Organization of the discussion at Nikko

There are broadly two categories of discussion: (1) based on science motivations and (2) based on methodology. Both are valid (although funding agencies and high priests of science place the former over the latter). Below, based on feedback received, I have listed nine science topics. Each topic is assigned one, two or three names. Regardless of the number of names the FIRST lead is the principal lead ( and it is with that person where the buck stops, using a favorite American expression). The lead is expected to first read bio sketches of the participants and invite members as needed. Equally participants are expected to read the manifesto below and contact appropriate leads.

Leads should feel free to expand or contract the manifesto assgined to them. Each lead is responsible for a total of 45 minutes broken as follows: a 15 minute (uninterruped) presentation of the major science goals, 5 minutes of discussion, 10 minutes (uninterrupted) of suggested projects and then 15 minutes of open discussion. The chair of the session will be asked to strictly follow the schedule.

Leads should assume that all participants have read through the description of the facilities & projects . So please do not spend any time describing the instruments or surveys. Go to the heart of the topic -- what are the major questions (and justify that they are major) and then whether TDAxMMS and/or robotic spectroscopy can address these questions.

I will leave to the leads to contact members (via Google pages or Skype or both) and prepare the presentation.

A. Science motivated discussion

  1. Distribution of matter on local BAO scale: SUZUKI & NUGENT. Derive distance to Ia hosting galaxies with Ia light curve and redshift from host galaxy. Subtract mean (Hubble) flow and ascribe remaining velocity to structures. Thus derive amount of matter on BAO scales (200 Mpc) using purely velocity information (not luminosity).
  2. Spectroscopic Survey for Nearby Galaxies. Alex KIM. The goal is to derive local galaxy luminosity function. Use bright time on DESI to undertake redshift measurements of galaxies above a certain brightness. Determine what is an interesting magnitude limit, how much DESI time is needed and whether the final result is the state-of-the art.
  3. The red-shift completeness of current galaxy samples. FREMLING. Use Ia supernovae to evaluate the completeness of catalogs of galaxy catalogs. Present preliminary results from pilot program with ZTF.
  4. An accurate assessment of the local stellar death rate. TANAKA & DE. Astronomers have worked hard to measure the star-formation rate. However, the star death rate (which is dominated by core-collapse SNe) is known to be perhaps, at best, at a precision of a factor two. The largest uncertainty come from sub-lumimous (a problem also related to the formation of black holes). The solution to this problem lies in undertaking a rigorous volume limited survey. Evaluate the precision of the death rate by combining ZTF with MMS (DESI, SDSS V).
  5. Exploring the phase space of extra-galactic explosions. MAEDA, MORIYA & JIANG. Massive TDA surveys are allowing astronomers to rapidly explore the phase space of explosions (super-luminous, macro, kilo, super-long duration, super-short duration, ...). Clearly, another ripe area for TDAxMMS. Add to this possibilitie of very short duration phenomenon (Tomo-e-Gozen).
  6. Early Observations of Explosions. TOMINAGA & HO. With little doubt the frontier field of progenitors of supernovae will benefit with the earliest time observations. High cadenced TDA surveys are now routinely finding <1-day old SNe and continuous cadenced suveys are tracing the light curve from explosion to supernova phase. Rapid spectroscopy is enabling detailed study of circumstellar matter (which is a diagnostic in itself).
  7. Search for Galactic Black Holes: Microlensing DAWSON & MAO We estimate that the galaxy has 1E8 black holes. We know only five high mass X-ray binaries & 50 low mass systems and one pure RV binary. Search for isolated black holes (disk-disk lensing) and self-lensing (binaries) to improve the census of Galactic black holes.
  8. Search for Galactic Black Holes: All Other Appproaches MAO, KAWAI & KULKARNI Ellipsoidal modulation (pre X-ray novae), X-ray noave ,post X-ray novae systems and massive RV searches.
  9. TDE ("leave no TDE behind") BLAGORODNOVA, RAU & YAN. All respectable galaxies host proportionally massive nuclear black holes. Only a percent, at any given time, are accreting copiously and shining as AGN. With sufficient cadence and patience one can find significant to dramatic changes in the AGN manifestation. For the majority, TDE allows both sensing the nuclear black hole and studying accretion physics & phenomenology. This is a major area of inquiry for ZTF & SRG and can be profitably be combined with MMS.

B. Methodology based discussions

I have gathered inputs and am thinking through carefully before making assignments. [Dedicated TDA+MMS, armada of SEDMs, combine different TDA surveys...]

Please wait for two days.