TY - JOUR AU - Pintér, Sándor AU - Balázs, Lajos AU - Bagoly, Zsolt AU - Tóth, László Viktor AU - Rácz, István AU - Horváth, István TI - Some statistical remarks on GRBs jointly detected by Fermi and Swift satellites JF - MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY J2 - MON NOT R ASTRON SOC VL - 527 PY - 2024 IS - 3 SP - 8931 EP - 8940 PG - 10 SN - 0035-8711 DO - 10.1093/mnras/stad3236 UR - https://m2.mtmt.hu/api/publication/34418073 ID - 34418073 N1 - A TKP2021-NVA-16 számú projekt a Kulturális és Innovációs Minisztérium Nemzeti Kutatási Fejlesztési és Innovációs Alapból nyújtott támogatásával a TKP2021-NVA pályázati program finanszírozásában valósult meg. AB - We made statistical analysis of the Fermi GBM and Swift BAT observational material, accumulated over 15 years. We studied how GRB parameters (T90 duration, fluence, peak flux) that were observed by only one satellite differ from those observed by both. In the latter case, it was possible to directly compare the values of the parameters that both satellites measured. The GRBs measured by both satellites were identified using the k-nearest neighbours algorithm in Euclidean distance. In the parameter space we determined the direction in which the jointly detected GRBs differ most from those detected by only one of the instruments using linear discriminant analyses. To get the strength of the relationship between the parameters obtained from the GBM and BAT, a canonical correlation was performed. The GBM and BAT T90 distributions were fitted with a linear combination of lognormal functions. The optimal number of such functions required for fit is two for GBM and three for BAT. Contrary to the widely accepted view, we found that the number of lognormal functions required for fitting the observed distribution of GRB durations does not allow us to deduce the number of central engine types responsible for GRBs. LA - English DB - MTMT ER - TY - JOUR AU - Horváth, István AU - Bagoly, Zsolt AU - Balázs, Lajos AU - Hakkila, Jon AU - Horváth, Zsuzsa AU - Joo, Andras Peter AU - Pintér, Sándor AU - Tóth, László Viktor AU - Veres, Peter AU - Rácz, István TI - Mapping the Universe with gamma-ray bursts JF - MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY J2 - MON NOT R ASTRON SOC VL - 527 PY - 2024 IS - 3 SP - 7191 EP - 7202 PG - 12 SN - 0035-8711 DO - 10.1093/mnras/stad3669 UR - https://m2.mtmt.hu/api/publication/34417072 ID - 34417072 N1 - A TKP2021-NVA-16 számú projekt a Kulturális és Innovációs Minisztérium Nemzeti Kutatási Fejlesztési és Innovációs Alapból nyújtott támogatásával a TKP2021-NVA pályázati program finanszírozásában valósult meg. AB - We explore large-scale cosmic structure using the spatial distribution of 542 gamma-ray bursts (GRBs) having accurately-measured positions and spectroscopic redshifts. Prominent cosmological clusters are identified in both the northern and southern galactic hemispheres (avoiding extinction effects in the plane of the Milky Way) using the Bootstrap Point-Radius method. The Northern Galactic hemisphere contains a significant group of four GRBs in the redshift range 0.59 ≤ z ≤ 0.62 (with a Bootstrap probability of p = 0.012) along with the previously-identified Hercules–Corona Borealis Great Wall (in the revised redshift range 0.9 ≤ z ≤ 2.1; p = 0.017). The Southern Galactic hemisphere contains the previously-identified Giant GRB Ring (p = 0.022) along with another possible cluster of 7 − 9 GRBs at 1.17 ≤ z ≤ 1.444 (p = 0.031). Additionally, both the Hercules–Corona Borealis Great Wall and the Giant GRB Ring have become more prominent as the GRB sample size has grown. The approach used here underscores the potential value of GRB clustering as a probe of large-scale cosmic structure, complementary to galaxy and quasar clustering. Because of the vast scale on which GRB clustering provides valuable insights, it is important that optical GRB monitoring continue so that additional spectroscopic redshift measurements should be obtained. LA - English DB - MTMT ER - TY - JOUR AU - Pintér, Sándor AU - Balázs, Lajos AU - Bagoly, Zsolt AU - Horváth, István TI - Gamma-Ray Bursts' redshift distribution's dependence on their duration JF - CONTRIBUTIONS OF THE ASTRONOMICAL OBSERVATORY SKALNATE PLESO J2 - CONTRIB ASTRON OBS SKALNATE PLESO VL - 53 PY - 2023 IS - 4 SP - 93 EP - 99 PG - 7 SN - 1335-1842 DO - 10.31577/caosp.2023.53.4.93 UR - https://m2.mtmt.hu/api/publication/34493609 ID - 34493609 AB - Gamma-ray bursts (GRBs) are distant, extremely energetic, short (about 0.1-1000 sec) cosmic transients, which could sample the whole observable Universe. Two of the Gamma-Ray Bursts' important properties are the duration and the distance of the burst. We analyzed these two important quantities of the phenomena. We mapped their two-dimensional distribution and explored some suspicious areas. As it is well known the short GRBs are closer than the others, hence we search for parts in the Universe where the GRBs duration differs from the others. We also analyze whether there are any areas where the redshifts are differing. LA - English DB - MTMT ER - TY - JOUR AU - Rácz, István AU - Balázs, Lajos AU - Horváth, István TI - Redshift dependence of GRBs' observed parameters JF - CONTRIBUTIONS OF THE ASTRONOMICAL OBSERVATORY SKALNATE PLESO J2 - CONTRIB ASTRON OBS SKALNATE PLESO VL - 53 PY - 2023 IS - 4 SP - 115 EP - 126 PG - 12 SN - 1335-1842 DO - 10.31577/caosp.2023.53.4.115 UR - https://m2.mtmt.hu/api/publication/34493608 ID - 34493608 AB - GRBs are extremely energetic short cosmic transients. Due to their huge energy output in a short time they can be observed at very large cosmological distances. Actually, they sample the whole observable Universe. As a consequence of their large distances, their observed duration, fluence and peak flux depend on the redshift. In the reality, however, this dependence can be observed only in the case if the intrinsic variance of these quantities in comoving frame do not exceed significantly that coming from different redhifts of the GRBs. Nevertheless, it is an important question whether the redshift dependence of the observed quantities could be extracted from the observational data. Using a training set consisting of GRBs having measured physical parameters and redshifts we are looking for the effect of the redshift on the observed data, using techniques available in multivariate data analysis. Creating a 3D parameter space from duration, fluence and peak flux, we define partitions in the distribution of data points and compare the redshift distributions within these partitions. Partitioning will be made by some hierarchical clustering algorithm and cutting the obtained agglomeration tree at different places to get partitions of different numbers. The distributions of redshifts within the partitions, obtained in this way, will be compared to see if there is any difference in redshift distribution between partitions at all. LA - English DB - MTMT ER - TY - CONF AU - Seli, Bálint Attila AU - Van Driel Gesztelyi, Lídia AU - Baker, Deborah AU - Laming, J. Martin AU - Kővári, Zsolt AU - Oláh, Katalin Ilona AU - Kriskovics, Levente AU - Vida, Krisztián AU - Balázs, Lajos TI - Stellar FIP effect from the empirical side T2 - 44th COSPAR Scientific Assembly. Held 16-24 July PY - 2022 UR - https://m2.mtmt.hu/api/publication/33087071 ID - 33087071 AB - The difference between the elemental abundances of the corona and the photosphere is an apparently common feature of stellar atmospheres. The abundance difference depends on the first ionization potential of the given element, so the phenomenon is known as the FIP effect. Here we explore the variation of the strength of the FIP effect for different types of stars, through the FIP bias parameter. Using a sample of 59 main sequence and evolved stars with known coronal abundances from the literature, we look for macroscopic, measurable parameters that affect the stellar FIP bias, and also re-evaluate the simple dependence on the effective temperature. LA - English DB - MTMT ER - TY - JOUR AU - Suleiman, Nofoz AU - Noboriguchi, Akatoki AU - Toba, Yoshiki AU - Balázs, Lajos AU - Burgarella, Denis AU - Kovacs, Timea AU - Marton, Gábor AU - Talafha, Mohammed AU - Frey, Sándor AU - Tóth, László Viktor TI - The statistical properties of 28 IR-bright dust-obscured galaxies and SED modelling using CIGALE JF - PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN J2 - PUBL ASTRON SOC JPN VL - 74 PY - 2022 IS - 5 SP - 1157 EP - 1185 PG - 29 SN - 0004-6264 DO - 10.1093/pasj/psac061 UR - https://m2.mtmt.hu/api/publication/33068861 ID - 33068861 N1 - Department of Astronomy, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/A, Budapest, H-1117, Hungary School of General Education, Shinshu University, 3-1-1 Asahi, Nagano, Matsumoto, 390-8621, Japan Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, 6-3 Aramaki, Aoba-ku, Miyagi, Sendai, 980-8578, Japan Graduate School of Science and Engineering, Ehime University, 2-5 Bunkyo-cho, Matsuyama, Ehime, 790-8577, Japan National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo, 181-8588, Japan Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto, Kyoto, 606-8502, Japan Academia Sinica Institute of Astronomy and Astrophysics, 11F Astronomy–Mathematics Building, AS/NTU, No.1, Section 4, Roosevelt Road, Taipei, 10617, Taiwan Research Center for Space and Cosmic Evolution, Ehime University, 2-5 Bunkyo-cho, Matsuyama, Ehime, 790-8577, Japan Konkoly Observatory, ELKH Research Centre for Astronomy and Earth Sciences, Konkoly Thege Miklós út 15-17, Budapest, H-1121, Hungary Aix Marseille Univ, CNRS, CNES, LAM, Marseille, France Institute of Physics, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/A, Budapest, H-1117, Hungary Cited By :1 Export Date: 1 December 2023 Correspondence Address: Suleiman, N.; Department of Astronomy, Hungary; email: n.suleiman@ttk.elte.hu AB - The aim of this study is to characterize the physical and statistical properties of a sample of infrared-bright dust-obscured galaxies (DOGs) by fitting their spectral energy distributions (SEDs). We examined 28 DOGs at redshifts 0.47 <= z <= 1.63 discovered by combining images of the Subaru Hyper Suprime-Cam (HSC) survey, the VISTA Kilo-degree Infrared Galaxy (VIKING) survey, and the Wide-field Infrared Survey Explorer (WISE) allsky survey, and detected at Herschel Spectral and Photometric Imaging Receiver (SPIRE) bands. We have detected a significant active galactic nucleus (AGN) contribution to the mid-infrared luminosity for 71% of DOGs. Our DOGs contain several types of AGNs; the majority of AGN emission originates from Type 2 AGNs. Our DOG sample shows very high values of stellar mass [log (M-*/M-circle dot) = 11.49 +/- 1.61] compared with other samples of DOGs selected at infrared wavelengths. Our study is promising to identify a new type of DOGs called "overweight" DOGs (ODOGs). ODOGs may indicate the end of the DOG phase, and then they become visible quasars. Principal component (PC) analysis is applied to reduce the number of dimensions of our sample, removing the dependency on the observed variables. There are two significant PCs describing 72.7% of the total variance. The first PC strongly correlates with redshift, dust luminosity, dust mass, and stellar mass, while far-ultraviolet (FUV) attenuation strongly correlates with the second PC, which is orthogonal to the first one. The partial correlation between the resulted physical parameters is tested, supporting the reliability of the correlations. LA - English DB - MTMT ER - TY - JOUR AU - Bagoly, Zsolt AU - Horváth, István AU - Rácz, István AU - Balázs, Lajos AU - Tóth, László Viktor TI - The Spatial Distribution of Gamma-Ray Bursts with Measured Redshifts from 24 Years of Observation JF - UNIVERSE J2 - UNIVERSE-BASEL VL - 8 PY - 2022 IS - 7 SP - 1 EP - 16 PG - 16 SN - 2218-1997 DO - 10.3390/universe8070342 UR - https://m2.mtmt.hu/api/publication/32977873 ID - 32977873 N1 - „A publikáció a Nemzeti Közszolgálati Egyetem 2020. évi Tématerületi Kiválóság Program keretében, a Fenntartható biztonság és társadalmi környezet elnevezésű projekt támogatásával valósult meg, az Innovációs és Technológiai Minisztérium Nemzeti Kutatási, Fejlesztési és Innovációs Alapból nyújtott támogatásával, a Nemzeti Kutatási, Fejlesztési és Innovációs Hivatal által kibocsátott támogatói okirat alapján.” Pályázat sorszáma: NKFIH-1273-6/2020 Támogató: NKFIH AB - Gamma-ray bursts (GRBs) are the most luminous objects known: they outshine their host galaxies, making them ideal candidates for probing large-scale structure. Our aim is to determine the Spatial Two-Point Correlation Function of the GRBs with spectroscopic redshifts. We used all observations till 4 June 2021, and we also split the data according to the origin of the redshift (afterglow or host galaxy). We analyzed the possible correlation between the GRB redshift and sky position. There is only one region, called the Faraway GRB Patch, where nine distant GRBs shows deviation from the randomness with an ≈1% significance, showing that the sky and the radial component of the GRB distribution could be factorized and both can be determined independently. The GRBs’ cumulative monthly distribution was used to show that it is impossible to synthesize the Sky Exposure Function, even from the perfect observational logs. We estimated the Sky Exposure Function using the Gaussian kernel, and with the radial distribution, it was used for the estimation of the Spatial Two-Point Correlation Function. Monte Carlo simulations were used to determine the Poissonian errors. Our result shows that the current Spatial Two-Point Correlation Function estimations are consistent with zero for the full and the afterglow/host galaxy datasets. LA - English DB - MTMT ER - TY - JOUR AU - Horváth, István AU - Rácz, István AU - Bagoly, Zsolt AU - Balázs, Lajos AU - Pintér, Sándor TI - Does the GRB Duration Depend on Redshift? JF - UNIVERSE J2 - UNIVERSE-BASEL VL - 8 PY - 2022 IS - 4 SP - 1 EP - 12 PG - 12 SN - 2218-1997 DO - 10.3390/universe8040221 UR - https://m2.mtmt.hu/api/publication/32773229 ID - 32773229 N1 - A publikáció a Nemzeti Közszolgálati Egyetem 2020. évi Tématerületi Kiválóság Program keretében, a Fenntartható biztonság és társadalmi környezet elnevezésű projekt támogatásával valósult meg, az Innovációs és Technológiai Minisztérium Nemzeti Kutatási, Fejlesztési és Innovációs Alapból nyújtott támogatásával, a Nemzeti Kutatási, Fejlesztési és Innovációs Hivatal által kibocsátott támogatói okirat alapján. LA - English DB - MTMT ER - TY - JOUR AU - Seli, Bálint Attila AU - Oláh, Katalin Ilona AU - Kriskovics, Levente AU - Kővári, Zsolt AU - Vida, Krisztián AU - Balázs, Lajos AU - Laming, J. M. AU - Van Driel Gesztelyi, Lídia AU - Baker, D. TI - Extending the FIP bias sample to magnetically active stars JF - ASTRONOMY & ASTROPHYSICS J2 - ASTRON ASTROPHYS VL - 659 PY - 2022 SN - 0004-6361 DO - 10.1051/0004-6361/202141493 UR - https://m2.mtmt.hu/api/publication/32726535 ID - 32726535 N1 - Konkoly Observatory, Research Centre for Astronomy and Earth Sciences (ELKH), Budapest, Hungary Eotvos University, Department of Astronomy, Pf. 32, Budapest, 1518, Hungary Space Science Division, Code 7684, Naval Research Laboratory, Washington, DC 20375, United States University College London, Mullard Space Science Laboratory, Holmbury St. Mary, Surrey, RH5 6NT, United Kingdom LESIA, Observatoire de Paris, Universite PSL, CNRS, Sorbonne Universite, Univ. Paris Diderot, Sorbonne Paris Cite, 5 place Jules Janssen, Meudon, 92195, France Export Date: 29 June 2022 CODEN: AAEJA Correspondence Address: Seli, B.; Konkoly Observatory, Hungary; email: seli.balint@csfk.org Funding details: 101öu13, 104öu2, NKFIH PD-134784 Funding details: Office of Naval Research, ONR Funding details: National Aeronautics and Space Administration, NASA, 80HQTR19T0029, 80HQTR20T0076 Funding details: Science and Technology Facilities Council, STFC, ST/S000240/1 Funding details: Hungarian Scientific Research Fund, OTKA, 2019-2.1.11-TÉT-2019-00056, K-131508, K129249, KH-130526, NN129075 Funding details: Nemzeti Kutatási Fejlesztési és Innovációs Hivatal, NKFIH Funding text 1: cA knolw edgements. We thank the referee for the useful suggestion concerning the connection between the (I)FIP and the heating of the stellar coronae. Konkoly Observatory, Budapest, Hungary hosted two workshops on Elemental Composition in Solar and Stellar Atmospheres (IFIPWS-1, 13-15 Feb, 2017 and IFIPWS-2, 27 Feb-1 Mar, 2018). The workshops have fostered collaboration by exploiting synergies in solar and stellar magnetic activity studies and exchanging experience and knowledge in both research fields. We thank G. Csörnyei for the useful discussions and enlightening ideas regarding statistical methods. This work was supported by the Hungarian National Research, Development and Innovation Office grants NKFIH (OTKA) K-131508, KH-130526, NN129075, K129249 and by the NKFIH grant 2019-2.1.11-TÉT-2019-00056. Authors acknowledge the financial support of the Austrian-Hungarian Action Foundation (101öu13, 104öu2). L.K. acknowledges the financial support of the Hungarian National Research, Development and Innovation Office grant NKFIH PD-134784. L.K. is a Bolyai János Research Fellow. J.M.L. was supported by the NASA Heliophysics Guest Investigator (80HQTR19T0029) and Supporting Research (80HQTR20T0076) programs, and by Basic Research FUnds of the Office of Naval Research. D.B. is funded under STFC consolidated grant number ST/S000240/1 and LvDG is partially funded under the same grant. Software: python (Van Rossum & Drake 2009), matplotlib (Hunter 2007), numpy (van der Walt et al. 2011), scipy (Virtanen et al. 2020), pandas (McKinney 2010), sklearn (Pedregosa et al. 2011). AB - Context. The different elemental abundances of the photosphere and the corona are striking features of not only the Sun, but of other stars as well. This phenomenon is known as the first ionisation potential (FIP) effect, and its strength can be characterized by the FIP bias, the logarithmic abundance difference between low- and high-FIP elements in the corona, compared to the photosphere. The FIP bias was shown to depend on the surface temperature of the star. Aims: We aim to extend the Teff−FIP bias relationship to a larger stellar sample and analyse the effect of other astrophysical parameters on the relation (e.g. surface gravity, age, activity indicators). Methods: We compiled FIP bias and other parameters for 59 stars for which coronal composition is available, now including evolved stars. Using principal component analysis and linear discriminant analysis, we searched for correlations with other astrophysical parameters within the sample that may influence the stellar FIP bias. Results: Adding stars to the Teff−FIP bias diagram unveiled new features in its structure. In addition to the previously known relationship, there appears to be a second branch: a parallel sequence about 0.5 dex above it. While the Teff remains the main determinant of the FIP bias, other parameters such as stellar activity indicators also have influence. We find three clusters in the FIP bias determinant parameter space. One distinct group is formed by the evolved stars. Two groups contain main sequence stars in continuation separated roughly by the sign change of the FIP-bias value. Conclusions: The new branch of the Teff−FIP bias diagram contains stars with higher activity level, in terms of X-ray flux and rotational velocity. The Rossby number also seems to be important, indicating possible dependence on the type of dynamo operating in these stars influencing their FIP bias. The two main-sequence clusters run from the earliest spectral types of A-F with shallow convection zones through G-K-early-M stars with gradually deeper convection zones, and they end with the fully convective M dwarf stars, depicting the change of the dynamo type with the internal differences of the main sequence stars in connection with the FIP-bias values. LA - English DB - MTMT ER - TY - JOUR AU - Tanvir, N. R. AU - Le Floc'h, E. AU - Christensen, L. AU - Caruana, J. AU - Salvaterra, R. AU - Ghirlanda, G. AU - Ciardi, B. AU - Maio, U. AU - D'Odorico, V. AU - Piedipalumbo, E. AU - Campana, S. AU - Noterdaeme, P. AU - Graziani, L. AU - Amati, L. AU - Bagoly, Zsolt AU - Balázs, Lajos AU - Basa, S. AU - Behar, E. AU - De Cia, A. AU - Valle, M. Della AU - De Pasquale, M. AU - Frontera, F. AU - Gomboc, A. AU - Gotz, D. AU - Horváth, István AU - Hudec, R. AU - Mereghetti, S. AU - O'Brien, P. T. AU - Osborne, J. P. AU - Paltani, S. AU - Rosati, P. AU - Sergijenko, O. AU - Stanway, E. R. AU - Szécsi, Dorottya AU - Tóth, László Viktor AU - Urata, Y. AU - Vergani, S. AU - Zane, S. TI - Exploration of the high-redshift universe enabled by THESEUS JF - EXPERIMENTAL ASTRONOMY J2 - EXP ASTRON VL - 52 PY - 2021 IS - 3 SP - 219 EP - 244 PG - 26 SN - 0922-6435 DO - 10.1007/s10686-021-09778-w UR - https://m2.mtmt.hu/api/publication/32152422 ID - 32152422 N1 - School of Physics and Astronomy, University of Leicester, University Road, Leicester, LE1 7RH, United Kingdom AIM, CEA-Irfu/DAp, CNRS, Université Paris-Saclay, Gif-sur-Yvette, F-91191, France Niels Bohr Institute, University of Copenhagen, Jagtvej 128, Copenhagen N, 2200, Denmark Department of Physics and Institute of Space Sciences and Astronomy, University of Malta, Msida, MSD 2080, Malta INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica, via Alfonso Corti 12, Milano, 20133, Italy INAF-Osservatorio Astronomico di Brera, Via Bianchi 46, Merate (LC), I-23807, Italy Max Planck Institute for Astrophysics, Karl-Schwarzschild-Str. 1, Garching, 85741, Germany INAF-Observatory of Trieste, via G. Tiepolo 11, Trieste, 34143, Italy Dipartimento di Fisica, Università degli Studi di Napoli Federico II, Naples, 80126, Italy I.N.F.N., Sez. di Napoli, Compl. Univ. Monte S. Angelo, via Cinthia, Napoli, 80126, Italy Institut d’Astrophysique de Paris, CNRS-SU, UMR 7095, 98bis bd Arago, Paris, 75014, France Dipartimento di Fisica, “Sapienza” Università di Roma, Piazzale Aldo Moro 5, Roma, 00185, Italy INAF/OAS-Bologna, via P. Gobetti 101, Bologna, I-40129, Italy Eövös University, Budapest, H-1117, Hungary CSFK Konkoly Observatory, Budapest, Hungary Department of Astronomy, Eövös University, Budapest, Hungary CNRS, CNES, LAM, Aix Marseille Universite, Marseille, France Department of Physics, Technion, Israel Department of Astronomy, University of Geneva, Chemin Pegasi 51, Versoix, 1290, Switzerland INAF-Capodimonte Observatory, Salita Moiariello 16, Napoli, 80131, Italy Department of Astronomy and Space Sciences, Istanbul University, Beyazıt, Istanbul, 34119, Turkey Dipartimento di Fisica e Scienze della Terra, Università di Ferrara, Via Saragat 1, Ferrara, I-44122, Italy Center for Astrophysics and Cosmology, University of Nova Gorica, Vipavska 13, Nova Gorica, 5000, Slovenia IRFU/Département d’Astrophysique, CEA, Université Paris-Saclay, Gif-sur-Yvette, F-91191, France University of Public Service, Budapest, Hungary Faculty of Electrical Engineering, Czech Technical University in Prague, Prague, Czech Republic Astronomical Institute, Czech Academy of Sciences, Ondrejov, Czech Republic Kazan Federal University, Kazan, Russian Federation INAF / IASF-Milano, via A. Corti 12, Milano, I-20133, Italy School of Physics and Astronomy, University of Leicester, University Road, Leicester, LE1 7RH, United Kingdom Department of Physics and Earth Sciences, University of Ferrara, Ferrara, Italy Astronomical Observatory of Taras Shevchenko, National University of Kyiv, Observatorna str., 3, Kyiv, 04053, Ukraine Main Astronomical Observatory of the National Academy of Sciences of Ukraine, Zabolotnoho str., 27, Kyiv, 03680, Ukraine Physical Sciences, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, United Kingdom Institute of Astronomy, Nicolaus Copernicus University, Toruń, 87-100, Poland I. Physikalisches Institut, Universität zu Köln, Cologne, D-50937, Germany Department of Astronomy, Eötvös Loránd University, Pázmány Péter sétány 1/A, Budapest, H-1117, Hungary Institute of Astronomy, National Central University, Chung-Li, 32054, Taiwan CNRS, GEPI, Observatoire de Paris, PSL University, Place Jules Janssen, Meudon, 92190, France Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, RH56NT, United Kingdom Cited By :15 Export Date: 30 January 2024 Correspondence Address: Tanvir, N.R.; School of Physics and Astronomy, University Road, United Kingdom; email: nrt3@le.ac.uk AB - At peak, long-duration gamma-ray bursts are the most luminous sources of electromagnetic radiation known. Since their progenitors are massive stars, they provide a tracer of star formation and star-forming galaxies over the whole of cosmic history. Their bright power-law afterglows provide ideal backlights for absorption studies of the interstellar and intergalactic medium back to the reionization era. The proposed THESEUS mission is designed to detect large samples of GRBs at z > 6 in the 2030s, at a time when supporting observations with major next generation facilities will be possible, thus enabling a range of transformative science. THESEUS will allow us to explore the faint end of the luminosity function of galaxies and the star formation rate density to high redshifts; constrain the progress of re-ionisation beyond z greater than or similar to 6; study in detail early chemical enrichment from stellar explosions, including signatures of Population III stars; and potentially characterize the dark energy equation of state at the highest redshifts. LA - English DB - MTMT ER -