Detection of a Type IIn Supernova in Optical Follow-Up Observations of IceCube Neutrino Events Magellan Workshop, 17{18 March 2016, DESY Hamburg Markus Voge, Nora Linn Strotjohann, Alexander Stasik 17 March 2016 Target: transient sources (< 100 s • neutrino burst): GRBs (Waxman & Bahcall 1997, Murase • & Nagataki 2006) SNe with jets (Razzaque, Meszaros, • Waxman 2005) More exotic phenomena? E.g. Fast • Radio Bursts (FRBs)? (Falcke & Rezzolla 2013) Online Neutrino Analysis Automatic search for interesting IceCube neutrino events • Realtime alerts sent to follow-up instruments • Multi-messenger: Combination with other data fruitful • Follow-up ensures access to data • 2 / 15 Online Neutrino Analysis Automatic search for interesting IceCube neutrino events • Realtime alerts sent to follow-up instruments • Multi-messenger: Combination with other data fruitful • Follow-up ensures access to data • Target: transient sources (< 100 s • neutrino burst): GRBs (Waxman & Bahcall 1997, Murase • & Nagataki 2006) SNe with jets (Razzaque, Meszaros, • Waxman 2005) More exotic phenomena? E.g. Fast • Radio Bursts (FRBs)? (Falcke & Rezzolla 2013) 2 / 15 The OFU and XFU system SN/GRB PTF (optical) Swift (X-ray) Alerts Alerts Madison/Bonn Iridium IceCube arXiv: 1309.6979 (p.40) 3 / 15 Online analysis scheme neutrino purity At least 8 coincident Trigger Level 0:0001% hits 2000 Hz ∼ Basic muon event se- Level 1 35 Hz 0:01% lection (tracks only) ∼ Up-going tracks Level 2 2 Hz 0:1% ∼ Neutrino selection OFU Level 3 mHz 90% (BDT) ∼ Neutrino multiplet ( 2ν): ≥ Time ∆T < 100s Space ∆Ψ < 3:5◦ PTF Calculate λ Swift 4 / 15 OFU/XFU: Measured multiplets and alerts Season Doublets Triplets PTF Alerts Swift alerts IC40 (08/09) 15 (8.6) 0 (0.003) | | IC59 (09/10) 29 (26.0) 0 (0.008) | | IC79 (10/11) 20 (27.1) 0 (0.008) 10 (6.4) 1 (1.0) IC86{1 (11/12) 49 (44.0) 0 (0.018) 8 (5.7) 6 (5.2) IC86{2 (12/13) 73 (64.2) 0 (0.028) 7 (7.8) 7 (7.1) IC86{3 (13/14) 72 (66.8) 0 (0.025) 5 (5.3) 4 (4.7) Sum 258 (236.7) 0 (0.09) 30 (25.2) 18 (17.9) Table: Multiplets and alerts of the Optical and X-ray Follow-Up (in brackets number of expected background alerts). 5 / 15 IceCube's first supernova 19.0 event 1 18.5 event 2 Alert from 2012-03-30: mean ν • 18.0 SN location Most significant neutrino ] PTF FoV • ◦ doublet to date: ∆T = 1:8 s, 17.5 00 01 02 03 04 05 ∆Ψ = 1:3 ◦ 17.0 SN PTF12csy found in PTF Declination [ • 16.5 images, very close to 06 07 08 09 10 11 neutrinos (0:2◦) 16.0 Late-time IIn SN, z = 0:068, • 15.5 300 Mpc 103.0 103.5 104.0 104.5 105.0 105.5 106.0 106.5 107.0 ∼ Right Ascension [◦] (arXiv:1506.03115) 6 / 15 IceCube's first supernova NEW REF 10" 10" SUB SDSS 10" 7 / 15 IceCube's first supernova 19.0 False alarm rate of neutrino event 1 • 1 18.5 event 2 alert alone: 0:2 yr− mean ν ∼ 18.0 SN location ] PTF FoV Chance probability (p-value) for ◦ • neutrino alert alone within DAQ 17.5 00 01 02 03 04 05 season: 12:7 % 17.0 Declination [ 16.5 06 07 08 09 10 11 16.0 SN explosion not coincident with neutrinos15.5 within a priori • 103.0 103.5 104.0 104.5 105.0 105.5 106.0 106.5 107.0 window of 5 days Right Ascension [ ] ± ◦ A posteriori probability for neutrino alert + any CCSN • detection, within neutrino error radius, within 300 Mpc: 1:4 % (2:2σ) Not significant considered coincidental • ) 8 / 15 Schematic picture of SNe IIn CSM eruption(s) before explosion Actual SN explosion CSM CSM ejecta Star SN shocks (Source: arXiv:1311.6778) 9 / 15 PTF12csy: spectrum Rest frame wavelength [A]˚ 3000 4000 5000 6000 7000 8000 9000 3 10 z = 0.068 δ β α Ne III H O III H O III N II Na I D H He I OI 2 γ 10 O II H H He I He I He I He I N II S II OI Sky Sky ⊕ ⊕ 1 Gemini N (175 d) 100 10 × 100 [a.u.] λ F 1 10− Keck I (454 d) 1 × 2 10− 3 10− 3000 4000 5000 6000 7000 8000 9000 10000 Observed wavelength [A]˚ Narrow emission lines on broad base (from ejecta-CSM interaction) • Resembles SN 2010jl spectrum (SN IIn with signs of particle acceleration) • 10 / 15 PTF12csy: light curve Explosion time 22 • − unknown: between Ni decay g 21 r 351 and 158 days − 2006gy (R) i before neutrino alert 20 z − 2010jl (V) Maximum (r-band) y • 19 perhaps about − 20 mag (comparison 18 with− 2010jl) − 17 latest super-luminous, − non-detection • ) Absolute magnitude light curve powered 16 − ν alert by interaction of SN Gemini N Keck ejecta with dense 15 − circumstellar medium 200 100 0 100 200 300 400 500 − − (CSM) Days since first detection (rest frame) 11 / 15 PTF12csy: host galaxy Very faint dwarf galaxy SDSS • J065832.82+171541.6 Redshift z = 0:068 determined • with O II and O III lines in late SN spectrum Host galaxy absolute magnitude • Mg 16:2 mag (fainter than Small≈ Magellanic− Cloud with MV = 16:9 mag) − Quite metal-poor • (12 + log O=H 8) ≈ Superluminous SNe IIn occur • frequently in subluminous, low-metallicity galaxies 12 / 15 PTF12csy: expected neutrino production 1 Model A Model by Murase et al. Model B (RS) • 0 Model B (FS) (arXiv:1012.2834): ejecta-CSM ]) -2 interaction leads to shocks -1 -2 [GeV cm accelerating particles (protons) ν φ -3 2 ν Neutrinos from pp interaction -4 log(E • -5 Expect at most 0.01 IceCube • -6 events within 100 1000 2 3 4 5 6 7 8 log(E [GeV]) days (SN far away,∼ 300− Mpc) ν Neutrino doublet within 2 sec, > 158 days (rest frame) after • SN explosion? Very unlikely that neutrinos and SN were correlated • (unless:) blitzar (Fast Radio Burst)?) 13 / 15 Result: • Null-result: fitted n of 0 • s Upper limits: 1500 Murase model A, 1300 Murase • model B fluence.∼ × ∼ × Nevertheless: complementary neutrino search Search for neutrinos over longer 1 − • 2 time scale (full year from May 2011 − ]) 2 3 to May 2012) − − 4 − Used Optical-Follow-Up dataset 5 • [GeV cm − ν φ 6 2 Std. neutrino point source ν − E Murase et al. (2011): • ( 7 − likelihood analysis with space and 10 8 Model A log − Model B - RS energy term: 9 − Model B - FS 10 Y ns ns − 2 3 4 5 6 7 8 (ns ) = Si +(1 )Bi (1) log (Eν [GeV]) L N − N 10 i Signal hypothesis: E 2 spectrum with cut-off at 1 PeV • − 14 / 15 Nevertheless: complementary neutrino search Search for neutrinos over longer 1 − • 2 time scale (full year from May 2011 − ]) 2 3 to May 2012) − − 4 − Used Optical-Follow-Up dataset 5 • [GeV cm − ν φ 6 2 Std. neutrino point source ν − E Murase et al. (2011): • ( 7 − likelihood analysis with space and 10 8 Model A log − Model B - RS energy term: 9 − Model B - FS 10 Y ns ns − 2 3 4 5 6 7 8 (ns ) = Si +(1 )Bi (1) log (Eν [GeV]) L N − N 10 i Signal hypothesis: E 2 spectrum with cut-off at 1 PeV • − Result: • Null-result: fitted n of 0 • s Upper limits: 1500 Murase model A, 1300 Murase • model B fluence.∼ × ∼ × 14 / 15 Summary IceCube's most significant neutrino doublet led to discovery of • a rare superluminous SN IIn Far away (300 Mpc) and old (160 days), correlation with • neutrinos unlikely No long term neutrino signal found in IceCube data • Interaction of ejecta with dense CSM • Particle acceleration and neutrino production likely, but at • undetectable luminosity See arXiv:1506.03115 for more detailed information • 15 / 15 Backup slides 16 / 15 Palomar Transient Factory Located in California • Mainly discovering/observing • SNe FoV: 2:3 3:5 • ◦ × ◦ 1.2 m telescope • Lim. mag. of up to 21 • Can take spectra for interesting • source candidates Follow-up since Aug. 2010 • 10 alerts per year • ∼ 17 / 15 Swift 10 ks exposure with XRT • (0:2 keV to 10 keV), more intensive follow-up (up to 2 weeks) possible Need `tiling' because of small • FoV ( 0:4 ) ∼ ◦ Follow-up since February 2011 • 7 alerts per year • ∼ 18 / 15 OFU test statistic λ 102 101 ] 1 100 − 1 10− 2 − FAR [yr 10 3 10− 4 10− 40 20 0 20 40 60 80 100 120 − − Test statistic value λ Test statistic λ (score value) • ∆Ψ2 λ = + 2 ln(2πσ2) σ2 q q (2) 2 θA ∆T 2 ln 1 exp 2 + 2 ln − − −2σw 100 s 2 2 2 2 2 2 1 σq = σ1 + σ2 and σw = 1/σ1 + 1/σ2 − • 19 / 15 PTF12csy: SED around day 177 1039 ] 1.8 × 1 − u ˚ A 1.6 From black body fit: 1 B • − 1.4 T = (7160 270) K, Lbol = b ± 42 1 1.2 g (5:53 1:18) 10 erg s− ± × 1.0 r (continuum emission) R 15 ) 0.8 Rphot = 1:7 10 cm i × Adding contribution from 0.6 • 0.4 spectral lines Hα,Hβ: Lbol = 42 1 0.2 (6:4 1:2) 10 erg s− ± × Differential Luminosity [erg0 s .0 2000 3000 4000 5000 6000 7000 8000 900010000 Observed Wavelength [A]˚ Using light curve to extrapolate: total radiated energy of • 50 Ebol = 2:1 10 erg within 400 days after first detection (SN 2008iy: 2 ×1050 erg, 2010jl: 4 1050 erg) Lower limit× on E , L , R ×(neglected explosion to first • bol bol phot detection, X-ray, γ-ray) 20 / 15 PTF12csy: X-rays Observations on 2012-04-20 and • 2012-11-14.