photometric search for weirdos in the sdss-ii sn survey dataphotometric search for weirdos in the...
TRANSCRIPT
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Photometric Search for Weirdos in the SDSS-II SN Survey Data
Ben DildayLCOGT & UC Santa Barbara
March 16, 2012
Photometric Identification of Supernovae
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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
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Photometric Identification of Supernovae
Gaussian process modellinggeneralized light-curve fit
set of observations y
mean function
covariance
predictive distributionson function space
fit parameters
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Photometric Identification of Supernovae
fit parameters
Squared exponential covariance function
For fitting, a Gaussian prior on σb12 +- a few
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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
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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
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Photometric Identification of Supernovae
91bg-like
!30 !20 !10 0 10 20 30 40 50 60
0
200
400
600
800
1000
SN006295
ugriz
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Photometric Identification of Supernovae
91bg-like
!30 !20 !10 0 10 20 30 40 50 60
0
500
1000
1500
2000
2500
SN018890
ugriz
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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
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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
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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
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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
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Photometric Identification of Supernovae
Pathological Fit
!30 !20 !10 0 10 20 30 40 50 600
1000
2000
3000
4000
5000
SN002409
ugriz
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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
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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
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Photometric Identification of Supernovae
probably super-luminous
Hydrogen poor CC(Quimbies)
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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
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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
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fast transients
confirmed Ias
fast weirdos!~25 objects
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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
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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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