A large high-altitude air-shower observatory (LHAASO)

A massive high-altitude air-shower observatory (LHAASO) is currently under construction at Shangri-La in Yunnan Province, China. The massive high-altitude air-shower Observatory is dedicated to developing sub-TeV gamma astronomy (Zhen 249). The proposed water Cherenkov detector array is a key component of the LHAASO mission (WCDA). It will serve as the foundation for a complete knowledge of the water Cherenkov method, as well as for studying astronomical problems and predicting air showers. The construction of the water Cherenkov detector array has been in sporadic operation in the sequence of the experiment since August 2011. (Cui et al. 88). It has helped in obtaining data, such as the cosmic muon signals and the counting rates of the PMTs (Cui et al. 89). The project contains a prototype array at 1% scale of the LHAASO-WCDA at Tibet, China (Zhen 249). Therefore, this study introduces a large high-altitude air-shower observatory (LHAASO) as a contemporary innovating in the field of autonomy and delineates its structure, associated components and its viability in the modern world of astronomy.

The Origin of Cosmic Rays:

Cosmic Rays for Large High Altitude Air Shower Observatory exist in the Non-thermal spectrum with few breaks. Cosmic Rays are usually suspected to originate from the Galaxy supernova remnants, and it takes ten percent of the kinetic energy converted into accelerated particles through diffusive shock (Zhen 249). According to Zhen (249), Cosmic Rays have a difficult to accelerate above 10 eV in SNRs. However, usual suspects above 10 eV include the extragalactic objects such as Gamma Ray Bursts or Active Galactic Nuclei. Therefore, the Scientific Motivation for Cosmic Ray Studies for LHAASO tracks back to the origin of Cosmic Rays with High Energy Gamma Rays (Cui et al. 89)

The Sky Maps of Cosmic Rays reveals that at higher energies, the statistics are more limited meaning that the setting of the upper limits. Also, at low energies, higher order multiple and significant dipoles have been observed (Zhen 249). Furthermore, at the highest energies, some correlations with the nearby extragalactic matter have been establishing, but the identification of sources remains unknown (Zhen 249). High-Energy Gamma Rays Counterpart of accelerated electrons (inverse Compton scattering, Bremsstrahlung) provides few pieces of evidence with current data, however, at TeV energies, there is the discovery of the~120 sources, but still, there a Crucial need to get more sources of phenomena such as cut-off above 100 TeV and spectral index.

Science Goals of a Wide-Field Instrument

The research seeks to address the Galactic Cosmic Ray Origins, which is to evaluate Galactic Diffuse Emission and the root source of Highest Energies in Gamma Rays. Another goal is to examine the Particle Acceleration in Jets (Cao, Zhen, and LHAASO 99). In this section, it focuses on the Ray Bursts at Highest Energies, the AGN Flaring, and the analysis of the Multi-wavelengths and multi-messenger campaigns. Additionally, LHAASO seeks to focus on complete all-sky survey γ-ray astronomy in the ~100 GeV-~1 PeV range (Gong et al. 1). That is, the high sensitivity and energy resolution, γ-hadron discrimination power, sources and energy spectrum, full duty cycle, wide FOV and sensitivity-transient, and the high angular resolution (Cui et al. 86-92). Finally, the project examines the Cosmic ray detection between 10 TeV and 100 PeV (Zhen 249). In this section, it seeks to Bridge between balloon-borne measurements or space and ground-based UHECR measurements, and unprecedented statistics for anisotropy studies in the knee region (Zhen 249).

Observations

The Large High Altitude Air Shower Observatory (LHAASO) project is a new cohort all-sky tool to examine the 'cosmic ray connection' over a joint study of gamma-rays and cosmic rays and in the full energy range of 1011 to 1017 eV. The primary phase of LHAASO consists of a 1 km2 array (LHAASO-KM2A), comprising 5635 scintillator detectors, with 15 m spacing, for detection of the electromagnetic particle(Cui et al. 86-92). Also, it contains an overlapping 1 km2 array of 1221 eV, 36 m2 underground water Cherenkov tanks, with 30 m spacing, for detecting the muon (hence the general sensitive area is 40,000 m2) (Zhen 249). Additionally, the LHAASO has a surface water Cherenkov detector facility which is close-packed with an area of 90,000 m2 (LHAASO-WCDA), which is four times that of HAWC. Additionally, it contains a fluorescence lenses and a 24 wide field-of-view air Cherenkov with 452 close-packed burst detectors, sited close to the Centre of the array, for detection of high energy secondary particles in the shower core region (LHAASO-SCDA) (Gong et al. 1).

Conclusion

LHAASO is anticipated to be the most sensitive mission to counter the built-up hitches in the Galactic cosmic ray physics through a joint study of charged-particle-induced extensive air showers and photon in the energy series of 1011 - 1017 eV (Zhen 249). The new cohort multi-component project will be able to continually survey the gamma-ray sky for transient and steady sources from 100 GeV to PeV energies, hence initiating for the first time the 102-103 TeV range to the straight interpretations of the high power sources of the cosmic ray. Also, the various observables (electronic, Cherenkov components, and muonic) that will be measured and recorded in the LHAASO will foster the examination of the propagation, acceleration, and origin of the radiation through a measurement of the energy spectrum, elemental composition, and anisotropy with exceptional resolution (Cao, Zhen, & LHAASO 95-98). It is worth noting that LHAASO can address the problems of cosmic ray physics at the same time. It is also essential to conclude that, LHAASO is a fundamental tool of high sensitivity that can operate unprecedented above 30 TeV to monitor the gamma sky permanently (Cui et al. 71).

Future work

Gamma ray source discovery of above 30 TeV is an inspiring methodology for the discovery of galactic cosmic radiation sources. The sky survey for gamma ray uses the wide field of view detector that is vital for people to accumulate numerous types of sources above 100 GeV. There is the need for further study to add powerful and Magic II-type telescopes in the proposed array to meet the goals of the A Large High Altitude Air Shower Observatory (Cao, Zhen, & LHAASO 95-98). The telescopes will boost the LHAASO in the source of morphologic investigation power (Gong et al. 1). Also, there is a future need to re-configure the field of view of the telescopes into suitable fluorescence light detector array to cover wider energy region above 100 PeV where the second knee point (Gong et al. 1)

Comments

LHAASO is a compact scheme, which fuels from a scientific society whose proficiency in the arena of high energy physics which is widely recognised and well-established. The experiment has very stimulating projections, being able to address all the major problems of cosmic ray physics at the same time. It is important to examine the Cosmos Rays in an original wide energy series 1011 - 1018 eV, from those visible in-universe with AMS and impending those reviewed by AUGER. Therefore, including, in addition to the 'knee', the whole region between 'knee' and 'ankle' where there is an expectation of the galactic/extra-galactic Cosmos Ray transition. At the same time it is proposed as a tool of high sensitivity - unprecedented above 30 TeV - to monitor 'all the sky all the time' a gamma-ray domain incredibly full of sources variable at all wavelengths (Cao, Zhen, & LHAASO 91). The experimental studies in the LHAASO are complementary with those of other Astroparticle Physics INFN programs (AMS, AUGER, JEM-EUSO, Fermi, CTA, Neutrino telescope), and will extend, clarify and deepen the Science developed by these programs (Cui et al. 90). The vast potential physics reach of LHAASO makes this experiment very attractive. The perspectives for an INFN participation of significant impact are very promising, solidly grounded in previous expertise.

There is an outstanding need determine the location, the information about the parent composition, and detect the wavelength of the rays so as to establish potential sources of the cosmos rays (Cui et al. 90). Finally, it is important to comment that the prototype array of water Cherenkov detectors has adequately reconstructed and detected shower events (Cao, Zhen, and LHAASO 96). Analysis of the data from the prototype array of water Cherenkov detectors together with the results of the ARGO-YBJ experiment shows that the angular resolution on detecting showers for the prototype array is within projects prospects, this indicates that there is no problem in the time measurements of the project (Cao, Zhen, and LHAASO 97). Therefore, LHAASO's location and its condensed structure of sensor arrays give it an unprecedented ability to spot ultra-high-energy γ-rays.

Work Cited

Cao, Zhen, and LHAASO collaboration. "Status of LHAASO updates from ARGO-YBJ." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 742 (2014): 95-98.

Cui, Shuwang, et al. "Simulation on gamma ray astronomy research with LHAASO-KM2A." Astroparticle Physics 54 (2014): 86-92.

Gong, Guanghua, et al. "Sub-nanosecond timing system design and development for LHAASO project." Proceedings of ICALEPCS2011, Grenoble, France (2011).

Zhen, C. A. O. "A future project at tibet: the large high altitude air shower observatory (LHAASO)." Chinese physics C 34.2 (2010): 249.