# Presentation: 584321

##  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

## HST Refurbishing led to a telescope with great ability to determine properties of dark energy

## A New Camera on HSTACS:Advanced Camera for Surveys

##  Big step forward:0.05 arcsecpixels

- 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

- 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)

- Adam Riess

**Notes:**
Fortunately we have friends who need deep and wide images with HST to
Study galaxy evolution and we have been able to hitch a ride on their program
Like the parasites we are and!

## 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

**Notes:**
GOODs observes 2 fields every 45 days, 15 tiles in the z-band and we search for supernovae.
So far we have found 5 or 6 each time we do this and 1 or 2 look like high-redshift Ia’s.  We
Then target with our ToO program to get the measurements we need.

## Before and After:Higher-Z Supernovae

## Determining the Type

## 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 ()
- 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

## Distances to 9%

## 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

**Look up there, Willem!**

## Slide 19

- Distinguishing SN Types by Colors

## Observed Colors of Higher-z Supernovae

## 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 grism spectrum

**NICMOS F110W**

**ACS F850lp**

- viz

**Notes:**
Our first target was Aphrodite (SN 2002fw).  New modes of HST are critical
To the measurements.

## The Rise and Fall

- Aug 1

- Sept 22

- Oct 1

- Oct 5

- Oct 10

- Oct 20

- Oct 30

- Oct 31

- Nov 17

- Nov 25

- Photometry enhanced by 0.05” pixels!

**Notes:**
Here is a short, independent film showing the time history of Aphrodite...you will see...

## Results from HST

- Seeing back to the era of ***de***celeration

## 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)

## Closing in the Contourson Riess et al2004astro-ph0402512

## Not just w, but w’  too!

- 1 from 

## 2004PANSProbing 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

## What next for HST?

## ESSENCEEquation of State: SupErNovae Trace Cosmic Expansion

- ESSENCE***E***quation of ***S***tate: ***S***up***E***r***N***ovae Trace ***C***osmic ***E***xpansion

## Supernovae, the microwave background,  and galaxy clustering

- will determine properties
- of the dark energy.
- This cannot fail to be interesting!  or something else.

****

## 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 -ray bursts & black hole formation

## Star formation rate (z)The Dahlen-Strolger diagram

## 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 -ray bursts and black hole formation for SN Ic

- Thinking the Unthinkablefor JDEM: DESTINY

- Use IR detectors only 0.85
- 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)

## Slide 45