) is studied to search for
circumstellar matter. Time series which resolve the profiles of
absorption lines such as NaI D or CaII H&K are expected to reveal
variations due to photoionisation and subsequent recombination of the
gases. The presence, composition, and geometry of circumstellar matter
may hint at the elusive progenitor system of SNe Ia and could also
affect the observed reddening law.
To date, there are few known cases of time-varying NaI D absorption
in SNe Ia, all of which occurred during relatively late phases of the
supernova (SN) evolution. Photoionisation, however, is predicted to
occur during the early phases of SNe Ia, when the supernovae peak in
the ultraviolet. We attempt, therefore, to observe early-time
absorption-line variations by obtaining high-resolution spectra of SNe
before maximum light
We have obtained photometry and high-resolution spectroscopy of SNe Ia
2013gh and iPTF 13dge, to search for absorption- line variations.
Furthermore, we study interstellar absorption features in relation to
the observed photometric colours of the SNe. Results. Both SNe display
deep NaI D and CaII H&K absorption features. Furthermore, small but
significant variations are detected in a feature of the NaI D profile
of SN 2013gh. The variations are consistent with either geometric
effects of rapidly moving or patchy gas clouds or photoionisation of
NaI gas at R~=1019cm from the explosion.
Our analysis indicates that it is necessary to focus on early phases
to detect photoionisation effects of gases in the circumstellar medium
of SNe Ia. Different absorbers such as NaI and CaII can be used to
probe for matter at different distances from the SNe. The nondetection
of variations during early phases makes it possible to put limits on
the abundance of the species at those distances.
Description:
Measured photometry of type Ia supernovae 2013gh and iPTF13dge are
presented. Furthermore, the effective light-curve-width-corrected
phase and the natural magnitude in specified filters have been
computed. Thereby, the corresponding Galactic absorption (Ax_MW) and
the filter corrections (Kx) to the corresponding rest-frame filter for
SN 2011fe as described by Amanullah et al. (2015MNRAS.453.3300A 2015MNRAS.453.3300A) are
presented. The corrected magnitude can be obtained as X-AXMW-KX.
All corrections have been calculated after the SN 2011fe template has
been reddened with the best-fit Fitzpatrick (1999PASP..111...63F 1999PASP..111...63F) law,
for each SN. Furthermore, the V magnitude and corrections for each
phase phase are included. The V magnitude was either measured (M) or
calculated (D) using the SNooPy model. The V magnitude is only shown
for data points used in the colour analysis, with phases between -10
and +35-days. The corrected colour can be obtained as
(X-AXMW-KX)-(V-AVMW-KV) and can be compared with the
corresponding colour of SN 2011fe in order to study the reddening laws
of the SNe.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 95 2 Supernova coordinates quoted from the discovery
telegrams
table2.dat 38 775 Measured photometry (datatable13gh.tex)
table3.dat 84 603 Stretch-colour fitted photometry
(colortable13gh.tex)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- Name SN name
12- 13 I2 h RAh SN right ascension (J2000)
15- 16 I2 min RAm SN right ascension (J2000)
18- 22 F5.2 s RAs SN right ascension (J2000)
24 A1 --- DE- SN declination sign (J2000)
25- 26 I2 deg DEd SN declination (J2000)
28- 29 I2 arcmin DEm SN declination (J2000)
31- 34 F4.1 arcsec DEs SN declination (J2000)
36- 38 F3.1 kpc r Projected distance from the host-galaxy
nuclei (1)
40- 42 F3.1 kpc e_r rms uncertainty on r
44- 51 A8 --- Host Host galaxy (2)
53- 54 I2 h RAHh Host galaxy right ascension (J2000)
56- 57 I2 min RAHm Host galaxy right ascension (J2000)
59- 62 F4.1 s RAHs Host galaxy right ascension (J2000)
64 A1 --- DEH- Host galaxy declination sign (J2000)
65- 66 I2 deg DEHd Host galaxy declination (J2000)
68- 69 I2 arcmin DEHm Host galaxy declination (J2000)
71- 72 I2 arcsec DEHs Host galaxy declination (J2000)
74- 79 F6.4 --- z Redshift
81- 84 I4 km/s HV Measured heliocentric recession velocity
86- 87 I2 Mpc DC Host galaxy comoving distance (3)
89 I1 Mpc e_DC rms uncertainty on DC
91- 95 F5.3 mag E(B-V)MW Milky Way extinction
--------------------------------------------------------------------------------
Note (1): The projected distances from the host-galaxy nuclei were calculated
based on the host-galaxy distances and the SN offsets.
Note (2): All host-galaxy data were obtained from the NASA Extragalactic
Database (NED), where HV is the measured heliocentric recession velocity and
the Milky Way extinctions are from the Schlafly & Finkbeiner
(2011ApJ...737..103S 2011ApJ...737..103S) calibration of the Schlegel et al. (1998ApJ...500..525S 1998ApJ...500..525S)
infrared-based dust maps.
Note (3): The host-galaxy comoving distances have been calculated based on the
redshift with H0=73±5km/s/Mpc.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Name SN name
11- 17 F7.1 d MJD Modified Julian Date
19- 27 A9 --- Filter Observational filter X (1)
29- 33 F5.2 mag Xmag Brightness in filter X
35- 38 F4.2 mag e_Xmag rms uncertainty on Xmag
--------------------------------------------------------------------------------
Note (1): Filter used:
ALFOSC UBVRi; LCOGT UBVRI griz; NOTCAM J and UVOT uvm2.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 A9 --- Name SN name
11- 17 F7.1 d MJD Modified Julian Date
19- 22 F4.1 d Phase Light-curve-width corrected phase
24- 32 A9 --- Filter Observational filter X (1)
34- 38 F5.2 mag Xmag Brightness in filter X
40- 43 F4.2 mag e_Xmag rms uncertainty on Xmag
45- 48 F4.2 mag AXMW Milky Way extinction in filter X
50- 54 F5.2 mag KX K-correction in filter X
56 A1 --- Match [MD] Method of V-band magnitude determination (2)
58- 62 F5.2 mag Vmag Brightness in V-band
64- 67 F4.2 mag e_Vmag rms uncertainty on Vmag
69- 72 F4.2 mag AVMW Milky Way extinction in V-band
74- 78 F5.2 mag KV K-correction in V-band
80- 84 F5.2 mag V-X Expected colour V-X from SN2011fe
--------------------------------------------------------------------------------
Note (1): Filter used:
ALFOSC UBRi; LCOGT UBRI griz and UVOT uvm2.
Note (2): Specifies whether the V magnitude was measured for the same
epoch (D) or if it was calculated using the SNooPy model (M).
--------------------------------------------------------------------------------
Acknowledgements:
Raphael Ferretti, raphael.ferretti(at)fysik.su.se
(End) Raphael Ferretti [OKC, Sweden], Patricia Vannier [CDS] 20-Jun-2016