Guo Shoujing telescope and the Milky Way Photo courtesy of the National Astronomical Observatory of the Chinese Academy of Sciences
On March 31, the National Astronomical Observatory of the Chinese Academy of Sciences released the sky survey dataset obtained by Guo Shoujing Telescope (hereinafter referred to as "LAMOST") - LAMOST DR10 (v1.0) dataset to domestic astronomers and international collaborators. The dataset contains a total of more than 22.29 million spectra, which is 2.9 times the sum of the published spectra of other international survey telescopes. So far, LAMOST has become the first sky survey project in the world to release a spectrum of more than 20 million.
Ten years of data, the world's most
According to researcher Zhao Yongyong, executive deputy director of the LAMOST Operation and Development Center, the DR10 dataset released this time is the spectral data obtained by LAMOST from October 2011 to June 2022, including 5923 low-resolution observation sky regions and 1951 medium-resolution observation sky regions. The 22.29 million spectral data released included 11.81 million low-resolution spectra and 10.48 million medium-resolution spectra, and both medium- and low-resolution spectra exceeded 10 million. In addition, the DR10 data includes a catalogue of about 9.61 million sets of stellar spectral parameters. LAMOST released the number of spectra and the number of stellar parameter star catalogs, ranking first in the world for ten consecutive years, and also made China in the international leading position in this field.
It is reported that the National Astronomical Science Data Center has built a LAMOST DR10 data release platform, and scientific users can log in to the website to query and download data.
Based in China, serving the world
"LAMOST has opened and led the road of international large-scale spectral survey, and has become a classic work of large-scale spectroscopic survey telescopes in the world." Zhao Yongheng said this about LAMOST.
Up to now, 1385 users from 194 scientific research institutions and universities in China, the United States, Germany, Belgium, Denmark and other countries and regions are using LAMOST data to carry out research work, and more than 1200 high-quality papers have been published and cited more than 13000 times. In the past two years, the scientific research output has shown a spurt growth trend, and the average number of papers published using LAMOST data has exceeded 200 per year, of which more than 40% of the scientific papers published by foreign astronomers have demonstrated the international influence of LAMOST data. The scientific output of LAMOST has entered the advanced ranks of international large (6~10 meters) astronomical telescopes.
Explore the universe and seize the commanding heights of science
LAMOST has helped astronomers around the world to achieve a number of record-breaking and high-level breakthroughs in the structure and formation of the Milky Way, the exploration of stellar physics, and the search for special and compact objects.
Series Achievement 1: Accurately draw a space-time "portrait" of the Milky Way. LAMOST's spectral data of the order of 20 million builds the foundation of the "digital galaxy", which is of irreplaceable scientific significance for drawing the space-time "portrait" of the Milky Way. From "height and weight" to "physical appearance" to "growth history", LAMOST helps astronomers paint a multi-dimensional picture of the Milky Way. For example, researchers have used observations from LAMOST and ESA's Gaia satellite to obtain the most accurate age information of 250,000 stars in the Milky Way to date, clearly restoring the growth history of the Milky Way in its infancy and adolescence from a timeline.
Series 2: Solve the mystery of the stellar world. In recent years, LAMOST has made a splash in the field of stellar physics. In early 2023, researchers used LAMOST to observe for the first time a very important fundamental theory in astrophysics, the "initial mass function of stars", which has changed significantly with the evolutionary history of the Milky Way and the environment. The discovery challenges the classical theory that the initial mass distribution law of stars remains unchanged everywhere in the universe, refreshes human understanding of this basic concept, and will have a profound impact on the research and development of many fields of astrophysics.
Series 3: Promote the new discoveries of the "Black Hole Hunter Program". Black holes are an extremely unique and very important type of celestial body and are a hot spot in the academic community. LAMOST launched the Black Hole Hunter Program, which aims to discover and measure more compact objects such as black holes and neutron stars. In 2022, based on LAMOST time-domain survey data, the research team discovered a ningzie neutron star about 1037 light-years from Earth. This is another important achievement of the LAMOST "Black Hole Hunter Program" in the field of compact object search after the identification of a ningning static star-level black hole in 2019. The advantages of LAMOST's large-scale sky survey allow astronomers to use the direction of sight monitoring method to find compact objects such as static black holes and neutron stars, breaking the observation limit of relying on X-rays to search for compact objects.
Series 4: Search for rare "stars" in the universe. In the vast universe, there are always some extraordinary celestial objects - strange and rare "stars". How to find out these rare objects? LAMOST provides the most comprehensive data for the "Star Sea Treasure" - in 2022, taking advantage of the LAMOST sky survey, astronomers discovered nine rare ultra-rich lithium dwarfs at one time. Until now, astronomers had only discovered four similar super-rich lithium dwarfs. Extremely cold dwarfs, extremely poor metal stars, high-speed stars, ultra-high-speed stars... These new discoveries are enriching people's understanding of the universe.
Series 5: Capturing information from the distant universe. Quasars are the brightest continuously luminous objects in the universe and are important probes for studying the distant universe. To date, the total number of quasars identified by LAMOST has reached 56,176, of which 24,127 were first discovered by LAMOST. This makes LAMOST the second largest quasar survey in the world. In 2022, astronomers discovered 1,547 compact galaxies in the LAMOST massive spectrum, of which 1,417 were newly discovered, including a large number of green pea, blueberry and purple grape galaxies. The farthest of these galaxies is about 9 billion light-years from Earth. This is the largest number of compact galaxies ever discovered at one time.
It is reported that the second phase of the LAMOST spectral survey mission will end in June 2023, and the third phase of the spectrum survey is scheduled to start in September 2023. At the beginning of 2023, the LAMOST DR8 spectroscopy database has been integrated with the CasJobs data system of the Sloan Digital Sky Survey Project (SDSS) in the United States, which is another cooperation between LAMOST spectroscopic database and the top international scientific data platform, which will significantly broaden the depth and breadth of LAMOST data use and further enhance LAMOST's international status and influence. Watching the starry sky, LAMOST will make more Chinese contributions to human exploration of the universe!
(Beijing, March 31 -- Qi Fang, reporter of this newspaper)
Source: Guangming Daily