J/ApJ/927/180 Type Icn SN2021csp photometry & spectra (Perley+, 2022)
The type Icn SN 2021csp: implications for the origins of the fastest supernovae
and the fates of Wolf-Rayet stars.
Perley D.A., Sollerman J., Schulze S., Yao Y., Fremling C., Gal-Yam A.,
Ho A.Y.Q., Yang Yi, Kool E.C., Irani I., Yan L., Andreoni I., Baade D.,
Bellm E.C., Brink T.G., Chen T.-W., Cikota A., Coughlin M.W., Dahiwale A.,
Dekany R., Duev D.A., Filippenko A.V., Hoeflich P., Kasliwal M.M.,
Kulkarni S.R., Lunnan R., Masci F.J., Maund J.R., Medford M.S., Riddle R.,
Rosnet P., Shupe D.L., Strotjohann N.L., Tzanidakis A., Zheng W.
<Astrophys. J., 927, 180 (2022)>
=2022ApJ...927..180P 2022ApJ...927..180P
ADC_Keywords: Supernovae; Photometry, ugriz; Ultraviolet; Spectra, optical
Keywords: Supernovae ; Core-collapse supernovae ; Wolf-Rayet stars ;
Stellar mass black holes ; Transient sources
Abstract:
We present observations of SN 2021csp, the second example of a newly
identified type of supernova (SN) hallmarked by strong, narrow, P Cygni
carbon features at early times (Type Icn). The SN appears as a fast
and luminous blue transient at early times, reaching a peak absolute
magnitude of -20 within 3 days due to strong interaction between fast
SN ejecta (v∼30000km/s) and a massive, dense, fast-moving C/O wind
shed by the WC-like progenitor months before explosion. The
narrow-line features disappear from the spectrum 10-20 days after
explosion and are replaced by a blue continuum dominated by broad Fe
features, reminiscent of Type Ibn and IIn supernovae and indicative of
weaker interaction with more extended H/He-poor material. The
transient then abruptly fades ∼60days post-explosion when interaction
ceases. Deep limits at later phases suggest minimal heavy-element
nucleosynthesis, a low ejecta mass, or both, and imply an origin
distinct from that of classical Type Ic SNe. We place SN 2021csp in
context with other fast-evolving interacting transients, and discuss
various progenitor scenarios: an ultrastripped progenitor star, a
pulsational pair-instability eruption, or a jet-driven fallback SN
from a Wolf-Rayet (W-R) star. The fallback scenario would naturally
explain the similarity between these events and radio-loud fast
transients, and suggests a picture in which most stars massive enough
to undergo a W-R phase collapse directly to black holes at the end of
their lives.
Description:
SN 2021csp (internally designated ZTF21aakilyd) was first detected in
an i-band image obtained on 2021 February 11 (MJD59256.4766) as part
of the ZTF high-cadence survey (Bellm+ 2019PASP..131f8003B 2019PASP..131f8003B).
The Zwicky Transient Facility (ZTF) is a combined public and private
time-domain optical sky survey, using a 47deg2 field-of-view camera
on the refurbished Samuel Oschin 48 inch Schmidt telescope (P48) at
Palomar Observatory. We used the IPAC forced-photometry pipeline
to obtain final P48 photometry and pre-explosion upper limits,
reported in Table 1. See Section 2.1.
We obtained ugriz imaging using the Infrared/Optical Imager (IO:O) on
the 2m robotic Liverpool Telescope (LT) starting from the first night
following the discovery and continuing until the object faded below
detection (55 days later).
We obtained additional ugri photometry using the Rainbow Camera of the
Spectral Energy Distribution Machine (SEDM) on the robotic Palomar
60-inch telescope (P60).
We observed the field of SN 2021csp with the Ultraviolet/Optical
Telescope (UVOT) on board the Neil Gehrels Swift Observatory beginning
2021 February 12 and continuing until the flux from the transient
faded below detectability a month later. An additional set of
observations between 2021 March 31 and 2021 April 21 were acquired to
constrain the host-galaxy flux.
We obtained five epochs of imaging with the Alhambra Faint Object
Spectrograph and Camera (ALFOSC) on the 2.56m Nordic Optical Telescope
(NOT). Observations were obtained on 2021 April 03, 2021 April 18,
2021 April 20, 2021 May 7, and 2021 July 1.
See Section 2.2.
We obtained an extensive series of optical spectra beginning prior to
the peak of the SN and extending until 80 days post-explosion in the
rest frame. A log of all spectroscopic observations, 25 epochs in
total, is provided in Table 2. See Section 3.
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
14 26 22.11 +05 51 33.1 SN 2021csp = ZTF21aakilyd
----------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 32 201 Photometry of SN 2021csp
table2.dat 140 28 Log of spectroscopic observations of SN 2021csp
sp/* . 29 Individual spectra in ASCII format
--------------------------------------------------------------------------------
See also:
II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)
V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)
J/MNRAS/397/1177 : Swift-XRT observations of GRBs (Evans+, 2009)
J/ApJ/702/226 : Swift/UVOT panchromatic obs. of SN 2008D (Modjaz+, 2009)
J/AJ/141/163 : Ultimate LC of SN 1998bw/GRB 980425 (Clocchiatti+, 2011)
J/MNRAS/417/916 : Supernovae in the Subaru Deep Field (Graur+, 2011)
J/other/Sci/337.444 : RV curves of Galactic massive O stars (Sana+, 2012)
J/MNRAS/425/1789 : Berkeley supernova Ia program. I. (Silverman+, 2012)
J/MNRAS/436/774 : Core collapse supernovae (type Ibc) (Eldridge+, 2013)
J/A+A/559/A114 : Updated O3N2 and N2 abundance indicators (Marino+, 2013)
J/ApJ/782/42 : Panchromatic observations of PTF11qcj (Corsi+, 2014)
J/ApJ/794/23 : Pan-STARRS1 transients optical photometry (Drout+, 2014)
J/A+A/565/A27 : Wolf-Rayet stars in Large Magellanic Cloud (Hainich+, 2014)
J/ApJ/792/30 : NEOWISE magnitudes for near-Earth objects (Mainzer+, 2014)
J/MNRAS/449/1921 : UV/opt/NIR photometry for Type Ibn SNe (Pastorello+, 2015)
J/MNRAS/453/3649 : Photometric data for ASASSN-15ed (Pastorello+, 2015)
J/ApJ/819/35 : LCs of four transients from PTF & SNLS (Arcavi+, 2016)
J/A+A/593/A68 : PTF12os and iPTF13bvn sp. and light curves (Fremling+, 2016)
J/A+A/594/A116 : HI4PI spectra and column density maps (HI4PI team+, 2016)
J/ApJ/851/107 : iPTF 16asu photometry follow-up (Whitesides+, 2017)
J/other/Sci/362.201 : iPTF 14gqr (SN 2014ft) photometry (De+, 2018)
J/MNRAS/481/894 : Rapidly evolving transients in the DES (Pursiainen+, 2018)
J/ApJ/887/169 : UV-Opt light curves of the type Ic SN 2018gep (Ho+, 2019)
J/ApJ/895/L23 : Radio obs. of the transient CSS161010 (Coppejans+, 2020)
J/ApJ/905/58 : The local universe with ZTF. I. Ca-rich gaps (De+, 2020)
J/ApJ/895/32 : Zwicky Transient Facility BTS. I. (Fremling+, 2020)
J/ApJ/902/86 : Type Ic SN 2020bvc UV to NIR LCs and opt. sp. (Ho+, 2020)
J/ApJ/895/49 : Opt. spectrum of ZTF18abvkwla & its host galaxy (Ho+, 2020)
J/ApJ/903/132 : Radio & optical observations of SN2020oi (Horesh+, 2020)
J/ApJ/902/46 : LCO network light curves of SN Ia 2018gv (Yang+, 2020)
J/ApJ/900/46 : UV, opt. & IR LC of supernova SN2019dge (Yao+, 2020)
J/A+A/651/A81 : SNe Ic from (i)PTF light curves (Barbarino+, 2021)
J/ApJ/912/46 : ZTF Type II supernovae with follow-up obs. (Bruch+, 2021)
J/ApJ/915/121 : Type Ic SN2018gep phot. & sp. follow-up (Pritchard+, 2021)
J/ApJS/255/29 : PTF core-collapse SN host-galaxy sample. I. (Schulze+, 2021)
J/ApJ/907/99 : Pre-explosion LC of 227 Supernovae (Strotjohann+, 2021)
J/ApJ/924/55 : UV and optical obs. of type Ic SN 2020oi (Gagliano+, 2022)
J/other/Nat/601.201 : Photometry of SN 2019hgp (Gal-Yam+, 2022)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Tel Telescope (1)
6- 15 F10.4 d MJD [59250.4/59341.1] Modified Julian Date
of Observation (JD-2400000.5)
17- 20 A4 --- Filt Filter (ugriz and UVW2, UVM2, UVW1)
22- 22 A1 --- l_omag Limit flag on omag
23- 27 F5.2 mag omag [17.27/24.8] Observed AB magnitude in Filt,
not corrected for Galactic extinction
29- 32 F4.2 mag e_omag [0.02/1.3]? Uncertainty in omag
--------------------------------------------------------------------------------
Note (1): Telescope as follows:
LT = the 2m robotic Liverpool Telescope using the Infrared/Optical
Imager (IO:O); 113 occurrences
UVOT = the Neil Gehrels Swift Observatory with the Ultraviolet/Optical
Telescope; 43 occurrences
P48 = the Zwicky Transient Facility (ZTF) with the Samuel Oschin 48-inch
Schmidt telescope at Palomar Observatory; 28 occurrences
P60 = the robotic Palomar 60-inch telescope using the Rainbow Camera of the
Spectral Energy Distribution Machine (SEDM); 9 occurrences
NOT = the 2.56m Nordic Optical Telescope using ALFOSC; 8 occurrences
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 "Y/M/D" Obs.date UT date of observation
13- 20 A8 "h:m:s" Obs.time UT time of observation
22- 30 F9.3 d MJD [59257.1/59350.4] Modified Julian Date
32- 37 F6.3 d Phase [2.47/88.41] Phase
39- 50 A12 --- Inst Facility/Instrument
52- 66 A15 s Exp Exposure time(s)
68- 86 A19 --- Grism Grism/Grating
88- 90 F3.1 arcsec Slit [0.2/3] Slit width
92- 95 I4 0.1nm lam1 [1230/4400] Wavelength lower range
96 A1 --- --- [-]
97- 101 I5 0.1nm lam2 [2050/10340] Wavelength upper range
103- 140 A38 --- FileName Name of the ASCII file in the
subdirectory "sp"; column added by CDS
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 17-Jan-2024