Posts
November 14, 2017 (JST)
Chemical make-ups of the Sun and a cluster of galaxies are similar
The observations made by the Soft X-ray Spectrometer (SXS) flown on the X-ray astronomical satellite ASTRO-H ("Hitomi") show that the proportions of iron-peak elements in the Perseus cluster are nearly identical to those measured in the Sun, unlike previously believed. The new research results suggest that the solar abundance of the chemical elements represents the average values of the neighboring universe. In addition, this study provides new insights into the mechanism of Type Ia supernova explosions, which are thought to be the major producers of the iron-peak elements. The SXS developed jointly by NASA and the Japan Aerospace Exploration Agency (JAXA) and their partners in Europe has provided an unprecedented detail of chemical make-ups of the hot gas in the neighboring universe.
The results are to be published in Nature online on November 13, 2017.
A cluster of galaxies contains hundreds of galaxies orbiting within hot (higher than millions of degrees Kelvin) plasma. From the beginning of the universe, the hot plasma in the cluster preserves the elements produced in the stars and supernova explosions, indicating that the hot plasma in a cluster can give the average chemical abundance in the current universe. Supernova explosions are categorized into several types. Of these, Type Ia supernova explosions are estimated to comprise 10%?40% of the total number of supernova explosions and are thought to be responsible for producing the majority of the iron-peak elements, including chromium, manganese, iron, and nickel. Different mechanisms of Type Ia explosions result in different abundance ratios of the iron-peak elements. Therefore, the chemical make-up of the iron-peak elements assists us in understanding the mechanism of Type Ia explosions and their progenitors.
Hot plasma in the clusters of galaxies has been intensively investigated to derive its chemical abundances. However, previous estimations are disputed because existing instruments did not have sufficient spectral resolution, and the characteristic X-ray emission of nickel is mixed with the strong characteristic X-ray emission of iron. This hampers the accurate measurements of the abundances of nickel and iron.
A research team led by Hiroya Yamaguchi (University of Maryland and Goddard NASA) and Kyoko Matsushita (Tokyo University of Science) analyzed data from the center of the Perseus cluster observed by ASTRO-H and successfully estimated the abundances the iron-peak elements based on the individual strengths of their characteristic X-rays. The unprecedented high-energy resolution of SXS enabled the resolution of the characteristic X-rays of iron and nickel.
Moreover, the team was able to detect weak chromium and manganese emission lines. The analysis showed that the abundance ratios of silicon, sulfur, argon, calcium, chromium, manganese, iron, and nickel are all same as those of the Sun despite these abundance ratios being believed to be higher than the solar value.
More to read
http://global.jaxa.jp/press/2017/11/20171114_hitomi.html#para2
Figure 1. The soft X-ray spectrometer onboard ASTRO-H acquired data from two overlapping regions in the center of the Perseus cluster (indicated by blue outlines) in February and March of 2016. The resulting spectrum has 30 times the detail of any previously captured X-ray spectra, demonstrating clear X-ray emission lines associated with chromium, manganese, nickel, and iron. The yellow line shows a spectrum obtained previously via a CCD instrument.
http://global.jaxa.jp/press/2017/11/20171114_hitomi.html#image1
Figure 2. Similar to Figure 1; however, this figure includes two small panels that compare the observational data (indicated by white lines) and theoretical expectations (indicated by red lines) of two important spectral regions in this study.
http://global.jaxa.jp/press/2017/11/20171114_hitomi.html#image2
Publication: Nature Astronomy (2017)
Published on line: 13 November 2017
Published: November 23 issue (UK time)
Title: Solar Abundance Ratios of the Iron-Peak Elements in the Perseus Cluster
Authors: Hitomi collaboration
Responsible author: Hiroya Yamaguchi, Kyoko Matsushita
doi: 10.1038/nature24301
URL:
http://global.jaxa.jp/press/2017/11/20171114_hitomi.html
National Research and Development Agency Japan Aerospace Exploration Agency (JAXA)
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Publisher :
Public Affairs Department
Japan Aerospace Exploration Agency (JAXA)
Ochanomizu sola city,
4-6 Kandasurugadai, Chiyoda-ku, Tokyo 101-8008 Japan
TEL:+81-3-5289-3650
JAXA WEB SITE :
http://global.jaxa.jp/
Chemical make-ups of the Sun and a cluster of galaxies are similar
The observations made by the Soft X-ray Spectrometer (SXS) flown on the X-ray astronomical satellite ASTRO-H ("Hitomi") show that the proportions of iron-peak elements in the Perseus cluster are nearly identical to those measured in the Sun, unlike previously believed. The new research results suggest that the solar abundance of the chemical elements represents the average values of the neighboring universe. In addition, this study provides new insights into the mechanism of Type Ia supernova explosions, which are thought to be the major producers of the iron-peak elements. The SXS developed jointly by NASA and the Japan Aerospace Exploration Agency (JAXA) and their partners in Europe has provided an unprecedented detail of chemical make-ups of the hot gas in the neighboring universe.
The results are to be published in Nature online on November 13, 2017.
A cluster of galaxies contains hundreds of galaxies orbiting within hot (higher than millions of degrees Kelvin) plasma. From the beginning of the universe, the hot plasma in the cluster preserves the elements produced in the stars and supernova explosions, indicating that the hot plasma in a cluster can give the average chemical abundance in the current universe. Supernova explosions are categorized into several types. Of these, Type Ia supernova explosions are estimated to comprise 10%?40% of the total number of supernova explosions and are thought to be responsible for producing the majority of the iron-peak elements, including chromium, manganese, iron, and nickel. Different mechanisms of Type Ia explosions result in different abundance ratios of the iron-peak elements. Therefore, the chemical make-up of the iron-peak elements assists us in understanding the mechanism of Type Ia explosions and their progenitors.
Hot plasma in the clusters of galaxies has been intensively investigated to derive its chemical abundances. However, previous estimations are disputed because existing instruments did not have sufficient spectral resolution, and the characteristic X-ray emission of nickel is mixed with the strong characteristic X-ray emission of iron. This hampers the accurate measurements of the abundances of nickel and iron.
A research team led by Hiroya Yamaguchi (University of Maryland and Goddard NASA) and Kyoko Matsushita (Tokyo University of Science) analyzed data from the center of the Perseus cluster observed by ASTRO-H and successfully estimated the abundances the iron-peak elements based on the individual strengths of their characteristic X-rays. The unprecedented high-energy resolution of SXS enabled the resolution of the characteristic X-rays of iron and nickel.
Moreover, the team was able to detect weak chromium and manganese emission lines. The analysis showed that the abundance ratios of silicon, sulfur, argon, calcium, chromium, manganese, iron, and nickel are all same as those of the Sun despite these abundance ratios being believed to be higher than the solar value.
More to read
http://global.jaxa.jp/press/
Figure 1. The soft X-ray spectrometer onboard ASTRO-H acquired data from two overlapping regions in the center of the Perseus cluster (indicated by blue outlines) in February and March of 2016. The resulting spectrum has 30 times the detail of any previously captured X-ray spectra, demonstrating clear X-ray emission lines associated with chromium, manganese, nickel, and iron. The yellow line shows a spectrum obtained previously via a CCD instrument.
http://global.jaxa.jp/press/
Figure 2. Similar to Figure 1; however, this figure includes two small panels that compare the observational data (indicated by white lines) and theoretical expectations (indicated by red lines) of two important spectral regions in this study.
http://global.jaxa.jp/press/
Publication: Nature Astronomy (2017)
Published on line: 13 November 2017
Published: November 23 issue (UK time)
Title: Solar Abundance Ratios of the Iron-Peak Elements in the Perseus Cluster
Authors: Hitomi collaboration
Responsible author: Hiroya Yamaguchi, Kyoko Matsushita
doi: 10.1038/nature24301
URL:
http://global.jaxa.jp/press/
National Research and Development Agency Japan Aerospace Exploration Agency (JAXA)
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Publisher :
Public Affairs Department
Japan Aerospace Exploration Agency (JAXA)
Ochanomizu sola city,
4-6 Kandasurugadai, Chiyoda-ku, Tokyo 101-8008 Japan
TEL:+81-3-5289-3650
JAXA WEB SITE :
http://global.jaxa.jp/
No comments:
Post a Comment