Title Monitoring of Radio Supernovae Pi S. Van Dyk Time 30 hrs per semester 1. Name: Monitoring of Radio Supernovae -- Schuyler Van Dyk, K. Weiler et al. 2. One short paragraph with science goal(s) The radio emission from supernovae (SNe) is one of the best probes of the final stages of evolution for the stellar progenitors. The nonthermal synchrotron arises from the interaction of the SN shock with the pre-supernova, wind-established, circumstellar medium (CSM). Knowledge of the CSM provides strict constraints on the progenitor's nature and evolution. However, the particle acceleration process is still not known, and the absorption mechanism, which arises from the CSM, is not completely obvious. Although progress has been made at centimeter wavelengths over the last two decades, little has been accomplished in the mm and submm due to the sensitivity constraints and difficulty in scheduling ToOs. Observing radio SNe (RSNe) at high frequencies will help constrain both the emission and absorption processes. Once a SN is detected in the mm and submm, it is vital to maintain nearly constant monitoring in all bands over the course of days to months. Such monitoring details the evolution of the RSN through maximum and into the exponential decline in each band. Together with cm wavelength monitoring, the well-developed radio light curves across the gamut of radio bands provide an accurate picture of the CSM, the mass-loss history of the progenitor prior to explosion, and the nature of the progenitor itself. The well-studied RSN SN1993J in M81 would have been visible for many years in all ALMA bands, but these local RSNe are relatively rare. A Virgo Cluster analog to SN 1993J would reach ~2 mJy at max within 10 days, and will be visible for ~100 days in Band 7 and ~600 days in Band 3. This analog easily could be detected out to a distance of ~60-70 Mpc. This is a standing program for the long-term monitoring of RSNe. 3. Number of sources Based on current supernova searches, we anticipate approximately 2 to 20 per semester. 4. Coordinates: 4.1. All over the sky. 4.2. Moving target: no 4.3. Time critical: very 5. Spatial scales: 5.1. Angular resolution (arcsec): any ALMA resolution 5.2. Range of spatial scales/FOV (arcsec): point sources 5.3. Single dish total power data: no 5.4. ACA: no 5.5. Subarrays: could do 6. Frequencies: 6.1. Receiver band: All. 6.2. Lines and Frequencies (GHz): --- continuum 6.3. Spectral resolution (km/s): --- N/A 6.4. Bandwidth or spectral coverage (km/s or GHz): --- 8 GHz 7. Continuum flux density: 7.1. Typical value (Jy): 0.001-0.1 7.2. Required continuum rms (Jy or K): 0.00006 (.06 mJy) 7.3. Dynamic range within image: >4 8. Line intensity: 8.1. Typical value (K or Jy): N/A 8.2. Required rms per channel (K or Jy): N/A 8.3. Spectral dynamic range: N/A 9. Polarization: no 10. Integration time for each observing mode/receiver setting (hr): typically 1/60 hr for Band 3 3/60 hr for Band 6 10/60 hr for Band 7 0.5 hr Band 9 (only if detected) 11. Total integration time for program (hr): total ToO monitoring time every month = 5 hrs (0.5 hr/source x 10 sources) Estimated ToO time every semester: on average, 30 hours, based on current monitoring programs at the VLA. 12. Comments on observing strategy (e.g. line surveys, Target of Opportunity, Sun, ...): This is a standing program to monitor the light curves of nearby known RSN, with scheduled observing files to be executed every month. ************************************************************************* Review Leonardo Testi (programs 3.5.5 and 3.5.6): The first is a ToO to measure mm fluxes of SN close to maximum, the second requires monitoring of a few SN. I could not really tell which is and if there is any difference in the targets between the two projects. I would think that one finds a bright supernova and then will want to follow it in the framework of the first project (? maybe I am missing the point here?). I think these should be combined in a single project that finds and follows the supernovae. Total time, for the three years (is it really required? how many SN you need?) would be a total of 2semx50hx3y=300h for the first part and 2semx30hx3y=150h for the second, and a grand total of 450 hrs. Following the time estimates, this time will correspond to approx 6-10 supernovae for the "first part" and 10 per semester for "second part". Taking intop account the "visibility" of SN for the monitoring, the time requested will allow to monitor approx 15 SN/yr, so it appears oversized compared to the first part (one finds 10 SN in 3 yrs, not all will be bright enough for monitoring, then how one selectes the ~45 SN for the monitoring?). I would say that, given the time requested for finding candidates, the monitoring should not exceed a total of at most 50hrs. This programme challenges operations, information- and data-flow. What is particularly critical is programme 3.5.5 (obviously). It is important to have this programme in to set the appropriate requirements on software and operations plan. Reply Jean Turner: Leonardo raises some good points. I attach slightly modified DRSPs. The first point is regarding why these are two DRSPs: the basic answer is that they are different kinds of scheduling. One is dynamic, the other not. I think the ToO should be separate from the monitoring. This is currently how it is handled at the VLA. The second is regarding the relative time estimate of the ToO and monitoring programs; Leonardo is making the reasonable assumption that they are the same sources, when in fact, they are not necessarily. Some RSN are detectable for nearly a decade, others fade within months. It is my impression that there are more RSN than can currently be monitored at the VLA, so only the "best" are followed. Generally the monitoring programs will be following RSN discovered outside the 3 yr time frame here (and this will be true for ALMA, which will initially be following up RSN discovered with the VLA). At some level the amount of time devoted to both of these programs, the ToO and the subsequent monitoring, is somewhat arbitrary. One can't monitor all the RSN. These numbers are roughly consistent with what is currently done at the VLA. It could be different for ALMA. The change I made to the DRSPs was to include in the total time request "based on current VLA programs" to explain the time estimate, which would address the 2nd point Leonardo raised. Comment Ewine: new DRSP is now baseline -------------------------------------------------- Review v2.0: 3.5.6 Monitoring of Radio Supernovae van Dyk 30 Did not change from earlier proposal, wich was extensively refereed.