off axis counterparts of sgrbs tagged by gravitational waves
DESCRIPTION
Off axis counterparts of SGRBs tagged by gravitational waves. Kazumi Kashiyama (Penn State) w ith K.Ioka , T.Nakamura and P. Meszaros. Why?. The era of gravitational wave astronomy will come soon!. 2 nd generation network . since 2015〜2017. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Off axis counterparts of SGRBs tagged by gravitational waves](https://reader036.vdocuments.us/reader036/viewer/2022062521/5681662a550346895dd98950/html5/thumbnails/1.jpg)
Off axis counterparts of SGRBs tagged by gravitational waves
Kazumi Kashiyama (Penn State)with K.Ioka, T.Nakamura and P. Meszaros
![Page 2: Off axis counterparts of SGRBs tagged by gravitational waves](https://reader036.vdocuments.us/reader036/viewer/2022062521/5681662a550346895dd98950/html5/thumbnails/2.jpg)
Why?The era of gravitational wave astronomy will come soon!
The “promising target” : compact binary mergers
Multi-messenger approach
since 2015 〜 20172nd generation network
Distance detectable : 〜 200Mpc, Event rate : 〜 40yr-1 for NS-NS merger
• GW detectors have bad eyesight! Angular resolution of 2nd generation 〜 10deg2
Off-axis X-ray, optical, radio counterpart searches
• SGRBs are the most reliable counterpart, but low-frequent. if θj 〜 0.1, the GW-SGRB simultaneous detection rate 〜 0.1yr-1
![Page 3: Off axis counterparts of SGRBs tagged by gravitational waves](https://reader036.vdocuments.us/reader036/viewer/2022062521/5681662a550346895dd98950/html5/thumbnails/3.jpg)
Point : “Pre-jet” envelope formation
Mildly relativistic! Optically thick! Neutron-rich!
Hyper-massive neutron star
Pre-jet envelope( Magnetically or Neutrino driven wind )
Tidal mass ejection
Rotational plane of binary
e.g. Lee et al. (2010) , Dessart et al. (2009), Shibata et al. (2011)
![Page 4: Off axis counterparts of SGRBs tagged by gravitational waves](https://reader036.vdocuments.us/reader036/viewer/2022062521/5681662a550346895dd98950/html5/thumbnails/4.jpg)
Possible off axis emissions from pre-jet envelope
Optical (kilonova) Radio active heating in the envelope (β-decay, fission, 56Ni→56Co→56Fe)
Interaction between the envelope and interstellar medium
Radio (afterglow)
〜 days
〜 years Nakar & Piran (2011)
Li & Paczynski (1998)Metzger et al. (2010)
UV-X-ray Interaction between the envelope and relativistic jets
≤ minutes???
![Page 5: Off axis counterparts of SGRBs tagged by gravitational waves](https://reader036.vdocuments.us/reader036/viewer/2022062521/5681662a550346895dd98950/html5/thumbnails/5.jpg)
relativistic jet cocoonBlack hole (magnetar) + accretion disk
Jet penetration problem in SGRBs
VS
![Page 6: Off axis counterparts of SGRBs tagged by gravitational waves](https://reader036.vdocuments.us/reader036/viewer/2022062521/5681662a550346895dd98950/html5/thumbnails/6.jpg)
Jet penetration problem in SGRBs
Faile
d Pen
etra
tion
Non-re
lativis
tic p
enet
ratio
n
Relati
vistic
pen
etra
tion
No coc
oon
( Fail → jet induced supernovae like? )Succeed penetration → jet+cocoon
![Page 7: Off axis counterparts of SGRBs tagged by gravitational waves](https://reader036.vdocuments.us/reader036/viewer/2022062521/5681662a550346895dd98950/html5/thumbnails/7.jpg)
Two possible off axis emissions from jet-envelope interaction
relativistic jetcocoon
Black hole (magnetar) + accretion disk
1. Hard X-rays from cocoon breakout2. Soft X-ray quasi-thermal emission from cocoon itself
![Page 8: Off axis counterparts of SGRBs tagged by gravitational waves](https://reader036.vdocuments.us/reader036/viewer/2022062521/5681662a550346895dd98950/html5/thumbnails/8.jpg)
X-rays from cocoon breakout
Too dim to be detected because of the small rcbo
cocoonjet
Energy budget of breakout photons:
@
Timescale of the emission:
Jet-cocoon dynamics →
![Page 9: Off axis counterparts of SGRBs tagged by gravitational waves](https://reader036.vdocuments.us/reader036/viewer/2022062521/5681662a550346895dd98950/html5/thumbnails/9.jpg)
UV-Soft X-rays from cocoon itself
cocoon
@
Adiabatic expansion:
Jet-cocoon dynamics →
Marginally detectable by future facilities?
for ~ minute @ soft X-ray or UV (down scattered)
![Page 10: Off axis counterparts of SGRBs tagged by gravitational waves](https://reader036.vdocuments.us/reader036/viewer/2022062521/5681662a550346895dd98950/html5/thumbnails/10.jpg)
Summary
• Off axis X-ray counterpart of compact binary mergers could be a key for GW astronomy.
• Consider jet and pre-jet envelope interaction– Cocoon breakout emission → too dim– Emission from cocoon itself• could be soft X-ray transient ~minute• might be detected by future facilities? • need to be modeled more precisely.
– Failed penetration cases could be also interesting.