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Smallest Galaxies Hosting Monster Black Holes: Study

Astronomers find wandering massive black holes in dwarf galaxies.



Artist’s conception of a dwarf galaxy, its shape distorted, most likely by a past interaction with another galaxy, and a massive black hole in its outskirts (pullout). The black hole is drawing in material that forms a rotating disk and generates jets of material propelled outward. Credit: Sophia Dagnello, NRAO/AUI/NSF

MONTANA (United States): Astronomers have discovered some of the smallest galaxies known to host massive black holes, findings which may reveal how such regions of space exhibiting ultrahigh gravitational force — that even light cannot escape from — formed in the early universe.

The study, published in the Astrophysical Journal, found 13 massive black holes, about 4,00,000 times as heavy as the Sun, in dwarf galaxies which are more than 100 times smaller than our own Milky Way.

According to the researchers, including those from Montana State University in the US, these galaxies are situated so far away that light from the Earth would take less than a billion years to reach them. “We hope that studying them and their galaxies will give us insights into how similar black holes in the early universe formed and then grew, through galactic mergers over billions of years, producing the supermassive black holes we see in larger galaxies today, with masses of many millions or billions of times that of the Sun,” said study co-author Amy Reines of Montana State University.

The scientists used the Very Large Array (VLA), a radio astronomy observatory located in central New Mexico in the US, to make the discovery. Previously in 2011, Reines and her colleagues used VLA to discover the first massive black hole in a dwarf starburst galaxy in 2011. Following this finding, the scientists started by choosing a sample of galaxies from the NASA-Sloan Atlas — a catalog of galaxies made with visible-light telescopes.

They selected galaxies with stars totalling less than 3 billion times the mass of the Sun. From this pool of galaxies, they picked ones which appeared in the National Radio Astronomy Observatory’s Faint Images of the Radio Sky at Twenty centimeters (FIRST) survey — an astronomical survey of the skies above the Earth’s Northern Hemisphere made using the VLA between 1993 and 2011.

The scientists then made more sensitive, high-resolution images of 111 of the selected galaxies. “The new VLA observations revealed that 13 of these galaxies have strong evidence for a massive black hole that is actively consuming surrounding material. We were very surprised to find that, in roughly half of those 13 galaxies, the black hole is not at the center of the galaxy, unlike the case in larger galaxies,”

Reines said. Based on the findings, the astronomers suggested that the galaxies may have merged with others earlier in their history.

They found this inference to be consistent with computer simulations predicting that roughly half of the massive black holes in dwarf galaxies were found wandering in the outskirts of their galaxies.

“This work has taught us that we must broaden our searches for massive black holes in dwarf galaxies beyond their centers to get a more complete understanding of the population and learn what mechanisms helped form the first massive black holes in the early universe,” Reines said.

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Research and Science

Gaganyaan Space Astronauts Training To Begin This Month

India’s heaviest launch vehicle “Bahubali” GSLV Mark-III will the carry astronauts to space. 




NEW DELHI: The training of the four test pilots of the Indian Air Force who have been selected for the Gaganyaan mission is scheduled to start this month, Jitendra Singh, minister of state, Prime Ministers Office, who also holds the space portfolio, said. All the four astronauts selected for the mission are men but their identity cannot be revealed.

The training will take place in Russia and will last for 11 months. After this intensive training, the astronauts will complete the training on the module back in India.

After 11 months of training in Russia, the astronauts will receive module-specific training in India. In that, they will be trained in crew and service module designed by ISRO, learn to operate it, work around it and do simulations.

The prototype of Gaganyaan which ISRO made public is similar to the Russian designs. Russia was not only the pioneer in space travel, but as of date, it is the only country which has the capability of sending astronauts to the International Space Station. China has also sent 14 people to space, some to its own space station, Tiangong 2, since 2003. Its last human space flight was in 2016. The design of its spacecraft also resembles the Russian one. However, China’s space programme remains insular.

The Gaganyaan mission comprises of three flights, the first two unmanned. The first of the flights is scheduled for the end of this year. The human flight is aimed for 2022, to coincide with the 75 anniversary of India’s independence. ISRO chairman K. Sivan recently said that only one astronaut would fly on this debut flight. This is as per international tradition. Even erstwhile USSR sent only one space traveller, Yuri Gagarin, on the maiden flight.

As per the ISRO sources, India’s heaviest launch vehicle “Bahubali” GSLV Mark-III will the carry astronauts to space.

Rs.10,000 crores have already been sanctioned by the Union Cabinet for the Gaganyaan project. This followed the announcement made by the Prime Minister Shri Narendra Modi on the Independence Day last year, stating that the Gaganyaan launch will coincide with the 75th year of India’s Independence.

The first Indian to go into space was Rakesh Sharma in 1984 but the spacecraft in which he went was not Indian. Gaganyaan will be the first-ever human space mission conceived and developed in India, as a distinct illustration of the Prime Minister’s Make in India vision.

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Research and Science

India Successfully Launches High-Power Communication Satellite GSAT-30

GSAT-30 will serve as a replacement to the ageing INSAT-4A spacecraft services with enhanced coverage.



FRENCH GUIANA: India’s high power communication satellite GSAT-30 was successfully launched onboard Ariane 5 rocket from French Guiana early today morning.

GSAT-30 is configured on ISRO’s enhanced I-3K Bus structure to provide communication services from Geostationary orbit in C and Ku bands. The satellite derives its heritage from ISRO’s earlier INSAT/GSAT satellite series.

Indian Space Research Organisation (ISRO) said the GSAT-30 is aimed at providing high-quality television, telecommunications and broadcasting services.

The 3,357-kg GSAT-30 derives its heritage from ISRO’s earlier INSAT/GSAT satellite series and is equipped with 12 C and 12 Ku band transponders.

GSAT-30 will serve as a replacement to the ageing INSAT-4A spacecraft services with enhanced coverage.

ISRO said that the satellite will provide Indian mainland and islands coverage in Ku-band and extended coverage in C-band covering Gulf countries, a large number of Asian countries and Australia.

With a mission life of 15 years, GSAT-30 is an operational communication satellite for DTH, television uplink and VSAT services.

ISRO said the communication payload of GSAT-30 is specifically designed and optimized to maximize the number of transponders on the spacecraft bus.

According to the space agency, the spacecraft will be extensively used for supporting VSAT network, television uplinking and teleport services, digital satellite newsgathering (DSNG), DTH television services, cellular backhaul connectivity and many such applications.

The designed in-orbit operational life of GSAT-30 is more than 15 years.

प्रमोचन भार / Launch Mass:
3357 kg
मिशन कालावधि / Mission Life :
More than 15 years
Ariane-5 VA-251
उपग्रह का प्रकार / Type of Satellite:
निर्माता / Manufacturer:
स्‍वामी / Owner:
अनुप्रयोग / Application:
कक्षा का प्रकार / Orbit Type:
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Research and Science

Vikram Lander Of Chandrayaan-2 Was Spotted By ISRO In September Itself

NASA said it was able to locate the debris after a tip-off by Shanmuga Subramanian from Chennai.



The scene above was captured from a Lunar Reconnaissance Orbiter Camera Quickmap fly-around of Chandrayaan 2 Lander Vikram’s targeted landing site between the Manzinus C and Simpelius N craters on the lunar south pole. Photo: NASA/Goddard/Arizona State University

BENGALURU (Karnataka): Indian Space Research Organisation (ISRO) Chief K Sivan has said that the Vikram Lander of Chandrayaan-2 had been spotted by the space agency’s own orbiter much ahead of NASA, which on Tuesday announced that it had located the debris of Vikram’s crash landing on the moon in September last year and credited a Chennai-based engineer for the finding.

Also Read: NASA Locates Chandrayaan-2’s Vikram Lander On Moon

ISRO official website has an entry dated September 10 that reads: “Vikram lander has been located by the orbiter of Chandrayaan-2, but no communication with it yet. All possible efforts are being made to establish communication with lander.”

ISRO chief’s comments came after NASA said that it had found the remains of the Vikram lander by its Lunar Reconnaissance Orbiter and credited the discovery to Chennai-based amateur astronomer and engineer Shanmuga Subramanium.

US space agency Nasa had Tuesday said that it had located the lander Vikram of India’s second moon mission Chandrayaan-2, around three months after Isro lost contact with it.

NASA released an image acquired by its Lunar Reconnaissance Orbiter Camera (LROC) on November 11, marking pieces of debris close to the proposed landing site of the Chandrayaan-2 lander.

NASA said it was able to locate the debris after a tip-off by Shanmuga Subramanian, a 33-year-old mechanical engineer and app developer from Chennai.

NASA’s LROC had captured an image of the landing site during a fly-by. The space agency said it couldn’t locate the lander based on the image due to the large shadows that covered the area.

The images were uploaded on September 26 and Subramanian was the first person to achieve positive identification of the Chandrayaan-2 lander. The first debris spotted by the Indian engineer was located 750 metres northwest of the impact site.

Early in October, Subramanian located a tiny spot which he believed was part of the Vikram lander’s debris. He tweeted about it and informed Isro and Nasa. On Tuesday, NASA tweeted confirming that Subramanian was spot on.

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