SETI with ZTF and LSST

Slides that were (remotely) presented at the VASCO: 1 meeting in Uppsala, describing thoughts on SETI (and specifically VASCO) studies using next-gen photometric surveys.

Transcript

1. SETI with ZTF & LSST (Next-gen time domain surveys) James R. A. Davenport NSF Astronomy & Astrophysics Postdoctoral Fellow, Western Washington University DIRAC Fellow, University of Washington jradavenport UNIVERSITY OF WASHINGTON VASCO Workshop, 2018-Feb-01 Vanishing & Appearing Sources over a Century of Observations
2. 2 jradavenport 2 Points to Cover: 1) We need SETI signals that ZTF/LSST can detect (e.g. VASCO, others) (e.g. alert streams) 2) We should utilize frameworks being built for other 
 science cases to do VASCO/SETI more easily
3. 3 I’m sure Ariel Goobar gave a great ZTF intro earlier! Zwicky Transient Facility jradavenport
4. 4 Very large FOV photometric survey Multiple filters, non-simultaneously 
 (unlike SDSS) Fairly deep (20.5 mag per visit) ~half of data is public immediately
 (all eventually), including alerts Zwicky Transient Facility In commissioning phase! jradavenport
5. 5 ZTF: 47sq deg field LSST: 9.6 sq deg field Large Synoptic Survey Telescope LSST = about 10x ZTF not worth going into detailed stats here In commissioning phase! jradavenport
6. 6 A new era for survey astronomy and thus SETI research! Need new “Optical SETI” techniques e.g. VASCO jradavenport
7. 7 VASCO: a well-defined measurement! BUT, a few types of stars will produce false positives (thankfully most are interesting too!) Simulated VASCO Data Time Flux Time Flux Beatriz Villarroel notes some interesting contamination in previous talks/work on VASCO. 
 Lars Mattsson probably will discuss more on Saturday jradavenport
8. 8 - RCorBor and similar dusty stars - YSO’s (FU Ori’s) - stellar mergers - He flash objects - “Boyajian’s star” - changing look AGN - flares, novae, SNe, transients… - stellar activity evolution - “Boyajian’s star” - massive star evolution - binary stars? - also AGN? VASCO: a well-defined measurement! BUT, a few types of stars will produce false positives (thankfully most are interesting too!) “Short” timescale “Long” timescale More room for discovery here! (my opinion) jradavenport
9. 9 “Boyajian’s star” 20% flux dips! Kepler 1-2% variation Ground-based Kepler slow 3% fade jradavenport
10. 10 “Boyajian’s star” jradavenport
11. 11 R Cor Bor’s 9 mag variability! both short and long-ish events jradavenport
12. 12 jradavenport FU Ori’s Several mag Fast rise slow decay
13. 13 other examples of “impossible” signals - very weird motion or controlled movement
 (e.g. if ʻOumuamua had changed course) - extreme variability or state changes - beacons (e.g. transit string) - coordinated variability (e.g. transit-network) Need new “Optical SETI” techniques jradavenport
14. 14 Also need to write down an (efficient) search algorithm 
 for each of these and a vetting/follow-up procedure 
 (easy to get far too many candidates) Possibly more discussion of this tomorrow in the ML/technology talks Need new “Optical SETI” techniques this may be biggest challenge
 (also my opinion) jradavenport
15. 15 Part 2: Alert Streams, a natural VASCO source We can get a lot for free… if we pose our questions “correctly” These are being developed NOW, will be streaming Not just for SNe any more! but typically based (in real time) on difference imaging ZTF Alert Distribution System
16. 16 Part 2: Alert Streams, a natural VASCO source We can get a lot for free… if we pose our questions “correctly” These are being developed NOW, will be streaming Not just for SNe any more! but typically based (in real time) on difference imaging ZTF Alert Distribution System Possible ZADS user
17. 17 jradavenport Part 2: Alert Streams, a natural VASCO source Example: Sparse cadence (ZTF or LSST) perfect for detecting these dips in difference images
18. 18 jradavenport Part 2: Alert Streams, a natural VASCO source Example: Sparse cadence (ZTF or LSST) perfect for detecting these dips in difference images Follow-up is key, and need
 a lot of time (at least initially)
19. 19 but, developing light curve analysis framework is an ongoing effort 
 at UW/DIRAC/LSST-DM for such projects! Part 2: Alert Streams, a natural VASCO source Currently no real way to do the slow part 
 using the alert stream architecture 
 (i.e. maybe not for free in real time) jradavenport
20. 20 We need to build (or find) tools for ZTF/LSST to search for these! alerts, crossmatch to catalogs, use 10-yr LSST baseline period searches via database? re-run every… year? looking for Shelling Points (see Jason Wright’s work) Need new spatial-temporal algorithms! - VASCO - very weird motion or controlled movement - extreme variability or state changes - beacons (e.g. transit string) - coordinated variability (e.g. transit-network) Examples of “impossible” signals Minor Planet Center, moving-obj pipeline alerts? jradavenport
21. 21 2 Points to Cover: 1) We need SETI signals that ZTF/LSST can detect Write these papers! Some work on this now with ZTF! 
 More needed 2) We should utilize frameworks being built for other 
 science cases to do VASCO/SETI more easily Conclusion jradavenport
22. 22 2 Points to Cover: 1) We need SETI signals that ZTF/LSST can detect Write these papers! Some work on this now with ZTF! 
 More needed 2) We should utilize frameworks being built for other 
 science cases to do VASCO/SETI more easily Conclusion jradavenport 3) Currently NO science working group on SETI for 
 either LSST or ZTF… can we change this?