せいめい望遠鏡による近傍超新星の観測

Keiichi Maeda (Kyoto Univ.), Miho Kawabata, Masayuki Yamanaka,Keisuke Isogai, Tatsuya Nakaoka (Hiroshima Univ.), Koji Kawabata,
Jian Jiang (U. Tokyo), Tomoki Morokuma, Mamoru Doi, Masaomi
Tanaka (Tohoku), Nozomu Tominaga (Konan U.), Takashi Moriya(NAOJ) et al.,On behalf of the Seimei-Kanata SN follow-up team & Tomo-e Gozen SN team

Type Ia Supernovae: Multiple Origins?
Thermonuclear explosion Explosion Mode(s)?
of a white dwarf, but…
Central Carbon ignition
Progenitor system(s)?
Single Degenerate (SD)MS/RG/He

Surface Helium
Ignition
KM+ 10WD
Double Degenerate (DD)
WDRoepke+ 12
Fink+ 10WD
Surface Carbon Ignition

SN Ia diversity• Standardized candles, but…
• Too much diversity to be asingle population.
• Indications for different
progenitors/explosions fordifferent classes.
• Bulk standard + rare outliers?
– No!

• A large fraction of the nearby
SNe have turned out to bepeculiar beasts. Much morediverse than expected.

Peak magTaubenberger
2017

Decline rate

Higher
Frontiers in Transient Sciencecadence
Unknown shorttime scale objects& just after theexplosion.

Largersamples
Unknown raretypes ofexplosions.

DeeperCooke+ 2015

Unknown faintobjects & longterm evolution.

See the poster by Morokuma et al.

New Time Domain Era

19 mag@ 60 Mpc
19 mag@ 25 Mpc

Tomo-e survey
Catch SNe in the first day.
© Morokuma
Pick up rare examples (with long-term observations).

The Seimei SN/Transient Program© Tanaka~ 5 / yr.
~ 50 / yr.

Roughly, ~ 10 classical nights + 10 ToO nights / semester.
soon-after-the-explosion SNe up to ~ 30 Mpc (golden set).
well-characterized SNe up to ~ 70 Mpc (a hunt for outliers).
Kawabata-san, Yamanaka-san, Isogai-san, …
So far mostly fueled by public surveys; Tomo-e to come.

Data taken also within the OISTER

Rapidly evolving + high velocity (HV) SN Ia 2019ein

Kawabata, KM 2020, ApJ

Zhao, KM+ submitted

Observations for the most infant phasefor HV SNe Ia.
No rapidly-evolving HV SNe wellobserved in the rising phase before.
“highest velocity” for SN Ia ever observed.

Implications for the SN Ia diversity and the explosion
Diversity:
HV SNe are not a one-parameter family;
not only the velocity but also the speedof the evolution does matter.
The explosion model:
Extended nuclear burning out to thesurface region in HV SNe.
Obs vs. model

Delayed Detonation
model (Iwamoto+1999)

SN 2019ein

• In the presentation, properties of two SNe Ia
were discussed, based on theSeimei/Kanata/Tomo-e data.
• The contents are in preparation, one by
Kawabata et al. and the other by Kawabata et al.
and Jiang et al.
• These are removed from the online proceedings
here.

Future (Spectroscopy) Perspectives© Tanaka

Now
Full spec+ Kools
Full spec← Infant+ TriCCS← Basic Infant
InfantBasic
Basic

Infant sample: soon-after-the-explosion SNe (down to -15 mag).
Basic sample: good characterization (a hunt for outliers: -17 mag).
We are now able to find weirdos at a rate of 1 in 50 SNe.
Will be able to do it for 1 / 200 SNe with full-spec Seimei + Kools.
Further down to 1 / 1,000 with TriCCS to come.
# Need a number of nights + human resource for science.

See the talk by Ohta et al.

TriCCS: new imager + spectrograph
Spectra @ 1 day for~ 30 SNe / yr within 60Mpc(currently <10 SNe reported)

3 channel CMOS camera(fully funded, 2021~)
Imager→spectrograph(fully funded, 2023~?)
A new postdoc, ~ Apr 2021?
TriCCS pipeline + obs(Job ad @ ~ Dec 2020)

Current Inst.
New

SN @ 60 Mpc
Narrow-line sensitivity

Take Away
• Peculiar beasts beyond known diversities havebeen regularly and routinely found.

• Infant phase observations routinely
performed with Seimei and Kanata telescopes.
• New insight obtained:– High velocity SNe: not a single param. family; extended burning.
– Two other SNe Ia: expanding the diversity; insights into theprogenitor systems and the explosion mechanisms.

• Will produce a complete census with coming updatein Seimei and instrument. Stay tuned!