1. Lessons Learned from Past/Ongoing Sky Survey Followup
Paula Szkody
University of Washington
HotWiring V
October 11, 2016

2. Survey Results (and Followup) depend on:
Limiting magnitude (aperture needed)
FOV (slit or multi-fiber)
Filter(s) (other filters or spectra)
Cadence (shorter)
Timespan covered (longer)
Data archive (immediate, easy access)

3. Past Useful Surveys (for CVs)
Palomar-Green, 1.2m(P48), deg2, ~1976, [U-B color], B=16, 35 CVs
Hamburg Survey,0.8m, deg2, [prism],B=18.5, 140 CVs (53 new)
FSVS, 2.5m, 23 deg2, , [BVI], mag – 2 CVs
2dF, 3.9m, 2 deg FOV, 740 deg2, , [spectra], B=21, ~21 CVs
SDSS (APO) – 2.5m, 10 deg2 FOV, 14,500 deg2, ,[ugriz], g=21
DR9 release of Legacy, phot + spectra – 285 CVs (204 new)
PanSTARRS1 (Haleakala) – 1.8m, 7 deg2 FOV, , 20.5 Data release 2016? 3pi + Medium Deep (60 epochs; 12x5 filters)
Palomar Transient Factory (PTF) – 1.2m, 7.3 deg2 FOV, , [R,g], 20.5
phot+ spectra followup on 1.5m-10m – 344 CVs (66 new)
DR1 released 2014 of selected fields
DR2 released 2015 of all data
DR3 release fall 2016 – light curves + more recent data

4. SDSS showed:
Not all objects of interest are red e.g. CVs and WDs mostly blue but CV color range too wide for positive ID

5. Need follow-up spectra for ID and properties!
Lesson learned
from SDSS and PTF:
polar
polar
Need follow-up spectra for ID and properties!
polar IP
Szkody et al. AJ Papers I-VIII IP wd
Groot et al, 2016

6. Computer + eye searches ID’d 285 CVs, 30 Polars, 6 IPs, 9 ZZ
followup phot+spect for Porb:
~ 100 nights APO (Szkody, Silvestri, Mukadam, etc)
~ 70 nights La Palma (Rodrigues-Gil,Gansicke et al.)
~ 100 nights USNO, UofA, MDM (Henden, Schmidt, Thorstensen, etc)
151 Periods determined then, ~175 now
Lesson learned: it takes a lot of telescope time to get Porb!

7. Gansicke et al. 2009, MNRAS, 397, 2170 from 126 periods (disks)
Prior to SDSS
SDSS results
Gansicke et al. 2009, MNRAS, 397, 2170 from 126 periods (disks)

8. Spectral Followup of systems found by CRTS ( Woudt et al
Spectral Followup of systems found by CRTS ( Woudt et al. 2012, Thorstensen & Skinner 2012, Szkody et al ) V=17-19
Gemini GMOS followup of mag CRTS sources in SDSS –Breedt et al. 2014
Large telescopes are necessary for many current survey followups!
8m – 45 min exposures

9. Ongoing Surveys
Intermediate Palomar Transient Factory (iPTF):
SkyMapper (Australia) : 1.35m, 5.7 deg2 FOV, , [uvgriz]
Catalina Real-Time Transient Survey (CRTS): Mt. Lemmon 1.5m, Catalina 0.7m, Siding Springs 0.5m, 2004-
ASAS (Pojmanski), MASTER (Lipunov): ASAS-SN (AssassinxOhio):4-14cm N&S all sky – 20,000 deg2/night, ASAS-SN Transients, ASAS-SN CV Patrol web pages, , MASTER-SAAO, 2014-
Gaia:1.5x0.5m, billion stars X 70 epochs, 20 mag
K2: 100 deg2 FOV for 80 days, K2-K7 in MAST, , ongoing data releases
LAMOST: 4m, 5deg FOV, , [spectra] DR1 of pilot 2012

10. Catalina Real-Time Transient Survey(CRTS)
Mt. Lemmon 1.5m(MLS), Catalina 0.7m(CSS), Siding Springs 0.5m(SSS)
1350 CVs by outburst
Drake et al
Lesson learned: easy immediate web access is productive!
Most are faint

11. Gaia Marshall

13. K2 Fields 60 CVs observed so far-K2-11 in progress
Long cadence = 30 min
Short cadence = 1 min
60 CVs observed so far-K2-11 in progress

14. K2-6 HS Vir Asymmetric=outside in, higher Mdot Higher Mdot
Symmetric =inside out, low Mdot ?

15. K2-3 Intermediate Polar FO Aqr
1 day of SC observations
Porb = 4.85 hr Pspin = 20.9 min

16. Bell et al. 2016 New outbursting WD in Kepler

17. Lesson learned: cadence and length of dataset matter !
Low Mdot
High Mdot
CRTS detecting outbursts
Lesson learned: cadence and length of dataset matter !

18. Future Surveys
ZTF
PanSTARRS ?
LSST

19. ZTF 2017-2020 47 deg2 FOV on 1.2m, 20.5 mag 2 community surveys:
Northern Sky Survey at 3 day cadence
Galactic Plane Survey: 288/yr |b|< 7 deg; dec>-30
Summer schools in August (Caltech) + workshop at 2017 Jan AAS meeting Texas

20. ZTF will use P48 + P60 + 200 in for followup
Survey optimized for existing telescope followup!

21. LSST
Southern Sky Survey, 8.4m, 9.6 deg2 FOV, 25,000 deg2, 30 min + 3 day cadence, ugrizy, ~800 images/object, 10 million alerts/night
Deep Drilling Fields

22. Organizational Needs:
Manage broker lists to identify interesting candidates for followup
Worldwide followup consortia to narrow list thru low res spectra; organize followup
Arrange multiwavelength TOO – UV (HST?), X-ray, Gamma-ray (Swift), radio (VLA)

23. Multiwavelength Obs of VW Hyi
Wheatley et al. 1996
Multiwavelength Obs of VW Hyi

24. Summary of what works colors are useful for some prelim classification
spectra are needed for positive ID, detailed classification
prompt alerts/display of candidates allows max access
coordination of telescopes, observers for subgroups
feedback display of followup prevents duplication
specific plans for long term followup
coordinated TACs for multiwavelength efficiency

25. Some problem areas proper size of working groups
software vs science groups
access to good data products
keeping records current