WO2014050024A1

WO2014050024A1 - Composite cosmic-ray-observation system

Info

Publication number: WO2014050024A1
Application number: PCT/JP2013/005501
Authority: WO
Inventors: 利貴國澤
Original assignee: Ｎｅｃ東芝スペースシステム株式会社
Priority date: 2012-09-25
Filing date: 2013-09-18
Publication date: 2014-04-03
Also published as: JPWO2014050024A1

Abstract

[Problem] To unitarily acquire and manage different observation data of cosmic rays to improve data reliability. [Solution] A composite cosmic-ray-observation system is configured from: an X-ray observation unit including an X-ray telescope mounted to an artificial satellite; a gamma-ray observation unit including a Cherenkov telescope disposed above ground; and a data management unit which gathers data observed by the X-ray telescope and the Cherenkov telescope, and coordinates and manages said data.

Description

Cosmic ray combined observation system

The present invention relates to a cosmic ray combined observation system.

Cosmic rays such as electron beams, X-rays, and γ rays are emitted from celestial bodies. Therefore, in the study of the existence of celestial bodies and the space structure, these cosmic rays are observed (see “0003” to “0029” etc. in Patent Document 1). At this time, an X-ray telescope is used for X-ray observation, and a Cherenkov telescope is used for γ-rays.

The X-ray telescope is operated in outer space, and the Cherenkov telescope is installed and operated on the ground. In the current operation mode, these linkages are not performed. That is, the X-ray telescope and the Cherenkov telescope are operated independently of each other. For this reason, the authenticity of the observation data by the X-ray telescope needs to be determined by observing a large number of data by the X-ray telescope. Similarly, the authenticity of observation data by the Cherenkov telescope needs to be determined by observing a large number of data by the Cherenkov telescope.

However, if both X-rays and γ-rays are cosmic rays emitted from the same celestial body, the X-ray telescope data and the Cherenkov telescope data have characteristics that can complement each other.

FIG. 7 is a diagram showing a wavelength spectrum with respect to the energy band of such X-rays and γ-rays. Curve C1 in FIG. 7 is an X-ray wavelength spectrum, and the energy band is as narrow as several hundred eV to several MeV. On the other hand, the curve C2 is a wavelength spectrum of γ-rays, and the energy band is as wide as several GeV to several TeV, up to about 10 ²⁰ eV.

As described above, the X-ray telescope that observes cosmic rays in outer space has a merit that it can observe the primary cosmic rays directly, although it has a narrow energy band, but has excellent energy resolution. In contrast, the atmospheric Cherenkov telescope that can be installed on the ground has a wide observable energy band.

JP 2011-180069 A

Although X-rays and γ-rays have different wavelength spectra in this way, the observation of astronomical objects is operated without cooperation between the X-ray telescope and the γ-ray telescope. There is a problem that cannot promote research such as.

The biggest reason why the observation data between the X-ray telescope and the γ-ray telescope is not linked is that the installation of the X-ray telescope and the Cherenkov telescope requires a huge installation cost and a long installation time. Can be mentioned.

Therefore, enabling the operation of the X-ray telescope and the Cherenkov telescope, which are currently operated independently, can promote research on celestial bodies and space structures while effectively utilizing the facilities. it can.

Therefore, a main object of the present invention is to provide a cosmic ray combined observation system capable of improving the reliability of data by centrally acquiring and managing observation data of different cosmic rays.

In order to solve the above problems, a cosmic ray combined observation system includes an X-ray observation unit including an X-ray telescope mounted on an artificial satellite, a γ-ray observation unit including a Cherenkov telescope installed on the ground, an X-ray telescope, A data management unit that collects data observed by the Cherenkov telescope and manages the data by associating these data with each other.

According to the present invention, since the observation data of different cosmic rays observed by the X-ray telescope and the Cherenkov telescope are acquired and managed in a unified manner, the reliability of the data is improved.

1 is a schematic diagram of a cosmic ray composite observation system according to a first embodiment of the present invention. It is a block diagram of a cosmic ray composite observation system. It is the schematic of the cosmic-ray composite observation system concerning 2nd Embodiment of this invention. It is the schematic diagram which showed the relationship between an image parameter and a shower. It is the figure which illustrated the shower shape by a gamma ray. It is the figure which illustrated the shower shape by a proton. It is a figure which shows the energy zone | band of a X-ray and a gamma ray.

A first embodiment of the present invention will be described. FIG. 1 is a schematic diagram of a cosmic ray combined observation system 2A using an X-ray telescope and an atmospheric Cherenkov telescope according to the present embodiment. FIG. 2 is a block diagram of the cosmic ray composite observation system 2A. In FIG. 1, the symbol E indicates the earth. Further, symbol P1 indicates a celestial body that can be viewed from the northern hemisphere, and symbol P2 indicates a celestial body that can be viewed from the southern hemisphere.

The cosmic ray combined observation system 2A includes a data management unit 11, a γ-ray observation unit 12, and an X-ray observation unit 14.

The γ-ray observation unit 12 includes a northern γ-ray observation unit 12a installed in the northern hemisphere for observing northern celestial bodies, and a southern γ-ray observation unit 12b installed in the southern hemisphere for observing southern celestial bodies. It is out. The north sky γ-ray observation unit 12a and the south sky γ-ray observation unit 12b are each constituted by an atmospheric Cherenkov telescope.

The reason why the gamma ray observation unit 12 is composed of the north sky gamma ray observation unit 12a and the south sky gamma ray observation unit 12b is to enable all sky observation. Therefore, when only the northern sky (south sky) is observed, it is not necessary to install it in the southern hemisphere (north hemisphere). However, for the purpose of the present invention, it is necessary to provide one or more units in either the northern hemisphere or the southern hemisphere.

With such an atmospheric Cherenkov telescope, cosmic rays (γ rays) in the energy band of several GeV to several TeV and about 10 ²⁰ eV at the maximum are observed.

Then, the observed data is transmitted to the data management unit 11 on the ground via wireless communication or a network line.

The X-ray observation unit 14 is composed of an X-ray telescope mounted on an artificial satellite flying along the polar orbit B. With this X-ray telescope, cosmic rays (X-rays) in the observation energy band of several hundred eV to several MeV are observed.

Since the X-ray telescope is mounted on an artificial satellite that flies along the polar orbit B, the relative longitude with the atmospheric Cherenkov telescope is always the same.

As described above, the γ-ray observation unit 12 is installed on the ground, and the X-ray telescope 14 is installed in outer space. Especially, the increase / decrease in the number of installed atmospheric Cherenkov telescopes 12, change / maintenance of the observation energy band, etc. There is an advantage that it can be easily performed compared to the X-ray telescope.

The data management unit 11 includes a request reception unit 11a, a search unit 11b, an observation condition setting unit 11c, a storage unit 11d, and a storage unit 11e. The data observed by the X-ray observation unit 14 and the γ-ray observation unit 12 is stored in the storage unit 11e under a predetermined condition, and the data stored in response to a request from a user such as a researcher is stored. provide. Further, when the user requests observation of a specific celestial body, the X-ray observation unit 14 and the γ-ray observation unit 12 are made to observe based on this request.

The request reception unit 11a receives a data request and an observation request from a user. When this request requires provision of data stored in the storage unit 11e, data identification information (eg, observation date, direction, etc.) included in the data request is extracted, and this data identification information is extracted. The data search command including it is output to the search unit 11b.

If the user requests observation, the observation condition information (for example, observation date, direction, etc.) is extracted from the observation request, and an observation command including this observation condition information is output to the observation condition setting unit 11c. To do.

The search unit 11b receives the data search command from the request reception unit 11a, searches the storage unit 11e based on the data identification information included in the data search command, reads out the corresponding data, and outputs it to the request reception unit 11a. To do.

The observation condition setting unit 11c receives the observation command from the request receiving unit 11a and extracts the observation condition information included in this observation example. And based on the observation schedule memorize | stored internally, it is judged whether the observation requested | required by observation condition information is possible. When it is determined that the observation is possible, it is determined whether the observation is performed by the north sky γ-ray observation unit 12a or the south sky γ-ray observation unit 12b. In the following description, it is assumed that the north sky γ-ray observation unit 12a determines that observation is possible.

When the observation condition setting unit 11c determines that the observation is possible, the observation condition setting unit 11c outputs an observation request acceptance signal indicating that the observation request is accepted to the request reception unit 11a, and the X-ray observation unit 14 and the corresponding γ-ray observation unit 12 An observation schedule update request is output to the north sky γ-ray observation unit 12a based on the above assumption.

The storage unit 11d stores the data observed by the X-ray observation unit 14 and the γ-ray observation unit 12 in the storage unit 11e. At this time, correspondence between data from the X-ray observation unit 14 (hereinafter referred to as X-ray observation data) and data from the γ-ray observation unit 12 (hereinafter referred to as γ-ray observation data) is performed.

This association has the following meaning. That is, high-energy electrons emitted from the celestial body become X-rays of several hundred eV to several MeV by synchrotron radiation. There are cases where the X-rays reach the vicinity of the earth as they are, and cases where the X-rays are bounced up to about several GeV to several TeV or more by inverse Compton scattering to become γ-rays. Therefore, when cosmic rays from the same date and direction are observed by X-ray observation and γ-ray observation, these X-ray observation and γ-ray observation can observe cosmic rays from the same object. High nature.

At this time, since the X-ray observation unit 14 is mounted on an artificial satellite flying in a polar orbit in outer space and the γ-ray observation unit 12 is installed on the ground, the X-ray observation unit 14 is relative to the γ-ray observation unit 12. The target position is constantly changing. Therefore, even if the X-ray observation unit 14 and the γ-ray observation unit 12 observe cosmic rays from the same celestial body, the observation time and the observation direction are different.

Therefore, when the storage unit 11d receives the X-ray observation data and the γ-ray observation data, the storage unit 11d converts each observation time and observation direction into an absolute time and an orientation in an absolute space and stores them. Thereby, the correspondence between the X-ray observation data and the γ-ray observation data is performed.

As described above, simultaneous observation and data utilization of different types of cosmic rays or cosmic rays having different energy ranges can be easily performed on the same celestial body. Therefore, the reliability of the results of those researches is improved.
Second Embodiment
Next, a second embodiment of the present invention will be described. In addition, about the same structure as 1st Embodiment, description is abbreviate | omitted suitably using the same code | symbol. In the first embodiment, the observation data obtained by the γ-ray observation unit 12 and the observation data obtained by the X-ray observation unit 14 are converted into absolute time and orientation in absolute space and stored. The stored data is provided in response to requests from users such as researchers.

However, it is rare that the γ-ray observation unit 12 and the X-ray observation unit 14 simultaneously observe γ-rays and X-rays from the same object. For this reason, even if the data of the observation data in the γ-ray observation unit 12 and the observation data in the X-ray observation unit 14 are coordinated, there may be a case in which data by one observation unit does not exist. Of course, when the user designates the same celestial body and requests observation from the X-ray observation unit 14 and the γ-ray observation unit 12, both data exist.

Therefore, in the present embodiment, when one observation unit observes cosmic rays, the other observation unit also automatically performs observation on a celestial body in the direction emitting the cosmic rays. In the following example, one observation unit will be described as a γ-ray observation unit 12 and the other observation unit as an X-ray observation unit 14.

FIG. 3 is a block diagram of the cosmic ray composite observation system 2B according to the present embodiment. This cosmic ray combined observation system 2B has a configuration in which an analysis unit 11f is added to the cosmic ray combined observation system 2A of the previous embodiment.

Then, when new observation data from the γ-ray observation unit 12 is stored in the storage unit 11e via the storage unit 11d, the analysis unit 11f analyzes the shower shape based on the observation data, and the γ-ray observation unit 12 It is determined whether the data observed in step 1 is from γ rays.

Specific explanation. The atmospheric Cherenkov telescope in the γ-ray observation unit 12 detects Cherenkov light collected by the reflecting mirror using a plurality of photomultiplier tubes. Therefore, the analysis unit 11f restores the shape of the image captured by the photomultiplier tube from the observation data received from the storage unit 11d. Then, the determination of whether the parent particle that has caused the air shower is a proton or an atomic nucleus or a gamma ray is performed using an imaging method.

The parameters used in this imaging method include the shower shape of the photon distribution in the field of view, the center of gravity angle α, the width w, the length L, the center distance D, and the like that represent the direction. FIG. 4 is a schematic diagram showing the relationship between these parameters and the shower. The width w is the standard deviation in the minor axis direction when the shower shape is approximated by an ellipse (dotted ellipse in FIG. 4), the length L is the standard deviation in the major axis direction of the ellipse, and the center distance D is the shower center of gravity (P2) And the center of the visual field (P1). The centroid angle α is an angle formed by a straight line (P4) connecting the shower centroid (P2) and the visual field center (P1) and a long axis (P3) of the shower shape approximated by an ellipse.

The shower shape of incident cosmic rays (primary particles) varies depending on whether they are hadrons or gamma rays. Therefore, the analysis unit 11f determines whether γ rays have been observed from the restored shower shape. FIG. 5 shows a shower shape by γ rays, and FIG. 6 shows a shower shape by protons. The closed curve in each figure shows an equal energy region, and the inner closed curve has higher energy.

The shower shape by γ rays is elliptical, but the proton shower shape is generally circular. Accordingly, the closed curve is approximated to an ellipse, and when the ratio of the short axis to the long axis (short axis / long axis) is equal to or less than a predetermined value, it is determined as γ-ray. That is, it is determined from the flatness of the ellipse.

When it is determined that γ rays have been observed in this way, the analysis unit 11f notifies the observation condition setting unit 11c of the observation direction. When the observation condition setting unit 11c receives the observation azimuth information from the analysis unit 11f, the observation condition setting unit 11c instructs the X-ray observation unit 14 to perform observation.

As a result, the observation of the cosmic ray observed in one observation unit can be automatically performed in the other observation unit, and the observation data of γ rays and X-rays are associated and stored in the storage unit. become able to.

This application claims priority based on Japanese Patent Application No. 2012-211030 filed on Sep. 25, 2012, the entire disclosure of which is incorporated herein.

2 Cosmic Ray Combined Observation System 11 Data Management Unit 11a Request Reception Unit 11b Search Unit 11c Observation Condition Setting Unit

11d Storage Unit

11e Storage Unit

11f Analysis Unit 12 γ-ray Observation Unit 12a Northern Sky γ-ray Observation Unit 12b Southern Sky γ-ray Observation Unit

Claims

X-ray observation means including an X-ray telescope mounted on an artificial satellite;
Γ-ray observation means including the Cherenkov telescope installed on the ground,
A cosmic ray composite observation system comprising: data management means for collecting data observed by the X-ray telescope and the Cherenkov telescope and managing the data by associating these data.
The cosmic ray composite observation system according to claim 1,
The γ-ray observing means is a north-sky γ-ray observing means for observing γ-rays from a celestial body located in the northern sky,
A cosmic ray combined observation system, comprising at least one of γ-ray observation means for observing γ-rays from celestial bodies located in the southern sky.
The cosmic ray composite observation system according to claim 1 or 2,
The cosmic ray combined observation system, wherein the artificial satellite equipped with the X-ray telescope flies in a polar orbit.
The cosmic ray composite observation system according to any one of claims 1 to 3,
The data management means includes storage means for storing X-ray observation data acquired by the X-ray observation means and γ-ray observation data acquired by the γ-ray observation means;
Storage means for collecting the X-ray observation data and the γ-ray observation data, associating them, and storing them in the storage means;
A request accepting means for accepting a data request indicating an external data request or an observation request for requesting observation;
A cosmic ray composite observation system, comprising: search means for retrieving data corresponding to the data request from the storage means when the request accepting means accepts the data request.
The cosmic ray composite observation system according to any one of claims 1 to 4,
An observation condition setting unit that manages an observation schedule performed by the X-ray observation unit and the γ-ray observation unit and causes the X-ray observation unit and the γ-ray observation unit to perform observation based on the observation schedule is provided. Cosmic ray combined observation system.
The cosmic ray composite observation system according to claim 5,
The observation condition setting unit, when receiving an observation request from the request reception unit, updates the observation schedule when responding to the observation request by checking the observation request with the observation schedule. Cosmic ray combined observation system.
The cosmic ray composite observation system according to any one of claims 1 to 6,
When one of the γ-ray observing means or the X-ray observing means observes cosmic rays, it is determined whether the observed observing means is a cosmic ray that should be observed, and should be observed originally In the case of cosmic rays, the cosmic ray composite observation system includes an analysis unit that instructs the other observation means to perform observation by instructing the observation direction.
The cosmic ray composite observation system according to claim 7,
A cosmic ray combined observation system, wherein the observation means determines whether or not a cosmic ray is to be observed from the flatness of a shower shape based on an image method.