# Presentation: 116039

## The Supernova Rate Derived from the Lick Observatory Supernova Search with KAIT

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

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

**June 28, 2007**

##   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)**

## Supernova Rates

**Cappellaro et al. 1999 (C99 hereafter)**
***5 surveys (1 visual, 4 photographic plates)**
***137 SNe in about 10****4**** galaxies**
***B-band luminosity normalization**
*** SN rate as a function of SN type (Ia, Ib/c, II)**
** ****and host morphology (E/S0, Sa/b, Sbc/d, Irr)**

**Mannucci et al. 2005 (M05 hereafter)**
**Same database as C99**
**K-band luminosity normalization**
**SNr versus galaxy color (B-K)**

**Benchmark for z = 0 SN rate:**

## Jesse

**Jesse Leaman**

## LOSS results (1998-2006): Leaman, Li, & AVF (2007, in prep.)

**844 SNe observed (600 LOSS discoveries & 240 independent confirmations)**
**SNe used* in the SN rate calculation for a given normalization technique and SN type:**

**Filter| Ia  | Ib/c | II  |  ? | Total**
**B      247   97  284   14  642**
**K      235   93  274   13  615 **
**B&K 227   87  265   12  591**
***Only SNe for which we have all **
**host galaxy information were included**

## SN rate = 

**No. of Supernovae**

**Total L   x  Total monitoring time**

## d = 100 MpcMag limit = 19 

**d = 100 Mpc****Mag limit = 19**** **

**Could see SN Ia for 125 d, SN Ib/c for 30 d, SN II-P for 130 d.**

**Ia**

**II-P**

**Ib/c**

**Control time (one epoch)**

**Notes:**
lc_ex.pdf

## Observation interval (days)

**Number of observations**

**2001********2003**

**After June 2004**

** ****t1      t2              t3**

**7d**

**14d**

**CT=130d**

**130d**

**130d**

**Total ct = 130d + 7d +14d**

**Obs intervals**

**Control time (multi epochs)**

**Notes:**
Loss in numbers

## Observation interval (days)

**Number of observations**

**2001********2003**

**After June 2004**

** ****t1      t2              t3**

**7d**

**14d**

**CT=130d**

**130d**

**130d**

**Total ct = 130d + 7d +14d**

**Obs intervals**

**Control time (multi epochs)**

**For SNe Ia, 92% of the observations use the obs interval for the control time -- nearly continuous coverage!**

**Notes:**
Loss in numbers

**Notes:**
Average_lightcurves.pdf

## Choice of light curves

**Very important; major source of uncertainty (especially for SNe Ib/c, II).**
**Different from C99 light curves (our curves are broader, so SN rate decreases).**
**In the process of determining more accurately.**
**Extinction,  luminosity scatter are not **
**   ****considered yet.**

## Detailed log files; data comparisons

**The limiting magnitude was calculated for every single observation over the course of the survey.**
**(Not done for previous nearby SN rate calculations.)**

## Units

**1 SNu = 1 SN / (100 yr) / (10****10**** L****Sun****)**
**     ****(SNuB, SNuK for B and K bands)**
**1 SNuM = 1 SN / (100 yr) / (10****10**** M****Sun****) **

**PRELIMINARY RESULTS**

## SN rate vs. Hubble typeB-band luminosity normalization

**Not much fluctuation in the SN Ia rate from early to late-type galaxies**

**Biggest change: SN Ib/c rate in late-type spirals**

## SN rate vs. Hubble type  K-band luminosity normalization

**An increasing trend for SN Ia rate from early to late-type galaxies**

**M05 values in irregular galaxies are too large**

## LOSS results: Nearby Supernova rate 

- LOSS sample:     566 SNe in 13,000 galaxies
- Cappellaro et al.: 137 SNe in   4,000 galaxies

- (Leaman et al.  2007, in prep.)

**Notes:**
SN rates

## SN Ia rate vs. galaxy color

**SN Ia rate proportional to (1) SFR [prompt] and (2) galaxy mass [tardy]**
**(confirms Mannucci et al. 2004, 2005, Scannapieco & Bildsten 2005, **
**Niel et al. 2006, Sullivan et al. 2006)**

**1 SNuM = 1 SN / (100 yr) / (10****10**** M****Sun****)**

## Milky Way Galaxy SN Rate

**MWG (Sbc) has K-band L = (5.15 ± 0.80) ******** 10****10**** L****Sun**** (Jarrett et al. 2003).**
**SN Ia: 0.3 SN/century**
**SN Ibc: 0.4 SN/century**
**SN II: 1.3 SN/century**
**Total: 1.9 SN/century (consistent with some other independent estimates: SNRs, pulsar birth rate, Fe abundance, etc.)**

## preliminary

**Triangle:  Cappellaro et al. 1999**
**Squares:  SDSS 2006, Madgwick et al. 2003, Blanc et al. 2004, Hardin et al. 2000**
** ****Neill et al. 2006, Pain et al. 2002, and the last three are from Dahlen et al. 2004**

**Volume SN Ia rate versus redshift**

- =SN delay function x cosmic SFH
- (Dahlen et al. 2004; Strolger et al. 2004)

**preliminary**

## Conclusions, I

**Uncertainties are significantly reduced**
**Increased number of SNe (~140 vs. ~600)**
**CCD camera and image subtraction (not photographic plates or by eye)**
**Limiting magnitude calculated for every observation**
**Nearly continuous search**

**Type Ia SN rate:**
**B-band: Independent of host morphology**
**K-band: increasing from early to late type galaxies**
**Mass: prompt and tardy components**

## Conclusions, II

**Type Ib/c & II SN rate:**
**B & K-band: increasing from early to late type galaxies**
**Mass: follows SFR**
**SN Ibc rate higher and SN II rate slightly lower than C99/M05 (choice of light curves is important).**

**Future refinements:**
**More representative light curves**
**More SN bins (e.g., IIn, II-P, II-L)**
**Consider extinction, L scatter**

##   Dependence of SN Ia rate on

**  ****Dependence of SN Ia rate on**
**light curve shape ****(work in progress)**

**Light-curve shape is correlated with L.**
**Different SNe Ia like different hosts.**

**SN Ia rate (E-Sc-Ir, ∆m15)**

**Things we need to do:**
**Determine control time for**
**      ****different L/light-curve shape**
**b)   Put all SNe Ia into different**
**      ****bins (from monitoring history)**