JIUQUAN, June 15 (Xinhua) -- China launched its first X-ray space telescope to observe black holes, pulsars and gamma-ray bursts, via a Long March-4B rocket from Jiuquan Satellite Launch Center in northwest China's Gobi Desert at 11 a.m. Thursday.

The 2.5-tonne Hard X-ray Modulation Telescope (HXMT), dubbed Insight, was sent into an orbit of 550 kilometers above the earth to help scientists better understand the evolution of black holes, and the strong magnetic fields and the interiors of pulsars.

Through the telescope, scientists will also study how to use pulsars for spacecraft navigation, and search for gamma-ray bursts corresponding to gravitational waves.

The result of the wisdom and efforts of several generations of Chinese scientists, Insight is expected to push forward the development of space astronomy and improve space X-ray detection technology in China.

OBSERVATORY IN SPACE

Insight can be regarded as a small observatory in space, as it carries a trio of detectors -- the high energy X-ray telescope (HE), the medium energy X-ray telescope (ME) and the low energy X-ray telescope (LE) -- that cover a broad energy band from 1 keV to 250 keV, said Lu Fangjun, chief designer of the payload.

Based on the demodulation technique first proposed by Li Tipei, an academician of the Chinese Academy of Sciences (CAS), in 1993, the HE has a total detection area of more than 5,000 square centimeters, the world's largest in its energy band.

"Given it has a larger detection area than other X-ray probes, HXMT can identify more features of known sources," said Xiong Shaolin, a scientist at the Institute of High Energy Physics of the CAS.

Chen Yong, chief designer of the LE, said X-rays of lower energy usually have more photons, so a telescope based on a focusing technique is not suitable for observing very bright objects emitting soft X-rays, as too many photons at a time will result in over-exposure.

But HXMT won't have that problem, as its collimators diffuse photons instead of focusing them. "No matter how bright the sources are, our telescope won't be blinded," said Chen.

According to Zhang Shuangnan, HXMT lead scientist, the satellite's developers found that a set of HXMT high-energy detectors, originally designed to shield background noises caused by unwanted X-ray photons, especially those from behind the telescope, could be adjusted to observe gamma-ray bursts.

The creative new function pushes the satellite's observation band up to 3 MeV and will get a very good energy spectrum, Zhang said.

BLACK HOLES, PULSARS

"We are looking forward to discovering new activities of black holes and studying the state of neutron stars under extreme gravity and density conditions, and physical laws under extreme magnetic fields. These studies are expected to bring new breakthroughs in physics," said Zhang.

Compared with X-ray astronomical satellites of other countries, HXMT has a larger detection area, broader energy range and wider field of view. These give it advantages in observing black holes and neutron stars emitting bright X-rays, and it can more efficiently scan the galaxy, Zhang said.

Other satellites have conducted sky surveys and found many celestial sources of X-rays. However, the sources are often variable, and occasional intense flares can be missed in just one or two surveys, according to Zhang.

New surveys can discover either new X-ray sources or new activities in known sources. So HXMT will repeatedly scan the Milky Way for active and variable celestial bodies emitting X-rays.

"There are so many black holes and neutron stars in the universe, but we don't have a thorough understanding of any of them. So we need new satellites to observe more," Zhang said.

Black holes remain a mystery. One of their many secrets is why they get "angry."

"Black holes will be the focus of our observation since they are very interesting, and can generate various types of radiation, including X-rays and high energy cosmic rays, as well as strong jets," said Zhang.

So far about 20 black holes have been found in our galaxy. "We hope our telescope can discover more black holes. We also hope to better observe the black holes already discovered."

If a black hole does nothing, it cannot be found. But if matter falls into a black hole, it is accelerated and heated during the process, emitting X-rays. Scientists might learn more about the characteristics of black holes from the X-rays.

Some times a black hole is calm, but other times it's very "bad tempered." When a black hole gets "angry," it generates very strong X-rays or gamma ray bursts or jet-flows, Zhang explained.

Other countries have sent several X-ray satellites into orbit, but most are suitable for observing only relatively calm black holes. However, HXMT is suitable for observing angry black holes and neutron stars.

"We are still not clear why some black holes suddenly get angry, since we haven't observed them for long enough," he said. "We plan to make a thorough survey of black holes and neutron stars in the galaxy."

A neutron star, or a pulsar, is so strange that when the first one was discovered, it was mistaken for signals from aliens. There are still many mysteries about this kind of star.

"We are still not clear about the interiors of pulsars. Current physical laws cannot describe the substances in the state of a pulsar well, since no lab on Earth can create a density as high as a pulsar. So we have to conduct more observations of pulsars," Zhang said.

With their super strong gravitational and electromagnetic fields and high density, pulsars are regarded as natural laboratories of extreme physical conditions. Scientists could study many phenomena that they cannot replicate on Earth by observing neutron stars.

EXPECTING SURPRISES

Since the detection of gravitational waves, scientists have been eager to find electromagnetic signals corresponding to the gravitational waves. This will be an important task for Insight.

Xiong said the position accuracy of all the gravitational wave events detected so far is still very poor.

If scientists can find electromagnetic signals happening at similar positions and times of gravitational wave events, it would increase the reliability of the detection. Combined analysis of gravitational wave and electromagnetic signals will help reveal more about the celestial bodies emitting gravitational waves, said Xiong.

Some scientists suspect that mysterious gamma-ray bursts could be electromagnetic signals corresponding to gravitational waves.

"Since gravitational waves were detected, the study of gamma-ray bursts has become more important. In astrophysics, it's insufficient to study just the gravitational wave signals. We need to use the corresponding electromagnetic signals, which are more familiar to astronomers, to facilitate the research on gravitational waves," Zhang said.

HXMT's effective detection area for monitoring gamma-ray bursts is 10 times that of the US Fermi space telescope. Scientists estimate that HXMT could detect almost 200 gamma-ray burst events a year.

"HXMT can play a vital role in searching for electromagnetic signals corresponding to gravitational waves," said Zhang. "If HXMT can detect electromagnetic signals corresponding to gravitational waves, it would be its most wonderful scientific finding."

"Our telescope may discover new phenomena, or even new celestial bodies. We are looking forward to new findings that nobody can predict. I hope my predictions are wrong since the most interesting astronomical discoveries are all out of expectations."

CHINA'S SPACE SCIENCE

CAS academician Gu Yidong said China still lags behind advanced levels in space science. "We should have a sense of urgency. It will take efforts to upgrade China's space science to advanced levels within two decades."

Arvind Parmar, head of the Scientific Support Office in the Science Directorate of European Space Agency (ESA), said HXMT will study X-rays from objects such as black holes, neutron stars and the remains of exploded stars. These are exciting topics for scientists all over the world. HMXT will join X-ray satellites already in operation. Each mission has its own strengths.

He said the ESA has a long history of collaborating with China on scientific missions. Once HXMT is launched and starts making observations, there is great potential for joint investigations with some ESA missions. Many scientific investigations benefit from data from more than one satellite.

"I am really impressed with how China is developing its scientific space program. The recent launches of the Dark Matter Particle Explorer and the Quantum Experiments at Space Scale missions highlight China's capabilities and commitment to science as does the range of missions under study for future launch opportunities," said Parmar.

Paolo Giommi, a senior scientist at the Italian Space Agency, said China's space science program foresees several satellites of increasing complexity and competitiveness. Together with the construction of large ground-based facilities, this will make China one of the major definitive producers of knowledge in space science.

Quelle: Xinhua

---

Update: 16.06.2017

.

China’s first astronomical satellite, an x-ray telescope that will search the sky for black holes, neutron stars, and other extremely energetic phenomena, raced into orbit today after a morning launch from the Gobi Desert.

The 2.5-ton Hard X-ray Modulation Telescope (HXMT), dubbed Insight according to the official Xinhua news agency, was carried aloft by a Long March-4B rocket from the Jiuquan Satellite Launch Center. The newest of several x-ray telescope in space, the HXMT will observe some of the most turbulent processes in the universe. The x-rays generated by those events cannot penetrate Earth’s atmosphere; they can only be observed by instruments mounted on high-altitude balloons or satellites. The HXMT carries three x-ray telescopes observing at energies ranging from 20 to 200 kilo-electron volts as well as an instrument to monitor the space environment, according to its designers. While orbiting 550 kilometers above the planet, the HXMT will perform an all-sky survey that is expected to discover a thousand new x-ray sources. Over an expected operating lifetime of 4 years, it will also conduct focused observations of black holes, neutron stars, and gamma ray bursts.

This latest achievement by China’s space science program “is certainly welcomed” by the astronomical community, says Andrew Fabian, a theoretical astrophysicist at the University of Cambridge in the United Kingdom. “It’s very meaningful that they’ve launched their first astronomical satellite and this will pave the way for others,” he says. Fabian predicts that the HXMT sky survey will prove particularly valuable for catching transient x-ray sources that emerge, flare up to tremendous brightness, and then just as quickly fade away. As yet, the processes behind x-ray transients are poorly understood. Other missions are also trying to catch transients in the act. But “any satellite looking at that phenomena is going to find interesting things and do good science,” Fabian says.

The HMXT is the last of the cluster of four space science missions covered under China’s 12th 5-year plan that were developed by the National Space Science Center (NSSC) of the Chinese Academy of Sciences in Beijing—the other three are a dark matter probe, a collection of microgravity experiments, and a test of long-range quantum entanglement. Funding constraints meant all four had to be developed simultaneously, and all four were launched over the course of 18 months. “This is not a sustainable way to have a science program,” NSSC Director Ji Wu told Science in a 2016 interview.

It would be better to get steady funding annually instead of in 5-year lump sums, he said. Nevertheless, NSSC has again gotten a 5-year budget to develop its next batch of four space science missions, all of which will likely be launched between 2020 and 2022. Among these is the Einstein Probe, a next-generation x-ray telescope that Fabian expects will build on the accomplishments of the HXMT.

Quelle: AAAS

+++

China Focus: China launches space telescope to search for black holes, pulsars

A Long March-4B rocket carrying X-ray space telescope to observe black holes, pulsars and gamma-ray bursts blasts off from Jiuquan Satellite Launch Center in northwest China's Gobi Desert, June 15, 2017. (Xinhua/Zhen Zhe)

by Xinhua writers Yu Fei, Quan Xiaoshu and Qu Ting

JIUQUAN, June 15 (Xinhua) -- China launched its first X-ray space telescope to observe black holes, pulsars and gamma-ray bursts, via a Long March-4B rocket from Jiuquan Satellite Launch Center in northwest China's Gobi Desert at 11 a.m. Thursday.

The 2.5-tonne Hard X-ray Modulation Telescope (HXMT), dubbed Insight, was sent into an orbit of 550 kilometers above the earth to help scientists better understand the evolution of black holes, and the strong magnetic fields and the interiors of pulsars.

Through the telescope, scientists will also study how to use pulsars for spacecraft navigation, and search for gamma-ray bursts corresponding to gravitational waves.

The result of the wisdom and efforts of several generations of Chinese scientists, Insight is expected to push forward the development of space astronomy and improve space X-ray detection technology in China.

OBSERVATORY IN SPACE

Insight can be regarded as a small observatory in space, as it carries a trio of detectors -- the high energy X-ray telescope (HE), the medium energy X-ray telescope (ME) and the low energy X-ray telescope (LE) -- that cover a broad energy band from 1 keV to 250 keV, said Lu Fangjun, chief designer of the payload.

Based on the demodulation technique first proposed by Li Tipei, an academician of the Chinese Academy of Sciences (CAS), in 1993, the HE has a total detection area of more than 5,000 square centimeters, the world's largest in its energy band.

"Given it has a larger detection area than other X-ray probes, HXMT can identify more features of known sources," said Xiong Shaolin, a scientist at the Institute of High Energy Physics of the CAS.

Chen Yong, chief designer of the LE, said X-rays of lower energy usually have more photons, so a telescope based on a focusing technique is not suitable for observing very bright objects emitting soft X-rays, as too many photons at a time will result in over-exposure.

But HXMT won't have that problem, as its collimators diffuse photons instead of focusing them. "No matter how bright the sources are, our telescope won't be blinded," said Chen.

According to Zhang Shuangnan, HXMT lead scientist, the satellite's developers found that a set of HXMT high-energy detectors, originally designed to shield background noises caused by unwanted X-ray photons, especially those from behind the telescope, could be adjusted to observe gamma-ray bursts.

The creative new function pushes the satellite's observation band up to 3 MeV and will get a very good energy spectrum, Zhang said.

BLACK HOLES, PULSARS

"We are looking forward to discovering new activities of black holes and studying the state of neutron stars under extreme gravity and density conditions, and physical laws under extreme magnetic fields. These studies are expected to bring new breakthroughs in physics," said Zhang.

Compared with X-ray astronomical satellites of other countries, HXMT has a larger detection area, broader energy range and wider field of view. These give it advantages in observing black holes and neutron stars emitting bright X-rays, and it can more efficiently scan the galaxy, Zhang said.

Other satellites have conducted sky surveys and found many celestial sources of X-rays. However, the sources are often variable, and occasional intense flares can be missed in just one or two surveys, according to Zhang.

New surveys can discover either new X-ray sources or new activities in known sources. So HXMT will repeatedly scan the Milky Way for active and variable celestial bodies emitting X-rays.

"There are so many black holes and neutron stars in the universe, but we don't have a thorough understanding of any of them. So we need new satellites to observe more," Zhang said.

Black holes remain a mystery. One of their many secrets is why they get "angry."

"Black holes will be the focus of our observation since they are very interesting, and can generate various types of radiation, including X-rays and high energy cosmic rays, as well as strong jets," said Zhang.

So far about 20 black holes have been found in our galaxy. "We hope our telescope can discover more black holes. We also hope to better observe the black holes already discovered."

If a black hole does nothing, it cannot be found. But if matter falls into a black hole, it is accelerated and heated during the process, emitting X-rays. Scientists might learn more about the characteristics of black holes from the X-rays.

Some times a black hole is calm, but other times it's very "bad tempered." When a black hole gets "angry," it generates very strong X-rays or gamma ray bursts or jet-flows, Zhang explained.

Other countries have sent several X-ray satellites into orbit, but most are suitable for observing only relatively calm black holes. However, HXMT is suitable for observing angry black holes and neutron stars.

"We are still not clear why some black holes suddenly get angry, since we haven't observed them for long enough," he said. "We plan to make a thorough survey of black holes and neutron stars in the galaxy."

A neutron star, or a pulsar, is so strange that when the first one was discovered, it was mistaken for signals from aliens. There are still many mysteries about this kind of star.

"We are still not clear about the interiors of pulsars. Current physical laws cannot describe the substances in the state of a pulsar well, since no lab on Earth can create a density as high as a pulsar. So we have to conduct more observations of pulsars," Zhang said.

With their super strong gravitational and electromagnetic fields and high density, pulsars are regarded as natural laboratories of extreme physical conditions. Scientists could study many phenomena that they cannot replicate on Earth by observing neutron stars.

EXPECTING SURPRISES

Since the detection of gravitational waves, scientists have been eager to find electromagnetic signals corresponding to the gravitational waves. This will be an important task for Insight.

Xiong said the position accuracy of all the gravitational wave events detected so far is still very poor.

If scientists can find electromagnetic signals happening at similar positions and times of gravitational wave events, it would increase the reliability of the detection. Combined analysis of gravitational wave and electromagnetic signals will help reveal more about the celestial bodies emitting gravitational waves, said Xiong.

Some scientists suspect that mysterious gamma-ray bursts could be electromagnetic signals corresponding to gravitational waves.

"Since gravitational waves were detected, the study of gamma-ray bursts has become more important. In astrophysics, it's insufficient to study just the gravitational wave signals. We need to use the corresponding electromagnetic signals, which are more familiar to astronomers, to facilitate the research on gravitational waves," Zhang said.

HXMT's effective detection area for monitoring gamma-ray bursts is 10 times that of the US Fermi space telescope. Scientists estimate that HXMT could detect almost 200 gamma-ray burst events a year.

"HXMT can play a vital role in searching for electromagnetic signals corresponding to gravitational waves," said Zhang. "If HXMT can detect electromagnetic signals corresponding to gravitational waves, it would be its most wonderful scientific finding."

"Our telescope may discover new phenomena, or even new celestial bodies. We are looking forward to new findings that nobody can predict. I hope my predictions are wrong since the most interesting astronomical discoveries are all out of expectations."

CHINA'S SPACE SCIENCE

CAS academician Gu Yidong said China still lags behind advanced levels in space science. "We should have a sense of urgency. It will take efforts to upgrade China's space science to advanced levels within two decades."

Arvind Parmar, head of the Scientific Support Office in the Science Directorate of European Space Agency (ESA), said HXMT will study X-rays from objects such as black holes, neutron stars and the remains of exploded stars. These are exciting topics for scientists all over the world. HMXT will join X-ray satellites already in operation. Each mission has its own strengths.

He said the ESA has a long history of collaborating with China on scientific missions. Once HXMT is launched and starts making observations, there is great potential for joint investigations with some ESA missions. Many scientific investigations benefit from data from more than one satellite.

"I am really impressed with how China is developing its scientific space program. The recent launches of the Dark Matter Particle Explorer and the Quantum Experiments at Space Scale missions highlight China's capabilities and commitment to science as does the range of missions under study for future launch opportunities," said Parmar.

Paolo Giommi, a senior scientist at the Italian Space Agency, said China's space science program foresees several satellites of increasing complexity and competitiveness. Together with the construction of large ground-based facilities, this will make China one of the major definitive producers of knowledge in space science.

Quelle: Xinhua

+++

Scientists voice expectations of China's new space telescope

China on Thursday launched a space telescope, the Hard X-ray Modulation Telescope (HXMT), or Insight, to observe black holes, neutron stars, gamma ray bursts and other celestial phenomena.

The result of the wisdom and painstaking efforts of several generations of Chinese scientists, the telescope is expected to push forward the development of space astronomy in China. Scientists from both home and abroad have high expectations of it.

"Before its launch, we could only use second-hand observation data from foreign satellites. It was very hard for Chinese astronomers to make important findings without our own instruments," said Xiong Shaolin, a scientist at the Institute of High Energy Physics of the Chinese Academy of Sciences (CAS).

"The only way to make original achievements is to construct our own observation instruments," Xiong said.

"Now Chinese scientists have created this space telescope with its many unique advantages, and it's quite possible we will discover new, strange and unexpected phenomena in universe."

Gou Lijun, a researcher at the National Astronomical Observatories of the CAS, said China missed opportunities for many discoveries as approval of Insight and its development and launch was postponed many times.

However, it is the first step for China in the field of X-ray astronomy and learning how to develop and operate a space telescope, Gou said.

"Although many advanced X-ray astronomical satellites from other countries are already in orbit, HXMT could still make important discoveries," said Gou. "The universe is full of surprises."

Zhang Shuangnan, lead scientist of HXMT, said the launch puts China in the vanguard of international X-ray astronomy with a dozen other X-ray satellites in orbit. This is both an opportunity and a challenge for China. HXMT will both compete and collaborate with other X-ray satellites.

The research and development of China's first X-ray astronomical satellite laid a good foundation for the development of future X-ray astronomical instruments, Zhang said.

Li Tipei, the CAS academician who first proposed the satellite in the early 1990s, said Chinese scientists could have made many great scientific discoveries if it had been launched within 10 years of first being mooted. Even so, he is confident the satellite can make new findings.

"Our satellite has advantages in detecting transient phenomena and X-ray explosions of celestial bodies. And its functions have expanded, as its developers added more detectors so it can cover a broader range of energy," Li said.

Gu Yidong, a CAS academician, said China still lags behind advanced levels in space science. "We should have a sense of urgency. We will make efforts to upgrade China's space science to advanced levels within two decades."

Filippo Frontera, a professor of the University of Ferrara and an associate scientist of Italy's National Institute of Astrophysics in Bologna, said the satellite will be a useful vehicle for the advancement of the high-energy astrophysics in China.

"The Chinese space program is very impressive. I expect that, with this program, China can become a leader in space science with great scientific and economic returns. Indeed, foreseen space missions require the development of new high-level technologies that can be later exploited in different fields, like medical physics, information technology, and so on," said Frontera.

Arvind Parmar, head of the Scientific Support Office in the Science Directorate of European Space Agency (ESA), said HXMT will study X-rays from objects such as black holes, neutron stars and the remains of exploded stars. These are exciting topics for scientists all over the world. HMXT will join X-rays satellites already in operation. Each mission has its own strengths.

He said the ESA has a long history of collaborating with China on scientific missions. Once HXMT is launched and starts making observations, there is great potential for joint investigations with some ESA missions. Many scientific investigations benefit from data from more than one satellite.

"I am really impressed with how China is developing its scientific space program. The recent launches of the Dark Matter Particle Explorer and the Quantum Experiments at Space Scale missions highlight Chinese capabilities and commitment to science as does the range of missions under study for future launch opportunities," said Parmar.

Andrea Santangelo, a scientist at the Institute of Astronomy and Astrophysics of Germany's University of Tubingen, said HXMT will have profound implications for the development of high-energy astrophysics in China. Being a national program with an international flavor, it will put China among the lead nations in X-ray astrophysics and space science.

As has happened for other nations, the know-how acquired during its development and the knowledge that will emerge from the analysis of the data will allow future generations of scientists to play a key role in understanding the universe at high energy, said Santangelo.

"HXMT will focus on the bright sources emitting X-rays. In particular, the mission capability of studying a broad band of energies will allow us to study the behavior of very exotic objects in the universe. Thanks to the broadband coverage of HXMT, we will see many aspects of the emission of objects in the X-rays. If one wants to study an elephant, one does not just look at its proboscis or its tail. We want to see and measure the proboscis, the tail and the body," Santangelo said.

Paolo Giommi, a senior scientist at the Italian Space Agency, said China's space science program foresees several satellites of increasing complexity and competitiveness. Together with the construction of large ground-based facilities, this will make China one of the major definitive producers of knowledge in space science.

Jonathan E. Grindlay, a professor at the Harvard Smithsonian Center for Astrophysics, said China is making rapid scientific progress in its space program. HXMT will be an important extension of high-energy astrophysics from space, and will complement other missions currently in operation as well as those being planned.

Quelle: Xinhua