J/ApJ/959/142 Long-rising Type II SNe in the ZTF CLU (Sit+, 2023)
Long-rising Type II supernovae in the Zwicky Transient Facility Census of the
Local Universe.
Sit T., Kasliwal M.M., Tzanidakis A., De K., Fremling C., Sollerman J.,
Gal-Yam A., Miller A.A., Adams S., Aloisi R., Andreoni I., Chu M.,
Cook D., Das K.K., Dugas A., Groom S.L., Ho A.Y.Q., Karambelkar V.,
Neill J.D., Masci F.J., Medford M.S., Purdum J., Sharma Y., Smith R.,
Stein R., Yan L., Yao Y., Zhang C.
<Astrophys. J., 959, 142 (2023)>
=2023ApJ...959..142S 2023ApJ...959..142S
ADC_Keywords: Supernovae; Spectra, optical; Photometry; Surveys
Keywords: Core-collapse supernovae ; Supernovae ; Type II supernovae ;
Galaxies ; Sky surveys ; Surveys ; Spectroscopy
Abstract:
SN 1987A was an unusual hydrogen-rich core-collapse supernova
originating from a blue supergiant star. Similar blue supergiant
explosions remain a small family of events, and are broadly
characterized by their long rises to peak. The Zwicky Transient
Facility Census of the Local Universe (CLU) experiment aims to
construct a spectroscopically complete sample of transients occurring
in galaxies from the CLU galaxy catalog. We identify 13 long-rising
(>40 days) Type II supernovae from the volume-limited CLU experiment
during a 3.5 yr period from 2018 June to 2021 December, approximately
doubling the previously known number of these events. We present
photometric and spectroscopic data of these 13 events, finding peak
r-band absolute magnitudes ranging from -15.6 to -17.5 mag and the
tentative detection of BaII lines in nine events. Using our CLU sample
of events, we derive a long-rising Type II supernova rate of
1.37-0.30+0.26x10-6Mpc-3/yr, ∼1.4% of the total core-collapse
supernova rate. This is the first volumetric rate of these events
estimated from a large, systematic, volume-limited experiment.
Description:
The Zwicky Transient Facility (ZTF) is an optical time-domain survey
on the 48 inch Schmidt telescope at Palomar Observatory. The ZTF
camera has a 47deg2 field of view, can achieve a survey speed of
∼3750deg2/hr, and reaches a median limiting magnitude of
rZTF∼20.5mag in its 30s exposures. This allows ZTF to observe the
entire northern sky with ∼3days cadence in gZTF and rZTF in the public
Northern Sky Survey.
The ZTF Census of the Local Universe (CLU) experiment aims to
construct a spectroscopically complete sample of transients in the
Local Universe.
See Section 2.1 for further explanations.
Our final sample consists of 13 long-rising SNe II with well-defined
light curves identified from the ZTF CLU experiment between
2018-Jun-01 and 2021-Dec-31 (Table 1).
See Section 2.2.
All long-rising SNe II in our sample were observed primarily in the
ZTF r and g filters, with some i-band detections for most sources as
well. See Section 3.
In general, spectroscopic follow-up for transients saved to CLU is
intended for classification, and as a result, the majority of our
sample only have one to two spectra as no further follow-up was
assigned after classification as an SN II.
The instruments regularly used for ZTF CLU classification are as
follows: the robotic Spectral Energy Distribution Machine (SEDM) on
the Palomar 60 inch telescope, the Double Beam Spectrograph (DBSP) on
the Palomar 200 inch Hale telescope, and the Low-Resolution Imaging
Spectrograph (LRIS) on the Keck I telescope. We supplement our spectra
with public data from the Transient Name Server (TNS) if available.
See Section 4.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 82 13 ZTF CLU sample of 13 long-rising SNe II
fig2.dat 48 904 Optical Light Curves (Data behind Figure 2)
fig3.dat 48 836 Optical Light Curves (Data behind Figure 3)
fig6.dat 34 23318 Optical Spectra (Data behind Figure 6)
fig7.dat 34 15210 Optical Spectra (Data behind Figure 7)
fig8.dat 34 20782 Optical Spectra (Data behind Figure 8)
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See also:
II/363 : The band-merged unWISE Catalog (Schlafly+, 2019)
J/MNRAS/395/1409 : Type II-P SN progenitor constraints (Smartt+, 2009)
J/A+A/537/A141 : UBVRI light curves of SN 2009E (Pastorello+, 2012)
J/ApJ/880/7 : Census of the Local Universe survey. I. (Cook+, 2019)
J/ApJ/882/L15 : SN 2018hna photometry & spectroscopy obs. (Singh+, 2019)
J/ApJ/905/58 : Local universe with ZTF. I. Ca-rich gap transients (De+, 2020)
J/ApJ/895/32 : Zwicky Transient Facility BTS. I. (Fremling+, 2020)
http://www.wis-tns.org/ : Transient Name Server (TNS) homepage
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- --- [SN]
4- 11 A8 --- SN Supernova (SN) designation
13- 24 A12 --- OName Other name (ZTF)
26- 27 I2 h RAh Hour of right ascension (J2000)
29- 30 I2 min RAm Minute of right ascension (J2000)
32- 36 F5.2 s RAs Second of right ascension (J2000)
38 A1 --- DE- Sign of declination (J2000)
39- 40 I2 deg DEd Degree of declination (J2000)
42- 43 I2 arcmin DEm Arcminute of declination (J2000)
45- 49 F5.2 arcsec DEs Arcsecond of declination (J2000)
51- 75 A25 --- Gal Host galaxy name
77- 82 F6.4 --- z [0.002/0.05] Redshift from NED
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Byte-by-byte Description of file: fig[23].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- --- [SN]
4- 11 A8 --- SN Supernova name
13- 23 F11.3 d JD Julian Date
25- 30 F6.3 mag ZTFmag [13.99/29.9] Apparent magnitude in Filt
32- 36 F5.3 mag e_ZTFmag [0.001/0.4]? Uncertainty on ZTFmag
38- 42 A5 --- Filt Filter used ("ztfg", "ztfr", "ztfi",
"sdssg", "sdssr", "sdssi")
44- 48 A5 --- magLim Upper limit on magnitude ("True" or "False")
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Byte-by-byte Description of file: fig[678].dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- SN Supernova name
10- 13 A4 --- Inst Instrument used ("DBSP", "LRIS", "SEDM")
15- 18 I4 d phase [-69/143] Supernova phase in observer days;
preceding -/+ indicates pre/post-peak
20- 26 F7.1 0.1nm lambda [3059/10311] Observed wavelength; angstroms
28- 34 F7.4 --- Flux [-8.03/13.3] Scaled flux
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 29-Jan-2026