11:25 Now we have Peter Nugent: SNe 1999as & 2007bi. Twin Pair Production SNe?
Bias in SN Searches: You find the kinds of things you’re looking for. KAIT, Zwicky & Amateurs: Targeting big galaxies. High-z searches. SNf and SDSS: Rolling searches.
SN 1999as: Search to find low z SNe using similar methods to high-z searches. ie. big fields not bright galaxies. SN 1999as found by NEAT. Something that showed up with nothing there.
Spectrum looks like a type Ibc. Some narrow features. Redshift of .1 Mag at max =-21.
Almost no evolution in spectral features over 25-55 days. Narrow features 1000 km/s wide at 10,000 km/s: Detached shell. Fe II and Ti II.
LC models: 5M Ni, Mtot = 50M, KE = 50 FOE.
Host spectrum: Metallicity < 1/3 Solar. Mv = -17.8
Other SNe like SN 1999as?: SN 2001bb Mabs = -17. Dropped like a rock. Similar spectrum with narrow Fe & Ti features.
No event like 99as, until....
SN factory: 10,000 images per night. 10% have 5sigma detections. Automated rejection tree knocks this down to 100 per night. Good at finding Type Ias.
Finding lots of Type Ias in low luminosity and low metallicity galaxies.
Deep Sky: 9 Years of data on the sky. Useful targeting aid. Allows the removal of distant AGN and variable stars.
SN 2007bi. Host Mg=-16.4 @ z=.127 Mv = -20.5. Like 99as. Slow decay LC at early times (again like 99as).
Prediscovery -50 d. (Would have been thrown out if known)
Why PPSN? Large 56Ni. Too much for “standard” mechanism. Large total mass. Large KE. Low Metallicy environment. What else could it be: CSM, but no smooth continuum and no narrow hydrogen....
Conclusions: What you find is what you get. These things have slow light curves and would get thrown out of Ia searches.
Discussion: Lots of questions about CSM interaction. Way to use interaction to power these things? What about lack of He in the spectra. Decay rate for 07bi consistent with Co decay... For a year!
Plug for the Palomar Transient Search. Coming in March.
Also. Both super Chandra SNe are in low metallicy galaxies.
Bias in SN Searches: You find the kinds of things you’re looking for. KAIT, Zwicky & Amateurs: Targeting big galaxies. High-z searches. SNf and SDSS: Rolling searches.
SN 1999as: Search to find low z SNe using similar methods to high-z searches. ie. big fields not bright galaxies. SN 1999as found by NEAT. Something that showed up with nothing there.
Spectrum looks like a type Ibc. Some narrow features. Redshift of .1 Mag at max =-21.
Almost no evolution in spectral features over 25-55 days. Narrow features 1000 km/s wide at 10,000 km/s: Detached shell. Fe II and Ti II.
LC models: 5M Ni, Mtot = 50M, KE = 50 FOE.
Host spectrum: Metallicity < 1/3 Solar. Mv = -17.8
Other SNe like SN 1999as?: SN 2001bb Mabs = -17. Dropped like a rock. Similar spectrum with narrow Fe & Ti features.
No event like 99as, until....
SN factory: 10,000 images per night. 10% have 5sigma detections. Automated rejection tree knocks this down to 100 per night. Good at finding Type Ias.
Finding lots of Type Ias in low luminosity and low metallicity galaxies.
Deep Sky: 9 Years of data on the sky. Useful targeting aid. Allows the removal of distant AGN and variable stars.
SN 2007bi. Host Mg=-16.4 @ z=.127 Mv = -20.5. Like 99as. Slow decay LC at early times (again like 99as).
Prediscovery -50 d. (Would have been thrown out if known)
Why PPSN? Large 56Ni. Too much for “standard” mechanism. Large total mass. Large KE. Low Metallicy environment. What else could it be: CSM, but no smooth continuum and no narrow hydrogen....
Conclusions: What you find is what you get. These things have slow light curves and would get thrown out of Ia searches.
Discussion: Lots of questions about CSM interaction. Way to use interaction to power these things? What about lack of He in the spectra. Decay rate for 07bi consistent with Co decay... For a year!
Plug for the Palomar Transient Search. Coming in March.
Also. Both super Chandra SNe are in low metallicy galaxies.
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