Photometric Search for Weirdos in the SDSS-II SN Survey Data

Ben DildayLCOGT & UC Santa Barbara

March 16, 2012

Photometric Identification of Supernovae

weirdos: rare / unusual astrophysical transients

Kulkarni & KasliwalTransients in the local universe

white paper http://arxiv.org/abs/0903.0218

Photometric Identification of Supernovae

ultra-luminous H-poor CC

circum-stellar interaction

05hk-like

dust-enshrouded massive star

point Ias2002bj/ 2010X

SDSS SN Survey

~ 300 deg**2

ugriz with ~ 2-4 day cadence

~ 500 confirmed SNe Ia

~100 confirmed SNe Ib/c, II

~1000 “good” Photometric

SNe

PTF09dav

Photometric Identification of Supernovae

Gaussian process modellinggeneralized light-curve fit

set of observations y

mean function

covariance

predictive distributionson function space

fit parameters

Photometric Identification of Supernovae

fit parameters

Squared exponential covariance function

For fitting, a Gaussian prior on σb12 +- a few

Photometric Identification of Supernovae

!30 !20 !10 0 10 20 30 40 50 60

0

2000

4000

6000

8000

10000

12000

14000

16000

SN005944

SN Ia @ z ~ 0.05

ugriz

Photometric Identification of Supernovae

SN Ia @ z ~ 0.05

!30 !20 !10 0 10 20 30 40 50 60

0

1000

2000

3000

4000

5000

6000

7000

8000

SN003901

ugriz

Photometric Identification of Supernovae

91bg-like

!30 !20 !10 0 10 20 30 40 50 60

0

200

400

600

800

1000

SN006295

ugriz

Photometric Identification of Supernovae

91bg-like

!30 !20 !10 0 10 20 30 40 50 60

0

500

1000

1500

2000

2500

SN018890

ugriz

Photometric Identification of Supernovae

SN Ib

!30 !20 !10 0 10 20 30 40 50 60

0

200

400

600

800

1000

1200

1400

1600

SN014492

ugriz

Photometric Identification of Supernovae

SN 2005hk(SN 2002cx-like)

!30 !20 !10 0 10 20 30 40 50 60

!10000

0

10000

20000

30000

40000

50000

60000

70000

SN008151

ugriz

Photometric Identification of Supernovae

SN 2005gj(SN 2002ic-like, Ia w/ CSM interaction)

!30 !20 !10 0 10 20 30 40 50 60

0

5000

10000

15000

20000

SN004524

ugriz

Photometric Identification of Supernovae

Type IIPlength scale is not constant

!30 !20 !10 0 10 20 30 40 50 60

!200

0

200

400

600

800

1000

1200

1400

1600

1800

SN003818

ugriz

Photometric Identification of Supernovae

Pathological Fit

!30 !20 !10 0 10 20 30 40 50 600

1000

2000

3000

4000

5000

SN002409

ugriz

Photometric Identification of Supernovae

Fast transient(point Ia candidate)

!30 !20 !10 0 10 20 30 40 50 60

!200

0

200

400

600

800

SN002140

ugriz

Photometric Identification of Supernovae

SN 2006gzSuper-luminous H poor SNe (Leloudas et al, 2012)

!30 !20 !10 0 10 20 30 40 50 60

0

500

1000

1500

2000

2500

3000

SN015557

ugriz

Photometric Identification of Supernovae

probably super-luminous

Hydrogen poor CC(Quimbies)

Photometric Identification of Supernovae

probably super-luminous

Hydrogen poor CC(Quimbies)

!30 !20 !10 0 10 20 30 40 50 60

!200

0

200

400

600

800

SN002538

Photometric Identification of Supernovae

n = 2 x nfilt + 3 x (nfilt-1)= 22 for ugriz

characterize SNe with derived quantities from the GP model

mea

n +

- st

d rise time: number of magnitudes rise from

-5 to 0 daysfall time: number of

magnitudes fall from 0 to +10 days

colors: early time (-5 days), at peak (0 days), late time (+10 days)

colors rise time/ decline time

fast transients

confirmed Ias

fast weirdos!~25 objects

a selection of 2010X-like/ point Ia candidates from SDSS-II

lack of hosts, α,δ distribution,

featureless spectra

implies probably

Milky Wayobjects

less fast; more point Ia-like

Ib SNe 4524=2005gj

high S/N well-sampled

SNe Ia

the realm of the weirdos!

dendrogram, using all candidates of type 111+ (confirmed Ias, Ib/cs, IIs and probable Ias)

cluster SNe using hierarchical clustering algorithm

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