Connect with us

Published

10 months ago

on

Almost seven years ago (September 14th, 2015), researchers at the Laser Interferometer Gravitational-wave Observatory (LIGO) detected gravitational waves (GWs) for the first time. Their results were shared with the world six months later and earned the discovery team the Noble Prize in Physics the following year. Since then, a total of 90 signals have been observed that were created by binary systems of two black holes, two neutron stars, or one of each. This latter scenario presents some very interesting opportunities for astronomers.

If a merger involves a black hole and neutron star, the event will produce GWs and a serious light display! Using data collected from the three black hole-neutron star mergers we’ve detected so far, a team of astrophysicists from Japan and Germany was able to model the complete process of the collision of a black hole with a neutron star, which included everything from the final orbits of the binary to the merger and post-merger phase. Their results could help inform future surveys that are sensitive enough to study mergers and GW events in much greater detail.

The research team was led by Kota Hayashi, a researcher with Kyoto University’s Yukawa Institute for Theoretical Physics (YITP). He was joined by multiple colleagues from YITP and Toho University in Japan and the Albert Einstein Institute at the Max Planck Institute for Gravitational Physics (MPIGP) in Postdam, Germany. The paper that describes their findings was led by YITP Prof. Koto Hayashi and recently appeared in the scientific journal Physical Review D.

compact objects
The mergers of compact objects discovered so far by LIGO and Virgo (in O1, O2, and O3a). Credit: LIGO Virgo Collaboration / Frank Elavsky, Aaron Geller / Northwestern

To recap, GWs are mysterious ripples in spacetime originally predicted by Einstein’s General Theory of Relativity. They are created whenever massive objects merge and create tidal disruptions to the very fabric of the Universe, which can be detected thousands of light-years away. To date, only three mergers have been observed involving a binary system consisting of a black hole and a neutron star. During one of these – GW170817, detected on August 17th, 2017 – astronomers detected an electromagnetic counterpart to the GWs it produced.

In the coming years, telescopes and interferometers of greater sensitivity are expected to see much more from these events. Based on the mechanics involved, scientists anticipate that black hole-neutron star mergers will include matter ejected from the system and a tremendous release of radiation (which might include short gamma-ray bursts). For their study, the team modeled what black hole-neutron star mergers would look like to test these predictions.

They selected two different model systems consisting of a rotating black hole and a neutron star, with the black hole set at 5.4 and 8.1 solar masses and the neutron star at 1.35 solar masses. These parameters were selected so that the neutron star was likely to be torn apart by tidal forces. The merger process was simulated using the computer cluster “Sakura” at the MPIGP’s Department of Computational Relativistic Astrophysics. In an MPIGP press release, Department director and co-author Masaru Shibata explained:

“We get insights into a process that lasts one to two seconds – that sounds short, but in fact a lot happens during that time: from the final orbits and the disruption of the neutron star by the tidal forces, the ejection of matter, to the formation of an accretion disk around the nascent black hole, and further ejection of matter in a jet. This high-energy jet is probably also a reason for short gamma-ray bursts, whose origin is still mysterious. The simulation results also indicate that the ejected matter should synthesize heavy elements such as gold and platinum.”

The team also shared the details of their simulation in an animation (shown above) via the Max Planck Institute for Gravitational Physics’ Youtube Channel. On the left side, the simulation shows the density profile as blue and green contours, the magnetic field lines that penetrate the black hole are shown as pink curves, and the matter ejected from the system as cloudy white
Did you miss our previous article…
https://www.mansbrand.com/lava-tubes-on-the-moon-maintain-comfortable-room-temperatures-inside/

Total
0
Shares
Share 0
Tweet 0
Pin it 0
Share 0
Related Topics:
Continue Reading
Click to comment

Leave a Reply

Your email address will not be published. Required fields are marked *

Frontier Adventure

Astronomers are Searching for a Galaxy-Wide Transmitter Beacon at the Center of the Milky Way

Published

7 hours ago

on

June 4, 2023

By

VLA MilkyWay NIK 1051 1024x683 1

It has been over sixty years since the first Search for Extraterrestrial Intelligence (SETI) survey occurred. This was Project Ozma, a survey led by Dr. Frank Drake (who devised the Drake Equation) that used the National Radio Astronomy Observatory (NRAO) in Green Bank, West Virginia, to listen for radio transmissions from Epsilon Eridani and Tau Ceti. While the search revealed nothing of interest, it paved the way for decades of research, theory, and attempts to find evidence of technological activity (aka. “technosignatures”).

The search continues today, with researchers using next-generation instruments and analytical methods to find the “needle in the cosmic haystack.” This is the purpose behind Breakthrough Listen Investigation for Periodic Spectral Signals (BLIPSS), a collaborative SETI project led by Cornell graduate student Akshay Suresh to look for technosignatures at the center of the Milky Way. In a recent paper, Suresh and his team shared their initial findings, which were made possible thanks to data obtained by the Greenbank Observatory and a proprietary algorithm they developed.

Suresh is a Ph.D. candidate at the Cornell Center for Astrophysics and Planetary Science who leads the BLIPPS campaign, a collaboration between Cornell University, the SETI Institute, and Breakthrough Listen. He and his colleagues were joined by astrophysicists from the Cahill Center for Astronomy and Astrophysics, the Institute for Mathematics, Astrophysics, and Particle Physics (IMAPP), the Institute of Space Sciences and Astronomy, and the International Centre for Radio Astronomy Research (ICRAR). Their paper, “A 4–8 GHz Galactic Center Search for Periodic Technosignatures,” appeared on May 30th in The Astronomical Journal.

VLA MilkyWay NIK 1051 1024x683 2
The Karl Jansky Very Large Array at night, with the Milky Way visible in the sky. Credit: NRAO/AUI/NSF; J. Hellerman

To date, all SETI surveys have been dedicated to looking for evidence of artificial radio transmissions. The accepted theory is that radio signatures would fall into one of two categories: narrowband intentional beacon emissions and broadband radiation leakage from radio transmitters. Of the two, the spectrotemporal characteristics (frequency over time) of radiation leakage are much harder to speculate about and likely to be weaker. For this reason, most modern SETI efforts have focused on looking for wideband searches for narrowband beacons from planetary systems or neighboring galaxies.

In particular, a rotating beacon near Galactic Center (GC) is considered a promising technosignature to SETI researchers. For an advanced species, such a beacon would provide a means for communicating with the entire galaxy without the need for direct contact. For species dying to know if they are alone in the Universe but not so eager as to advertise their location, a beacon is doubly attractive because it would also allow some anonymity to be maintained. As Suresh told Universe Today via email:

“From a game theory perspective, the core of the Milky Way is a likely “Schelling point” by which different alien worlds may establish communication without prior contact. For instance, intelligent aliens may choose to transmit beacons toward the center of the Milky Way to reach a maximum number of targets. Equivalently, such aliens may also transmit directly away from the center of the Milky Way, knowing that societies like ours will look towards the core of the galaxy.”

For their search, the team employed a fast folding algorithm (FFA), an open-source machine learning software designed to detect periodic events within time series data. They first tested this algorithm on known pulsars, successfully detecting the expected periodic emissions. They then consulted datasets obtained by the 100-meter Green Bank Telescope (GBT) – part of the Breakthrough Listen’s network – on a region at the center of the Milky Way during a 4.5-hour observing period. This region measures 50 light-years in diameter and encompasses over half a million stars.

https://mansbrand.com/jupiters-stripes-change-color-now-we-might-know-why/

Continue Reading

Frontier Adventure

Jupiter’s “Stripes” Change Color. Now We Might Know Why

Published

17 hours ago

on

June 4, 2023

By

image 1

While Jupiter’s Great Red Spot is one of the most well-known spectacles in the solar system, Jupiter’s clouds and stripes that are responsible for the planet’s weather patterns are highly regarded, as well. Though not nearly as visible in an amateur astronomy telescope, Jupiter’s multicolored, rotating, and swirling cloud stripes are a sight to behold for any astronomy fan when seen in up-close images. And, what makes these stripes unique is they have been observed to change color from time to time, but the question of what causes this color change to occur has remained elusive.

This is what a recent study published in Nature Astronomy hopes to address as an international team of researchers examine how Jupiter’s massive magnetic field could be responsible for Jupiter’s changing stripe colors. This study was led by Dr. Kumiko Hori of Kobe University and Dr. Chris Jones of the University of Leeds and holds the potential to help scientists better understand how a planet’s magnetic field could influence a planet’s weather patterns. In this case, Jupiter’s massive magnetic field influencing its massive, swirling clouds.

“If you look at Jupiter through a telescope, you see the stripes, which go round the equator along lines of latitude,” explains Dr. Jones. “There are dark and light belts that occur, and if you look a little bit more closely, you can see clouds zipping around carried by extraordinarily strong easterly and westerly winds. Near the equator, the wind blows eastward but as you change latitude a bit, either north or south, it goes westward. And then if you move a little bit further away it goes eastward again. This alternating pattern of eastward and westward winds is quite different from weather on Earth.”

While previous studies have demonstrated that Jupiter’s appearance is somehow altered by infrared fluctuations approximately 50 km (31 mi) below the gas cloud surface, this most recent study demonstrates the infrared fluctuations could be caused by Jupiter’s magnetic field, the source of which, like Earth, is far deeper inside the planet.

“Every four or five years, things change,” said Dr. Jones. “The colors of the belts can change and sometimes you see global upheavals when the whole weather pattern goes slightly crazy for a bit, and it has been a mystery as to why that happens.”

image 1 1
Infrared images of Jupiter obtained by a ground-based telescope displaying changes in the color of Jupiter’s clouds between 2001 and 2011 (dashed blue lines). (Credit: Arrate Antuñano/NASA/IRTF/NSFCam/SpeX)

For the study, the researchers analyzed data collected over several years from NASA’s Juno spacecraft to both observe and measure variations in Jupiter’s magnetic field, more commonly known as oscillations. Despite Jupiter’s massive radiation belt which can cause immense harm to any spacecraft, Juno has been orbiting the solar system’s largest planet since 2016 and is frequently lauded for it still being active despite the constant bombardment from the radiation.

From the data, the team was able to monitor the magnetic field’s waves and oscillations. They focused on a specific area of the magnetic field dubbed the Great Blue Spot, which is invisible to the naked eye and located near Jupiter’s equator. While this spot has been observed to be traveling eastwards on Jupiter, the data from this study indicates the spot is slowing down, which the team interprets as the start of an oscillation within the magnetic field, meaning the spot could eventually slow enough to where it reverses direction and starts traveling westwards.

imagesjuno20190520PIA23229 16 750
Still image taken from a video animation featuring Jupiter’s massive magnetic field at one instant in time, specifically its Great Blue Spot located near
Did you miss our previous article…
https://mansbrand.com/crs-28-mission/

Continue Reading

Frontier Adventure

CRS-28 Mission

Published

1 day ago

on

June 3, 2023

By

hqdefault

hqdefault 1

SpaceX is targeting Saturday, June 3 for Falcon 9’s launch of Dragon’s 28th Commercial Resupply Services (CRS-28) mission to the International Space Station from Launch Complex 39A (LC-39A) at NASA’s Kennedy Space Center in Florida. The instantaneous launch window is at 12:35 p.m. ET (16:35 UTC) and a backup launch opportunity is available on Sunday, June 4 at 12:12 p.m. ET (16:12 UTC).

This is the fifth flight of the first stage booster supporting this mission, which previously launched Crew-5, GPS III Space Vehicle 06, Inmarsat I-6 F2, and one Starlink mission. Following stage separation, Falcon 9 will land on the A Shortfall of Gravitas droneship in the Atlantic Ocean.

CRS-28 is the fourth flight for this Dragon spacecraft, which previously flew CRS-21, CRS-23, and CRS-25 to the space station. After an approximate 41-hour flight, Dragon will autonomously dock with the orbiting laboratory on Monday, June 5 at approximately 5:38 a.m. ET (9:38 UTC).

A live webcast of this mission will begin about 20 minutes prior to liftoff.

Did you miss our previous article…
https://mansbrand.com/you-can-detect-tsunamis-as-they-push-the-atmosphere-around/

Continue Reading

Trending