230 likes | 247 Views
The Lick Obs Supernova Search (LOSS). Weidong Li & Alex Filippenko. University of California, Berkeley. Finding SNe: A Numer Game (I). SNe/year. 1885 -- 1949: 0-6 1950 -- 1980: 20 1980 -- 1990: 30 1991 -- 1996: 70 1997 -- 2000: 180 2001 -- 2003: 300. Reasons:.
E N D
The Lick Obs Supernova Search (LOSS) Weidong Li & Alex Filippenko University of California, Berkeley
Finding SNe: A Numer Game (I) SNe/year 1885 -- 1949: 0-6 1950 -- 1980: 20 1980 -- 1990: 30 1991 -- 1996: 70 1997 -- 2000: 180 2001 -- 2003: 300 Reasons: • affordable CCD camera • Commercial 14”--32” tel • Computer + automation • High-z SN search
Finding SNe: A Number Game (II) Current active nearby SN searches LOSS 336 SNe (1998-2003) UC Berkeley SN factory83 SNe (2002-2003) LBL Puckett 67 SNe (1998-2003) Amateur Boles 57 SNe (1997-2003) Amateur Armstrong 46 SNe (1998-2003) Amateur Evans 41 SNe (1981-2003) Amateur Currently operation on hold
Finding SNe: Not Only a Number Game • Scientific Goals of LOSS • Monitor a well-defined galaxy sample • Find lots of SNe and find them young • Do photometric followups for many SNe • Detailed log files for everyday observation • GRB followup New
KAIT 30 inch (0.75 m) mirror Funded by NSF, the Sylvia & Jim Katzman Foundation, AutoScope Corp., Sun Microsystems, Hewlett-Packard Co., the University of California (Berkeley and Santa Cruz), and NASA. Lick Observatory, Mt. Hamilton, near San Jose, CA
KAIT Hardware Telescope Secondary Cameras Weatherstation Step motors Guider Apogee filterwheel • 30 inch R-C telescope, f/8.2 • Laser optical encoders • Compact and light-weight • Precise secondary maneuver • 20 slot filter wheel • Apogee AP7 camera, 6.8’ • FOV, 0.8”/pix • Off-axis guiding • Automatic weatherstation
KAIT Software HETE-2 Fully robotic obs GCN • Hardware control • Obs schedule and control • SN search schedule • SN search image processing • GRB response KAIT pc1 pc2 pc3 workstation workstation 90 miles Lick Obs. Berkeley
KAIT GRB Program • Program to respond to GRB alerts promptly • Interrupt KAIT and take a pre-arranged • sequence of images • Reaching 19th mag within 60s of alerts • Unfiltered obs will use filters System GRB 020813 • A mix of automatic and manually remote obs • Slow early-time power-law decline index GRB 021211 Obs. • Obs started at t=105s after burst • 18 data points in the first 10 minutes • One of the best early GRB light curves • One of the few GRBs with reverse • shock emission detected
LOSS in Numbers 1. No. of galaxies monitored: 19,000 No. of images per night 20s 19th mag 110 img/hr 700-1300 img/night Interval distribution t < 10 days (80%) Most SNe are discovered young!!!
LOSS in Numbers 3. No. of SN discoveries 95? Oh, No! • Year LOSS SNe • 20 • 40 • 38 • 68 • 82 • 95
KAIT Photometry Followup • 10% -- 20% of the KAIT time • ~40% of LOSS SNe: some photometry • ~25% of LOSS SNe: good photometry • Daily around max, every 2-7 days after max • 196 SNe observed as of Nov 10,2003. Distribution of SN followup When? Some Good Great Total SN Ia48 1470 132 SN II10 2125 56 SN Ibc1 1 6 8 We are working on them. Why not Ib/c?? 1. rare Total: 196 2. tough
Light curves of SNe (SN Ia) Li et al. 2001
Light curves of SNe (SN II-P) Leonard et al. 2002
Published Results in the past 5 years W. Li, A. V. Filippenko, E. Gates et al. 2001, PASP, 113, 1178 M. Modjaz, W. Li, A. V. Filippenko et al. 2001, PASP,113, 308 W. C. G. Ho, S. D. Van Dyk, C. Y. Peng et al. 2001, PASP, 113, 1349 W. Li, A. V. Filippenko, S. D. Van Dyk et al. 2002, PASP, 114, 403 W. Li, A. V. Filippenko, R. Chornock et al. 2003, PASP, 115, 453 SN Ia photometry SN Ia statistics A. G. Riess, A. V. Filippenko, W. Li et al. 1999, AJ, 118, 2675 W. Li, A. V. Filippenko, A. G. Riess et al. 2001, ApJ, 546, 719 W. Li, A. V. Filippenko, A. G. Riess et al. 2001, ApJ, 546, 734 T. Matheson, A. V. Filippenko, R. Chornock et al. 2000, AJ, 119, 2303 T. Matheson, A. V. Filippenko, W. Li et al. 2001, AJ, 121, 1648 R. Foley, M. Papenkova, B. Swift et al. 2003, PASP, 115, 1220 SN Ib/c S. D. Van Dyk, C. Y. Peng, J. Y. King et al. 2000, PASP, 112, 1532 D. C. Leonard, A. V. Filippenko, W. Li et al. 2002, AJ, 124, 2490 D. C. Leonard, A. V. Filippenko, E. L. Gates et al. 2002, PASP, 114, 35 D. C. Leonard, A. V. Filippenko, R. Chornock, W. Li 2002, AJ, 124, 2506 S. D. Van Dyk, W. Li, A. V. Filippenko 2003, PASP, 115, 1289 SN II SN rates S. van den Bergh, W. Li, A. V. Filippenko 2002, PASP, 114, 820 S. Van den Bergh, W. Li, A. V. Filippenko 2003, PASP, 115, 1280 W. Li, A. V. Filippenko, R. Chornock, S. Jha 2003, ApJ, 586, L9 W. Li, A. V. Filippenko, R. chornock, S. Jha 2003, PASP, 115, 844 GRB
LOSS in the future A stable nearby SN search engine In collaboration with CfA, CSP: more followup Publish existing photometry database: SNe Ia: correlation, H0, local flow SNe II : correlation, EPM SNe Ibc: correlation, SN/GRB connection SN rate, statistics GRB followup in the Swift era
Conclusions KAIT is conducting the world’s most successful search for very nearby SNe, and has yielded interesting results on the statistics and photometric properties of SNe and GRB optical afterglows. We have shown that good science can be done with a small telescope when correctly engineered and programmed.