Macronova and its Radio-Remnant Kenta Hotokezaka (Hebrew - PowerPoint PPT Presentation

Macronova and its Radio-Remnant Kenta Hotokezaka (Hebrew University) recent collaborators T. Piran, R. Sari, A. Horesh (Hebrew), E. Nakar (Tel Aviv) ASKAP S. Nissanke (Radboud), G. Hallinan (Caltech), J. Lazio (JPL) P . Beniamini (IPA), M. Tanaka (NAOJ), S. Wanajo (Sophia) Y. Fan, Z.-P . Jin (PMO), S. Covino, P . D’Avanzo (INAF)

Outline • Back of envelope calculation of beta decay heating • “Historical” Kilonova/Macronova candidates • Radio remnant (1) After short GRB afterglows (2) Radio GW counterparts • Discussion

Macronova: Thermal emission from the merger ejecta Li and Paczynski 1998, Kulkarni 2005 , Metzger+10, Tanvir+13, Berger+13 t < t diff ρ T high Heat generation (radioactive decay) Power Expansion t > t diff ρ t > t diff T low Escaping photon luminosity Time The first candidate: GRB 130603B Tanvir+13, Berger+13

Key ingredients of Macronova studies (1) Mass Ejection: mass and velocity Talks by Kyutoku, Kiuchi, Fujibayashi, Fernandez (2) Radioactive heating rate Talks by Wanajo, Martinez-Pinedo, Lippuner, Barnes (3) Opacity Talk by Barnes

R-process in Neutron Star Merger Ejecta Latter & Schramm 74, Metzger+10, Goriely+11, Korobkin+12, Wanajo+14, Lippuner & Roberts 15, Wu+16 Lippuner & Roberts 15 ✓ Almost all material is synthesized in heavy r-process elements. ✓ Nuclei are initially far from the stability line.

Macronova Heating rate Lippuner & Roberts 15 V. Fit window Data Normalized log heating rate (plus o ff set) Y e = 0 . 04 Fit s = 100 k B baryon − 1 ⌧ = 0 . 29 ms h ∆ ln ✏ / ln ✏ i = 3 . 45 ⇥ 10 − 2 Y e = 0 . 25 Korobkin+12 s = 56 k B baryon − 1 ⌧ = 170 ms h ∆ ln ✏ / ln ✏ i = 1 . 03 ⇥ 10 − 2 Y e = 0 . 35 s = 10 k B baryon − 1 ⌧ = 7 . 1 ms h ∆ ln ✏ / ln ✏ i = 3 . 34 ⇥ 10 − 3 Y e = 0 . 16 NSM-solar: 90 ≤ A ≤ 238 s = 2 . 4 k B baryon − 1 10 12 ⌧ = 59 ms Energy generation rate [erg/s/g] total h ∆ ln ✏ / ln ✏ i = 1 . 02 ⇥ 10 − 3 γ -ray 10 11 neutrino Y e = 0 . 50 s = 1 . 0 k B baryon − 1 electron ⌧ = 0 . 49 ms h ∆ ln ✏ / ln ✏ i = 2 . 28 ⇥ 10 − 4 10 10 10 − 2 10 − 1 10 1 10 2 10 3 1 10 9 Time [day] KH+16 10 8 10 7 see also Metzger+10, Goriely+11, Roberts+11, 0.1 1 10 Grosmann+14,Wanajo+14,Barnes+16 Time [day] ⌘ − 1 . 3 ⇣ A s imple power low of the heating rate: ˙ Q ( t ) ≈ 10 10 erg / s / g t day There must be a simple way to describe this.

Quick review of macronova heating KH, Sari, Piran in prep. Nuclides with contribute to the energy generation. τ ∼ t Beta decay energy Heating rate/nucleus ˙ dt ∼ E ( t ) Q ( t ) ∼ − E ( t ) dN t 10 2 beta decay chain 10 1 Two conditions: t= τ 1 10 0 (2) The total number of dN/dt [1/s] t= τ 2 nuclei conserves. ∝ 1/t 10 -1 10 -2 t= τ 3 (2) t > tau_1. 10 -3 t= τ 4 10 -4 0.01 0.1 1 10 100 1000 t [s]

Quick review of macronova heating KH, Sari, Piran in prep. in Fermi’s theory of beta decay ( m e , c, ~ , G F ) 1) A fundamental timescale of beta decay: p Fermi time ¯ ν e t F ≡ 2 π 3 ~ 7 e c 4 ≈ 9000 s G 2 m 5 F e − G F n

Quick review of macronova heating KH, Sari, Piran in prep. in Fermi’s theory of beta decay ( m e , c, ~ , G F ) 1) A fundamental timescale of beta decay: p Fermi time ¯ ν e t F ≡ 2 π 3 ~ 7 e c 4 ≈ 9000 s G 2 m 5 F e − 2) Fermi’s golden rule: G F d 1 dp e p 2 e dp ν p 2 R R τ ∝ dE ν n (for ) ∝ E 5 E � m e c 2 ⌘ − 0 . 2 E ( t ) ∼ m e c 2 ⇣ t t F

Quick review of macronova heating KH, Sari, Piran in prep. The heating rate per nucleus: ⌘ − 1 . 2 ⇣ ∼ m e c 2 Q ( t ) ∼ E ( t ) ˙ t t t F t F The heating rate per unit mass: ⌘ � 1 . 2 ⌘ � 1 . 2 ⇣ ⇣ ∼ 10 10 erg / s / g c 2 ˙ m e 1 t t Q ( t ) ∼ h A i m p t F t F day h A i ⇠ 200 For the ejecta with 0.01Msun = 2x10^31 g: Luminosity ~ 2x10^41 erg/s at 1 day ~ 2x10^40 erg/s at 1 week

A bit more detail KH, Sari, Piran in prep. Z p ( E 0 ) |M N | 2 1 dpF ( Z, E ) p 2 ( E � E 0 ) 2 , = (5) t F τ 0 where the variables in the integral are in units of m e and c . | ψ e ( r n ) | 2 Z ⇠ F ( Z, E ) , (7) = | ψ e ( r n ) | 2 Z =0 2(1 + s ) [(2 s !) 2 ] (2 p ρ ) 2 s � 2 e πη | ( s � 1 + i η )! | 2 , = where η = Zq 2 e / ~ v , ρ = r n / ( ~ /m e c ), s = (1 � ( Z α ) 2 ) 1 / 2 , q e is the electron charge, and α ⇡ 1 / 137 is the fine-structure ⌘ − 1 8 − 6 1 . 2 · 10 10 t ⇣ |M N | 2 5 erg day h A i − 1 5 s · g ( t . t R ) , > < 200 0 . 05 ˙ Q ( t ) ⇡ (14) ⌘ − 1 − 4 − 1 0 . 3 · 10 10 t ⇣ |M N | 2 3 erg 70 h A i − 1 day h Z i s · g ( t & t NC ) , 3 3 > : 200 0 . 05

Analytic vs database approaches KH, Sari, Piran in prep. 10 16 1 Formula Eq.(13) 10 15 HW+16 Normalized e - heating rate 10 14 e - heating rate [erg/s/g] 10 13 10 12 10 11 10 10 10 9 0.1 10 8 Formula Eq.(13) 10 7 NR-Coulomb HW+16 10 6 10 0 10 1 10 2 10 3 10 4 10 5 10 6 10 7 10 0 10 1 10 2 10 3 10 4 10 5 10 6 10 7 time [s] time [s] The analytic formula nicely describe the heating rate from the nuclear database. Note that forbidden transitions and the decrease of the total number of radioactive nuclei slightly change our formula. Metzger et al 2010 show the slope of the heating with a different assumption from ours, disappearing chains. In reality, it is between the two assumptions.

Gamma-ray escape KH+16 1day, 3Mpc, 0.01Msun 10 -4 The optical depth of gamma rays: rest frame Flux [photons/s/keV/cm 2 ] v = 0.3c v = 0.05c 10 -5 « 2 „ t di ff , o c κ γ τ γ ( t ) , ≈ 10 -6 v t κ o 10 -7 « 2 „ „ t di ff , o « κ γ 0 . 02 ≈ t 0 . 05 cm 2 / g 10 -8 « − 1 “ v „ ” − 1 10 -9 κ o , × 10 cm 2 / g 0 . 3 c 10 -10 1 10 100 1000 10000 Energy [keV] The diffuse-out time of thermal photons, M ej =0.01M sun i.e. the peak timescale of macronovae. 0.7 Thermalization efficiency 0.6 0.5 0.4 Spontaneous fission and alpha decay may 0.3 contribute to the heating rate at late time. 0.2 (KH+16, Barnes+16) NSM-solar 0.1 NSM-fission NSM-wind 0 0.1 1 10 Time [day]

Outline • Back of envelope calculation of beta decay heating • “Historical” Kilonova/Macronova candidates • Radio remnant (1) After short GRB afterglows (2) Radio GW counterparts • Discussion

GRB 060614 Yang+15, Jin+15 < Spectrum evolution ) ( - a - b µ n n = ) Redding with time is not expected in afterglows. It is consistent with a macronova. b = � µ - a = � ~ a = � - 3 � ´ - - - - s 2 n n ~ ~ a = c � b = - 2 ~ s b = � a = � ~ » > ~ - + < � 4 > = � ~ ~ ~ � - � 4 ~ ~

Macronova interpretation of a red bump of GRB 050709 It can be a macronova. Jin, KH + 16 !! !! '"# '"# !"# M !"#$ %&'()*+ ,-.+/ ., a '"! '"! c r o - n !"& !"& o v a !" !" !"% !"% m r o d !"$ !"$ e l !"# !"# g !"! !"! !# !# # # ( ( ) ) '! '! !"#$ %$#&'()*" l *+,-.,/01 2'! !" 345 . Excess in !$ !$ Hubble 814W e d afterglow? !% !% . :')#; - !& !& < - = > e !' !' ) ) ! ! " " $ $ )( )( !( !( "( "( #( #( 6 *+,- .+/0- 123.4 5678.9 f

Three macronova candidates -17 10 41 erg/s 130603B -16 Absolute Vega magnitude -15 050709 -14 060614 10 40 erg/s -13 -12 050709 VLT I 050709 F814W -11 060614 VLT I 060614 F814W 130603B F160W -10 2 4 6 8 10 20 40 Days in the rest frame Peak luminosity ~ 10^41 erg/s. • The I-band light curves of 050709 and 060614 are quite similar. •

Macronova Summary Eiso Macronova Redshift T90 (s) Note (10^51 erg) (erg/s) 0.1 10^41 very small GRB 050709 0.16 0.07 (+130) (I-band) host not really 5 10^41 GRB 060614 0.125 2.5 a short (+97) (I-band) burst 10^41 the first GRB 130603B 0.356 0.18 2.1 (H-band) candidate GRB 150101B <10^42 Early type 0.134 0.012 0.013 no detection (H-band) host Note that the detections rely on a few data points.

Outline • Back of envelope calculation of beta decay heating • “Historical” Kilonova/Macronova candidates • Radio remnant (1) After short GRB afterglows (2) Radio GW counterparts • Discussion

Relativistic Explosions & Radio emission Time Scale log10(E) v/c Detected SNe II >10 year 51 0.01 yes SNe Ibc 1 month 48 0.3 yes SNe Ia >10 year 51 0.01 yes (galactic) GRBs 1 month 51 1 yes TDEs (jet) a few year 52 1 yes optical TDEs 1 year 48 0.1 yes Magnetar GF 1 month 45 0.3 yes (galactic) NS mergers a few year 50.5 0.3 no

Synchrotron Radio Flare from Blast Wave (Newtonian) Blast Wave in the ISM => particle acceleration=> Synchrotron Radiation B amplification t peak ≈ 80 day E 1 / 3 50 n 1 / 3 β − 5 / 3 i p=2.5 F peak ≈ 3 mJy E 50 � 11 / 4 n 7 / 8 ✏ 7 / 8 B, − 1 ✏ 3 / 2 27 ⌫ − 3 / 4 e, − 1 D − 2 i 9 ⌫ m ≈ 1 GHz n 1 / 2 ✏ 1 / 2 B, − 1 ✏ 2 e, − 1 � 5 Nakar & Piran 11, KH+16