Soheb Mandhai
Gather.town id
TA03
Poster Title
Tracing the orbital evolution of isolated compact binaries within their evolving host galaxies
Institution
University of Leicester
Abstract (short summary)
The electromagnetic counterparts (EMC) of gravitational wave (GW) events arising from the coalescence of two merging compact objects, namely a neutron star paired with another neutron star (NSNS)/black-hole (BHNS), have become increasingly topical over the last few years following the GW170817A. In this study, we explore the host environments and offsets of these binaries upon merging. This is accomplished by seeding and dynamically evolving synthetic isolated systems within hydrodynamical galaxies produced by the cosmological simulation, EAGLE. This approach also allows for constraints to be placed on the relative cosmic rate of EM bright binary mergers. Using constraints on the mass ratio of the primary and secondary compact objects, we explore the likelihood of observing potential short-duration gamma-ray bursts (SGRBs) using the Swift/BAT instrument resulting from these systems and compare them to real observations.
Plain text (extended) Summary
[Note to reader: This segment gives an overview of the entire poster and the work contained.]
Introduction:
This poster was created by Soheb Mandhai. A final year PhD student at the University of Leicester, working with compact binaries in the context of multi-messenger of astrophysics. If there are any questions regarding the research covered in this work, please send an email to SFM13@leicester.ac.uk
Slide 1:
Why Are Compact Binaries Special? –
Compact binaries consist of two stellar objects that are formed following the death of a star. In context of this work, we are interested in binaries that consist of a neutron star that is paired with another neutron star or black hole.
These systems can produce distortions in space-time known as gravitational waves. Which can be used to probe and understand the neutron star (NS)/black-hole (BH) components at an unprecedented level.
Upon merging, systems with at least one neutron star may produce an electromagnetic counterpart such as a short-duration gamma-ray burst (SGRB) or a kilonova.
The first coincident detection of a gravitational wave resulting from the merger of two neutron stars, GW170817A, with a short-duration gamma-ray burst, GRB 1708017A, sparked the multi-messenger era in astrophysics!
Slide 2:
The Migration of Compact Binaries:
In our work, we seed synthetic binaries into hydrodynamical galaxies from the EAGLE cosmological simulation. [Description of Text and Figure] The binaries are randomly placed within their allocated host galaxy based on the mass distribution of the stellar disk. Initially, the binaries will consist of two massive stars. These stars will eventually undergo a supernova. The primary, more massive star, will undergo a supernova and produce a remnant neutron star or black-hole. The companion star will eventually follow and produce one of the two compact objects of interest for this study. Each supernova may also impart a systematic velocity change on the orbit of the binary. Finally, the binaries will coalesce. If they coalesce at a considerable distance from their host galaxy, they may be considered host-less if observed.
Slide 3:
Host Demographics of these binaries:
We find that the majority of binaries merge with hosts (the parent galaxies) that are late-type galaxies such as spiral galaxies akin to the Milky Way. This accounts for 60-70% of systems. The remaining 40-30% would merge in early-type galaxies such as old elliptical galaxies.
Further consideration of the spatial information of the binaries following the orbital evolution. We find that 23% and 43% of double neutron star and black-hole-neutron star systems, respectively, would appear host-less. The host-less demographic corresponds to cases where a binary has either merged distant to its host galaxy. In cases where the host galaxy is appears faint in the sky, observations of the binary may also be classified it as host-less. Also shown, the late-type fractions are 51% and 40% for the two types of binaries, respectively. The early-type fractions are 26% and 17%, respectively.
Slide 4:
Summary:
[Summary of the aforementioned]
We explore the fraction of the systems within our study that can produce an electromagnetic counterpart such as a gamma-ray burst. We then plotted the project on-sky distances (also known as the impact parameter) against the redshift of the binaries [reference to Figure]. We then overplotted SGRBs with associated hosts. There is a reasonable consistency between our predicted results and the observations. From the Figure, we see clustering of the observed impact parameters and redshift within the bounds predicted by our study.
Introduction:
This poster was created by Soheb Mandhai. A final year PhD student at the University of Leicester, working with compact binaries in the context of multi-messenger of astrophysics. If there are any questions regarding the research covered in this work, please send an email to SFM13@leicester.ac.uk
Slide 1:
Why Are Compact Binaries Special? –
Compact binaries consist of two stellar objects that are formed following the death of a star. In context of this work, we are interested in binaries that consist of a neutron star that is paired with another neutron star or black hole.
These systems can produce distortions in space-time known as gravitational waves. Which can be used to probe and understand the neutron star (NS)/black-hole (BH) components at an unprecedented level.
Upon merging, systems with at least one neutron star may produce an electromagnetic counterpart such as a short-duration gamma-ray burst (SGRB) or a kilonova.
The first coincident detection of a gravitational wave resulting from the merger of two neutron stars, GW170817A, with a short-duration gamma-ray burst, GRB 1708017A, sparked the multi-messenger era in astrophysics!
Slide 2:
The Migration of Compact Binaries:
In our work, we seed synthetic binaries into hydrodynamical galaxies from the EAGLE cosmological simulation. [Description of Text and Figure] The binaries are randomly placed within their allocated host galaxy based on the mass distribution of the stellar disk. Initially, the binaries will consist of two massive stars. These stars will eventually undergo a supernova. The primary, more massive star, will undergo a supernova and produce a remnant neutron star or black-hole. The companion star will eventually follow and produce one of the two compact objects of interest for this study. Each supernova may also impart a systematic velocity change on the orbit of the binary. Finally, the binaries will coalesce. If they coalesce at a considerable distance from their host galaxy, they may be considered host-less if observed.
Slide 3:
Host Demographics of these binaries:
We find that the majority of binaries merge with hosts (the parent galaxies) that are late-type galaxies such as spiral galaxies akin to the Milky Way. This accounts for 60-70% of systems. The remaining 40-30% would merge in early-type galaxies such as old elliptical galaxies.
Further consideration of the spatial information of the binaries following the orbital evolution. We find that 23% and 43% of double neutron star and black-hole-neutron star systems, respectively, would appear host-less. The host-less demographic corresponds to cases where a binary has either merged distant to its host galaxy. In cases where the host galaxy is appears faint in the sky, observations of the binary may also be classified it as host-less. Also shown, the late-type fractions are 51% and 40% for the two types of binaries, respectively. The early-type fractions are 26% and 17%, respectively.
Slide 4:
Summary:
[Summary of the aforementioned]
We explore the fraction of the systems within our study that can produce an electromagnetic counterpart such as a gamma-ray burst. We then plotted the project on-sky distances (also known as the impact parameter) against the redshift of the binaries [reference to Figure]. We then overplotted SGRBs with associated hosts. There is a reasonable consistency between our predicted results and the observations. From the Figure, we see clustering of the observed impact parameters and redshift within the bounds predicted by our study.
URL
URL: www.sohebmandhai.com, E-mail: sfm13@leicester.ac.uk, Twitter: @TheAstroPhoenix
Poster file