scholarly journals Constraining the Neutron Star Radius with Joint Gravitational-wave and Short Gamma-Ray Burst Observations of Neutron Star–Black Hole Coalescing Binaries

2019 ◽  
Vol 877 (2) ◽  
pp. 94 ◽  
Author(s):  
Stefano Ascenzi ◽  
Nicola De Lillo ◽  
Carl-Johan Haster ◽  
Frank Ohme ◽  
Francesco Pannarale
Keyword(s):  
Black Hole ◽  
Neutron Star ◽  
Gravitational Wave ◽  
Gamma Ray ◽  
Gamma Ray Burst ◽  
Neutron Star Radius

scholarly journals The Gravity Collective: A Search for the Electromagnetic Counterpart to the Neutron Star–Black Hole Merger GW190814

2021 ◽  
Vol 923 (2) ◽  
pp. 258
Author(s):  
Charles D. Kilpatrick ◽  
David A. Coulter ◽  
Iair Arcavi ◽  
Thomas G. Brink ◽  
Georgios Dimitriadis ◽  
...  
Keyword(s):  
Black Hole ◽  
Neutron Star ◽  
Gamma Ray ◽  
Absolute Magnitude ◽  
Host Galaxy ◽  
Opening Angle ◽  
Gamma Ray Burst ◽  
Localization Region ◽  
Rule Out

Abstract We present optical follow-up imaging obtained with the Katzman Automatic Imaging Telescope, Las Cumbres Observatory Global Telescope Network, Nickel Telescope, Swope Telescope, and Thacher Telescope of the LIGO/Virgo gravitational wave (GW) signal from the neutron star–black hole (NSBH) merger GW190814. We searched the GW190814 localization region (19 deg2 for the 90th percentile best localization), covering a total of 51 deg2 and 94.6% of the two-dimensional localization region. Analyzing the properties of 189 transients that we consider as candidate counterparts to the NSBH merger, including their localizations, discovery times from merger, optical spectra, likely host galaxy redshifts, and photometric evolution, we conclude that none of these objects are likely to be associated with GW190814. Based on this finding, we consider the likely optical properties of an electromagnetic counterpart to GW190814, including possible kilonovae and short gamma-ray burst afterglows. Using the joint limits from our follow-up imaging, we conclude that a counterpart with an r-band decline rate of 0.68 mag day−1, similar to the kilonova AT 2017gfo, could peak at an absolute magnitude of at most −17.8 mag (50% confidence). Our data are not constraining for “red” kilonovae and rule out “blue” kilonovae with M > 0.5 M ⊙ (30% confidence). We strongly rule out all known types of short gamma-ray burst afterglows with viewing angles <17° assuming an initial jet opening angle of ∼5.°2 and explosion energies and circumburst densities similar to afterglows explored in the literature. Finally, we explore the possibility that GW190814 merged in the disk of an active galactic nucleus, of which we find four in the localization region, but we do not find any candidate counterparts among these sources.

Anatomy of a merger

2019 ◽  
pp. 541-580
Author(s):  
Nils Andersson
Keyword(s):  
Black Hole ◽  
Neutron Star ◽  
Binary System ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Late Time ◽  
Tidal Effects ◽  
Gamma Ray Burst ◽  
Love Numbers ◽  
Star Binary

This chapter discusses the different stages of an inspiralling neutron star binary system, through the formation of a black hole and the possible emergence of a gamma-ray burst. Tidal effects and the information encoded in the so-called Love numbers are explored. The violent dynamics of the merger is considered and models of gamma-ray bursts and the late time kilonova emission are also explored.

scholarly journals Protomagnetar research through an analysis of the X-ray plateau in the multi-messengar era

2020 ◽  
Vol 641 ◽  
pp. A56
Author(s):  
Xiaoxiao Ren ◽  
Daming Wei ◽  
Zhenyu Zhu ◽  
Yan Yan ◽  
Chengming Li
Keyword(s):  
Neutron Star ◽  
Equation Of State ◽  
Gravitational Wave ◽  
Gamma Ray ◽  
Equations Of State ◽  
Electromagnetic Emission ◽  
Gamma Ray Bursts ◽  
Gamma Ray Burst ◽  
X Ray ◽  
Binary Neutron Star

The joint detection of the gravitational wave signal and the electromagnetic emission from a binary neutron star merger can place unprecedented constraint on the equation of state of supranuclear matter. Although a variety of electromagnetic counterparts have been observed for GW170817, including a short gamma-ray burst, kilonova, and the afterglow emission, the nature of the merger remnant is still unclear, however. The X-ray plateau is another important characteristics of short gamma-ray bursts. This plateau is probably due to the energy injection from a rapidly rotating magnetar. We investigate what we can learn from the detection of a gravitational wave along with the X-ray plateau. In principle, we can estimate the mass of the merger remnant if the X-ray plateau is caused by the central magnetar. We selected eight equations of state that all satisfy the constraint given by the gravitational wave observation, and then calculated the mass of the merger remnants of four short gamma-ray bursts with a well-measured X-ray plateau. If, on the other hand, the mass of the merger remnant can be obtained by gravitational wave information, then by comparing the masses derived by these two different methods can further constrain the equation of state. We discuss the possibility that the merger product is a quark star. In addition, we estimate the possible mass range for the recently discovered X-ray transient CDF-S XT2 that probably originated from a binary neutron star merger. Finally, under the assumption that the post-merger remnant of GW170817 was a supramassive neutron star, we estimated the allowed parameter space of the supramassive neutron star and find that in this case, the magnetic dipole radiation energy is so high that it may have some effects on the short gamma-ray burst and kilonova emission. The lack of detection of these effects suggests that the merger product of GW170817 may not be a supermassive neutron star.

scholarly journals Black-hole–Neutron-star Mergers Are Unlikely Multimessenger Sources

2021 ◽  
Vol 923 (1) ◽  
pp. L2
Author(s):  
Giacomo Fragione
Keyword(s):  
Black Hole ◽  
Neutron Star ◽  
Equation Of State ◽  
Gravitational Wave ◽  
Internal Structure ◽  
Binary Stars ◽  
Statistical Study ◽  
Gamma Ray ◽  
High Rate ◽  
Upper Limit

Abstract The promise by the LIGO/Virgo/Kagra (LVK) collaboration to detect black-hole–neutron-star (BH–NS) mergers via gravitational wave (GW) emission has recently been fulfilled with the detection of GW200105 and GW200115. Mergers of BH–NS binaries are particularly exciting for their multimessenger potential since GW detection can be followed by an electromagnetic (EM) counterpart (kilonova, gamma-ray burst, afterglow) that can reveal important information on the equation of state (EOS) of NSs and the nature of the BH spin. This can happen whenever the NS does not directly plunge into the BH, but rather is tidally disrupted, leaving behind debris to accrete. We carry out a statistical study of the binary stars that evolve to form a BH–NS binary and compute the rate of merger events that can be followed by an EM counterpart. We find that ≳50% of the mergers can lead to an EM counterpart only in the case where BHs are born highly spinning (χ BH ≳ 0.7), while this fraction does not exceed about 30% for stiff NS EOSs and a few percent for soft NS EOSs for low-spinning BHs (χ BH ≲ 0.2), suggesting that a high rate of EM counterparts of BH–NS would provide support for high natal BH spins. However, the possibilities that BHs are born with near-maximal spins and that NS internal structure is described by a stiff EOS are disfavored by current LVK constraints. Considering that these values only represent an upper limit to observe an EM counterpart due to current observational limitations, such as brightness sensitivity and sky localization, BH–NS mergers are unlikely multimessenger sources.

scholarly journals DETECTABILITY OF GRAVITATIONAL WAVE BURSTS FROM A CLASS OF NEUTRON STAR STARQUAKE GRB MODELS

1996 ◽  
Vol 05 (01) ◽  
pp. 35-43 ◽  
Author(s):  
J.E. HORVATH
Keyword(s):  
Neutron Star ◽  
Gravitational Wave ◽  
Large Class ◽  
High Frequency ◽  
Gamma Ray ◽  
Cosmological Models ◽  
Gamma Ray Burst ◽  
Released Energy ◽  
Wave Bursts ◽  
Prime Target

A large class of gamma-ray burst (GRB) models (overwhelming until recently) involve-the release of energy in a neutron star quake. Even though the extreme isotropy of the GRB sky established by the BATSE experiment has now shifted the interest to cosmological models, the former starquake scenarios are still attractive and may naturally produce a gravitational wave burst which carries most of the released energy. We discuss the prospects for detection of these high-frequency bursts by the forthcoming interferometers and spheroidal antennas, emphasizing the most recent results on the distribution and nature of the GRB sources. We find that, even if the overall picture is correct, the positive detection of GRB-associated gravitational wave bursts is unlikely and therefore these events will not be a prime target for the detectors.

scholarly journals Binary Neutron Star and Short Gamma-Ray Burst Simulations in Light of GW170817

Galaxies ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 119 ◽  
Author(s):  
Antonios Nathanail
Keyword(s):  
Neutron Star ◽  
Gravitational Wave ◽  
Electromagnetic Radiation ◽  
Numerical Simulations ◽  
Gravitational Waves ◽  
Gamma Ray ◽  
Numerical Relativity ◽  
Gamma Ray Burst ◽  
Binary Neutron Star ◽  
The Status

In the dawn of the multi-messenger era of gravitational wave astronomy, which was marked by the first ever coincident detection of gravitational waves and electromagnetic radiation, it is important to take a step back and consider our current established knowledge. Numerical simulations of binary neutron star mergers and simulations of short GRB jets must combine efforts to understand such complicated and phenomenologically rich explosions. We review the status of numerical relativity simulations with respect to any jet or magnetized outflow produced after merger. We compare what is known from such simulations with what is used and obtained from short GRB jet simulations propagating through the BNS ejecta. We then review the established facts on this topic, as well as discuss things that need to be revised and further clarified.

Cosmic Spacequakes

2019 ◽  
pp. 138-145
Author(s):  
Nicholas Mee
Keyword(s):  
Neutron Star ◽  
Gravitational Wave ◽  
Gamma Ray ◽  
Dwarf Galaxies ◽  
Dwarf Galaxy ◽  
Exceptional Case ◽  
Heavy Elements ◽  
Gamma Ray Burst ◽  
Wave Signal ◽  
Binary Neutron Star

The fourth gravitational wave signal detected by LIGO GW170817 coincided with a short gamma ray burst and these signals have been interpreted as the result of a binary neutron star merger. It is thought that gold and other heavy elements are produced in binary neutron star collisions and the GW170817 event has provided support for this idea. Further evidence that heavy elements are produced in extremely rare events such as binary neutron star mergers has been deduced from the scarcity of these elements in dwarf galaxies. The Reticulum II dwarf galaxy is an exceptional case that does contain heavy elements that might have been created in a single such event.

BLACK HOLE–NEUTRON STAR COALESCING BINARIES

2010 ◽  
Vol 19 (08n10) ◽  
pp. 1241-1248
Author(s):  
V. FERRARI ◽  
L. GUALTIERI ◽  
F. PANNARALE
Keyword(s):  
Black Hole ◽  
Neutron Star ◽  
Gravitational Wave ◽  
Gamma Ray ◽  
Equations Of State ◽  
Cutoff Frequency ◽  
Tidal Interactions ◽  
Stable Circular Orbit ◽  
Innermost Stable Circular Orbit ◽  
Laser Interferometers

Coalescing black hole–neutron star binaries have been invoked as possible progenitors of short gamma-ray bursts and are also among the most promising gravitational wave sources to be detected by ground-based laser interferometers. When the star is disrupted by tidal interactions before reaching the innermost stable circular orbit, the gravitational wave signal emitted by the system is expected to exhibit a cutoff frequency which is a distinctive feature of the waveform. We evaluate this frequency for several equations of state, describing the matter inside the neutron star, and combinations of the binary parameters. We show that, if this frequency will be found in a detected gravitational wave, it will provide valuable information on the behavior of matter in the stellar core.

scholarly journals Pulsations in short gamma ray bursts from black hole-neutron star mergers

2013 ◽  
Vol 87 (8) ◽  
Author(s):  
Nicholas Stone ◽  
Abraham Loeb ◽  
Edo Berger
Keyword(s):  
Black Hole ◽  
Neutron Star ◽  
Gamma Ray ◽  
Gamma Ray Bursts
Sign in / Sign up

Export Citation Format

Share Document