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We study the luminosity function of long gamma-ray bursts (LGRBs) using the peak flux obtained from three LGRB samples with known redshifts: (a) a sample of 251 LGRBs from the Swift/BAT satellite/instrument; (b) a sample of 37 LGRBs from the Fermi/GBM telescope; (c) a sample of 152 GRBs from the Konus-Wind instrument. For the Swift/BAT and Fermi/GBM samples, we use data available on the Swift Burst Analyser websites (http://www.swift.ac.uk/burst%5fanalyser; (Evans at al. in Astron. Astrophys. 519:102, 2010)) and (http://swift.gsfc.nasa.gov/archive/grb/table/) and on the Fermi website (https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html; (Gruber et al. in Astrophys. J. Suppl. Ser. 211(1):12, 2014; von Kienlin et al. in Astrophys. J. Suppl. Ser. 211(1):13, 2014; Bhat et al. in Astrophys. J. Suppl. Ser. 223(2):28, 2016)) to calculate the luminosity at the peak of the flux by using a cut-off power-law spectrum (CPL). For the Konus-Wind sample, we use the Yonetoku correlation relationship (Yonetoku et al. in Publ. Astron. Soc. Jpn. 62:1495, 2010) to determine the isotropic luminosity from the energy at the peak of the flux measured in the source frame (Minaev and Pozanenko in Mon. Not. R. Astron. Soc. 492(2):1919, 2019). With these three samples (totalling 439 GRBs), we use the Monte Carlo method to synthesize 10,000 "artificial" GRBs similar to each real GRB by considering that each physical quantity observed obeys a normal distribution, where the tabulated value and uncertainty represent the mean and the 3 σ error. The results obtained for the luminosity function from our data samples are consistent with those published in previous works. [ABSTRACT FROM AUTHOR]

We are developing and operating the automatic telescope Aoyama Gakuin University Robotic Optical Monitor for Astrophysical objects (AROMA) in the Sagamihara Campus of Aoyama Gakuin University. AROMA is composed of two observational equipments, AROMA-N and AROMA-W. AROMA-N is a 30-cm aperture telescope system for rapid follow-up observations of the optical afterglow of gamma-ray bursts. Automatic analysis pipeline for AROMA-N has been developed and is working. The other observational equipment AROMA-W is a wide-field observation system using multiple digital single-lens reflex cameras. It covers a large FOV of about 35° × 25°. AROMA-W provides photometric data in four bands with a limiting V magnitude of about 12-13 mag. Software to analyze massive image data automatically is being developed. We plan to monitor the luminosities of all the stars in the FOV of AROMA-W, detect optical transients, and trigger a follow-up observation with AROMA-N. We report on the development status and observational results of AROMA. [ABSTRACT FROM AUTHOR]

The gravitational wave/γ-ray burst GW/GRB170817 event marked the beginning of the era of multi-messenger astrophysics, in which new observations of Gravitational Waves (GW) are combined with traditional electromagnetic observations from the very same astrophysical source. In the next few years, Advanced LIGO/VIRGO and KAGRA in Japan and LIGO-India will reach their nominal/ultimate sensitivity. In the electromagnetic domain, the Vera C. Rubin Observatory and the Cherenkov Telescope Array (CTA) will come online in the next few years, and they will revolutionize the investigation of transient and variable cosmic sources in the optical and TeV bands. The operation of an efficient X-ray/γ-ray all-sky monitor with good localisation capabilities will play a pivotal role in providing the high-energy counterparts of the GW interferometers and Rubin Observatory, bringing multi-messenger astrophysics to maturity. To reach the required precision in localisation and timeliness for an unpredictable physical event in time and space requires a sensor distribution covering the whole sky. We discuss the potential of large-scale, small-platform-distributed architectures and constellations to build a sensitive X-ray/γ-ray all-sky monitor and the programmatic implications of this, including the set-up of an efficient assembly line for both hardware development and data analysis. We also discuss the potential of a constellation of small platforms operating at other wavelengths (UV/IR) that are capable of repointing quickly to follow-up high-energy transients. [ABSTRACT FROM AUTHOR]