@article{MTMT:34418073,
	title = {Some statistical remarks on GRBs jointly detected by Fermi and Swift satellites},
	url = {https://m2.mtmt.hu/api/publication/34418073},
	author = {Pintér, Sándor and Balázs, Lajos and Bagoly, Zsolt and Tóth, László Viktor and Rácz, István and Horváth, István},
	doi = {10.1093/mnras/stad3236},
	journal-iso = {MON NOT R ASTRON SOC},
	journal = {MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY},
	volume = {527},
	unique-id = {34418073},
	issn = {0035-8711},
	abstract = {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.},
	keywords = {Telescopes; gamma-ray burst: general; Instrumentation: detectors; Space vehicles: instruments; fmethods: statistical},
	year = {2024},
	eissn = {1365-2966},
	pages = {8931-8940},
	orcid-numbers = {Pintér, Sándor/0000-0002-5755-7956; Bagoly, Zsolt/0000-0002-2679-7594; Tóth, László Viktor/0000-0002-5310-4212; Rácz, István/0000-0002-4595-6933; Horváth, István/0000-0002-1343-1761}
}

@article{MTMT:34417072,
	title = {Mapping the Universe with gamma-ray bursts},
	url = {https://m2.mtmt.hu/api/publication/34417072},
	author = {Horváth, István and Bagoly, Zsolt and Balázs, Lajos and Hakkila, Jon and Horváth, Zsuzsa and Joo, Andras Peter and Pintér, Sándor and Tóth, László Viktor and Veres, Peter and Rácz, István},
	doi = {10.1093/mnras/stad3669},
	journal-iso = {MON NOT R ASTRON SOC},
	journal = {MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY},
	volume = {527},
	unique-id = {34417072},
	issn = {0035-8711},
	abstract = {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.},
	keywords = {methods: data analysis; methods: statistical; cosmology: observations; (cosmology:) large-scale structure of universe; (stars:) gamma-ray burst: general; (transients:) gammaray bursts},
	year = {2024},
	eissn = {1365-2966},
	pages = {7191-7202},
	orcid-numbers = {Horváth, István/0000-0002-1343-1761; Bagoly, Zsolt/0000-0002-2679-7594; Pintér, Sándor/0000-0002-5755-7956; Tóth, László Viktor/0000-0002-5310-4212; Rácz, István/0000-0002-4595-6933}
}

@article{MTMT:34493609,
	title = {Gamma-Ray Bursts' redshift distribution's dependence on their duration},
	url = {https://m2.mtmt.hu/api/publication/34493609},
	author = {Pintér, Sándor and Balázs, Lajos and Bagoly, Zsolt and Horváth, István},
	doi = {10.31577/caosp.2023.53.4.93},
	journal-iso = {CONTRIB ASTRON OBS SKALNATE PLESO},
	journal = {CONTRIBUTIONS OF THE ASTRONOMICAL OBSERVATORY SKALNATE PLESO},
	volume = {53},
	unique-id = {34493609},
	issn = {1335-1842},
	abstract = {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.},
	keywords = {data analysis; GAMMA-RAY BURSTS},
	year = {2023},
	eissn = {1336-0337},
	pages = {93-99},
	orcid-numbers = {Pintér, Sándor/0000-0002-5755-7956; Bagoly, Zsolt/0000-0002-2679-7594; Horváth, István/0000-0002-1343-1761}
}

@article{MTMT:34493608,
	title = {Redshift dependence of GRBs' observed parameters},
	url = {https://m2.mtmt.hu/api/publication/34493608},
	author = {Rácz, István and Balázs, Lajos and Horváth, István},
	doi = {10.31577/caosp.2023.53.4.115},
	journal-iso = {CONTRIB ASTRON OBS SKALNATE PLESO},
	journal = {CONTRIBUTIONS OF THE ASTRONOMICAL OBSERVATORY SKALNATE PLESO},
	volume = {53},
	unique-id = {34493608},
	issn = {1335-1842},
	abstract = {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.},
	keywords = {cosmology; statistical; gamma-ray burts},
	year = {2023},
	eissn = {1336-0337},
	pages = {115-126},
	orcid-numbers = {Rácz, István/0000-0002-4595-6933; Horváth, István/0000-0002-1343-1761}
}

@CONFERENCE{MTMT:33087071,
	title = {Stellar FIP effect from the empirical side},
	url = {https://m2.mtmt.hu/api/publication/33087071},
	author = {Seli, Bálint Attila and Van Driel Gesztelyi, Lídia and Baker, Deborah and Laming, J. Martin and Kővári, Zsolt and Oláh, Katalin Ilona and Kriskovics, Levente and Vida, Krisztián and Balázs, Lajos},
	booktitle = {44th COSPAR Scientific Assembly. Held 16-24 July},
	unique-id = {33087071},
	abstract = {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.},
	year = {2022},
	orcid-numbers = {Seli, Bálint Attila/0000-0002-3658-2175; Kővári, Zsolt/0000-0001-5160-307X}
}

@article{MTMT:33068861,
	title = {The statistical properties of 28 IR-bright dust-obscured galaxies and SED modelling using CIGALE},
	url = {https://m2.mtmt.hu/api/publication/33068861},
	author = {Suleiman, Nofoz and Noboriguchi, Akatoki and Toba, Yoshiki and Balázs, Lajos and Burgarella, Denis and Kovacs, Timea and Marton, Gábor and Talafha, Mohammed and Frey, Sándor and Tóth, László Viktor},
	doi = {10.1093/pasj/psac061},
	journal-iso = {PUBL ASTRON SOC JPN},
	journal = {PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN},
	volume = {74},
	unique-id = {33068861},
	issn = {0004-6264},
	abstract = {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.},
	keywords = {GALAXIES; surveys; catalogs},
	year = {2022},
	eissn = {2053-051X},
	pages = {1157-1185},
	orcid-numbers = {Frey, Sándor/0000-0003-3079-1889; Tóth, László Viktor/0000-0002-5310-4212}
}

@article{MTMT:32977873,
	title = {The Spatial Distribution of Gamma-Ray Bursts with Measured Redshifts from 24 Years of Observation},
	url = {https://m2.mtmt.hu/api/publication/32977873},
	author = {Bagoly, Zsolt and Horváth, István and Rácz, István and Balázs, Lajos and Tóth, László Viktor},
	doi = {10.3390/universe8070342},
	journal-iso = {UNIVERSE-BASEL},
	journal = {UNIVERSE},
	volume = {8},
	unique-id = {32977873},
	abstract = {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.},
	year = {2022},
	eissn = {2218-1997},
	pages = {1-16},
	orcid-numbers = {Bagoly, Zsolt/0000-0002-2679-7594; Horváth, István/0000-0002-1343-1761; Rácz, István/0000-0002-4595-6933; Balázs, Lajos/0000-0003-0951-6217; Tóth, László Viktor/0000-0002-5310-4212}
}

@article{MTMT:32773229,
	title = {Does the GRB Duration Depend on Redshift?},
	url = {https://m2.mtmt.hu/api/publication/32773229},
	author = {Horváth, István and Rácz, István and Bagoly, Zsolt and Balázs, Lajos and Pintér, Sándor},
	doi = {10.3390/universe8040221},
	journal-iso = {UNIVERSE-BASEL},
	journal = {UNIVERSE},
	volume = {8},
	unique-id = {32773229},
	year = {2022},
	eissn = {2218-1997},
	pages = {1-12},
	orcid-numbers = {Horváth, István/0000-0002-1343-1761; Rácz, István/0000-0002-4595-6933; Bagoly, Zsolt/0000-0002-2679-7594; Pintér, Sándor/0000-0002-5755-7956}
}

@article{MTMT:32726535,
	title = {Extending the FIP bias sample to magnetically active stars},
	url = {https://m2.mtmt.hu/api/publication/32726535},
	author = {Seli, Bálint Attila and Oláh, Katalin Ilona and Kriskovics, Levente and Kővári, Zsolt and Vida, Krisztián and Balázs, Lajos and Laming, J. M. and Van Driel Gesztelyi, Lídia and Baker, D.},
	doi = {10.1051/0004-6361/202141493},
	journal-iso = {ASTRON ASTROPHYS},
	journal = {ASTRONOMY & ASTROPHYSICS},
	volume = {659},
	unique-id = {32726535},
	issn = {0004-6361},
	abstract = {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.},
	year = {2022},
	eissn = {1432-0746},
	orcid-numbers = {Seli, Bálint Attila/0000-0002-3658-2175; Kővári, Zsolt/0000-0001-5160-307X}
}

@article{MTMT:32152422,
	title = {Exploration of the high-redshift universe enabled by THESEUS},
	url = {https://m2.mtmt.hu/api/publication/32152422},
	author = {Tanvir, N. R. and Le Floc'h, E. and Christensen, L. and Caruana, J. and Salvaterra, R. and Ghirlanda, G. and Ciardi, B. and Maio, U. and D'Odorico, V. and Piedipalumbo, E. and Campana, S. and Noterdaeme, P. and Graziani, L. and Amati, L. and Bagoly, Zsolt and Balázs, Lajos and Basa, S. and Behar, E. and De Cia, A. and Valle, M. Della and De Pasquale, M. and Frontera, F. and Gomboc, A. and Gotz, D. and Horváth, István and Hudec, R. and Mereghetti, S. and O'Brien, P. T. and Osborne, J. P. and Paltani, S. and Rosati, P. and Sergijenko, O. and Stanway, E. R. and Szécsi, Dorottya and Tóth, László Viktor and Urata, Y. and Vergani, S. and Zane, S.},
	doi = {10.1007/s10686-021-09778-w},
	journal-iso = {EXP ASTRON},
	journal = {EXPERIMENTAL ASTRONOMY},
	volume = {52},
	unique-id = {32152422},
	issn = {0922-6435},
	abstract = {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.},
	keywords = {GAMMA-RAY BURSTS; ABUNDANCES; REIONIZATION; Star forming galaxies},
	year = {2021},
	eissn = {1572-9508},
	pages = {219-244},
	orcid-numbers = {Bagoly, Zsolt/0000-0002-2679-7594; Horváth, István/0000-0002-1343-1761; Tóth, László Viktor/0000-0002-5310-4212}
}