Acta Polytechnica https://doi.org/10.14311/AP.2025.65.0065 Acta Polytechnica 65(1):65–72, 2025 © 2025 The Author(s). Licensed under a CC-BY 4.0 licence Published by the Czech Technical University in Prague MASS GROWTH OF MASSIVE QUIESCENT GALAXIES IN THE ILLUSTRIS TNG SIMULATION Bendegúz Koncza,b,∗, András Péter Joób a University of Debrecen, Doctoral School of Physics, Bem tér 18/B, 4026 Debrecen, Hungary b Eötvös Loránd University, Department of Astronomy, Pázmány Péter sétány 1/A, 1117 Budapest, Hungary ∗ corresponding author: konczbendeguz@gmail.com Abstract. Interactions between galaxies could potentially lead to increased rates of star formation within these galaxies, potentially leading to the occurrence of multiple core-collapse supernovae and the ejection of hot gas. Numerical simulations are crucial for understanding the formation and evolution of galaxies. Using the IllustrisTNG cosmological simulation, we show how the massive quiescent galaxies evolve in cosmic times. We use the merger tree from the TNG300-1 simulation to demonstrate the impact of dwarf galaxies on the mass augmentation of these galaxies during the early Universe. We made a galaxy sample with restrictions on the specific star formation rate log(sSFR) and mass (M). Most of the mergers have a <1:1 000 ratio to the host galaxy and 5–25 % of the falling material is connected to the merger events. These results show that dwarf galaxies could play a significant role in the growth of these massive galaxies. Keywords: Galaxies: evolution, galaxies: star formation, galaxies: interactions, methods: numerical. 1. Introduction Star formation in the Universe has been studied sev- eral surveys (see e.g. [1–3]), and it has already been shown using ISO (Infrared Space Observatory [4]) ob- servations that the star formation rate density (SFRD) has decreased in the last 5 billion years. This was pre- ceded by the so-called “cosmic noon” (see e.g. [5, 6]) when most of the still visible stars were formed. Fre- quent galaxy interactions are a characteristic feature of this period and can be studied using cosmological simulations. It is worth noting, however, that gamma-ray bursts (GRBs) may also provide a clue to star formation in the early universe. As is well known, these phenom- ena are not only the largest energy emitters in the Universe after the Big Bang, but a significant fraction of them, the hypernovas, are associated with high star formation regions, despite the ultra-low metallic- ity of these stars [7]. As is well known, these bursts can vary significantly, both in length and intensity, which also carry the physical characteristics of the en- vironment around the GRB [8, 9]. However, another interesting fact is that GRBs fill space in an abso- lutely non-isotropic way, with significant clustering and anisotropy [10–13]. Previous studies examined, how galaxy mergers can quench the star formation in galaxies. Using sim- ulations, Pontzen et al. [14] showed, how mergers can start the quenching mechanism due to mechan- ical disruption, where the timescale of these events is about 250 Myr. Based on a sample of ∼500 post- merger galaxies, Ellison et al. [15] found, that merg- ers can indeed lead to a rapid halt in star forma- tion. In addition, there is also observational evi- dence that this process occurs in a short period of time [16, 17]. IllustrisTNG [18–22] is a suite of large volume, cos- mological, gravo-magneto-hydrodynamic simulations including a comprehensive model for galaxy formation. Each TNG simulation self-consistently solves for the coupled evolution of dark matter, cosmic gas, lumi- nous stars, and supermassive black holes from redshift z = 127 to 0 and generates 100 resulting snapshots from z = 20 to 0. We used the TNG300-1 run for anal- ysis, the second largest simulation box which has the size of 302.6 Mpc3 and contains more than 30 billion resolution elements, therefore, enabling the study of galaxy clustering. There have been many publications on this topic using the IllustrisTNG simulation: Genel et al. [23] focused on the size evolution of quenched galaxies, and found that M∗ > 109.5M⊙ experience a steep size growth after their quenching time, while the mass of more massive galaxies increases less due to collisions. Davies et al. [24] examined the quench- ing and morphological evolution of central galaxies. Luo et al. [25] investigated the massive spiral galax- ies, and their results suggest that the cooling from the hot gaseous halo in quenched spiral galaxies is suppressed by massive black holes. Quai et al. [26] presented an analysis of post-merger galaxies. They found that only 5 % of post-merger galaxies quench within 500 Myr after they merge. Xu et al. [27] inves- tigated massive quenched central disk galaxies, and showed that mini-mergers have mainly contributed to the growth of their SMBHs. Previous articles have not dealt with the mass distribution of galaxies that have merged into larger galaxies, which is one of the major topics of this study. 65 https://doi.org/10.14311/AP.2025.65.0065 https://creativecommons.org/licenses/by/4.0/ https://www.cvut.cz/en Bendegúz Koncz, András Péter Joó Acta Polytechnica 2. Methods We used the IllustrisTNG 300-1 merger tree, which links sub-haloes to their progenitors and descendants. It is created by the Sublink algorithm [28] that follows these steps: First, it identifies the candidates for each subhalo, looking for galaxies in the following snapshot that share particles with the selected galaxy. The sec- ond step involves scoring the candidates using a merit function, which determines the binding energy rank of each particle within the galaxies. The final step is iden- tifying the unique descendant, which is determined to be the subhalo with the highest score. To construct the merger tree, Springel et al. [29] developed a linked- list structure that allows each subhalo to be assigned pointers to “key” subhalos. The “descendant” refers to the unique subsequent subhalo related to the subhalo in question. The “next progenitor” is the subhalo that shares the same descendant as the subhalo in question and has the next largest “mass history” following the progenitor. In our case, the progenitor galaxies are those subhalos for which the descendants and next progenitors have been determined. To analyse the merger trees, we used the Sublink tree files. These are divided into 125 separate files, each containing approximately 25 million galaxies. We made a galaxy sample with star formation rates log(sSFR) < −10.5 and with masses log( M∗ M⊙ ) > 10.6 to reduce our sam- ple only to those galaxies, which are massive and are in a quiescent state. After making this sample, we searched for the next progenitor galaxies which are connected to the massive galaxy. We used our method in a single merger tree since the merger trees are independent and have similar average character- istics [30] as we found in our previous paper. Using these criteria, we have found approximately 3 500 mas- sive quiescent galaxies in the chosen merger tree. In our analysis, we have focused on the number of galaxy mergers, the mass distribution of the NextProgenitor galaxies, and the star formation rate history of the subhalo in question. We calculated mass ratios for the NextProgenitor galaxies, dividing their masses by the masses of the FirstProgenitor galaxies, the massive galaxies they merge into. We didn’t include galaxies at higher redshifts z > 8, because there are only a few galaxies in general and the number of mergers is also low at higher redshifts. As a further investigation, we selected three galaxies with the following SubhaloIDs at z = 0: ID 0, ID 736368 and ID 1094694, where we have selected the first two for their large number of progenitors and the third one for an example with fewer galaxy mergers. The listed SubhaloIDs are con- nected to the galaxy at z = 0, for which we selected the FirstProgenitor galaxies at higher redshifts. 3. Results First, we collected all merger companions for the 38 galaxies and compared their NextProgenitors (Ap- pendix Tables 1 and 2). From the data, we can see Figure 1. Mass distribution of the NextProgenitor galaxies of the subhalo ID 0. Most of the galaxies have approximately 109M⊙, more than half of the sample. The number of galaxies decreases with in- creasing mass, and there are only a few galaxies with a mass of ∼1011M⊙. that more massive galaxies have more mergers. Most of these galaxies have 1–5 × 1012M⊙ mass, which is similar to the Milky Way [31]. There are some ex- ceptions, with lower masses and some subhalos are supermassive, such the ID 0, which has greater mass than 1.2 × 1014M⊙. Others have discussed these mas- sive galaxies in the IllusrisTNG simulation in previous articles, see e.g. [32–34]. These galaxies encountered 100–200 mergers during their history. The median mass of the mergers is similar for all galaxies, at 0.088–0.104 (1010M⊙), which means, that most of these mergers are dwarf galaxies. If we compare the sum of the progenitors’ mass to the SubhaloMass of the massive galaxy, we can see that in most of the cases, 5–25 % of the falling material is connected to these merger events. The merger companions’ mass for each galaxy under discussion can be found in Ap- pendix Table 2, where the mass of the progenitors is divided into 5 groups based on their relative mass to the subhalo in question. In each column on the left side is the number of the galaxies, and on the right is the percentage of all companions of that galaxy. Except for the smallest galaxies, most of the mergers have a < 1 1 000 ratio to the host galaxy. We consider mergers with a ratio of < 1 10 to be minor. Because of the large number of minor mergers, we divided them into subgroups: < 1 100 and < 1 1 000 . This means that dwarf galaxies play an important role in the evolution of these galaxies. From these galaxies, we have selected the ID 0 subhalo, which is the most massive one in our sam- ple. It has 22 392 merger companions and the ad- ditional material collected through mergers is more than 2.6 × 1013M⊙. We investigated the companions of this subhalo. In Figure 1, the mass distribution 66 vol. 65 no. 1/2025 Mass growth of massive quiescent galaxies . . . Figure 2. Mass ratio distribution of the NextPro- genitor galaxies of subhalo ID 0, where their mass is compared to the FirstProgenitor galaxy at the red- shift of the NextProgenitor. Most of the galaxies have a 10−6 mass ratio relative to the galaxy they have been merged into. of the NextProgenitors is shown. We can see, that most of the galaxies (more than half of the compan- ions) have about 109M⊙, which means that these are dwarf galaxies. For higher masses, the number of mergers is decreasing, there are only 5 galaxies with around 1011M⊙. In Figure 2, the same galaxies are selected, but in this figure, their mass is compared to the FirstProgenitor galaxy, at the same redshift at which the merger event took place. In the following step, we focused on the star for- mation history and the number of merger events. We investigated 3 different subhalos with the following IDs: ID 0, ID 736368, and ID 1094694. First, we compared their star formation rate and the number of events at different redshifts, shown in Figure 3. Before the subhalo was quenched, there was a star formation peak at z < 0.5 at all three galaxies. At z > 1.5, there was no significant increase in the star formation. The number of galaxy mergers was relatively low as well before z > 2. The galaxies with more merger events (ID 0 and ID 736368) have encountered their merger events mostly at z < 2. We can assume that the appearance of these merger events and the increase in star formation are in connection. Due to the galaxy interaction, active star formation started a few million years later. Next to the number of progenitors, we compared their total mass to the star formation, see Figure 4. Since most of these galaxies have similar masses, there is no significant difference between the number of mergers and the total mass of these com- panions. There are cases when a larger galaxy merges into the galaxy in question, where one galaxy can in- fluence the total mass, but according to Figure 1, only a few galaxies have significantly larger mass than the average. In the case of the ID 1094694 galaxy, there (a). ID 0. (b). ID 736368. (c). ID 1094694. Figure 3. Star formation rate history (red line) and the number of infalling galaxies (green dots) versus the redshift at 0 < z < 8. On the three panels, different subhalos are shown: ID 0, ID 736368, and ID 1094694. The star formation rate of the top two galaxies increases as the number of collisions increases, while at the bottom the smaller number of mergers has no significant effect. 67 Bendegúz Koncz, András Péter Joó Acta Polytechnica (a). ID 0. (b). ID 736368. (c). ID 1094694. Figure 4. Star formation rate history (red line) and the mass of the infalling galaxies (ΣMd, blue dots) versus the redshift at 0 < z < 8. On the three panels, different subhalos are shown: ID 0, ID 736368, and ID 1094694. Star formation in the top two galaxies increases with the amount of falling material, while in the bottom one we see no correlation, although the masses are orders of magnitude smaller. are only 220 merger events, and the falling material is an order of magnitude smaller than the other two galaxies. Therefore, the impact of the mergers is not significant, in this case, the star formation increase may have a different cause. 4. Conclusion In our work, we examined the growth of massive quiescent galaxies through galaxy mergers using the IllustrisTNG simulation. We made a highly restricted galaxy sample (which contains 38 galaxies) with star formation rates log(sSFR) < −10.5 and with masses log( M∗ M⊙ ) > 10.6, and focused on those galaxies, which merge into these galaxies. We found that the me- dian mass of the mergers is similar for all galaxies, 0.088–0.104 (1010M⊙), which means, that the ma- jority of these merging galaxies are dwarfs. Most of the mergers have a ratio < 1 1 000 to the host galaxy and 5–25 % of the falling material is connected to the merger events. We note that our sample of merging galaxies may include some false positives identified by the SUBFIND algorithm, such as disk fragments, as the merger trees lack the necessary flag to filter out these “non-cosmological” structures. This could introduce a bias towards the number of minor merg- ers; however, we anticipate only a subtle impact on the assembled mass. A more robust analysis could be attempted by linking the merger tree subhalos to the group catalogues of the corresponding simulation volume. Nonetheless, our results suggest that dwarf galaxies could play a significant role in the growth of these massive galaxies. We investigated three individual subhalos and found that in two cases, where the number of galaxies merg- ers was significant, these merger events can lead to a rapid star formation, after which the quenched state occurs. It would be worth making a larger galaxy sample with less strict limits so that we can study galaxy mergers in general. Comparing the results with future observations is essential, as recent telescope measure- ments, such as the JWST or SDSS, can determine the merger history of these galaxies. Acknowledgements We are grateful to L. Viktor Tóth for his supervision of this work and to the High Energy Astronomy Research Team (HEART [35]) for their support and thoughtful feedback. The IBWS conference participation of B. Koncz was subsidized by the Dean’s Council of ELTE Eötvös Loránd University Faculty of Science, Budapest. References [1] M. Stickel, S. Bogun, D. Lemke, et al. The ISOPHOT far-infrared serendipity north ecliptic pole minisurvey. Astronomy & Astrophysics 336:116–122, 1998. [2] L. V. Tóth, S. Hotzel, O. Krause, et al. ISOPHOT serendipity survey observations of interstellar clouds I. Detection of the coldest cores in chamaeleon. Astronomy & Astrophysics 364:769–779, 2000. 68 vol. 65 no. 1/2025 Mass growth of massive quiescent galaxies . . . [3] P. Héraudeau, S. Oliver, C. del Burgo, et al. The European large area ISO survey – VIII. 90-µm final analysis and source counts. Monthly Notices of the Royal Astronomical Society 354(3):924–934, 2004. https: //doi.org/10.1111/j.1365-2966.2004.08259.x [4] M. F. Kessler, J. A. Steinz, M. E. Anderegg, et al. The Infrared Space Observatory (ISO) mission. Astronomy & Astrophysics 315(2):L27–L31, 1996. [5] P. Madau, M. Dickinson. Cosmic star-formation history. Annual Review of Astronomy and Astrophysics 52:415–486, 2014. https://doi.org/10.1146/annurev- astro-081811-125615 [6] N. Suleiman, A. Noboriguchi, Y. Toba, et al. The statistical properties of 28 IR-bright dust-obscured galaxies and SED modelling using CIGALE. Publications of the Astronomical Society of Japan 74(5):1157–1185, 2022. https://doi.org/10.1093/pasj/psac061 [7] I. I. Rácz, A. J. Hortobagyi. Studying the variability of the X-ray spectral parameters of high-redshift GRBs’ afterglows. Astronomische Nachrichten 339(5):347–351, 2018. https://doi.org/10.1002/asna.201813503 [8] I. I. Rácz, L. G. Balázs, I. Horvath, et al. Statistical properties of Fermi GBM GRBs’ spectra. Monthly Notices of the Royal Astronomical Society 475(1):306– 320, 2018. https://doi.org/10.1093/mnras/stx3152 [9] I. Horvath, I. I. Rácz, Z. Bagoly, et al. Does the GRB duration depend on redshift? Universe 8(4):221, 2022. https://doi.org/10.3390/universe8040221 [10] L. G. Balázs, A. Mészáros, I. Horváth, R. Vavrek. An intrinsic anisotropy in the angular distribution of gamma-ray bursts. Astronomy and Astrophysics Supplement Series 138:417–418, 1999. https://doi.org/10.1051/aas:1999290 [11] A. Mészáros, Z. Bagoly, I. Horváth, et al. A remarkable angular distribution of the intermediate subclass of gamma-ray bursts. The Astrophysical Journal 539(1):98, 2000. https://doi.org/10.1086/309193 [12] A. Mészáros, Z. Bagoly, R. Vavrek. On the existence of the intrinsic anisotropies in the angular distributions of gamma-ray bursts. Astronomy & Astrophysics 354:1–6, 2000. https://doi.org/10.48550/arXiv.astro-ph/9912037 [13] R. Vavrek, L. G. Balázs, A. Mészáros, et al. Testing the randomness in the sky-distribution of gamma-ray bursts. Monthly Notices of the Royal Astronomical Society 391(4):1741–1748, 2008. https: //doi.org/10.1111/j.1365-2966.2008.13635.x [14] A. Pontzen, M. Tremmel, N. Roth, et al. How to quench a galaxy. Monthly Notices of the Royal Astronomical Society 465(1):547–558, 2016. https://doi.org/10.1093/mnras/stw2627 [15] S. L. Ellison, S. Wilkinson, J. Woo, et al. Galaxy mergers can rapidly shut down star formation. Monthly Notices of the Royal Astronomical Society: Letters 517(1):L92–L96, 2022. https://doi.org/10.1093/mnrasl/slac109 [16] C. Mancini, A. Renzini, E. Daddi, et al. Star formation and quenching among the most massive galaxies at z ∼1.7. Monthly Notices of the Royal Astronomical Society 450(1):763–786, 2015. https://doi.org/10.1093/mnras/stv608 [17] G. Barro, S. M. Faber, A. Dekel, et al. Caught in the act: Gas and stellar velocity dispersions in a fast quenching compact star-forming galaxy at z ∼ 1.7. The Astrophysical Journal 820(2):120, 2016. https://doi.org/10.3847/0004-637X/820/2/120 [18] D. Nelson, A. Pillepich, V. Springel, et al. First results from the IllustrisTNG simulations: The galaxy colour bimodality. Monthly Notices of the Royal Astronomical Society 475(1):624–647, 2018. https://doi.org/10.1093/mnras/stx3040 [19] F. Marinacci, M. Vogelsberger, R. Pakmor, et al. First results from the IllustrisTNG simulations: Radio haloes and magnetic fields. Monthly Notices of the Royal Astronomical Society 480(4):5113–5139, 2018. https://doi.org/10.1093/mnras/sty2206 [20] A. Pillepich, D. Nelson, L. Hernquist, et al. First results from the IllustrisTNG simulations: The stellar mass content of groups and clusters of galaxies. Monthly Notices of the Royal Astronomical Society 475(1):648– 675, 2018. https://doi.org/10.1093/mnras/stx3112 [21] V. Springel, R. Pakmor, A. Pillepich, et al. First results from the IllustrisTNG simulations: Matter and galaxy clustering. Monthly Notices of the Royal Astronomical Society 475(1):676–698, 2018. https://doi.org/10.1093/mnras/stx3304 [22] J. P. Naiman, A. Pillepich, V. Springel, et al. First results from the IllustrisTNG simulations: A tale of two elements – chemical evolution of magnesium and europium. Monthly Notices of the Royal Astronomical Society 477(1):1206–1224, 2018. https://doi.org/10.1093/mnras/sty618 [23] S. Genel, D. Nelson, A. Pillepich, et al. The size evolution of star-forming and quenched galaxies in the IllustrisTNG simulation. Monthly Notices of the Royal Astronomical Society 474(3):3976–3996, 2018. https://doi.org/10.1093/mnras/stx3078 [24] J. J. Davies, R. A. Crain, B. D. Oppenheimer, J. Schaye. The quenching and morphological evolution of central galaxies is facilitated by the feedback-driven expulsion of circumgalactic gas. Monthly Notices of the Royal Astronomical Society 491(3):4462–4480, 2020. https://doi.org/10.1093/mnras/stz3201 [25] Y. Luo, Z. Li, X. Kang, et al. What has quenched the massive spiral galaxies? Monthly Notices of the Royal Astronomical Society: Letters 496(1):L116–L121, 2020. https://doi.org/10.1093/mnrasl/slaa099 [26] S. Quai, M. H. Hani, S. L. Ellison, et al. Interacting galaxies in the IllustrisTNG simulations – III. (The rarity of) quenching in post-merger galaxies. Monthly Notices of the Royal Astronomical Society 504(2):1888–1901, 2021. https://doi.org/10.1093/mnras/stab988 [27] Y. Xu, Y. Luo, X. Kang, et al. Quenching of massive disk galaxies in the IllustrisTNG simulation. The Astrophysical Journal 928(2):100, 2022. https://doi.org/10.3847/1538-4357/ac53ab [28] V. Rodriguez-Gomez, S. Genel, M. Vogelsberger, et al. The merger rate of galaxies in the Illustris simulation: A comparison with observations and semi-empirical models. Monthly Notices of the Royal Astronomical Society 449(1):49–64, 2015. https://doi.org/10.1093/mnras/stv264 69 https://doi.org/10.1111/j.1365-2966.2004.08259.x https://doi.org/10.1111/j.1365-2966.2004.08259.x https://doi.org/10.1146/annurev-astro-081811-125615 https://doi.org/10.1146/annurev-astro-081811-125615 https://doi.org/10.1093/pasj/psac061 https://doi.org/10.1002/asna.201813503 https://doi.org/10.1093/mnras/stx3152 https://doi.org/10.3390/universe8040221 https://doi.org/10.1051/aas:1999290 https://doi.org/10.1086/309193 https://doi.org/10.48550/arXiv.astro-ph/9912037 https://doi.org/10.1111/j.1365-2966.2008.13635.x https://doi.org/10.1111/j.1365-2966.2008.13635.x https://doi.org/10.1093/mnras/stw2627 https://doi.org/10.1093/mnrasl/slac109 https://doi.org/10.1093/mnras/stv608 https://doi.org/10.3847/0004-637X/820/2/120 https://doi.org/10.1093/mnras/stx3040 https://doi.org/10.1093/mnras/sty2206 https://doi.org/10.1093/mnras/stx3112 https://doi.org/10.1093/mnras/stx3304 https://doi.org/10.1093/mnras/sty618 https://doi.org/10.1093/mnras/stx3078 https://doi.org/10.1093/mnras/stz3201 https://doi.org/10.1093/mnrasl/slaa099 https://doi.org/10.1093/mnras/stab988 https://doi.org/10.3847/1538-4357/ac53ab https://doi.org/10.1093/mnras/stv264 Bendegúz Koncz, András Péter Joó Acta Polytechnica [29] V. Springel, S. D. M. White, A. Jenkins, et al. Simulations of the formation, evolution and clustering of galaxies and quasars. Nature 435(7042):629–636, 2005. https://doi.org/10.1038/nature03597 [30] B. Koncz, A. P. Joó, S. Pintér. Investigating star formation in Illustris TNG galaxy mergers. Contributions of the Astronomical Observatory Skalnaté Pleso 53(4):153–163, 2023. https://doi.org/10.31577/caosp.2023.53.4.153 [31] G. Fragione, A. Loeb. Constraining the Milky Way mass with hypervelocity stars. New Astronomy 55:32–38, 2017. https://doi.org/10.1016/j.newast.2017.03.002 [32] E. L. Łokas. Tidal evolution of galaxies in the most massive cluster of IllustrisTNG-100. Astronomy & Astrophysics 638:A133, 2020. https://doi.org/10.1051/0004-6361/202037643 [33] T. M. Jackson, A. Pasquali, C. Pacifici, et al. The stellar mass assembly of low-redshift, massive, central galaxies in SDSS and the TNG300 simulation. Monthly Notices of the Royal Astronomical Society 497(4):4262–4275, 2020. https://doi.org/10.1093/mnras/staa2306 [34] G. Zeng, L. Wang, L. Gao. Formation of massive disc galaxies in the IllustrisTNG simulation. Monthly Notices of the Royal Astronomical Society 507(3):3301–3311, 2021. https://doi.org/10.1093/mnras/stab2294 [35] Eötvös Loránd University. The High Energy Astronomy Research Team (HEART), 2025. [2024-07-10]. https://physics.elte.hu/KRFT_heart 70 https://doi.org/10.1038/nature03597 https://doi.org/10.31577/caosp.2023.53.4.153 https://doi.org/10.1016/j.newast.2017.03.002 https://doi.org/10.1051/0004-6361/202037643 https://doi.org/10.1093/mnras/staa2306 https://doi.org/10.1093/mnras/stab2294 https://physics.elte.hu/KRFT_heart vol. 65 no. 1/2025 Mass growth of massive quiescent galaxies . . . Appendix A. Data sets of galaxies SubhaloID Number SubhaloMass ΣMNext Median Mass ratio of mergers (F.P.) mass [%] 0 22 392 127 397.82 2 635.83 0.091 2.068 736368 7 497 36 020.56 898.84 0.087 2.495 1018388 585 776.10 105.77 0.087 13.629 1048329 293 519.71 57.140 0.095 10.994 1058913 462 664.53 65.209 0.091 9.812 1069625 168 376.50 24.11 0.096 6.403 1075230 270 245.08 41.71 0.092 17.018 1085744 229 235.72 35.70 0.096 15.145 1089872 219 276.92 32.31 0.092 11.667 1094694 220 266.73 28.639 0.092 10.737 1099774 163 228.91 30.09 0.092 13.143 1104150 403 115.74 65.10 0.095 56.244 1116698 267 196.44 130.59 0.096 66.480 1121509 189 234.78 53.27 0.092 22.691 1125518 229 161.15 33.57 0.092 20.832 1130071 130 150.86 37.05 0.093 24.555 1132394 207 106.83 30.03 0.100 28.105 1136811 140 134.39 28.10 0.096 20.906 1140268 44 143.12 7.85 0.104 5.483 1142320 107 131.81 15.02 0.096 11.398 1144944 111 117.70 24.31 0.104 20.655 1147617 436 84.51 65.28 0.096 77.251 1155194 134 126.78 22.31 0.103 17.599 1157655 106 115.05 19.16 0.094 16.652 2780287 2 896 22 357.31 482.27 0.088 2.157 2875663 655 2 145.17 93.53 0.088 4.360 3358682 2 263 8 755.08 299.17 0.092 3.417 4021974 37 53.52 4.16 0.090 7.764 4023572 22 34.01 2.40 0.100 7.065 4026317 9 10.23 1.08 0.084 10.549 4027444 20 10.41 5.08 0.103 48.769 4028529 9 6.18 0.91 0.092 14.662 4501970 7 4.74 0.67 0.087 14.177 4503693 5 7.21 0.41 0.088 5.752 4505129 6 6.27 1.65 0.098 26.318 4575694 3 569 18 502.54 427.16 0.088 2.309 7115908 1 125 4 922.47 145.89 0.088 2.964 11088783 902 6 064.25 280.99 0.088 4.633 Table 1. Details of the progenitors connected to the massive quiescent galaxies. The columns are as follows: (1) SubhaloID of the massive quiescent galaxy, (2) number of galaxies that have merged into this at all redshift, (3) SubhaloMass of the FirstProgenitor of the Subhalo in question, (4) sum of the masses of the NextProgenitor galaxies, (5) median mass of the NextProgenitor galaxies, (6) NextProgenitors mass ratio to the SubhaloMass. 71 Bendegúz Koncz, András Péter Joó Acta Polytechnica SubhaloID > 1 10 ratio > 1 100 ratio > 1 1000 ratio 1 1000 > ratio Tiny ( 1 100 >) [pc/%] [pc/%] [pc/%] [pc/%] mass ratio [%] 0 0 / 0.00 3 / 0.01 83 / 0.38 22 280 / 99.61 91.07 736368 0 / 0.00 128 / 1.71 74 / 0.99 7 292 / 97.30 19.21 1018388 1 / 0.17 8 / 1.39 131 / 22.74 436 / 75.69 61.22 1048329 2 / 0.68 10 / 3.45 62 / 21.38 216 / 74.48 13.95 1058913 0 / 0.00 12 / 2.60 71 / 15.37 379 / 81.03 50.50 1069625 0 / 0.00 21 / 12.50 22 / 13.10 125 / 74.40 22.89 1075230 3 / 1.11 13 / 4.81 100 / 37.04 154 / 57.04 4.54 1085744 4 / 1.75 9 / 3.93 50 / 21.83 166 / 72.49 19.95 1089872 2 / 0.91 9 / 4.11 47 / 21.46 161 / 73.52 28.43 1094694 0 / 0.00 15 / 6.82 46 / 20.91 159 / 72.27 37.77 1099774 2 / 1.23 12 / 7.36 52 / 31.90 97 / 59.51 1.45 1104150 2 / 0.49 11 / 2.73 78 / 19.35 312 / 77.42 29.29 1116698 1 / 0.37 17 / 6.37 44 / 16.48 205 / 76.78 10.48 1121509 2 / 1.06 12 / 6.35 35 / 18.52 140 / 74.07 0.86 1125518 2 / 0.87 8 / 3.49 47 / 20.52 172 / 75.11 2.49 1130071 10 / 7.69 10 / 7.69 45 / 34.62 65 / 50.00 0.18 1132394 0 / 0.00 6 / 2.90 75 / 36.23 126 / 60.87 77.10 1136811 0 / 0.00 23 / 16.43 48 / 34.29 69 / 49.29 28.02 1140268 2 / 4.54 10 / 22.73 18 / 40.91 14 / 31.82 11.10 1142320 0 / 0.00 13 / 12.15 41 / 38.32 53 / 49.53 24.40 1144944 0 / 0.00 16 / 14.41 54 / 48.65 41 / 36.94 29.53 1147617 0 / 0.00 12 / 2.75 84 / 19.27 340 / 77.98 52.14 1155194 2 / 1.49 14 / 10.45 58 / 43.28 60 / 44.78 14.74 1157655 1 / 0.94 13 / 12.26 44 / 41.51 48 / 45.28 29.38 2780287 1 / 0.03 13 / 0.45 137 / 4.73 2 745 / 94.79 47.59 2875663 7 / 1.07 5 / 0.76 22 / 3.36 621 / 94.81 1.77 3358682 0 / 0.00 8 / 0.35 62 / 2.74 2 193 / 96.91 66.34 4021974 1 / 2.70 11 / 29.73 25 / 67.57 0 / 0.00 18.08 4023572 1 / 4.54 9 / 40.91 11 / 50.00 1 / 4.55 7.76 4026317 3 / 33.33 6 / 66.67 0 / 0.00 0 / 0.00 0.00 4027444 9 / 45.00 9 / 45.00 2 / 10.00 0 / 0.00 0.07 4028529 1 / 11.11 7 / 77.78 1 / 11.11 0 / 0.00 2.45 4501970 2 / 28.57 5 / 71.43 0 / 0.00 0 / 0.00 0.00 4503693 1 / 20.00 3 / 60.00 1 / 20.00 0 / 0.00 1.59 4505129 2 / 33.33 4 / 66.67 0 / 0.00 0 / 0.00 0.00 4575694 0 / 0.00 17 / 0.48 65 / 1.82 3 487 / 97.70 45.40 7115908 0 / 0.00 8 / 0.71 71 / 6.31 1 046 / 92.98 71.96 11088783 4 / 0.44 20 / 2.22 30 / 3.33 848 / 94.01 0.27 Table 2. Details of the progenitors connected to the massive quiescent galaxies. The columns are as follows: (1) SubhaloID of the massive quiescent galaxy, (2) mumber of galaxies and their rate to all progenitors that have the mass ratio > 1 10 with the Subhalo in question, (3),(4),(5) same as (2) but with other ratios, (6) progenitors with 1 100 mass ratio total mass relative to the galaxy in question. 72 Acta Polytechnica 65(1):65–72, 2025 1 Introduction 2 Methods 3 Results 4 Conclusion Acknowledgements References A Data sets of galaxies