Recent Studies on Type Ia Supernovae

Science Update: SN2011fe in M101 (Pinwheel Galaxy)

• Peter Nugent (LBNL/UCB)

Major Points

• AAAC Meeting

• The integrated role of all 3 agencies in the discovery and follow-up of SN 2011fe.
• The level of computing required to deliver such discoveries.

PTF (2009-2013)

• AAAC Meeting

• 92 Mpixels, 1” resolution, 2.0” seeing, R/g=21 in 60s
• 2 cadences SN & Dynamic with g in dark time & R in bright time

PTF Science

• AAAC Meeting

PTF Key Projects
Various SNe	Dwarf novae
Transients in nearby galaxies	Core collapse SNe
RR Lyrae	Solar system objects
CVs	AGN
AM CVn	Blazars
Galactic dynamics	LIGO & Neutrino transients
Flare stars	Hostless transients
Nearby star kinematics	Orphan GRB afterglows
Type Ia Supernovae	Eclipsing stars and planets
Tidal events	H-alpha ½ sky survey

• The power of PTF resides in its diverse science goals
• and follow-up.

PTF Pipeline

• AAAC Meeting

• 128 MB/90s
• 50 GB/night

Real-time Pipeline

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• NERSC GLOBAL FILESYSTEM
• 240TB

• Data
• Transfer
• Nodes

• Science
• Gateway
• Node 2

• Science
• Gateway
• Node 1

• Observatory

• PTF
• Collaboration
• via Web

• Processing/db

• Carver
• 3200
• core IBM

• Subtractions

• ~1 hour turnaround

PTF: Real or Bogus

• AAAC Meeting

• PTF produces 1 million candidates during a typical night:
• Most of these are not real
• Image Artifacts
• Misalignment of images due to poor sky conditions
• Image saturation from bright stars
• 50k are asteroids
• 1-2k are variable stars
• 100 supernovae
• 1-2 new, young supernovae or other explosions
• Help from Bloom et al. NSF-CDI project:
• Real-time Classification of Massive Time-series Data Streams

Real or Bogus

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• moon

• 4096 X 2048 CCD images - over 3000 per night

Real or Bogus

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• 230 bogus candidates, 2 variable stars, 4 asteroids and the youngest Type Ia supernovae observed to date….

• PTF10ygu: Caught
• 2 days after explosion

Citizen Scientists…

• AAAC Meeting

• http:// supernova.galaxyzoo.org keeps chugging along (Smith et al., 2010)
• Typically we have them scan ~200 candidates in 12 hrs after the night is finished. They get the list of the top 100 real-bogus, top 100 S/N, and top 100 via host-size of all new candidates.

• PTF11gdm

PTF Sky Coverage

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• 1000

• 100

• 100

• 0

• To date:
• 1301 Spectroscopically typed supernovae
• 105 Galactic Transients
• 104 Transients in M31
• 2.5 years, over 1 million images taken.
• 35 refereed publications.

SN 2011fe (PTF11kly)

• AAAC Meeting

• Peter Nugent

• 180k views on YouTube, 50+ newspaper articles, PBS Newshour, BBC, NPR…

• AAAC Meeting

• Peter Nugent

• Swift

• HST

• SN 2011fe was caught within 11 hrs +/- 20 min. of explosion.
• First spectra
• ~24 hr later.
• Peaked @ mag 9.9, making it the 5th brightest SN in last 100 years.

• AAAC Meeting

• Peter Nugent

• SYNAPPS spectrum synthesis fits on NERSC’s Hopper commenced 1 hour after first spectrum was reduced.
• Finished analysis 30 hours after SN was first detected!

• Ca II

• Si II

• S II

• Mg II

• Fe II

• O I

• Ca II

• AAAC Meeting

• Peter Nugent

• AAAC Meeting

• Peter Nugent

• Rules out red giant companions and a lot of double degenerate models.

• AAAC Meeting

• Peter Nugent

• HST Pre-imaging of the field where SN 2011fe was found.

• AAAC Meeting

• Peter Nugent

• Constraints on the progenitor system.
• Basically all we can have are a double degenerate system or a low mass main sequence companion.
• Nature: Nugent et al. and Li et al.

• AAAC Meeting

• Peter Nugent

• DOE/HEP: NERSC computing facilities, SCIentific Discovery through Advanced Computing program and staff and scientific leadership in the SN Ia experiment for PTF.
• NSF: Direct support of PTF and support from the Cyber Enabled Discovery and Innovation Program - real-time classification.
• NASA: Swift, Chandra and HST for both pre-explosion imaging (optical and x-ray) and follow-up after discovery in the ultra-violet.

• Agencies