せいめい望遠鏡による系外突発天体観測プログラム
2023 Seimei UM, 2023.09.12

Keiichi Maeda (Department of Astronomy, Kyoto University)

Type Ia
supernova

Core-collapse
supernova

Stellar Evolution and Supernovae (SNe)SN Ia
CC-SNGRB

H-burning WS, 2009.2.19-20

# Explosions of massive stars at the end of their lives.

Unresolved problems for Core Collapse SNe (CC SNe)
• Explosion mechanism.
• Final evolution of massive stars (single & binary).
– Progenitor at the time of the explosion.
– Mass loss in the final decades.
Arnett+Meakin 11mag

SN?

-10 mag
Thoene+ 16years# Thermonuclear explosions of White dwarfs (WDs).

Unresolved problems for SNe Ia• Explosion mechanism (multiple paths?).
Central Carbon ignition• Progenitor systems.
Single Degenerate (SD)
MS/RSG/He

Surface Helium
Ignition
KM+ 10WD
Double Degenerate (DD)WD

Roepke+ 12
Fink+ 10WD
Surface Carbon Ignition

HigherFrontiers in Transient Science cadence
Known
transients, butfrom thebeginning.

Unknown shorttime scaleobjects.

Largersamples
Cooke+ 2015

Rare types ofexplosions.

Extragalactic Transience w/ Seimei: since 2019

ToO：rapid classification, high-cadence especially at thebeginning. Fill in the gap of the classical nights.

Classical： (half x 2) / a week, long monitoring.

Candidate selection for Seimei
Own interface(Kawabata,Nakaoka)

ToOSelection（host galaxy, luminosity…）

Transient Name
Server (TNS)

ZTF, PS, ATLAS, …

Tomo-e SN server

Papers
Refereed Journals (published + nearly accepted)• Gangopadhyay, Maeda, Singh et al. 2023, ApJ, (almost) accepted (SN Iib/Ib 2022crv); talk
• Kuncarayakti, Sollerman, Izzo, Maeda, et al. 2023, A&A, in press (SN “Ic-CSM” 2022xxf)• Uno, Nagao, Maeda, et al. 2023, ApJ, 944, 204 (SN Ia-CSM 2020uem); talk
• Uno, Maeda, Nagao, et al. 2023, ApJ, 944, 203 (SN Ia-CSM 2020uem); talk• Jiang, Maeda, Kawabata, et al. 2021, ApJL, 923, L8 (over-luminous SN Ia 2020hvf)• Kawabata, Maeda, Yamanaka, et al. 2021, PASJ, 73, 1295 (SN “Iax” 2019muj)• Nakaoka, Maeda, Yamanaka, et al. 2021, ApJ, 912, 30 (Ca-rich transient 2019ehk)• Kawabata, Maeda, Yamanaka et al. 2020, ApJ, 893, 143 (“infant” SN Ia 2019ein)• Singh, Sahu, Anupama, et al. 2019, ApJL, 882 L15 (SN1987A-like 2018hna)+ a number of classification reports (mostly Taguchi et al.)• Taguchi, Maeda, Uno, TNS Class. Rep. 15501 (SN II within 7 hrs of the discovery).
• Taguchi, Uno, Nagao, Maeda, TNS Class. Rep. 14478 (TDE)One highlight: A new population of SNe
within C/O-rich CSM• Peculiar SN Ic 2022xxf (Kuncarayakti, Izzo, Sollerman, KM+ 2023).
• Double-peaked light curve (few examples known).
• Global observation network, in multi-wavelength.
• Explosion of a C+O star, surrounded by C/O-rich CSM(huge mass-loss… challenge to stellar evolution).

Another example to come; KM+ in prep., w/ Seimei dataModel⇔data development

Model foroverluminous SNe Ia

KM+ 2023

Jiang, KM+ 2021
Seimei / Tomo-eSubaru. JWST[OI] as a coolant
Dust formation

Siebert+2023

Siebert+ 2023

Model⇔data development
Ready to apply
to new data

Ogawa, KM,
Kawabata 2023,
ApJ, in press

Siebert+ 2023

Infant SNe (by GMOS: KM+)

New direction: TDE & related objects• Nearest “TDE” classified by Seimei (Taguchi, Uno, Nagao, KM+ 2023).
• Seimei ⇒ Subaru (polarization).
• Strong polarization level, with interesting behaviors.
• Probably a “faked” TDE (identifying a new population of AGN?).

Uno, KM+, in prep.

New Direction: Time-resolved obs.
• 23B-N-CT10 / 23B-K-0015.
• Search for short-timescalevariabilities for “extragalactic”
transients w/ TriCCS.
• Central engine, newborn NS.
• Targets:– Luminous-fast-blue-opticaltransients (LFBOTs, AT2018cow).
– TDEs (and TDE-like transients).
– (very) nearby SNe, NS-NS, NS-BH.
– GRBs?

New Direction: 8m to Seimei• Initial “dark” phase by 8m (e.g., GMOS).
⇔ Later follow-up by Seimei.
• GMOS-N rToO accepted in S23A.
– 10 hrs in July-August (maintenance…).
– Infant SNe “入れ食い” 状態.
• Our system for the infant SN search and ToO has
worked perfectly.

– Peculiar rapid transient (KM+, in prep.).
– Unfortunately Semei in the maintenance…

– Proven to be very powerful.
• Submitted for Subaru⇔Gemini S24A.

New Direction: multi-wavelength• (As an example) ALMA proposal acceptedfor infant SNe (one of only 3 ToO proposal
accepted for cycle 10).
• So far three papers from the ALMA infant SNprogram.
• To coordinate w/ Seimei (North vs. South…)• New SN just triggered in the north
hemisphere (and the queue for Seimei).

Taguchi, Kawabata, Maeda, …

GW counterpart search with TriCCS• Developing a system for GW counterpart search/followup triggered by LIGO/Virgo alerts (through J-GEM).
• Observing flowchart:– J-GEM:• Compute the 3D likelihood map for a LIGO/Virgo GW alert.
• Pickup possible host galaxies from the GLATE catalog, and put ranks.

– Seimei:• Continuously monitor the J-GEM server.
• Trigger ToO for “good” events (e.g., <100 deg2, NS involved).
• Execute a automatic-observation script.
– Observing in the queue mode, visibility vs. association ranking.

• Reduction pipeline (next page).

• Currently Virgo offline, so few good events.

Kawabata, Taguchi, Maeda, …

TriCCS imaging reduction pipeline• A new PC installed for the on-sitereduction.
• Current features.
– Dark, Flat, WCS, stacking⇒ Science image.
– For GW counterpart search,the data are sent to theJ-GEM server⇒ difference image⇒ photometry.

Summary
Accelerated publications for the SN/transient program.

Coupled with the model/theory activities.
New directions/functions:- TDEs and related phenomena.
- Time-resolved observations for extragalactic transients.
- Seimei ⇒8 m, but also 8m ⇒ Seimei.
- Multi-wavelength, e.g., coordinated with ALMA.
Preparing for multi-messenger:- GW counterpart search pipeline (Taguchi+).
- TriCCS reduction pipeline (Kawabata+).