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Dynamic Andromeda: Novae and Variable Stars in M31. Yi Cao 2 nd year graduate at Caltech On Behalf of the Palomar Transient Factory collaboration. Outline. Novae R Coronae Borealis s tars. (Credit: P. Nugent). Summary of PTF M31 Surveys. Filter: R or g Exp. Time: 60 sec
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Dynamic Andromeda:Novae and Variable Stars in M31 Yi Cao 2nd year graduate at Caltech On Behalf of the Palomar Transient Factory collaboration
Outline • Novae • R Coronae Borealis stars (Credit: P. Nugent) Yi Cao / Tsinghua Transient Workshop
Summary of PTF M31 Surveys Filter: R or g Exp. Time: 60 sec Field of View: 7.2 deg2 Limiting mag: 20 Cadence: 10min-1d Epochs: 1400 Yi Cao / Tsinghua Transient Workshop
Phase Space of Cosmic Explosions (Kasliwal, 2011, PhD Thesis) Yi Cao / Tsinghua Transient Workshop
Nova Explosion Mechanism Periodic explosions in some white dwarf binary systems Yi Cao / Tsinghua Transient Workshop
Nova light curves: diversity Vega mag: Red: R (PTF) Blue: B Green: g AB mag: Purple: NUV magnitude Time (days) (Cao et al. 2012) Yi Cao / Tsinghua Transient Workshop
Nova light curves: diversity Vega mag: Red: R (PTF) Blue: B Green: g AB mag: Purple: NUV magnitude Time (days) (Cao et al. 2012) Yi Cao / Tsinghua Transient Workshop
Nova light curves: diversity Vega mag: Red: R (PTF) Blue: B Green: g AB mag: Purple: NUV magnitude Time (days) (Cao et al. 2012) Yi Cao / Tsinghua Transient Workshop
Nova light curves: “MMRD” Relation (Kasliwal et al. 2011) (Cao et al. 2012) Yi Cao / Tsinghua Transient Workshop
R Coronae Borealis stars Yi Cao / Tsinghua Transient Workshop
R CorBorStars outside the Milky Way and Magellanic Clouds (Tang, Caoet al. in prep.) Yi Cao / Tsinghua Transient Workshop
Summary • Novae show diverse photometry evolution, which implies rich explosion mechanisms. • There is a subclass of novae that do not obey empirical “MMRD” relation. • Systematical search for M31 RCB stars will help determine their rate and improve our understanding of white dwarf binaries. Yi Cao / Tsinghua Transient Workshop
Beyond Palomar Transient Factory Yi Cao On Behalf of collaboration of iPTF and ZTF
PTF Cadence:5 day to 3 day to 2 day • July 2009: Commissioned • Rest of 2009: Station Fire • Year 2010 • Cadence of 5 day + 1 day • (twice a night) • Early 2011: 1000+ SN mark • Year 2011: • Cadence of 3 day + 1 day • (twice a night) • Year 2012: • Cadence of 2 day only • (twice a night) 5 day to 3 day 1 day
Palomar Transient Factory Yi Cao / Tsinghua Transient Workshop
Fast cadence • Orphan GRB • Shock breakout of core-collapse supernovae • Infant Type Ia supernova • The unanticipated Yi Cao / Tsinghua Transient Workshop
“Orphan” Afterglow of GRB? Cenko et al. 2012, submitted Yi Cao / Tsinghua Transient Workshop
Robo-AO (PI: Barenec)(S. Tendulkar’s Thesis Project) • Robo-AO • Fully-automated AO system • UV laser beacon • Visible + NIR observations • Rapid response: < 60 s overhead Electronics Rack 1.5-m telescope Cassegrain Instrument Laser Projector Caltech, USA & IUCAA, India • Performance • 44” FoV • 0.11” FWHM in r’ band • 16 mag tip-tilt star • ~20% z’ band Strehl Yi Cao / Tsinghua Transient Workshop
Robo-AO 2 “ One Robo-AO night! • Large Surveys (Area + Time) • Stellar + asteroid multiplicity • Kepler Planet Candidates • Transient response • TDF vs central SN • Progenitor location • Resolved photometry Yi Cao / Tsinghua Transient Workshop
SED Machine (PI: Konidaris)(Grad. student: S. Ben Ami) Yi Cao / Tsinghua Transient Workshop
Software: Automatic Classifier Yi Cao / Tsinghua Transient Workshop
iPTF • P48 survey telescope + P60 SED machine + P60 Robo-AO + P200 follow-up • Start from 2013 • Big focus on supernovae: • Early discovery of SN Ia (Yi Cao’s thesis project) • Shock breakout of Core-collapse SNe Yi Cao / Tsinghua Transient Workshop
The new Zwicky Transient Facility (ZTF) will find rare fast transients beginning in 2015. New ZTF camera: 12 6k x 6k e2v CCDs Existing PTF camera MOSAIC 12k
P60: Follow-Up The SED Machine PI: N. Konidaris P48 Discovery: 35 sqdeg! PI: S. Kulkarni P200: Spectroscopy The Zwicky Transient Facility