A comparison between SALT/SAAO observations and kilonova models for AT 2017gfo: the first electromagnetic counterpart of a gravitational wave transient-GW170817

被引：39

作者：

Buckley, David A. H. ^{[1
,2
]}

Andreoni, Igor ^{[3
,4
,5
]}

Barway, Sudhanshu ^{[1
]}

Cooke, Jeff ^{[3
,4
,6
]}

Crawford, Steven M. ^{[1
,2
]}

Gorbovskoy, Evgeny ^{[7
]}

Gromadzki, Mariusz ^{[8
]}

Lipunov, Vladimir ^{[7
,9
]}

Mao, Jirong ^{[10
,11
,12
]}

Potter, Stephen B. ^{[1
]}

Pretorius, Magaretha L. ^{[1
,13
]}

Pritchard, Tyler A. ^{[3
]}

Romero-Colmenero, Encarni ^{[1
,2
]}

Shara, Michael M. ^{[14
,15
]}

Vaisanen, Petri ^{[1
,2
]}

Williams, Ted B. ^{[1
]}

机构：

[1] South African Astron Observ, POB 9, ZA-7935 Cape Town, South Africa

[2] Southern African Large Telescope Fdn, POB 9, ZA-7935 Cape Town, South Africa

[3] Swinburne Univ Technol, Ctr Astrophys & Supercomp, POB 218,H29, Hawthorn, Vic 3122, Australia

[4] Australian Res Council, Ctr Excellence Gravitat Wave Discovery OzGrav, Canberra, ACT, Australia

[5] Australian Astron Observ, 105 Delhi Rd, N Ryde, NSW 2113, Australia

[6] Australian Res Council, Ctr Excellence All Sky Astrophys CAASTRO, Canberra, ACT, Australia

[7] Moscow MV Lomonosov State Univ, Sternberg Astron Inst, Universitesky Pr,13, Moscow 119234, Russia

[8] Warsaw Univ, Astron Observ, Al Ujazdowskie 4, PL-00478 Warsaw, Poland

[9] Moscow MV Lomonosov State Univ, Phys Dept, GSP-1, Moscow 119991, Russia

[10] Chinese Acad Sci, Yunnan Observ, Kunming 650011, Yunnan, Peoples R China

[11] Chinese Acad Sci, Ctr Astron Mega Sci, 20A Datun Rd, Beijing 100012, Peoples R China

[12] Chinese Acad Sci, Key Lab Struct & Evolut Celestial Objects, Kunming 650011, Yunnan, Peoples R China

[13] Univ Cape Town, Dept Astron, Private Bag X3, ZA-7701 Rondebosch, South Africa

[14] Amer Museum Nat Hist, Dept Astrophys, Cent Pk West & 79th St, New York, NY 10024 USA

[15] Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England

来源：

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY | 2018年 / 474卷 / 01期

基金：

澳大利亚研究理事会; 中国国家自然科学基金; 新加坡国家研究基金会;

关键词：

gravitational waves; nuclear reactions; nucleosynthesis; abundances; binaries: close; gamma-ray burst: individual: GRB 170817A; stars: neutron; stars:; winds; outflows; NEUTRON-STAR; R-PROCESS; NUCLEOSYNTHESIS; MERGERS; BURSTS;

D O I：

10.1093/mnrasl/slx196

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We report on SALT low-resolution optical spectroscopy and optical/IR photometry undertaken with other SAAO telescopes (MASTER-SAAO and IRSF) of the kilonova AT 2017gfo (a.k.a. SSS17a) in the galaxy NGC4993 during the first 10 d of discovery. This event has been identified as the first ever electromagnetic counterpart of a gravitational wave event, namely GW170817, which was detected by the LIGO and Virgo gravitational wave observatories. The event is likely due to a merger of two neutron stars, resulting in a kilonova explosion. SALT was the third observatory to obtain spectroscopy of AT 2017gfo and the first spectrum, 1.2 d after the merger, is quite blue and shows some broad features, but no identifiable spectral lines and becomes redder by the second night. We compare the spectral and photometric evolution with recent kilonova simulations and conclude that they are in qualitative agreement for post-merger wind models with proton: nucleon ratios of Y-e = 0.25-0.30. The blue colour of the first spectrum is consistent with the lower opacity of the lanthanide-free r-process elements in the ejecta. Differences between the models and observations are likely due to the choice of system parameters combined with the absence of atomic data for more elements in the ejecta models.

引用

页码：L71 / L75

页数：5

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