The Origin of the Prompt Emission for Short GRB 170817A: Photosphere Emission or Synchrotron Emission?

被引：43

作者：

Meng, Yan-Zhi ^{[1
,2
]}

Geng, Jin-Jun ^{[3
,4
]}

Zhang, Bin-Bin ^{[3
,4
]}

Wei, Jun-Jie ^{[1
]}

Xiao, Di ^{[3
,4
]}

Liu, Liang-Duan ^{[3
,4
]}

Gao, He ^{[5
]}

Wu, Xue-Feng ^{[1
]}

Liang, En-Wei ^{[6
,7
]}

Huang, Yong-Feng ^{[3
,4
]}

Dai, Zi-Gao ^{[3
,4
]}

Zhang, Bing ^{[8
]}

机构：

[1] Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Jiangsu, Peoples R China

[2] Univ Chinese Acad Sci, Beijing 100049, Peoples R China

[3] Nanjing Univ, Sch Astron & Space Sci, Nanjing 210093, Jiangsu, Peoples R China

[4] Nanjing Univ, Key Lab Modern Astron & Astrophys, Minist Educ, Nanjing, Jiangsu, Peoples R China

[5] Beijing Normal Univ, Dept Astron, Beijing 100875, Peoples R China

[6] Guangxi Univ, Dept Phys, Nanning 530004, Peoples R China

[7] Guangxi Univ, GXU NAOC Ctr Astrophys & Space Sci, Nanning 530004, Peoples R China

[8] Univ Nevada, Dept Phys & Astron, Las Vegas, NV 89154 USA

来源：

ASTROPHYSICAL JOURNAL | 2018年 / 860卷 / 01期

基金：

中国博士后科学基金; 中国国家自然科学基金;

关键词：

gamma-ray burst: general; gravitational waves; radiation mechanisms: thermal; GAMMA-RAY-BURSTS; HIGH-RESOLUTION CALCULATIONS; MERGING NEUTRON-STARS; THERMAL EMISSION; ELECTROMAGNETIC COUNTERPARTS; STRUCTURED JETS; LORENTZ FACTOR; LIGHT CURVES; SPECTRA; EVOLUTION;

D O I：

10.3847/1538-4357/aac2d9

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

The first gravitational-wave event from the merger of a binary neutron star system (GW170817) was detected recently. The associated short gamma-ray burst (GRB 170817A) has a low isotropic luminosity (similar to 10(47) erg s(-1)) and a peak energy E-p similar to 145 keV during the initial main emission between -0.3 and 0.4 s. The origin of this short GRB is still under debate, but a plausible interpretation is that it is due to the off-axis emission from a structured jet. We consider two possibilities. First, since the best-fit spectral model for the main pulse of GRB 170817A is a cutoff power law with a hard low-energy photon index (alpha = -0.62-(+0.54)(0.49)), we consider an off-axis photosphere model. We develop a theory of photosphere emission in a structured jet and find that such a model can reproduce a low-energy photon index that is softer than a blackbody through enhancing high-latitude emission. The model can naturally account for the observed spectrum. The best-fit Lorentz factor along the line of sight is similar to 20, which demands that there is a significant delay between the merger and jet launching. Alternatively, we consider that the emission is produced via synchrotron radiation in an optically thin region in an expanding jet with decreasing magnetic fields. This model does not require a delay of jet launching but demands a larger bulk Lorentz factor along the line of sight. We perform Markov Chain Monte Carlo fitting to the data within the framework of both models and obtain good fitting results in both cases.

引用

页数：11

共 90 条

[1] GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral [J].

Abbott, B. P. ;

Abbott, R. ;

Abbott, T. D. ;

Acernese, F. ;

Ackley, K. ;

Adams, C. ;

Adams, T. ;

Addesso, P. ;

Adhikari, R. X. ;

Adya, V. B. ;

Affeldt, C. ;

Afrough, M. ;

Agarwal, B. ;

Agathos, M. ;

Agatsuma, K. ;

Aggarwal, N. ;

Aguiar, O. D. ;

Aiello, L. ;

Ain, A. ;

Ajith, P. ;

Allen, B. ;

Allen, G. ;

Allocca, A. ;

Altin, P. A. ;

Amato, A. ;

Ananyeva, A. ;

Anderson, S. B. ;

Anderson, W. G. ;

Angelova, S. V. ;

Antier, S. ;

Appert, S. ;

Arai, K. ;

Araya, M. C. ;

Areeda, J. S. ;

Arnaud, N. ;

Arun, K. G. ;

Ascenzi, S. ;

Ashton, G. ;

Ast, M. ;

Aston, S. M. ;

Astone, P. ;

Atallah, D. V. ;

Aufmuth, P. ;

Aulbert, C. ;

AultONeal, K. ;

Austin, C. ;

Avila-Alvarez, A. ;

Babak, S. ;

Bacon, P. ;

Bader, M. K. M. .

PHYSICAL REVIEW LETTERS, 2017, 119 (16)

[2] Multi-messenger Observations of a Binary Neutron Star Merger [J].

Abbott, B. P. ;

Abbott, R. ;

Abbott, T. D. ;

Acernese, F. ;

Ackley, K. ;

Adams, C. ;

Adams, T. ;

Addesso, P. ;

Adhikari, R. X. ;

Adya, V. B. ;

Affeldt, C. ;

Afrough, M. ;

Agarwal, B. ;

Agathos, M. ;

Agatsuma, K. ;

Aggarwal, N. ;

Aguiar, O. D. ;

Aiello, L. ;

Ain, A. ;

Ajith, P. ;

Allen, B. ;

Allen, G. ;

Allocca, A. ;

Altin, P. A. ;

Amato, A. ;

Ananyeva, A. ;

Anderson, S. B. ;

Anderson, W. G. ;

Angelova, S. V. ;

Antier, S. ;

Appert, S. ;

Arai, K. ;

Araya, M. C. ;

Areeda, J. S. ;

Arnaud, N. ;

Arun, K. G. ;

Ascenzi, S. ;

Ashton, G. ;

Ast, M. ;

Aston, S. M. ;

Astone, P. ;

Atallah, D. V. ;

Aufmuth, P. ;

Aulbert, C. ;

AultONeal, K. ;

Austin, C. ;

Avila-Alvarez, A. ;

Babak, S. ;

Bacon, P. ;

Bader, M. K. M. .

ASTROPHYSICAL JOURNAL LETTERS, 2017, 848 (02)

[3] Gravitational Waves and Gamma-Rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A [J].

Abbott, B. P. ;

Abbott, R. ;

Abbott, T. D. ;

Acernese, F. ;

Ackley, K. ;

Adams, C. ;

Adams, T. ;

Addesso, P. ;

Adhikari, R. X. ;

Adya, V. B. ;

Affeldt, C. ;

Afrough, M. ;

Agarwal, B. ;

Agathos, M. ;

Agatsuma, K. ;

Aggarwal, N. ;

Aguiar, O. D. ;

Aiello, L. ;

Ain, A. ;

Ajith, P. ;

Allen, B. ;

Allen, G. ;

Allocca, A. ;

Aloy, M. A. ;

Altin, P. A. ;

Amato, A. ;

Ananyeva, A. ;

Anderson, S. B. ;

Anderson, W. G. ;

Angelova, S. V. ;

Antier, S. ;

Appert, S. ;

Arai, K. ;

Araya, M. C. ;

Areeda, J. S. ;

Arnaud, N. ;

Arun, K. G. ;

Ascenzi, S. ;

Ashton, G. ;

Ast, M. ;

Aston, S. M. ;

Astone, P. ;

Atallah, D. V. ;

Aufmuth, P. ;

Aulbert, C. ;

AultONeal, K. ;

Austin, C. ;

Avila-Alvarez, A. ;

Babak, S. ;

Bacon, P. .

ASTROPHYSICAL JOURNAL LETTERS, 2017, 848 (02)

[4] FERMI OBSERVATIONS OF GRB 090902B: A DISTINCT SPECTRAL COMPONENT IN THE PROMPT AND DELAYED EMISSION [J].

Abdo, A. A. ;

Ackermann, M. ;

Ajello, M. ;

Asano, K. ;

Atwood, W. B. ;

Axelsson, M. ;

Baldini, L. ;

Ballet, J. ;

Barbiellini, G. ;

Baring, M. G. ;

Bastieri, D. ;

Bechtol, K. ;

Bellazzini, R. ;

Berenji, B. ;

Bhat, P. N. ;

Bissaldi, E. ;

Blandford, R. D. ;

Bloom, E. D. ;

Bonamente, E. ;

Borgland, A. W. ;

Bouvier, A. ;

Bregeon, J. ;

Brez, A. ;

Briggs, M. S. ;

Brigida, M. ;

Bruel, P. ;

Burgess, J. M. ;

Burrows, D. N. ;

Buson, S. ;

Caliandro, G. A. ;

Cameron, R. A. ;

Caraveo, P. A. ;

Casandjian, J. M. ;

Cecchi, C. ;

Celik, Oe. ;

Chekhtman, A. ;

Cheung, C. C. ;

Chiang, J. ;

Ciprini, S. ;

Claus, R. ;

Cohen-Tanugi, J. ;

Cominsky, L. R. ;

Connaughton, V. ;

Conrad, J. ;

Cutini, S. ;

d'Elia, V. ;

Dermer, C. D. ;

de Angelis, A. ;

de Palma, F. ;

Digel, S. W. .

ASTROPHYSICAL JOURNAL LETTERS, 2009, 706 (01) :L138-L144

[5] THE APPEARANCE OF HIGHLY RELATIVISTIC, SPHERICALLY SYMMETRICAL STELLAR WINDS [J].

ABRAMOWICZ, MA ;

NOVIKOV, ID ;

PACZYNSKI, B .

ASTROPHYSICAL JOURNAL, 1991, 369 (01) :175-178

[6] Relativistic outflows from remnants of compact object mergers and their viability for short gamma-ray bursts [J].

Aloy, MA ;

Janka, HT ;

Müller, E .

ASTRONOMY & ASTROPHYSICS, 2005, 436 (01) :273-311

[7]

[Anonymous], 2017, ARXIV171006979

[8]

[Anonymous], 2017, arXiv:1712.03237

[9]

[Anonymous], LVC GRB COORDINATES

[10]

[Anonymous], 2017, ASTROPHYS J, DOI [DOI 10.3847/2041-8213/AA9B2B, 10.3847/2041-8213/aa9b2b]

← 1 2 3 4 5 6 7 8 9 →