Targets of Interest: AM CVn SystemsAM CVn systems are rare, ultra­compact binaries. Their extremely shortorbital periods are possible due to theirHe­rich, H­deficient composition. Theyare particularly interesting from anevolutionary point of view, and most arebelieved to be the end product ofdetached white dwarf binaryevolution[10]. Their population densityhas proven difficult to measure, aspopulation synthesis estimates havepoorly matched observational evidence[11]. Verifying the models used for theseestimates is one of the key goals of thePTF AM CVn System search. Simulation rendering of an AM CVn system

WD AccretorM = 0.5 - 1 .0Mʘ

• Porb = 5 – 65 minutes• Population density poorly understood

He-rich donorM < 0.1Mʘ

Helium accretion diskwith hot spot

PTF Photomeric PipelineVariable source work with the PTFrequires well­calibrated data. We havedeveloped a relative photometriccalibration pipeline that provides 0.5%photometric accuracy over multi­yearlight curves in a fully automaticfashion. Moreover, it is able to handlebad weather and non­photometricnights without generating erroneousvalues. With 300 million light curvesover > 16,000 deg2 to R~20.6, the PTF photometric "database" is oneof the widest, deepest, and best calibrated synoptic surveys available.

Photometric accuracy ofa typical PTF field

Palomar Transient FactoryThe Palomar Transient Factory[7,8] is a wide­field synoptic survey thatuses the Palomar 48" Oschin Schmidt Telescope to image up to 2,000sq. deg. of the sky per night to a 5σ depth of R~20.6.Already amazingly successful in the discovery of supernovae, thecompletion of the PTF photometric pipeline provides an unprecedentedlook at the variability of sources over >16,000 sq. deg. of the sky.

(Ultra­)Compact Binaries fromthe Palomar Transient FactoryThomas A. Prince1,2,3, Eric Bellm1, Shrinivas Kulkarni1, David Levitan1, Bruce Margon4, and Paul Groot5, on behalf of the PTF Collaboration6

1. Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125.2. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91125.3. E­mail: prince@srl.caltech.edu4. Department of Astronomy and Astrophysics, University of California, 1156 High Street, Santa Cruz, CA 95064, USA.5. Department of Astrophysics, IMAPP, Radboud University Nijmegen, P.O. Box 9010, 6500 GL Nijmegen, The Netherlands.6. http://www.astro.caltech.edu/ptf/7. Law, N. M., Kulkarni, S. R., Dekany, R. G. et al., 2009, PASP, 121, 1395.8. Rau, A., Kulkarni, S. R., Law, N. M. et al, 2009, PASP, 121, 1334.9. Gänsicke, B. T., Dillon, M., Southworth, J. et al, 2009, MNRAS, 397, 2170.

10. Nelemans, G., Portegies Zwart, S. F., Verbunt, F., and Yungelson, L. R., 2001, A&A, 368, 939.11. Carter, P. J., Marsh, T. R., Steeghs, D. et al, 2012, MNRAS, in press.12. Levitan, D., Fulton, B. J., Groot, P. J. et al, 2011, ApJ, 739, 68.13. Levitan, D., Kupfer, T., Groot, P. J. et al, 2013, MNRAS, in press.

(Ultra­)Compact BinariesSome of the most interesting astrophysical sources are compact binaries. Formed fromcomplex evolutionary methods, these sources are unique probes of extremeastrophysics. Although rare and difficult to identify, many of these systems do showphotometric variability that can be detected in synoptic surveys. Here, we present workby the Palomar Transient Factory (PTF) collaboration to identify and better understanddwarf novae, AM CVn systems, and redback/black widow pulsars.

Outbursting System SearchOne particular aproach to the identification of (ultra­)compact binaries is our search for outburstingsystems. Specfically, we denote any source withphotometric variability of >1.5 mag that is sustainedover >1 day to be outbursting.This project has already identified several hundrednew dwarf novae, six new IP candidates (see poster byMargon et al.; 148.10), and seven new AM CVnsystems (see below and talk by Levitan on Thursday ­401.01D). All outbursting system candidates areselected from the database of light curves, andspectroscopically confirmed using low­resolution spectra at collaboration telescopes.

Example outbursting light curve from the PTF

Targets of Interest: Dwarf NovaeH­rich dwarf novae (DN) are relativelynumerous, well­understood systems, yetstill many questions remain about thisclass of systems. In particular, theirevolution is not fully understood, includingthe 2–3h "period gap" and the "periodminimum". The most homogeneouslyselected sample of dwarf novae is currentlyfrom the SDSS spectroscopic survey[9],and is limited by the selection criteria thatthe SDSS uses to identify spectroscopictargets. The PTF allows us to search forthese systems from their outbursts, thusproviding a separate sample from those previously known. Thus far, wehave spectroscopically confirmed >200 new DN and have additionallyidentified outbursts in ~100 more previously known DN. The PTF sampleappears to have a similar period distribution to the SDSS sample.

The newly identified DNs, all with spectra, havealso allowed us to identify candidates withpossible pulsating accretors. Such systemstypically have accretion wings from the whitedwarf accretor around the typical H emissionlines. We are now conducting follow­up high­speed observations of these systems.

New AM CVn Systems DiscoveredThe PTF has discovered seven new AM CVnsystems: this represents 20% of the knownpopulation[12,13]. Of even more interest is thatthese systems were identified systematicallyfrom their outbursts. Previous populationstudies of AM CVn systems were basedprimarily on systems selected from the SDSS,either from spectra or colors. Our surveyprovides an independently obtained sample ofthe AM CVn system population that wasselected not by the complex color cuts of theSDSS survey, but based on a color­independentoutburst selection. By combining this samplewith an understanding of the outburst dutycycle of AM CVn systems (using combined lightcurves from multiple synoptic surveys), we will be able to verify the latestobservational predictions of the AM CVn system population density.

PTFS1119aq: an Eclipsing AM CVn SystemOf great interest is the AM CVn system PTFS1119aq,which was found to be eclipsing with an orbital period of~22.5 min. PTFS1119aq is the shortest orbital­period AMCVn system known to outburst and is also the secondknown eclipsing AM CVn system, although the eclipses inPTFS1119aq are only grazing. Additional such eclipsingsystems will help us better understand these uniquesystems by better constraining the masses and orbits ofthe system components.

Targets of Interest: PulsarsA significant fraction of Fermi pulsars haveproven to be eclipsing black widow orredback systems, where a spun­upmillisecond pulsar ablates its low­masscompanion. These systems provide anevolutionary link between NS X­raybinaries and isolated MSPs, and theypermit measurement of NS masses. PTFphotometry is enabling modelling of radio­identified Fermi black widows such as PSRJ2129­04 (Bellm et al, poster 154.10), andwe continue to search for new Fermicounterparts via their optical variability. Folded R­band magnitudes for PSFJ2129­04 showing ellipsoidal variability

Six of the newly discovered AM CVn Systemsfrom the PTF

Phase­binned light curve ofPTFS1119aq folded at 22.5 min.

Comparison of the period distribution ofknown dwarf novae detected in both thePTF and in the SDSS

Absorption wing spectra of a DNwith a possible pulsating accretor