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A Blunder Undone Robert P. Kirshner Harvard-Smithsonian Center for Astrophysics. Wide Field Observations of Supernovae from Space. Robert P. Kirshner Harvard-Smithsonian Center for Astrophysics. Searching for Supernovae with HST. Back to the age of de celeration.
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A Blunder UndoneRobert P. KirshnerHarvard-Smithsonian Center for Astrophysics Wide Field Observations of Supernovae from Space Robert P. Kirshner Harvard-Smithsonian Center for Astrophysics
Searching for Supernovae with HST Back to the age of deceleration
HST Refurbishing led to a telescope with great ability to determine properties of dark energy
HST Today • Telescope and instruments are working great => GOODS! • New set of instruments ready to install: COS, WF3 • Needs a Shuttle Mission-Top science priority, NASA has balked. • NRC Committee to recommend ways to get the most from HST
The GOODs ACS Treasury Program & The Higher-Z Supernova Search Team Adam Riess Sees farther than others: 1.2< z < 1.8 supernovae Riess (STScI) Strolger (STScI) Tonry (UH) Filippenko (UCB) Kirshner (CfA) Challis (CfA) Casertano, (STScI) Dickinson (STScI) Giavalisco (STScI) Ferguson (STScI)
Searching for SNe Ia with ACS 5 z-band epochs, spaced by 45 days, simultaneous v,i band, 120 tiles CDFS=08/02-02/03 HDFN=11/02-05/03
Mass is destiny for stars • High mass stars (> 8 solar masses) can ignite Carbon in their cores when it is not degenerate => go all the way to iron & core collapse 100x larger energy output (n) • Low mass stars are degenerate at the end of helium burning, stable or (in a binary) vulnerable to thermonuclear runaway • SN Ia --white dwarf merger or accretion from companion. 2002ic, Hamuy et al.
Saurabh Jha Word of the day: Lucubration: Earnest study at night
Light Curves: Clues to Luminosity U-Band for Higher-z
Light Curve Shapes => L Thesis, Saurabh Jha, Harvard University
Move to the IR? Luminosity has weak dependence on light curve shape Reddening less of a problem Present database not adequate but Carnegie Supernova Project is in full swing-- big mistake to build JDEM on assumptions of 1998 CfA to add 2MASS telescope
Statistics of SN in Higher-Z Sample • 42 supernovae detected, m<25 • 25 have colors of SN I • 17 “not Ia”, putatively “core collapse”-- no explicit follow-up, but some data on the CC objects • SN rates(z) for Ia and for “not Ia” determined by Dahlen and Strolger
Worries • Bright SN Ib/c • Same zone in color and magnitude • Not expected to be a major contaminant of the SN Ia sample • Bright Ib/c ~ 20% of the SN Ib/c which are ~1/3 of the core collapse sample
Higher-z SN Ia New Object with SN Ia Colors ACS F850lp ACS grism spectrum NICMOS F110W viz
The Rise and Fall Oct 20 Oct 1 Nov 17 Aug 1 Oct 5 Sept 22 Oct 30 Oct 31 Nov 25 Oct 10 Photometry enhanced by 0.05” pixels!
Seeing back to the era of deceleration Results from HST
Evidence for a change in cosmic acceleration: cosmic jerk Future: Acceleration without end? Big rip?
A Less Prejudiced View Riess & Higher-z astro-ph0402512
A More Familiar Plot Data from Riess et al. 2004, includes Knop et al. (2003); Tonry et al. (2003); Barris et al (2003)
Not just w, but w’ too! 1s from L
2004PANSProbing Acceleration Now with Supernovae • Observing supernovae from space to learn about Dark Energy now! • 270 HST orbits in Cycle 13 • Higher-z Team (Adam Riess, PI) • Future depends on HST repair
Supernovae, the microwave background, and galaxy clustering will determine properties of the dark energy. This cannot fail to be interesting! L or something else. L
Where will we be when JDEM flies? • 3 x larger sample from HST at z>1, much more if HST is refurbished • WFC3 would provide IR experience if HST is refurbished • 200 SNIa from ESSENCE, similar from CFH Legacy 0.3< z <0.7 • Contributions from Sloan, Quest, DMC, Pan-STARRS, LSST?
Core Collapse Supernovae Massive progenitors => Close tracer of current star formation rate Conversely, every known supernova in an Elliptical is an SN Ia SN IIL, SNIIP, SN IIn, SN Ib, SN Ic all found locally only in galaxies with current star formation Differences due to degree of mass loss SN Ic linked with g-ray bursts & black hole formation
SN II for Cosmology • Expanding Photosphere method provides independent distances to SN II (Kirshner & Kwan 1974, Wagoner, Narayan, Doug Leonard, Mario Hamuy, Peter Nugent) • Systematic problems with theoretical models • Should be simpler in the IR
The Strange Case of SN 1999em in NGC 1637 • EPM: Leonard et al. : 8.2 +/- 0.6 Mpc • Hamuy et al.: 7.5 +/- 0.5 Mpc • Cepheid distance 50% different!
Thinking about Core Collapse SN • Use SN II for Expanding Photosphere Distances (Kirshner & Kwan 1974) ; • Ho= 73+/-7 from Schmidt, & Kirshner, & Eastman (1992) • Try IR-only version
Thinking about Core Collapse SN • Determine SFR from SN in completely unbiased way • Probe connection with g-ray bursts and black hole formation for SN Ic
Thinking the Unthinkablefor JDEM: DESTINY • Use IR detectors only 0.85m - 1.7m • Use a grism for much simpler spectrograph • Divide labor with ground-based systems at z~0.5 (going lower drives field-of-view and pixel size) • Focus simpler mission on SN and the Dark Energy
A More Familiar Plot Data from Riess et al. 2004, includes Knop et al. (2003); Tonry et al. (2003); Barris et al (2003)