Dynamic Andromeda: Novae and Variable Stars in M31 Yi Cao 2 nd year graduate at Caltech On Behalf of...

Dynamic Andromeda:Novae and Variable Stars in M31

Yi Cao2nd year graduate at Caltech

On Behalf of the Palomar Transient Factory collaboration

Yi Cao / Tsinghua Transient Workshop 2

Outline

• Novae• R Coronae

Borealis stars

(Credit: P. Nugent)

Nov 6, 2012


Summary of PTF M31 Surveys

Filter: R or gExp. Time: 60 secField of View: 7.2 deg2

Limiting mag: 20Cadence: 10min-1dEpochs: 1400

Nov 6, 2012


Phase Space of Cosmic Explosions

(Kasliwal, 2011, PhD Thesis)Nov 6, 2012


Nova Explosion Mechanism

Periodic explosions in some white dwarf binary systems

Nov 6, 2012


Nova light curves: diversity

(Cao et al. 2012)

Vega mag:Red: R (PTF)Blue: BGreen: g

AB mag:Purple: NUV

Time (days)

mag

nitu

de

Nov 6, 2012

Yi Cao / Tsinghua Transient Workshop 7(Cao et al. 2012)


AB mag:Purple: NUV

Time (days)

mag

nitu

de


Nov 6, 2012



(Cao et al. 2012)


AB mag:Purple: NUV

Time (days)

mag

nitu

de

Nov 6, 2012


Nova light curves: “MMRD” Relation

(Cao et al. 2012)(Kasliwal et al. 2011)

Nov 6, 2012


R Coronae Borealis stars

Nov 6, 2012


R Cor Bor Stars outside the Milky Way and Magellanic Clouds

Nov 6, 2012

(Tang, Cao et al. in prep.)


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.

Nov 6, 2012

Beyond Palomar Transient Factory

Yi CaoOn Behalf of collaboration of iPTF

and ZTF

14

PTF Cadence:5 day to 3 day to 2 day

Oct 31, 2012

• July 2009: Commissioned• Rest of 2009: Station Fire

• Year 2010Cadence 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)

1 day5 day to 3 day

Yi Cao / Tsinghua Transient Workshop 15Nov 6, 2012

Palomar Transient Factory


Fast cadence

• Orphan GRB• Shock breakout of core-collapse supernovae• Infant Type Ia supernova• The unanticipated

Nov 6, 2012


“Orphan” Afterglow of GRB?

Cenko et al. 2012, submitted

Nov 6, 2012


Robo-AO (PI: Barenec)(S. Tendulkar’s Thesis Project)

Electronics Rack

Cassegrain Instrument

Laser Projector

1.5-m telescope

Robo-AO

• Fully-automated AO system

• UV laser beacon

• Visible + NIR observations

• Rapid response: < 60 s overhead

Performance

• 44” FoV

• 0.11” FWHM in r’ band

• 16 mag tip-tilt star

• ~20% z’ band Strehl

Caltech, USA & IUCAA, India

Nov 6, 2012


Robo-AO

2 “

One Robo-AO night!

• Transient response

– TDF vs central SN

– Progenitor location

– Resolved photometry

• Large Surveys (Area + Time)

– Stellar + asteroid multiplicity

– Kepler Planet CandidatesNov 6, 2012


SED Machine (PI: Konidaris)(Grad. student: S. Ben Ami)

Nov 6, 2012

21

SED Machine Robotic Spectroscopy


Software: Automatic Classifier

Nov 6, 2012


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

Nov 6, 2012

24

The new Zwicky Transient Facility (ZTF) will find rare fast transients beginning in 2015.

PTF ZTF

Active Area 7.26 deg2 35 deg2

Readout time 36 sec 10 sec

Relative Survey Rate 1x 6x

Filters Mould R, g’

r’, g’

New ZTF camera: 12 6k x 6k e2v CCDs

Existing PTF camera MOSAIC 12k

The Zwicky Transient Facility

P48Discovery: 35 sq deg!

PI: S. Kulkarni

P60:Follow-Up

The SED MachinePI: N. Konidaris

P200:Spectroscopy

Dynamic Andromeda: Novae and Variable Stars in M31 Yi Cao 2 nd year graduate at Caltech On Behalf of...

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