# Presentation: 746846

## Searching for Asymmetries in SNe Ia via Spectropolarimetry Alex Filippenko (UC Berkeley), in collaboration with Doug Leonard & Ryan Chornock (Leonard et al. 2005, ApJ, 632, 450) 

**June 26, 2007**

## Slide 2

**Normal SN Ia**
**Low pol., rising to the red. Line features visible.**

**High-velocity SNe Ia: 02bf, 02bo, 04dt**

## Slide 6

## Slide 7

## (Leonard et al. 2005, ApJ, 632, 450)

**(****Leonard et al. 2005, ApJ, 632, 450)**

**Slightly subluminous  SN Ia**
**High pol.; partly intrinsic, but very high dust pol. efficiency, too. **

## Conclusions, SNe Ia

**All are intrinsically polarized.**
**Continuum pol.: suggests minor-to-major axis ratio of ~0.9 if viewed equator-on (Höflich 1991 models).**
**Line pol.: suggests partial obscuration of the photosphere by clumpy, newly synthesized intermediate-mass elements.**
**High-velocity SNe Ia have the strongest line pol.: clumps have greater optical depth than in normal SNe Ia. High EWs. More of the C and O fused to IMEs.**

## The Lick Observatory Supernova Search (LOSS) with the Katzman Automatic Imaging Telescope (KAIT)

**Alex Filippenko**
**Department of Astronomy**
**University of California, Berkeley**

**(Main collaborators: W. Li, J. Leaman, M. Ganeshalingam)**

**June 26, 2007**

## Katzman Automatic Imaging Telescope (KAIT)

**Katzman Automatic Imaging Telescope (KAIT)**

**(Laurie Hatch)**

**Notes:**
AF-06-1422.jpg
KAIT at Lick Observatory, as seen from the outside.
(Was 63_KAIT.1024x661.jpg)
Credit: Laurie Hatch

##   30 inch (0.76 m) mirror

-   **30 inch (0.76 m) mirror**

** **
**Lick Observatory,**
**Mt. Hamilton (4200’),**
**near San Jose, CA**

**Funded by NSF, the Sylvia & Jim Katzman Foundation, the TABASGO Foundation, AutoScope Corp., Sun Microsystems, Hewlett-Packard Co., the University of California (Berkeley and Santa Cruz), and NASA.**

**(Laurie Hatch)**

## 30 inch R-C telescope, f/8.2

**30 inch R-C telescope, f/8.2**
**Laser optical encoders**
**Compact and lightweight**
**Precise secondary maneuver**
**20 slot filter wheel**

**Apogee AP7 camera, 6.7’**
**  ****FOV,  0.8”/pix**
**Off-axis guiding**
**Automatic weather station**

**Telescope**

**Secondary**

**Cameras**

**Weather station**

**Stepper motors**

**Guider**

**Apogee**

**Filter wheel**

- KAIT Hardware

**Weidong Li (UCB)**

**Notes:**
weidong.jpg

##   Hardware control

- workstation

- workstation

- Swift

- pc1

- pc2

- pc3

- GCN

**Berkeley **

**Lick Obs.**

- KAIT

**90 miles**

- KAIT Software

- Fully robotic observations

-   **Hardware control**
**  ****Obs schedule and control**
**  ****SN search schedule**
**  ****SN search image processing**
**  ****GRB response**

## Scientific motivation of LOSS

-  **Monitor a well-defined galaxy sample**
** ****Find lots of young SNe (****search engine****)**
** ****Photometric follow-up obs. (****database****)**
** ****Detailed log files (****SN rate, statistics****)**
** ****GRB follow-up observations**
**KAIT can take 700-1300 SN search images per night, plus do some follow-up obs.**

## LOSS sample 

- LOSS sample
- galaxies

- (hours)

- (degrees)

- (km/s)

- R.A.

- Dec.

- Redshift

- Selected from RC3, UGC, ESO-Uppsala
- Limits on declination, redshift
- Limits on brightness, diameter of galaxies
- 14,000 fields, ~20,000 galaxies

## LOSS Cadence: 2-12 days

- 2001 - 2007, 1.5 million obs

- Observation interval (days)

- No
- of
- obs

- 200 gal:       every 2 days
- 5,000 gal:   every 5 days
- 10,000 gal: every 10 days

## LOSS seeing: 2-3”

- FWHM (seeing; arcsec)

- No
- of
- obs

- 2001-2007
- All obs.

**Notes:**
Loss in numbers

## KAIT

- Part of Lick Observatory

## LOSS: typical depth (17.0-19.5 mag)

**Lmag = Lmag(intensity, FWHM, sky)**

- 6,000 obs, ~100 fields

## SN Ia 1998dh before/after

**SN 1998de before/after**

**Notes:**
AF-03W-138-r (rotated 90 deg).

**SN 2001en**

**Cosmic ray**

**New image**

**Template**

**Difference (after much processing)**

**Undergraduate students confirm, and find the trickier ones, by eye. (Auto-observe some candidates.)**

**NGC 523**

**KAIT Supernova Search & Analysis Team, May 2005**

**Notes:**
May 6, 2005 group photo of KAIT SN searchers (but some missing: Katsuki, Harish Khandrika, Brian Beutler (gone?), Matthew Moore; new ones like Prakash? And one other -- look up)
Mohan Ganeshalingam, Brandon Swift, Sung Park, Jayme Burkett, Nick Ponticello (new), John Graham, Harrison Pugh (Berkeley High School student).

## The KAIT SN Search at Lick Obs.

**1997: ****1**** (SN 1997bs)**
**1998: 20 (world record)**
**1999: 40 (world record)**
**2000: 38 (including SN 2000A)**
**2001: 68 (world record; SN 2001A)**
**2002: 82 (world record)**
**2003: 95 (world record)**
**2004: 83     2005: 82     2006:  84**
**2007: 37 through June 25**
**http://astron.berkeley.edu/~bait/kait.html**

**Notes:**

SN 1997bs is a SN of questionable integrity, given its name, SN 1997bs.

**LOSS SNe, m < 19 mag when discovered**

**Notes:**
sn.year.gif

## SN 1998dh(Type Ia)

-                         **Age:**
**                  ****-6 days**
**                 ****Maximum**
**                ****+26 days**
**               ****+47 days**
**              ****+102 days**

**Notes:**
Now, the lifecycle of an SN Ia can be described in distinct stages....

**Mohan Ganeshalingam**

**Notes:**
09/24/04 UT Lick “Research trip” -- Brandon Swift and Mohan Ganeshalingam

## Template subtraction; SN photometry

** ****(Automatic pipeline****: ****Mohan Ganeshalingam)**

## SN Ia

**SN Ia**

**Notes:**
AF-06-1297.jpg
Type Ia supernova light curves, from KAIT.
Credit: Weidong Li, Mohan Ganeshalingam, and Alex Filippenko

## SN II

**Notes:**
AF-06-1296.jpg
Type II supernova light curves, from KAIT.
Credit: Weidong Li, Mohan Ganeshalingam, and Alex Filippenko

## LOSS results: follow-up efforts

**Prompt alerts to 80 astronomers/SN observers**
**CfA Supernova program (Kirshner et al.)**
**Carnegie Supernova Program (CSP)**
**Follow up with our own telescope network**

**10-20% of time**
**   ****Photometry;**
**   ****calibration**

**2-3 nights/mon**
**   ****Calibration;**
**   ****photometry**

**2-3 nights/mon**
**spectroscopy**

**Occasional**
**spectroscopy**

**KAIT**

**Lick 1-m**

**Lick 3-m**

**Keck I/II 10-m**

## SN rates from KAIT to be discussed on Thursday morning!

**(Jesse Leaman PhD thesis, UC Berkeley)**

## On-going/planned projects:

- Photometry pipeline/data release
- Impact on Cosmology (low-z SN Ia sample)
- Hubble constant/Hubble bubble
- Distance fitters/extinction laws
- Local peculiar flow
- Low-z SN Ia sample (properties/statistics)
- Low-z SNe II (photometry/spectroscopy)
- Low-z SNe Ib/c
- Low-z SNe IIn, II-L, II-P
- Radial/spatial distribution of SNe
- Many Individual interesting objects
- SN rates/statistics
- SN luminosity function