scholarly journals Future merger of the Milky Way with the Andromeda galaxy and the fate of their supermassive black holes

2020 ◽  
Vol 642 ◽  
pp. A30
Author(s):  
Riccardo Schiavi ◽  
Roberto Capuzzo-Dolcetta ◽  
Manuel Arca-Sedda ◽  
Mario Spera
Keyword(s):  
Black Holes ◽  
Gravitational Wave ◽  
Relative Motion ◽  
Milky Way ◽  
Close Approach ◽  
Supermassive Black Holes ◽  
Andromeda Galaxy ◽  
The Galaxy ◽  
Inner Region ◽  
First Time

Our Galaxy and the nearby Andromeda galaxy (M 31) are the most massive members of the Local Group, and they seem to be a bound pair, despite the uncertainties on the relative motion of the two galaxies. A number of studies have shown that the two galaxies will likely undergo a close approach in the next 4−5 Gyr. We used direct N-body simulations to model this interaction to shed light on the future of the Milky Way – Andromeda system and for the first time explore the fate of the two supermassive black holes (SMBHs) that are located at their centers. We investigated how the uncertainties on the relative motion of the two galaxies, linked with the initial velocities and the density of the diffuse environment in which they move, affect the estimate of the time they need to merge and form “Milkomeda”. After the galaxy merger, we follow the evolution of their two SMBHs up to their close pairing and fusion. Upon the fiducial set of parameters, we find that Milky Way and Andromeda will have their closest approach in the next 4.3 Gyr and merge over a span of 10 Gyr. Although the time of the first encounter is consistent with other predictions, we find that the merger occurs later than previously estimated. We also show that the two SMBHs will spiral in the inner region of Milkomeda and coalesce in less than 16.6 Myr after the merger of the two galaxies. Finally, we evaluate the gravitational-wave emission caused by the inspiral of the SMBHs, and we discuss the detectability of similar SMBH mergers in the nearby Universe (z ≤ 2) through next-generation gravitational-wave detectors.

scholarly journals The collision between the Milky Way and Andromeda and the fate of their Supermassive Black Holes

2019 ◽  
Vol 14 (S351) ◽  
pp. 161-164 ◽  
Author(s):  
Riccardo Schiavi ◽  
Roberto Capuzzo-Dolcetta ◽  
Manuel Arca Sedda ◽  
Mario Spera
Keyword(s):  
Black Holes ◽  
Velocity Vector ◽  
Milky Way ◽  
Orbital Motion ◽  
Initial Conditions ◽  
Dynamical Evolution ◽  
Close Approach ◽  
Supermassive Black Holes ◽  
Andromeda Galaxy ◽  
Proper Resolution

AbstractOur Galaxy and the nearby Andromeda Galaxy (M31) form a bound system, even though the relative velocity vector of M31 is currently not well constrained. Their orbital motion is highly dependent on the initial conditions, but all the reliable scenarios imply a first close approach in the next 3–5 Gyrs. In our study, we simulate this interaction via direct N-body integration, using the HiGPUs code. Our aim is to investigate the dependence of the time of the merger on the physical and dynamical properties of the system. Finally, we study the dynamical evolution of the two Supermassive Black Holes placed in the two galactic centers, with the future aim to achieve a proper resolution to follow their motion until they form a tight binary system.

scholarly journals The New Astronomy: Observing Our Universe With Light and Gravity

2019 ◽  
Vol 7 ◽  
Author(s):  
Joey Shapiro Key ◽  
LIGO Scientific Collaboration
Keyword(s):  
Black Holes ◽  
South America ◽  
Neutron Stars ◽  
Gravitational Wave ◽  
Gravitational Waves ◽  
Gamma Ray ◽  
Distant Galaxy ◽  
The World ◽  
The Galaxy ◽  
First Time

On a summer day in 2017, astronomers around the world received a message about an exciting collision of two stars far, far away. The message was sent by a team of astronomers from the LIGO and Virgo observatories. These new observatories are very different from the telescopes we have used to study our Universe up until now. LIGO and Virgo are gravitational wave observatories, listening for quiet ripples in spacetime created by the collisions of distant black holes and neutron stars. On August 17, 2017 LIGO and Virgo detected a signal that astronomers named GW170817, from the collision of two neutron stars. Less than two seconds later, NASA's Fermi satellite caught a signal, known as a gamma-ray burst, and within minutes, telescopes around the world began searching the sky. Telescopes in South America found the location of the collision in a distant galaxy known as NGC 4993. For the weeks and months that followed, astronomers watched the galaxy and the fading light from the collision. This is a new kind of multi-messenger astronomy where, for the first time, the same event was observed by both gravitational waves and light.

Erratum: “Wandering Supermassive Black Holes in Milky-Way-mass Halos” (2018, ApJL, 857, L22)

2021 ◽  
Vol 909 (2) ◽  
pp. L30
Author(s):  
Michael Tremmel ◽  
Fabio Governato ◽  
Marta Volonteri ◽  
Andrew Pontzen ◽  
Thomas R. Quinn
Keyword(s):  
Black Holes ◽  
Milky Way ◽  
Supermassive Black Holes

The stellar graveyard

2019 ◽  
pp. 177-206
Author(s):  
Nils Andersson
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Neutron Stars ◽  
Gravitational Wave ◽  
Stellar Evolution ◽  
White Dwarfs ◽  
Supermassive Black Holes ◽  
Compact Objects ◽  
Fermi Gases ◽  
The 1950S

This chapter introduces the different classes of compact objects—white dwarfs, neutron stars, and black holes—that are relevant for gravitational-wave astronomy. The ideas are placed in the context of developing an understanding of the likely endpoint(s) of stellar evolution. Key ideas like Fermi gases and the Chandrasekhar mass are discussed, as is the emergence of general relativity as a cornerstone of astrophysics in the 1950s. Issues associated with different formation channels for, in particular, black holes are considered. The chapter ends with a discussion of the supermassive black holes that are found at the centre of galaxies.

scholarly journals Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). VIII. A less biased view of the early co-evolution of black holes and host galaxies

2019 ◽  
Vol 71 (6) ◽  
Author(s):  
Takuma Izumi ◽  
Masafusa Onoue ◽  
Yoshiki Matsuoka ◽  
Tohru Nagao ◽  
Michael A Strauss ◽  
...  
Keyword(s):  
Black Holes ◽  
Far Infrared ◽  
Supermassive Black Holes ◽  
Host Galaxies ◽  
Star Forming ◽  
Wide Range ◽  
The Galaxy ◽  
Order Of Magnitude ◽  
Local Relation ◽  
Almost All

Abstract We present ALMA [C ii] line and far-infrared (FIR) continuum observations of three $z \gt 6$ low-luminosity quasars ($M_{\rm 1450} \gt -25$ mag) discovered by our Subaru Hyper Suprime-Cam (HSC) survey. The [C ii] line was detected in all three targets with luminosities of $(2.4\mbox{--}9.5) \times 10^8\, L_{\odot }$, about one order of magnitude smaller than optically luminous ($M_{\rm 1450} \lesssim -25$ mag) quasars. The FIR continuum luminosities range from $\lt 9 \times 10^{10}\, L_{\odot }$ (3 $\sigma$ limit) to ${\sim } 2 \times 10^{12}\, L_{\odot }$, indicating a wide range in star formation rates in these galaxies. Most of the HSC quasars studied thus far show [C ii]/ FIR luminosity ratios similar to local star-forming galaxies. Using the [C ii]-based dynamical mass ($M_{\rm dyn}$) as a surrogate for bulge stellar mass ($M_{\rm\, bulge}$), we find that a significant fraction of low-luminosity quasars are located on or even below the local $M_{\rm\, BH}$–$M_{\rm\, bulge}$ relation, particularly at the massive end of the galaxy mass distribution. In contrast, previous studies of optically luminous quasars have found that black holes are overmassive relative to the local relation. Given the low luminosities of our targets, we are exploring the nature of the early co-evolution of supermassive black holes and their hosts in a less biased way. Almost all of the quasars presented in this work are growing their black hole mass at a much higher pace at $z \sim 6$ than the parallel growth model, in which supermassive black holes and their hosts grow simultaneously to match the local $M_{\rm\, BH}$–$M_{\rm\, bulge}$ relation at all redshifts. As the low-luminosity quasars appear to realize the local co-evolutionary relation even at $z \sim 6$, they should have experienced vigorous starbursts prior to the currently observed quasar phase to catch up with the relation.

The mass distribution of Galactic double neutron stars: constraints on the gravitational-wave sources like GW170817

2019 ◽  
Vol 488 (4) ◽  
pp. 5020-5028 ◽  
Author(s):  
Jianwei Zhang ◽  
Yiyan Yang ◽  
Chengmin Zhang ◽  
Wuming Yang ◽  
Di Li ◽  
...  
Keyword(s):  
Neutron Star ◽  
Gravitational Wave ◽  
Mass Distribution ◽  
Mass Ratio ◽  
Important Indicator ◽  
Distribution Ranges ◽  
The Galaxy ◽  
Merger Event ◽  
Credible Intervals ◽  
First Time

ABSTRACT The merger event of double neutron star (DNS) system (GW170817) was detected by the gravitational-wave (GW) detectors (Advanced LIGO and Advanced Virgo) in 2017 for the first time, so their mass distribution has become a significant topic with the new round GW hunting (O3) in 2019. A few models (e.g. Gaussian, two-Gaussian, or mixture-Gaussian) were adopted to draw the mass distribution of observed Galactic DNS systems, however, there is no a confirmed model now due to the small size of DNS samples (N < 20). Here we focus on determining the most probable distribution ranges of DNS masses without model selection by assuming the neutron star masses to be uniformly distributed between the lower and upper bounds. We apply a Bayesian analysis and Markov chain Monte Carlo simulation to 15 Galactic DNS systems, and obtain that the component masses of DNS systems should mainly fall in the range of 1.165–1.590 M⊙, and the predominant ranges for the total mass, mass ratio, and chirp mass lie in 2.535–2.867 M⊙, 0.741–0.995, and 1.115–1.237 M⊙, respectively. Our results are in agreement with the properties of DNS in GW170817, whose 90 per cent credible intervals for the component masses, total masses, mass ratio, and chirp masses are 1.16–1.60 M⊙, $2.73_{-0.01}^{+0.04}\, \mathrm{ M}_\odot$, 0.73–1.00, and $1.186_{-0.001}^{+0.001}\, \mathrm{ M}_\odot$, respectively. The above similarity is an important indicator that reveals the source of GW170817 to be a DNS system from the galaxy NGC 4993, and our results can be tested by the forthcoming GW hunting O3.

scholarly journals Present state and promises to unravel the structure and kinematics of the Milky Way with the RAVE survey

2008 ◽  
Vol 4 (S254) ◽  
pp. 453-460 ◽  
Author(s):  
M. Steinmetz ◽  
A. Siebert ◽  
T. Zwitter ◽  
Keyword(s):  
Milky Way ◽  
Large Fraction ◽  
Radial Velocities ◽  
Schmidt Telescope ◽  
Milky Way Galaxy ◽  
Giant Stars ◽  
The Galaxy ◽  
Second Year ◽  
Scientific Results ◽  
First Time

AbstractThe RAdial Velocity Experiment (RAVE) is an ambitious survey to measure the radial velocities, temperatures, surface gravities, metallicities and abundance ratios for up to a million stars using the 1.2-m UK Schmidt Telescope of the Anglo-Australian Observatory (AAO), over the period 2003–2011. The survey represents a big advance in our understanding of our own Milky Way galaxy. The main data product will be a southern hemisphere survey of about a million stars. Their selection is based exclusively on their I–band colour, so avoiding any colour-induced bias. RAVE is expected to be the largest spectroscopic survey of the Solar neighbourhood in the coming decade, but with a significant fraction of giant stars reaching out to 10 kpc from the Sun. RAVE offers the first truly representative inventory of stellar radial velocities for all major components of the Galaxy. Here we present the first scientific results of this survey as well as its second data release which doubles the number of previously released radial velocities. For the first time, the release also provides atmospheric parameters for a large fraction of the second year data, making it an unprecedented tool to study the formation of the Milky Way. Plans for further data releases are outlined.

Preferential Accretion in the Supermassive Black Holes of Milky Way-size Galaxies Due to Direct Feeding by Satellites

2018 ◽  
Vol 860 (1) ◽  
pp. 20 ◽  
Author(s):  
N. Nicole Sanchez ◽  
Jillian M. Bellovary ◽  
Kelly Holley-Bockelmann ◽  
Michael Tremmel ◽  
Alyson Brooks ◽  
...  
Keyword(s):  
Black Holes ◽  
Milky Way ◽  
Supermassive Black Holes
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