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1. Detection of very-high-energy gamma-ray emission from Eta Carinae during its 2020 periastron passage

Author

Collaboration, H. E. S. S., Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Bradascio, F., Brose, R., Brown, A., Brun, F., Bruno, B., Burger-Scheidlin, C., Casanova, S., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Collins, T., Cotter, G., Mbarubucyeye, J. Damascene, Scarpin, J. de Assis, Devin, J., Djannati-Ataï, A., Djuvsland, J., Dmytriiev, A., Egberts, K., Einecke, S., Ernenwein, J. -P., Nieves, C. Escañuela, Feijen, K., Filipovic, M., Fontaine, G., Funk, S., Gabici, S., Glicenstein, J. F., Grolleron, G., Grondin, M. -H., Haerer, L., Heß, B., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Jardin-Blicq, A., Jung-Richardt, I., Katarzyński, K., Khatoon, R., Khélifi, B., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Lang, R. G., Stum, S. Le, Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Luashvili, A., Mackey, J., Malyshev, D., Marandon, V., Marcowith, A., Martí-Devesa, G., Marx, R., Mehta, A., Mitchell, A., Moderski, R., Moghadam, M. O., Mohrmann, L., Moulin, E., de Naurois, M., Niemiec, J., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Pensec, U., Pühlhofer, G., Quirrenbach, A., Ravikularaman, S., Regeard, M., Reimer, A., Reimer, O., Remy, Q., Ren, H., Reville, B., Rieger, F., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sabri, K., Sahakian, V., Salzmann, H., Santangelo, A., Sasaki, M., Schäfer, J., Schüssler, F., Schutte, H. M., Shapopi, J. N. S., Spencer, S., Stawarz, Ł., Steenkamp, R., Steinmassl, S., Steppa, C., Streil, K., Tanaka, T., Terrier, R., Tluczykont, M., Tsirou, M., Tsuji, N., van Eldik, C., Vecchi, M., Venter, C., Wach, T., Wagner, S. J., Werner, F., White, R., Wierzcholska, A., Zacharias, M., Zdziarski, A. A., Zech, A., and Żywucka, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The colliding-wind binary system $\eta$ Carinae has been identified as a source of high-energy (HE, below $\sim$100\,GeV) and very-high-energy (VHE, above $\sim$100\,GeV) gamma rays in the last decade, making it unique among these systems. With its eccentric 5.5-year-long orbit, the periastron passage, during which the stars are separated by only $1-2$\,au, is an intriguing time interval to probe particle acceleration processes within the system. In this work, we report on an extensive VHE observation campaign that for the first time covers the full periastron passage carried out with the High Energy Stereoscopic System (H.E.S.S.) in its 5-telescope configuration with upgraded cameras. VHE gamma-ray emission from $\eta$ Carinae was detected during the periastron passage with a steep spectrum with spectral index $\Gamma= 3.3 \pm 0.2_{\mathrm{stat}} \, \pm 0.1_{\mathrm{syst}}$. Together with previous and follow-up observations, we derive a long-term light curve sampling one full orbit, showing hints of an increase of the VHE flux towards periastron, but no hint of variability during the passage itself. An analysis of contemporaneous Fermi-LAT data shows that the VHE spectrum represents a smooth continuation of the HE spectrum. From modelling the combined spectrum we conclude that the gamma-ray emission region is located at distances of ${\sim}10 - 20$\,au from the centre of mass of the system and that protons are accelerated up to energies of at least several TeV inside the system in this phase., Comment: Accepted at A&A; 11 pages, 9 figures

Published
2025

2. High-Statistics Measurement of the Cosmic-Ray Electron Spectrum with H.E.S.S

Author

Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Borowska, J., Bouyahiaoui, M., Brose, R., Brown, A., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Bylund, T., Casanova, S., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Collins, T., Cotter, G., Mbarubucyeye, J. Damascene, Devin, J., Djuvsland, J., Dmytriiev, A., Egberts, K., Einecke, S., Ernenwein, J. -P., Fegan, S., Feijen, K., Fontaine, G., Funk, S., Gabici, S., Gallant, Y. A., Glicenstein, J. F., Glombitza, J., Grolleron, G., Heß, B., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzynski, K., Kerszberg, D., Khatoon, R., Khelifi, B., Kluzniak, W., Komin, Nu., Kosack, K., Kostunin, D., Kundu, A., Lang, R. G., Stum, S. Le, Leitl, F., Lemiere, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Luashvili, A., Mackey, J., Malyshev, D., Marandon, V., Marinos, P., Marti-Devesa, G., Marx, R., Meyer, M., Mitchell, A., Moderski, R., Moghadam, M. O., Mohrmann, L., Montanari, A., Moulin, E., de Naurois, M., Niemiec, J., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, D., Pensec, U., Peron, G., Pühlhofer, G., Punch, M., Quirrenbach, A., Ravikularaman, S., Regeard, M., Reimer, A., Reimer, O., Reis, I., Ren, H., Reville, B., Rieger, F., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Salzmann, H., Santangelo, A., Sasaki, M., Schäfer, J., Schüssler, F., Schutte, H. M., Shapopi, J. N. S., Sharma, A., Sol, H., Spencer, S., Stawarz, L., Steinmassl, S., Steppa, C., Suzuki, H., Takahashi, T., Tanaka, T., Taylor, A. M., Terrier, R., Tsirou, M., van Eldik, C., Vecchi, M., Venter, C., Vink, J., Wach, T., Wagner, S. J., Wierzcholska, A., Zacharias, M., Zdziarski, A. A., Zech, A., and Zywucka, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Owing to their rapid cooling rate and hence loss-limited propagation distance, cosmic-ray electrons and positrons (CRe) at very high energies probe local cosmic-ray accelerators and provide constraints on exotic production mechanisms such as annihilation of dark matter particles. We present a high-statistics measurement of the spectrum of CRe candidate events from 0.3 to 40 TeV with the High Energy Stereoscopic System (H.E.S.S.), covering two orders of magnitude in energy and reaching a proton rejection power of better than $10^{4}$. The measured spectrum is well described by a broken power law, with a break around 1 TeV, where the spectral index increases from $\Gamma_1 = 3.25$ $\pm$ 0.02 (stat) $\pm$ 0.2 (sys) to $\Gamma_2 = 4.49$ $\pm$ 0.04 (stat) $\pm$ 0.2 (sys). Apart from the break, the spectrum is featureless. The absence of distinct signatures at multi-TeV energies imposes constraints on the presence of nearby CRe accelerators and the local CRe propagation mechanisms., Comment: main paper: 8 pages, 4 figures, supplemental material: 12 pages, 14 figures, accepted for publication in Physical Review Letters https://journals.aps.org/prl/

Published
2024
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3. H.E.S.S. observations of the 2021 periastron passage of PSR B1259-63/LS 2883

Author

Collaboration, H. E. S. S., Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Borowska, J., Bouyahiaoui, M., Brose, R., Brown, A., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Caroff, S., Casanova, S., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Cotter, G., Mbarubucyeye, J. Damascene, Devin, J., Djuvsland, J., Dmytriiev, A., Egberts, K., Einecke, S., Ernenwein, J. -P., Fontaine, G., Funk, S., Gabici, S., Gallant, Y. A., Glawion, D., Glicenstein, J. F., Goswami, P., Grolleron, G., Haerer, L., Heß, B., Hofmann, W., Holch, T. L., Holler, M., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyński, K., Khangulyan, D., Khatoon, R., Khélifi, B., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Kundu, A., Lang, R. G., Stum, S. Le, Leitl, F., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Mackey, J., Malyshev, D., Martí-Devesa, G., Marx, R., Mehta, A., Meintjes, P. J., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Murach, T., de Naurois, M., Niemiec, J., Ohm, S., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Pensec, U., Peron, G., Prokhorov, D. A., Pühlhofer, G., Punch, M., Quirrenbach, A., Regeard, M., Reimer, A., Reimer, O., Reis, I., Ren, H., Rieger, F., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Salzmann, H., Santangelo, A., Sasaki, M., Schäfer, J., Schüssler, F., Schutte, H. M., Shapopi, J. N. S., Spencer, S., Stawarz, Ł., Steenkamp, R., Steinmassl, S., Steppa, C., Streil, K., Sushch, I., Takahashi, T., Tanaka, T., Taylor, A. M., Terrier, R., Thorpe-Morgan, C., Tluczykont, M., Unbehaun, T., van Eldik, C., van Soelen, B., Vecchi, M., Venter, C., Vink, J., Wach, T., Wagner, S. J., Werner, F., Wierzcholska, A., Zacharias, M., Zdziarski, A. A., Zech, A., and Żywucka, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

PSR B1259-63 is a gamma-ray binary system that hosts a pulsar in an eccentric orbit, with a 3.4 year period, around an O9.5Ve star. At orbital phases close to periastron passages, the system radiates bright and variable non-thermal emission. We report on an extensive VHE observation campaign conducted with the High Energy Stereoscopic System, comprised of ~100 hours of data taken from $t_p-24$ days to $t_p+127$ days around the system's 2021 periastron passage. We also present the timing and spectral analyses of the source. The VHE light curve in 2021 is consistent with the stacked light curve of all previous observations. Within the light curve, we report a VHE maximum at times coincident with the third X-ray peak first detected in the 2021 X-ray light curve. In the light curve -- although sparsely sampled in this time period -- we see no VHE enhancement during the second disc crossing. In addition, we see no correspondence to the 2021 GeV flare in the VHE light curve. The VHE spectrum obtained from the analysis of the 2021 dataset is best described by a power law of spectral index $\Gamma = 2.65 \pm 0.04_{\text{stat}}$ $\pm 0.04_{\text{sys}}$, a value consistent with the previous H.E.S.S. observations of the source. We report spectral variability with a difference of $\Delta \Gamma = 0.56 ~\pm~ 0.18_{\text{stat}}$ $~\pm~0.10_{\text{sys}}$ at 95% c.l., between sub-periods of the 2021 dataset. We also find a linear correlation between contemporaneous flux values of X-ray and TeV datasets, detected mainly after $t_p+25$ days, suggesting a change in the available energy for non-thermal radiation processes. We detect no significant correlation between GeV and TeV flux points, within the uncertainties of the measurements, from $\sim t_p-23$ days to $\sim t_p+126$ days. This suggests that the GeV and TeV emission originate from different electron populations., Comment: accepted to A&A

Published
2024

4. Unveiling extended gamma-ray emission around HESS J1813-178

Author

Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Baktash, A., Martins, V. Barbosa, Barnard, J., Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Borowska, J., Bouyahiaoui, M., Breuhaus, M., Brose, R., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Caroff, S., Casanova, S., Cecil, R., Celic, J., Cerruti, M., Chambery, P., Chand, T., Chen, A., Chibueze, J., Chibueze, O., Cotter, G., Mbarubucyeye, J. Damascene, Djannati-Ataï, A., Dmytriiev, A., Doroshenko, V., Einecke, S., Ernenwein, J. -P., Feijen, K., Filipovic, M., Fontaine, G., Füßling, M., Funk, S., Gabici, S., Gallant, Y. A., Ghafourizadeh, S., Giavitt, G., Glawion, D., Glicenstein, J. F., Goswami, P., Grolleron, G., Grondin, M. -H., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Katarzyński, K., Khatoon, R., Khélifi, B., Klepser, S., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Kundu, A., Lang, R. G., Stum, S. Le, Leitl, F., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Mackey, J., Malyshev, D., Marandon, V., Marinos, P., Martí-Devesa, G., Marx, R., Mehta, A., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Murach, T., de Naurois, M., Niemiec, J., Noel, A. Priyana, O'Brien, P., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Prokhorov, D. A., Pühlhofer, G., Punch, M., Quirrenbach, A., Regeard, M., Reichherzer, P., Reimer, A., Reimer, O., Ren, H., Renaud, M., Reville, B., Rieger, F., Roellinghoff, G., Rudak, B., Sahakian, V., Salzmann, H., Sasaki, M., Schüssler, F., Schutte, H. M., Shapopi, J. N. S., Specovius, A., Spencer, S., Steenkamp, R., Steinmassl, S., Steppa, C., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Terrier, R., Tluczykont, M., Tsuji, N., Unbehaun, T., van Eldik, C., Vecchi, M., Veh, J., Venter, C., Vink, J., Wach, T., Wagner, S. J., Wierzcholska, A., Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zouari, S., and Żywucka, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

HESS J1813$-$178 is a very-high-energy $\gamma$-ray source spatially coincident with the young and energetic pulsar PSR J1813$-$1749 and thought to be associated with its pulsar wind nebula (PWN). Recently, evidence for extended high-energy emission in the vicinity of the pulsar has been revealed in the Fermi Large Area Telescope (LAT) data. This motivates revisiting the HESS J1813$-$178 region, taking advantage of improved analysis methods and an extended data set. Using data taken by the High Energy Stereoscopic System (H.E.S.S.) experiment and the Fermi-LAT, we aim to describe the $\gamma$-ray emission in the region with a consistent model, to provide insights into its origin. We performed a likelihood-based analysis on 32 hours of H.E.S.S. data and 12 years of Fermi-LAT data and fit a spectro-morphological model to the combined datasets. These results allowed us to develop a physical model for the origin of the observed $\gamma$-ray emission in the region. In addition to the compact very-high-energy $\gamma$-ray emission centered on the pulsar, we find a significant yet previously undetected component along the Galactic plane. With Fermi-LAT data, we confirm extended high-energy emission consistent with the position and elongation of the extended emission observed with H.E.S.S. These results establish a consistent description of the emission in the region from GeV energies to several tens of TeV. This study suggests that HESS J1813$-$178 is associated with a $\gamma$-ray PWN powered by PSR J1813$-$1749. A possible origin of the extended emission component is inverse Compton emission from electrons and positrons that have escaped the confines of the pulsar and form a halo around the PWN., Comment: 13+5 pages, 13+11 figures. Accepted for publication in A&A. Corresponding authors: T.Wach, A.Mitchell, V.Joshi, P.Chamb\'ery

Published
2024
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5. Spectrum and extension of the inverse-Compton emission of the Crab Nebula from a combined Fermi-LAT and H.E.S.S. analysis

Author

Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Baktash, A., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Borowska, J., Bradascio, F., Breuhaus, M., Brose, R., Brown, A., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Bylund, T., Caroff, S., Casanova, S., Cecil, R., Celic, J., Cerruti, M., Chambery, P., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Cotter, G., Cristofari, P., Devin, J., Djannati-Ataï, A., Djuvsland, J., Dmytriiev, A., Einecke, S., Ernenwein, J. -P., Fegan, S., Feijen, K., Filipović, M., Fontaine, G., Füßling, M., Funk, S., Gabici, S., Gallant, Y. A., Giavitto, G., Glawion, D., Glicenstein, J. F., Glombitza, J., Goswami, P., Grolleron, G., Grondin, M. -H., Haerer, L., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Jamrozy, M., Jankowsky, F., Joshi, V., Kasai, E., Katarzyński, K., Khatoon, R., Khélifi, B., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Kundu, A., Lang, R. G., Stum, S. Le, Leitl, F., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Luashvili, A., Mackey, J., Malyshev, D., Marandon, V., Marinos, P., Martí-Devesa, G., Marx, R., Mehta, A., Meyer, M., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Murach, T., de Naurois, M., Niemiec, J., O'Brien, P., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Peron, G., Prokhorov, D. A., Pühlhofer, G., Punch, M., Quirrenbach, A., Regeard, M., Reichherzer, P., Reimer, A., Reimer, O., Ren, H., Renaud, M., Reville, B., Rieger, F., Roellinghoff, G., Rudak, B., Sahakian, V., Salzmann, H., Sasaki, M., Schüssler, F., Schutte, H. M., Shapopi, J. N. S., Specovius, A., Spencer, S., Stawarz, Ł., Steenkamp, R., Steinmassl, S., Steppa, C., Streil, K., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Terrier, R., Tluczykont, M., Tsuji, N., Unbehaun, T., van Eldik, C., Vecchi, M., Veh, J., Venter, C., Vink, J., Wach, T., Wagner, S. J., Wierzcholska, A., Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zouari, S., Żywucka, N., and Harding, A.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The Crab Nebula is a unique laboratory for studying the acceleration of electrons and positrons through their non-thermal radiation. Observations of very-high-energy $\gamma$ rays from the Crab Nebula have provided important constraints for modelling its broadband emission. We present the first fully self-consistent analysis of the Crab Nebula's $\gamma$-ray emission between 1 GeV and $\sim$100 TeV, that is, over five orders of magnitude in energy. Using the open-source software package Gammapy, we combined 11.4 yr of data from the Fermi Large Area Telescope and 80 h of High Energy Stereoscopic System (H.E.S.S.) data at the event level and provide a measurement of the spatial extension of the nebula and its energy spectrum. We find evidence for a shrinking of the nebula with increasing $\gamma$-ray energy. Furthermore, we fitted several phenomenological models to the measured data, finding that none of them can fully describe the spatial extension and the spectral energy distribution at the same time. Especially the extension measured at TeV energies appears too large when compared to the X-ray emission. Our measurements probe the structure of the magnetic field between the pulsar wind termination shock and the dust torus, and we conclude that the magnetic field strength decreases with increasing distance from the pulsar. We complement our study with a careful assessment of systematic uncertainties., Comment: 18+6 pages, 15+2 figures. Accepted for publication in A&A. Corresponding authors: M. Meyer, L. Mohrmann, T. Unbehaun. v2: after A&A language editing

Published
2024
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6. Curvature in the very-high energy gamma-ray spectrum of M87

Author

Collaboration, H. E. S. S., Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Bradascio, F., Brose, R., Brun, F., Bruno, B., Burger-Scheidlin, T. Bulik C., Bylund, T., Casanova, S., Cecil, R., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Collins, T., Cotter, G., Mbarubucyeye, J. Damascene, Djannati-Ataï, A., Djuvsland, J., Dmytriiev, A., Egberts, K., Einecke, S., Fegan, S., Fontaine, G., Funk, S., Gabici, S., Glicenstein, J. F., Glombitza, J., Grolleron, G., Haerer, L., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyński, K., Khatoon, R., Khélifi, B., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Kundu, A., Lang, R. G., Stum, S. Le, Leitl, F., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Lypova, I., Luashvili, A., Mackey, J., Malyshev, D., Martí-Devesa, G., Marx, R., Mehta, A., Meyer, M., Mitchell, A., Moderski, R., Moghadam, M. O., Mohrmann, L., Montanari, A., Moulin, E., Murach, T., de Naurois, M., Niemiec, J., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Panny, S., Panter, M., Parsons, R. D., Pensec, U., Pita, S., Pühlhofer, G., Punch, M., Quirrenbach, A., Regeard, M., Reimer, A., Reimer, O., Ren, H., Reville, B., Rieger, F., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Salzmann, H., Santangelo, A., Sasaki, M., Schüssler, F., Schutte, H. M., Shapopi, J. N. S., Sol, H., Spencer, S., Stawarz, Ł., Steenkamp, R., Steinmassl, S., Steppa, C., Streil, K., Takahashi, T., Tanaka, T., Taylor, A. M., Terrier, R., Tsirou, M., van Eldik, C., Venter, C., Vink, J., Wach, T., Wagner, S. J., Wierzcholska, A., Zacharias, M., Zdziarski, A. A., Zech, A., Zilberman, P., and Zywucka, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The radio galaxy M87 is a variable very-high energy (VHE) gamma-ray source, exhibiting three major flares reported in 2005, 2008, and 2010. Despite extensive studies, the origin of the VHE gamma-ray emission is yet to be understood. In this study, we investigate the VHE gamma-ray spectrum of M87 during states of high gamma-ray activity, utilizing 20.2$\,$ hours the H.E.S.S. observations. Our findings indicate a preference for a curved spectrum, characterized by a log-parabola model with extra-galactic background light (EBL) model above 0.3$\,$TeV at the 4$\sigma$ level, compared to a power-law spectrum with EBL. We investigate the degeneracy between the absorption feature and the EBL normalization and derive upper limits on EBL models mainly sensitive in the wavelength range 12.4$\,$$\mu$m - 40$\,$$\mu$m., Comment: 10 pages, 7 figures. Accepted for publication in A&A. Corresponding authors: Victor Barbosa Martins, Rahul Cecil, Iryna Lypova, Manuel Meyer, Perri Zilberman. Supplementary material: https://zenodo.org/records/10781524

Published
2024
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7. Acceleration and transport of relativistic electrons in the jets of the microquasar SS 433

Author

Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Borowska, J., Bouyahiaou, M., Breuhau, M., Brose, R., Brown, A. M., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Caroff, S., Casanova, S., Cecil, R., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Cotter, G., Dai, S., Mbarubucyeye, J. Damascene, Djannati-Ataï, A., Dmytriiev, A., Doroshenko, V., Egberts, K., Einecke, S., Ernenwein, J. -P., Filipovic, M., Fontaine, G., Funk, S., Gabici, S., Ghafourizadeh, S., Giavitto, G., Glawion, D., Glicenstein, J. F., Grolleron, G., Haerer, L., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Jamrozy, M., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyński, K., Khatoon, R., Khélifi, B., Klepser, S., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Kundu, A., Lang, R. G., Stum, S. Le, Leitl, F., Lemière, A., Lenain, J. -P., Leuschner, F., Lohse, T., Luashvili, A., Mackey, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Martí-Devesa, G., Marx, R., Mehta, A., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Murach, T., Nakashima, K., de Naurois, M., Niemiec, J., Noel, A. Priyana, Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Peron, G., Prokhorov, D. A., Pühlhofer, G., Punch, M., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Ren, H., Renaud, M., Reville, B., Rieger, F., Rowell, G., Rudak, B., Ricarte, H. Rueda, Ruiz-Velasco, E., Sahakian, V., Salzman, H., Santangelo, A., Sasaki, M., Schäfer, J., Schüssler, F., Schwanke, U., Shapopi, J. N. S., Sol, H., Specovius, A., Spencer, S., Stawarz, Ł., Steenkamp, R., Steinmassl, S., Steppa, C., Streil, K., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Taylor, A. M., Terrier, R., Tsirou, M., Tsuji, N., Unbehaun, T., van Eldik, C., Vecchi, M., Veh, J., Venter, C., Vink, J., Wach, T., Wagner, S. J., Werner, F., White, R., Wierzcholska, A., Wong, Yu Wun, Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zouari, S., and Żywucka, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

SS 433 is a microquasar, a stellar binary system with collimated relativistic jets. We observed SS 433 in gamma rays using the High Energy Stereoscopic System (H.E.S.S.), finding an energy-dependent shift in the apparent position of the gamma-ray emission of the parsec-scale jets. These observations trace the energetic electron population and indicate the gamma rays are produced by inverse-Compton scattering. Modelling of the energy-dependent gamma-ray morphology constrains the location of particle acceleration and requires an abrupt deceleration of the jet flow. We infer the presence of shocks on either side of the binary system at distances of 25 to 30 parsecs and conclude that self-collimation of the precessing jets forms the shocks, which then efficiently accelerate electrons., Comment: Submitted 20th Apr. 2023, published 25th January 2024 (accepted version)

Published
2024
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8. Joint H.E.S.S. and Fermi-LAT analysis of the region around PSR J1813-1749

Author

Wach, T., Mitchell, A. M. W., Joshi, V., and Funk, S.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

HESS J1813-178 is one of the brightest sources detected during the first HESS Galactic Plane survey. The compact source, also detected by MAGIC, is believed to be a pulsar wind nebula powered by one of the most powerful pulsars known in the Galaxy, PSR J1813-1749 with a spin-down luminosity of $\dot{\mathrm{E}} = 5.6 \cdot 10^{37}\,\mathrm{erg}\,\mathrm{s}^{-1}$. With its extreme physical properties, as well as the pulsar's young age of 5.6 kyrs, the $\gamma$-rays detected in this region allow us to study the evolution of a highly atypical system. Previous studies of the region in the GeV energy range show emission extended beyond the size of the compact H.E.S.S. source. Using the archival H.E.S.S. data with improved background methods, we perform a detailed morphological and spectral analysis of the region. Additionally to the compact, bright emission component, we find significantly extended emission, whose position is coincident with HESS J1813-178. We reanalyse the region in GeV and derive a joint-model in order to find a continuous description of the emission in the region from GeV to TeV. Using the results derived in this analysis, as well as X-ray and radio data of the region, we perform multi-wavelength spectral modeling. Possible hadronic or leptonic origins of the $\gamma$-ray emission are investigated, and the diffusion parameters necessary to explain the extended emission are examined., Comment: 8 pages, 4 figures, 1 table, In proceedings of ICRC2023

Published
2023

9. The vanishing of the primary emission region in PKS 1510-089

Author

Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Martins, V. Barbosa, Barnard, J., Batzofin, R., Becherini, Y., Berge, D., Bernloehr, K., Bi, B., de Lavergne, M. de Bony, Boettcher, M., Boisson, C., Bolmont, J., Borowska, J., Bouyahiaoui, M., Bradascio, F., Breuhaus, M., Brose, R., Brown, A. M., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Caroff, S., Casanova, S., Cecil, R., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Cotter, G., Mbarubucyeye, J. Damascene, Davids, I. D., Djannati-Atai, A., Dmytriiev, A., Doroshenko, V., Egberts, K., Einecke, S., Ernenwein, J. -P., Fegan, S., Fontaine, G., Fuessling, M., Funk, S., Gabici, S., Ghafourizadeh, S., Giavitto, G., Glawion, D., Glicenstein, J. F., Goswami, P., Grolleron, G., Haerer, L., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyski, K., Khatoon, R., Khelifi, B., Klu/'zniak, W., Komin, Nu., Kosack, K., Kostunin, D., Lang, R. G., Stum, S. Le, Leitl, F., Lemiere, A., Lenain, J. -P., Leuschner, F., Luashvili, A., Mackey, J., Marandon, V., Marchegiani, P., Marti-Devesa, G., Marx, R., Mehta, A., Meyer, M., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., de Naurois, M., Niemiec, J., Noel, A. Priyana, O'Brien, P., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Peron, G., Prokhorov, D. A., Puehlhofer, G., Punch, M., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Ren, H., Rieger, F., Rowell, G., Rudak, B., Ricarte, H. Rueda, Ruiz-Velasco, E., Sahakian, V., Salzmann, H., Sanchez, D. A., Santangelo, A., Sasaki, M., Schuessler, F., Schutte, H. M., Schwanke, U., Shapopi, J. N. S., Sol, H., Specovius, A., Spencer, S., Stawarz, L., Steenkamp, R., Steinmassl, S., Steppa, C., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Terrier, R., Tsuji, N., van Eldik, C., van Soelen, B., Vecchi, M., Veh, J., Vink, J., Wach, T., Wagner, S. J., Wierzcholska, A., Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zouari, S., Zywucka, N., Buckley, D. A. H., Cooper, J., and Groenewald, D.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract

In July 2021, PKS 1510-089 exhibited a significant flux drop in the high-energy gamma-ray (by a factor 10) and optical (by a factor 5) bands and remained in this low state throughout 2022. Similarly, the optical polarization in the source vanished, resulting in the optical spectrum being fully explained through the steady flux of the accretion disk and the broad-line region. Unlike the aforementioned bands, the very-high-energy gamma-ray and X-ray fluxes did not exhibit a significant flux drop from year to year. This suggests that the steady-state very-high-energy gamma-ray and X-ray fluxes originate from a different emission region than the vanished parts of the high-energy gamma-ray and optical jet fluxes. The latter component has disappeared through either a swing of the jet away from the line-of-sight or a significant drop in the photon production efficiency of the jet close to the black hole. Either change could become visible in high-resolution radio images., Comment: 18 pages, 4 figures, 6 tables; accepted for publication in ApJ Letters; corresponding authors: Joleen Barnard, Markus Boettcher, Hester Schutte, Michael Zacharias

Published
2023
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10. Constraining the cosmic-ray pressure in the inner Virgo Cluster using H.E.S.S. observations of M 87

Author

Collaboration, H. E. S. S., Aharonian, F., Benkhali, F. Ait, Arcaro, C., Aschersleben, J., Backes, M., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., Borowska, J., Bradascio, F., Breuhaus, M., Brose, R., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Bylund, T., Caroff, S., Casanova, S., Cecil, R., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Cotter, G., Mbarubucyeye, J. Damascene, Djannati-Ataï, A., Egberts, K., Ernenwein, J. -P., de Clairfontaine, G. Fichet, Filipovic, M., Fontaine, G., Füßling, M., Funk, S., Gabici, S., Ghafourizadeh, S., Giavitto, G., Glawion, D., Glicenstein, J. F., Goswami, P., Grolleron, G., Grondin, M. -H., Haerer, L., Haupt, M., Hermann, G., Hinton, J. A., Holch, T. L., Horns, D., Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyński, K., Khatoon, R., Khélifi, B., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Lang, R. G., Stum, S. Le, Leitl, F., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Lohse, T., Luashvili, A., Lypova, I., Mackey, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Marinos, P., Martí-Devesa, G., Marx, R., Meyer, M., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Muller, J., Nakashima, K., de Naurois, M., Niemiec, J., Noel, A. Priyana, O'Brien, P., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Panny, S., Panter, M., Parsons, R. D., Peron, G., Pita, S., Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Renaud, M., Rieger, F., Rowell, G., Rudak, B., Velasco, E. Ruiz, Sahakian, V., Salzmann, H., Sanchez, D. A., Santangelo, A., Sasaki, M., Schäfer, J., Schüssler, F., Schwanke, U., Shapopi, J. N. S., Sol, H., Specovius, A., Spencer, S., Stawarz, Ł., Steenkamp, R., Steinmassl, S., Steppa, C., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Taylor, A. M., Terrier, R., Tsirou, M., Tsuji, N., Uchiyama, Y., van Eldik, C., van Soelen, B., Vecchi, M., Veh, J., Venter, C., Vink, J., Wach, T., Wagner, S. J., White, R., Wierzcholska, A., Wong, Yu Wun, Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zouari, S., and Żywucka, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract

The origin of the gamma-ray emission from M87 is currently a matter of debate. This work aims to localize the VHE (100 GeV-100 TeV) gamma-ray emission from M87 and probe a potential extended hadronic emission component in the inner Virgo Cluster. The search for a steady and extended gamma-ray signal around M87 can constrain the cosmic-ray energy density and the pressure exerted by the cosmic rays onto the intra-cluster medium, and allow us to investigate the role of the cosmic rays in the active galactic nucleus feedback as a heating mechanism in the Virgo Cluster. H.E.S.S. telescopes are sensitive to VHE gamma rays and have been utilized to observe M87 since 2004. We utilized a Bayesian block analysis to identify M87 emission states with H.E.S.S. observations from 2004 until 2021, dividing them into low, intermediate, and high states. Because of the causality argument, an extended ($\gtrsim$kpc) signal is allowed only in steady emission states. Hence, we fitted the morphology of the 120h low state data and found no significant gamma-ray extension. Therefore, we derived for the low state an upper limit of 58"(corresponding to $\approx$4.6kpc) in the extension of a single-component morphological model described by a rotationally symmetric 2D Gaussian model at 99.7% confidence level. Our results exclude the radio lobes ($\approx$30 kpc) as the principal component of the VHE gamma-ray emission from the low state of M87. The gamma-ray emission is compatible with a single emission region at the radio core of M87. These results, with the help of two multiple-component models, constrain the maximum cosmic-ray to thermal pressure ratio $X_{{CR,max.}}$$\lesssim$$0.32$ and the total energy in cosmic-ray protons (CRp) to $U_{CR}$$\lesssim$5$\times10^{58}$ erg in the inner 20kpc of the Virgo Cluster for an assumed CRp power-law distribution in momentum with spectral index $\alpha_{p}$=2.1., Comment: 15 pages, 7 figures. Accepted for publication in A&A. Corresponding authors: Victor Barbosa Martins, Stefan Ohm, Cornelia Arcaro, Natalia \.Zywucka, Mathieu de Naurois

Published
2023
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11. HESS J1809$-$193: a halo of escaped electrons around a pulsar wind nebula?

Author

Collaboration, H. E. S. S., Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Böttcher, M., Boisson, C., Bolmont, J., Borowska, J., Bouyahiaoui, M., Bradascio, F., Breuhaus, M., Brose, R., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Bylund, T., Caroff, S., Casanova, S., Celic, J., Cerruti, M., Chambery, P., Chand, T., Chen, A., Chibueze, J., Chibueze, O., Mbarubucyeye, J. Damascene, Djannati-Ataï, A., Dmytriiev, A., Einecke, S., Ernenwein, J. -P., Feijen, K., Filipovic, M., Fontaine, G., Füßling, M., Funk, S., Gabici, S., Gallant, Y. A., Ghafourizadeh, S., Giavitto, G., Giunti, L., Glawion, D., Goswami, P., Grolleron, G., Grondin, M. -H., Haerer, L., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyński, K., Khélifi, B., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Lang, R. G., Stum, S. Le, Leitl, F., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Lohse, T., Luashvili, A., Lypova, I., Mackey, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Marinos, P., Martí-Devesa, G., Marx, R., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Muller, J., Nakashima, K., de Naurois, M., Niemiec, J., Noel, A. Priyana, Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Prokhorov, D. A., Pühlhofer, G., Punch, M., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Renaud, M., Reville, B., Rieger, F., Rowell, G., Rudak, B., Sahakian, V., Santangelo, A., Sasaki, M., Schutte, H. M., Schwanke, U., Shapopi, J. N. S., Sol, H., Specovius, A., Spencer, S., Stawarz, Ł., Steenkamp, R., Steinmassl, S., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Terrier, R., Thorpe-Morgan, C., Tsirou, M., Tsuji, N., Uchiyama, Y., van Eldik, C., Vecchi, M., Veh, J., Venter, C., Vink, J., Wach, T., Wagner, S. J., White, R., Wierzcholska, A., Wong, Yu Wun, Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zouari, S., and Żywucka, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Context. HESS J1809$-$193 is an unassociated very-high-energy $\gamma$-ray source located on the Galactic plane. While it has been connected to the nebula of the energetic pulsar PSR J1809$-$1917, supernova remnants and molecular clouds present in the vicinity also constitute possible associations. Recently, the detection of $\gamma$-ray emission up to energies of $\sim$100 TeV with the HAWC observatory has led to renewed interest in HESS J1809$-$193. Aims. We aim to understand the origin of the $\gamma$-ray emission of HESS J1809$-$193. Methods. We analysed 93.2 h of data taken on HESS J1809$-$193 above 0.27 TeV with the High Energy Stereoscopic System (H.E.S.S.), using a multi-component, three-dimensional likelihood analysis. In addition, we provide a new analysis of 12.5 yr of Fermi-LAT data above 1 GeV within the region of HESS J1809$-$193. The obtained results are interpreted in a time-dependent modelling framework. Results. For the first time, we were able to resolve the emission detected with H.E.S.S. into two components: an extended component that exhibits a spectral cut-off at $\sim$13 TeV, and a compact component that is located close to PSR J1809$-$1917 and shows no clear spectral cut-off. The Fermi-LAT analysis also revealed extended $\gamma$-ray emission, on scales similar to that of the extended H.E.S.S. component. Conclusions. Our modelling indicates that based on its spectrum and spatial extent, the extended H.E.S.S. component is likely caused by inverse Compton emission from old electrons that form a halo around the pulsar wind nebula. The compact component could be connected to either the pulsar wind nebula or the supernova remnant and molecular clouds. Due to its comparatively steep spectrum, modelling the Fermi-LAT emission together with the H.E.S.S. components is not straightforward. (abridged), Comment: 14 pages, 10 figures. Accepted for publication in A&A. Corresponding authors: Vikas Joshi, Lars Mohrmann

Published
2023
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12. A background-estimation technique for the detection of extended gamma-ray structures with IACTs.

Author

Wach, T., Mitchell, A., and Mohrmann, L.

Subjects
*GAMMA rays, *THREE-dimensional modeling, *DATA analysis, *TELESCOPES, *ALGORITHMS
Abstract

Context. Estimation of the number of cosmic-ray-induced background events is a challenging task for Imaging Atmospheric Cherenkov Telescopes (IACTs). Most approaches rely on a model of the background signal derived from archival observations, which is then normalised to the region of interest (ROI) and respective observation conditions using emission-free regions in the observation. However, this is disadvantageous for the analysis of large, extended γ-ray structures, where no sufficient source-free region can be found. Aims. We aim to address this issue by estimating the normalisation of a three-dimensional background model template from separate, matched observations of emission-free sky regions. As a result, the need for an emission-free region in the field of view of the observation becomes unnecessary. Methods. To this end, we implemented an algorithm to identify observation pairs with the most closely matching observation conditions. We used the open-source analysis package Gammapy to estimate the background rate, facilitating seamless adaptation of the framework to many γ-ray detection facilities. We employed public data from the High Energy Stereoscopic System (H.E.S.S.) to validate this methodology. Results. The analysis demonstrates that employing a background rate estimated through this run-matching approach yields results consistent with those obtained using the standard application of the background model template. Furthermore, we confirm the compatibility of the source parameters obtained through this approach with previous publications, and present an analysis employing the background model template approach, along with an estimation of the statistical and systematic uncertainties introduced by this method. [ABSTRACT FROM AUTHOR]

Published
2024
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13. HESS observations of the 2021 periastron passage of PSR B1259-63/LS 2883

Author

Aharonian, F., Ait Benkhali, F., Aschersleben, J., Ashkar, H., Backes, M., Barbosa Martins, V., Batzofin, R., Becherini, Yvonne, Berge, D., Bernloehr, K., Boettcher, M., Boisson, C., Bolmont, J., de Bony de Lavergne, M., Borowska, J., Bouyahiaoui, M., Brose, R., Brown, A., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Caroff, S., Casanova, S., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Cotter, G., Damascene Mbarubucyeye, J., Devin, J., Djuvsland, J., Dmytriiev, A., Egberts, K., Einecke, S., Ernenwein, J. -p., Fontaine, G., Funk, S., Gabici, S., Gallant, Y. A., Glawion, D., Glicenstein, J. F., Goswami, P., Grolleron, G., Haerer, L., Hess, B., Hofmann, W., Holch, T. L., Holler, M., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzynski, K., Khangulyan, D., Khatoon, R., Khelifi, B., Kluzniak, W., Komin, Nu., Kosack, K., Kostunin, D., Kundu, A., Lang, R. G., Le Stum, S., Leitl, F., Lemiere, A., Lemoine-Goumard, M., Lenain, J. -p., Leuschner, F., Mackey, J., Malyshev, D., Marti-Devesa, G., Marx, R., Mehta, A., Meintjes, P. J., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Murach, T., de Naurois, M., Niemiec, J., Ohm, S., de Ona Wilhelmi, E., Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Pensec, U., Peron, G., Prokhorov, D. A., Puehlhofer, G., Punch, M., Quirrenbach, A., Regeard, M., Reimer, A., Reimer, O., Reis, I., Ren, H., Rieger, F., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Salzmann, H., Santangelo, A., Sasaki, M., Schaefer, J., Schuessler, F., Schutte, H. M., Shapopi, J. N. S., Spencer, S., Stawarz, L., Steenkamp, R., Steinmassl, S., Steppa, C., Streil, K., Sushch, I., Takahashi, T., Tanaka, T., Taylor, A. M., Terrier, R., Thorpe-Morgan, C., Tluczykont, M., Unbehaun, T., van Eldik, C., van Soelen, B., Vecchi, M., Venter, C., Vink, J., Wach, T., Wagner, S. J., Werner, F., Wierzcholska, A., Zacharias, M., Zdziarski, A. A., Zech, A., Zywucka, N., Aharonian, F., Ait Benkhali, F., Aschersleben, J., Ashkar, H., Backes, M., Barbosa Martins, V., Batzofin, R., Becherini, Yvonne, Berge, D., Bernloehr, K., Boettcher, M., Boisson, C., Bolmont, J., de Bony de Lavergne, M., Borowska, J., Bouyahiaoui, M., Brose, R., Brown, A., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Caroff, S., Casanova, S., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Cotter, G., Damascene Mbarubucyeye, J., Devin, J., Djuvsland, J., Dmytriiev, A., Egberts, K., Einecke, S., Ernenwein, J. -p., Fontaine, G., Funk, S., Gabici, S., Gallant, Y. A., Glawion, D., Glicenstein, J. F., Goswami, P., Grolleron, G., Haerer, L., Hess, B., Hofmann, W., Holch, T. L., Holler, M., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzynski, K., Khangulyan, D., Khatoon, R., Khelifi, B., Kluzniak, W., Komin, Nu., Kosack, K., Kostunin, D., Kundu, A., Lang, R. G., Le Stum, S., Leitl, F., Lemiere, A., Lemoine-Goumard, M., Lenain, J. -p., Leuschner, F., Mackey, J., Malyshev, D., Marti-Devesa, G., Marx, R., Mehta, A., Meintjes, P. J., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Murach, T., de Naurois, M., Niemiec, J., Ohm, S., de Ona Wilhelmi, E., Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Pensec, U., Peron, G., Prokhorov, D. A., Puehlhofer, G., Punch, M., Quirrenbach, A., Regeard, M., Reimer, A., Reimer, O., Reis, I., Ren, H., Rieger, F., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Salzmann, H., Santangelo, A., Sasaki, M., Schaefer, J., Schuessler, F., Schutte, H. M., Shapopi, J. N. S., Spencer, S., Stawarz, L., Steenkamp, R., Steinmassl, S., Steppa, C., Streil, K., Sushch, I., Takahashi, T., Tanaka, T., Taylor, A. M., Terrier, R., Thorpe-Morgan, C., Tluczykont, M., Unbehaun, T., van Eldik, C., van Soelen, B., Vecchi, M., Venter, C., Vink, J., Wach, T., Wagner, S. J., Werner, F., Wierzcholska, A., Zacharias, M., Zdziarski, A. A., Zech, A., and Zywucka, N.

Abstract

PSR B1259-63/LS 2883 is a gamma-ray binary system that hosts a pulsar in an eccentric orbit, with a 3.4 yr period, around an O9.5Ve star (LS 2883). At orbital phases close to periastron passages, the system radiates bright and variable non-thermal emission, for which the temporal and spectral properties of this emission are, for now, poorly understood. In this regard, very high-energy (VHE) emission is especially useful to study and constrain radiation processes and particle acceleration in the system. We report on an extensive VHE observation campaign conducted with the High Energy Stereoscopic System, comprised of approximately 100 h of data taken over five months, from t(p) - 24 days to t(p) + 127 days around the system's 2021 periastron passage (where t(p) is the time of periastron). We also present the timing and spectral analyses of the source. The VHE light curve in 2021 is consistent overall with the stacked light curve of all previous observations. Within the light curve, we report a VHE maximum at times coincident with the third X-ray peak first detected in the 2021 X-ray light curve. In the light curve - although sparsely sampled in this time period - we see no VHE enhancement during the second disc crossing. In addition, we see no correspondence to the 2021 GeV flare in the VHE light curve. The VHE spectrum obtained from the analysis of the 2021 dataset is best described by a power law of spectral index Gamma = 2.65 +/- 0.04(stat) +/- 0.04(sys), a value consistent with the spectral index obtained from the analysis of data collected with H.E.S.S. during the previous observations of the source. We report spectral variability with a difference of Delta Gamma = 0.56 +/- 0.18(stat) +/- 0.10(sys) at 95% confidence intervals, between sub-periods of the 2021 dataset. We also detail our investigation into X-ray/TeV and GeV/TeV flux correlations in the 2021 periastron passage. We find a linear correlation between contemporaneous flux values of X-ray and TeV datase

Published
2024
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14. The Vanishing of the Primary Emission Region in PKS 1510–089

Author

Aharonian, F., primary, Benkhali, F. Ait, additional, Aschersleben, J., additional, Ashkar, H., additional, Backes, M., additional, Martins, V. Barbosa, additional, Barnard, J., additional, Batzofin, R., additional, Becherini, Y., additional, Berge, D., additional, Bernlöhr, K., additional, Bi, B., additional, de Bony de Lavergne, M., additional, Böttcher, M., additional, Boisson, C., additional, Bolmont, J., additional, Borowska, J., additional, Bouyahiaoui, M., additional, Bradascio, F., additional, Breuhaus, M., additional, Brose, R., additional, Brown, A. M., additional, Brun, F., additional, Bruno, B., additional, Bulik, T., additional, Burger-Scheidlin, C., additional, Caroff, S., additional, Casanova, S., additional, Cecil, R., additional, Celic, J., additional, Cerruti, M., additional, Chand, T., additional, Chandra, S., additional, Chen, A., additional, Chibueze, J., additional, Chibueze, O., additional, Cotter, G., additional, Damascene Mbarubucyeye, J., additional, Davids, I. D., additional, Djannati-Ataï, A., additional, Dmytriiev, A., additional, Doroshenko, V., additional, Egberts, K., additional, Einecke, S., additional, Ernenwein, J.-P., additional, Fegan, S., additional, Fontaine, G., additional, Füßling, M., additional, Funk, S., additional, Gabici, S., additional, Ghafourizadeh, S., additional, Giavitto, G., additional, Glawion, D., additional, Glicenstein, J. F., additional, Goswami, P., additional, Grolleron, G., additional, Haerer, L., additional, Hofmann, W., additional, Holch, T. L., additional, Holler, M., additional, Horns, D., additional, Jamrozy, M., additional, Jankowsky, F., additional, Joshi, V., additional, Jung-Richardt, I., additional, Kasai, E., additional, Katarzyński, K., additional, Khatoon, R., additional, Khélifi, B., additional, Kluźniak, W., additional, Komin, Nu., additional, Kosack, K., additional, Kostunin, D., additional, Lang, R. G., additional, Le Stum, S., additional, Leitl, F., additional, Lemière, A., additional, Lenain, J.-P., additional, Leuschner, F., additional, Luashvili, A., additional, Mackey, J., additional, Marandon, V., additional, Marchegiani, P., additional, Martí-Devesa, G., additional, Marx, R., additional, Mehta, A., additional, Meyer, M., additional, Mitchell, A., additional, Moderski, R., additional, Mohrmann, L., additional, Montanari, A., additional, Moulin, E., additional, de Naurois, M., additional, Niemiec, J., additional, Priyana Noel, A., additional, O’Brien, P., additional, Ohm, S., additional, Olivera-Nieto, L., additional, de Ona Wilhelmi, E., additional, Ostrowski, M., additional, Panny, S., additional, Panter, M., additional, Peron, G., additional, Prokhorov, D. A., additional, Pühlhofer, G., additional, Punch, M., additional, Quirrenbach, A., additional, Reichherzer, P., additional, Reimer, A., additional, Reimer, O., additional, Ren, H., additional, Rieger, F., additional, Rowell, G., additional, Rudak, B., additional, Ricarte, H. Rueda, additional, Ruiz-Velasco, E., additional, Sahakian, V., additional, Salzmann, H., additional, Sanchez, D. A., additional, Santangelo, A., additional, Sasaki, M., additional, Schüssler, F., additional, Schutte, H. M., additional, Schwanke, U., additional, Shapopi, J. N. S., additional, Sol, H., additional, Specovius, A., additional, Spencer, S., additional, Stawarz, Ł., additional, Steenkamp, R., additional, Steinmassl, S., additional, Steppa, C., additional, Sushch, I., additional, Suzuki, H., additional, Takahashi, T., additional, Tanaka, T., additional, Terrier, R., additional, Tsuji, N., additional, van Eldik, C., additional, van Soelen, B., additional, Vecchi, M., additional, Veh, J., additional, Vink, J., additional, Wach, T., additional, Wagner, S. J., additional, Wierzcholska, A., additional, Zacharias, M., additional, Zargaryan, D., additional, Zdziarski, A. A., additional, Zech, A., additional, Zouari, S., additional, Żywucka, N., additional, Buckley, D. A. H., additional, Cooper, J., additional, and Groenewald, D., additional

Published
2023
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15. HESS J1809-193 : A halo of escaped electrons around a pulsar wind nebula?

Author

Aharonian, F., Ait Benkhali, F., Aschersleben, J., Ashkar, H., Backes, M., Barbosa Martins, V., Batzofin, R., Becherini, Yvonne, Berge, D., Boettcher, M., Boisson, C., Bolmont, J., Borowska, J., Bouyahiaoui, M., Bradascio, F., Breuhaus, M., Brose, R., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Bylund, Tomas, Caroff, S., Casanova, S., Celic, J., Cerruti, M., Chambery, P., Chand, T., Chen, A., Chibueze, J., Chibueze, O., Damascene Mbarubucyeye, J., Djannati-Atai, A., Dmytriiev, A., Einecke, S., Ernenwein, J. -p., Feijen, K., Filipovic, M., Fontaine, G., Fuessling, M., Funk, S., Gabici, S., Gallant, Y. A., Ghafourizadeh, S., Giavitto, G., Giunti, L., Glawion, D., Goswami, P., Grolleron, G., Grondin, M. -h., Haerer, L., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzynski, K., Khelifi, B., Kluzniak, W., Komin, Nu., Kosack, K., Kostunin, D., Lang, R. G., Le Stum, S., Leitl, F., Lemiere, A., Lemoine-Goumard, M., Lenain, J. -p., Leuschner, F., Lohse, T., Luashvili, A., Lypova, I., Mackey, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Marinos, P., Marti-Devesa, G., Marx, R., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Muller, J., Nakashima, K., de Naurois, M., Niemiec, J., Priyana Noel, A., Ohm, S., Olivera-Nieto, L., de Ona Wilhelmi, E., Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Prokhorov, D. A., Puehlhofer, G., Punch, M., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Renaud, M., Reville, B., Rieger, F., Rowell, G., Rudak, B., Sahakian, V., Santangelo, A., Sasaki, M., Schutte, H. M., Schwanke, U., Shapopi, J. N. S., Sol, H., Specovius, A., Spencer, S., Stawarz, L., Steenkamp, R., Steinmassl, S., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Terrier, R., Thorpe-Morgan, C., Tsirou, M., Tsuji, N., Uchiyama, Y., van Eldik, C., Vecchi, M., Veh, J., Venter, C., Vink, J., Wach, T., Wagner, S. J., White, R., Wierzcholska, A., Wong, Yu Wun, Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zouari, S., Zywucka, N., Aharonian, F., Ait Benkhali, F., Aschersleben, J., Ashkar, H., Backes, M., Barbosa Martins, V., Batzofin, R., Becherini, Yvonne, Berge, D., Boettcher, M., Boisson, C., Bolmont, J., Borowska, J., Bouyahiaoui, M., Bradascio, F., Breuhaus, M., Brose, R., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Bylund, Tomas, Caroff, S., Casanova, S., Celic, J., Cerruti, M., Chambery, P., Chand, T., Chen, A., Chibueze, J., Chibueze, O., Damascene Mbarubucyeye, J., Djannati-Atai, A., Dmytriiev, A., Einecke, S., Ernenwein, J. -p., Feijen, K., Filipovic, M., Fontaine, G., Fuessling, M., Funk, S., Gabici, S., Gallant, Y. A., Ghafourizadeh, S., Giavitto, G., Giunti, L., Glawion, D., Goswami, P., Grolleron, G., Grondin, M. -h., Haerer, L., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzynski, K., Khelifi, B., Kluzniak, W., Komin, Nu., Kosack, K., Kostunin, D., Lang, R. G., Le Stum, S., Leitl, F., Lemiere, A., Lemoine-Goumard, M., Lenain, J. -p., Leuschner, F., Lohse, T., Luashvili, A., Lypova, I., Mackey, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Marinos, P., Marti-Devesa, G., Marx, R., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Muller, J., Nakashima, K., de Naurois, M., Niemiec, J., Priyana Noel, A., Ohm, S., Olivera-Nieto, L., de Ona Wilhelmi, E., Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Prokhorov, D. A., Puehlhofer, G., Punch, M., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Renaud, M., Reville, B., Rieger, F., Rowell, G., Rudak, B., Sahakian, V., Santangelo, A., Sasaki, M., Schutte, H. M., Schwanke, U., Shapopi, J. N. S., Sol, H., Specovius, A., Spencer, S., Stawarz, L., Steenkamp, R., Steinmassl, S., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Terrier, R., Thorpe-Morgan, C., Tsirou, M., Tsuji, N., Uchiyama, Y., van Eldik, C., Vecchi, M., Veh, J., Venter, C., Vink, J., Wach, T., Wagner, S. J., White, R., Wierzcholska, A., Wong, Yu Wun, Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zouari, S., and Zywucka, N.

Abstract

Context. HESS J1809-193 is an unassociated very-high-energy gamma-ray source located on the Galactic plane. While it has been connected to the nebula of the energetic pulsar PSR J1809-1917, supernova remnants and molecular clouds present in the vicinity also constitute possible associations. Recently, the detection of gamma-ray emission up to energies of similar to 100 TeV with the HAWC observatory has led to renewed interest in HESS J1809-193.Aims. We aim to understand the origin of the gamma-ray emission of HESS J1809-193.Methods. We analysed 93.2 h of data taken on HESS J1809-193 above 0.27 TeV with the High Energy Stereoscopic System (H.E.S.S.), using a multi-component, three-dimensional likelihood analysis. In addition, we provide a new analysis of 12.5 yr of Fermi-LAT data above 1 GeV within the region of HESS J1809-193. The obtained results are interpreted in a time-dependent modelling framework.Results. For the first time, we were able to resolve the emission detected with H.E.S.S. into two components: an extended component (modelled as an elongated Gaussian with a 1-sigma semi-major and semi-minor axis of similar to 0.62 degrees and similar to 0.35 degrees, respectively) that exhibits a spectral cutoff at similar to 13 TeV, and a compact component (modelled as a symmetric Gaussian with a 1-sigma radius of similar to 0.1 degrees) that is located close to PSR J1809-1917 and shows no clear spectral cutoff. The Fermi-LAT analysis also revealed extended gamma-ray emission, on scales similar to that of the extended H.E.S.S. component.Conclusions. Our modelling indicates that based on its spectrum and spatial extent, the extended H.E.S.S. component is likely caused by inverse Compton emission from old electrons that form a halo around the pulsar wind nebula. The compact component could be connected to either the pulsar wind nebula or the supernova remnant and molecular clouds. Due to its comparatively steep spectrum, modelling the Fermi-LAT emission together with

Published
2023
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16. HESS J1809−193 : a halo of escaped electrons around a pulsar wind nebula?

Author

Aharonian, F., Ait Benkhali, F., Aschersleben, J., Ashkar, H., Backes, M., Barbosa Martins, V., Batzofin, R., Becherini, Y., Berge, D., Böttcher, M., Boisson, C., Bolmont, J., Borowska, J., Bouyahiaoui, M., Bradascio, F., Breuhaus, M., Brose, R., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Bylund, T., Caroff, S., Casanova, S., Celic, J., Cerruti, M., Chambery, P., Chand, T., Chen, A., Chibueze, J., Chibueze, O., Damascene Mbarubucyeye, J., Djannati-Ataï, A., Dmytriiev, A., Einecke, S., Ernenwein, J. -P., Feijen, K., Filipovic, M., Fontaine, G., Füßling, M., Funk, S., Gabici, S., Gallant, Y. A., Ghafourizadeh, S., Giavitto, G., Giunti, L., Glawion, D., Goswami, P., Grolleron, G., Grondin, M. -H., Haerer, L., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Huang, Zhiqiu, Jamrozy, Marek, Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyński, K., Khélifi, B., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Lang, R. G., Le Stum, S., Leitl, F., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leuschner, F., Lohse, T., Luashvili, A., Lypova, I., Mackey, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Marinos, P., Martí-Devesa, G., Marx, R., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Muller, J., Nakashima, K., de Naurois, M., Niemiec, J., Noel, Angel, Ohm, S., Olivera-Nieto, L., de Ona Wilhelmi, E., Ostrowski, Michał, Panny, S., Panter, M., Parsons, R. D., Prokhorov, D. A., Pühlhofer, G., Punch, M., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Renaud, M., Reville, B., Rieger, F., Rowell, G., Rudak, B., Sahakian, V., Santangelo, A., Sasaki, M., Schutte, H. M., Schwanke, U., Shapopi, J. N. S., Sol, H., Specovius, A., Spencer, S., Stawarz, Łukasz, Steenkamp, R., Steinmassl, S., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Terrier, R., Thorpe-Morgan, C., Tsirou, M., Tsuji, N., Uchiyama, Y., van Eldik, C., Vecchi, M., Veh, J., Venter, C., Vink, J., Wach, T., Wagner, S. J., White, R., Wierzcholska, Alicja, Wong, Yu Wun, Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zouari, S., and Żywucka, N.

Subjects
non-thermal [radiation mechanisms], general [gamma rays], acceleration of particles, individual: PSR J1809-1917 [pulsars]
Abstract

Context. HESS J1809−193 is an unassociated very-high-energy γ-ray source located on the Galactic plane. While it has been connected to the nebula of the energetic pulsar PSR J1809−1917, supernova remnants and molecular clouds present in the vicinity also constitute possible associations. Recently, the detection of γ-ray emission up to energies of ∼100 TeV with the HAWC observatory has led to renewed interest in HESS J1809−193. Aims. We aim to understand the origin of the γ-ray emission of HESS J1809−193. Methods. We analysed 93.2 h of data taken on HESS J1809−193 above 0.27 TeV with the High Energy Stereoscopic System (H.E.S.S.), using a multi-component, three-dimensional likelihood analysis. In addition, we provide a new analysis of 12.5 yr of Fermi-LAT data above 1 GeV within the region of HESS J1809−193. The obtained results are interpreted in a time-dependent modelling framework. Results. For the first time, we were able to resolve the emission detected with H.E.S.S. into two components: an extended component (modelled as an elongated Gaussian with a 1-σ semi-major and semi-minor axis of ∼0.62° and ∼0.35°, respectively) that exhibits a spectral cutoff at ∼13 TeV, and a compact component (modelled as a symmetric Gaussian with a 1-σ radius of ∼0.1°) that is located close to PSR J1809−1917 and shows no clear spectral cutoff. The Fermi-LAT analysis also revealed extended γ-ray emission, on scales similar to that of the extended H.E.S.S. component. Conclusions. Our modelling indicates that based on its spectrum and spatial extent, the extended H.E.S.S. component is likely caused by inverse Compton emission from old electrons that form a halo around the pulsar wind nebula. The compact component could be connected to either the pulsar wind nebula or the supernova remnant and molecular clouds. Due to its comparatively steep spectrum, modelling the Fermi-LAT emission together with the H.E.S.S. components is not straightforward.

Published
2023

17. HESS J1809$-$193: a halo of escaped electrons around a pulsar wind nebula?

Author

Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Barbosa Martins, V., Batzofin, R., Becherini, Y., Berge, D., Böttcher, M., Boisson, C., Bolmont, J., Borowska, J., Bouyahiaoui, M., Bradascio, F., Breuhaus, M., Brose, R., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Bylund, T., Caroff, S., Casanova, S., Celic, J., Cerruti, M., Chambery, P., Chand, T., Chen, A., Chibueze, J., Chibueze, O., Mbarubucyeye, J. Damascene, Djannati-Ataï, A., Dmytriiev, A., Einecke, S., Ernenwein, J.-P., Feijen, K., Filipovic, M., Fontaine, G., Füßling, M., Funk, S., Gabici, S., Gallant, Y. A., Ghafourizadeh, S., Giavitto, G., Giunti, L., Glawion, D., Goswami, P., Grolleron, G., Grondin, M.-H., Haerer, L., Hinton, J. A., Hofmann, W., Holch, T. L., Holler, M., Horns, D., Huang, Zhiqiu, Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzynski, K., Khélifi, B., Klúzniak, W., Komin, Nu., Kosack, K., Kostunin, D., Lang, R. G., Le Stum, S., Leitl, F., Lemière, A., Lemoine-Goumard, M., Lenain, J.-P., Leuschner, F., Lohse, T., Luashvili, A., Lypova, I., Mackey, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Marinos, P., Martí-Devesa, G., Marx, R., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Muller, J., Nakashima, K., de Naurois, M., Niemiec, J., Noel, A. Priyana, Ohm, S., Olivera-Nieto, L., de Ona Wilhelmi, E., Ostrowski, M., Panny, S., Panter, M., Parsons, R. D., Prokhorov, D. A., Pühlhofer, G., Punch, M., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Renaud, M., Reville, B., Rieger, F., Rowell, G., Rudak, B., Sahakian, V., Santangelo, A., Sasaki, M., Schutte, H. M., Schwanke, U., Shapopi, J. N. S., Sol, H., Specovius, A., Spencer, S., Stawarz, Ł., Steenkamp, R., Steinmassl, S., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Terrier, R., Thorpe-Morgan, C., Tsirou, M., Tsuji, N., Uchiyama, Y., van Eldik, C., Vecchi, M., Veh, J., Venter, C., Vink, J., Wach, T., Wagner, S. J., White, R., Wierzcholska, A., Wong, Yu Wun, Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zouari, S., Żywucka, N., H. E. S. S. Collaboration, Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des Deux Infinis Bordeaux (LP2I - Bordeaux), Université de Bordeaux (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Particules de Montpellier (LUPM), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), and H.E.S.S.

Subjects
electron, dimension: 3, halo, FOS: Physical sciences, GeV, GLAST, VHE, dimension, HESS, supernova, TeV, cloud, pulsar, High Energy Astrophysical Phenomena (astro-ph.HE), energy: high, high, observatory, 3 [dimension], ddc:520, high [energy], spectral, time dependence, galaxy, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], HAWC, energy
Abstract

Astronomy and astrophysics 672, A103 (2023). doi:10.1051/0004-6361/202245459, Context. HESS J1809−193 is an unassociated very-high-energy γ-ray source located on the Galactic plane. While it has been connected to the nebula of the energetic pulsar PSR J1809−1917, supernova remnants and molecular clouds present in the vicinity also constitute possible associations. Recently, the detection of γ-ray emission up to energies of ∼100 TeV with the HAWC observatory has led to renewed interest in HESS J1809−193.Aims. We aim to understand the origin of the γ-ray emission of HESS J1809−193.Methods. We analysed 93.2 h of data taken on HESS J1809−193 above 0.27 TeV with the High Energy Stereoscopic System (H.E.S.S.), using a multi-component, three-dimensional likelihood analysis. In addition, we provide a new analysis of 12.5 yr of Fermi-LAT data above 1 GeV within the region of HESS J1809−193. The obtained results are interpreted in a time-dependent modelling framework.Results. For the first time, we were able to resolve the emission detected with H.E.S.S. into two components: an extended component (modelled as an elongated Gaussian with a 1-σ semi-major and semi-minor axis of ∼0.62° and ∼0.35°, respectively) that exhibits a spectral cutoff at ∼13 TeV, and a compact component (modelled as a symmetric Gaussian with a 1-σ radius of ∼0.1°) that is located close to PSR J1809−1917 and shows no clear spectral cutoff. The Fermi-LAT analysis also revealed extended γ-ray emission, on scales similar to that of the extended H.E.S.S. component.Conclusions. Our modelling indicates that based on its spectrum and spatial extent, the extended H.E.S.S. component is likely caused by inverse Compton emission from old electrons that form a halo around the pulsar wind nebula. The compact component could be connected to either the pulsar wind nebula or the supernova remnant and molecular clouds. Due to its comparatively steep spectrum, modelling the Fermi-LAT emission together with the H.E.S.S. components is not straightforward.Key words: acceleration of particles / radiation mechanisms: non-thermal / pulsars: individual: PSR J1809-1917 / gamma rays: general⋆ Corresponding authors; e-mail: contact.hess@hess-experiment.eu, Published by EDP Sciences, Les Ulis

Published
2023
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18. Constraining the cosmic-ray pressure in the inner Virgo Cluster using H.E.S.S. observations of M 87

Author

Aharonian, F., Ait Benkhali, F., Arcaro, C., Aschersleben, J., Backes, M., Barbosa Martins, V., Batzofin, R., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., Borowska, J., Bradascio, F., Breuhaus, M., Brose, R., Brun, F., Bruno, B., Bulik, T., Burger-Scheidlin, C., Bylund, T., Caroff, S., Casanova, S., Cecil, R., Celic, J., Cerruti, M., Chand, T., Chandra, S., Chen, A., Chibueze, J., Chibueze, O., Cotter, G., Damascene Mbarubucyeye, J., Djannati-Ataï, A., Egberts, K., Ernenwein, J.-P., Fichet de Clairfontaine, G., Filipovic, M., Fontaine, G., Füßling, M., Funk, S., Gabici, S., Ghafourizadeh, S., Giavitto, G., Glawion, D., Glicenstein, J. F., Goswami, P., Grolleron, G., Grondin, M.-H., Haerer, L., Haupt, M., Hermann, G., Hinton, J. A., Holch, T. L., Horns, D., Jamrozy, M., Jankowsky, F., Joshi, V., Jung-Richardt, I., Kasai, E., Katarzyński, K., Khatoon, R., Khélifi, B., Kluźniak, W., Komin, Nu., Kosack, K., Kostunin, D., Lang, R. G., Le Stum, S., Leitl, F., Lemière, A., Lemoine-Goumard, M., Lenain, J.-P., Leuschner, F., Lohse, T., Luashvili, A., Lypova, I., Mackey, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Marinos, P., Martí-Devesa, G., Marx, R., Meyer, M., Mitchell, A., Moderski, R., Mohrmann, L., Montanari, A., Moulin, E., Muller, J., Nakashima, K., de Naurois, M., Niemiec, J., Priyana Noel, A., O’Brien, P., Ohm, S., Olivera-Nieto, L., de Ona Wilhelmi, E., Panny, S., Panter, M., Parsons, R. D., Peron, G., Pita, S., Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Reichherzer, P., Reimer, A., Reimer, O., Renaud, M., Rieger, F., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Salzmann, H., Sanchez, D. A., Santangelo, A., Sasaki, M., Schäfer, J., Schüssler, F., Schwanke, U., Shapopi, J. N. S., Sol, H., Specovius, A., Spencer, S., Stawarz, Ł., Steenkamp, R., Steinmassl, S., Steppa, C., Sushch, I., Suzuki, H., Takahashi, T., Tanaka, T., Taylor, A. M., Terrier, R., Tsirou, M., Tsuji, N., Uchiyama, Y., van Eldik, C., van Soelen, B., Vecchi, M., Veh, J., Venter, C., Vink, J., Wach, T., Wagner, S. J., White, R., Wierzcholska, A., Wong, Y. W., Zacharias, M., Zargaryan, D., Zdziarski, A. A., Zech, A., Zouari, S., Żywucka, N., HESS Collaboration, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des Deux Infinis Bordeaux (LP2I - Bordeaux), Université de Bordeaux (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Particules de Montpellier (LUPM), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), and H.E.S.S.

Subjects
gamma ray, emission, causality, VHE [gamma ray], gamma ray, VHE, cosmic radiation: energy, FOS: Physical sciences, energy, density, feedback, power spectrum, gamma ray: energy spectrum, Bayesian, rotation, thermal, cosmic radiation [p], energy [cosmic radiation], emission [gamma ray], HESS, TeV, cosmic radiation: pressure, energy: density, AGN, cluster, p, cosmic radiation, energy spectrum [gamma ray], High Energy Astrophysical Phenomena (astro-ph.HE), radio wave, cosmic radiation, energy, cosmic radiation, pressure, Astrophysics - Astrophysics of Galaxies, pressure [cosmic radiation], gamma ray: emission, VIRGO, gamma ray: VHE, p: cosmic radiation, Astrophysics of Galaxies (astro-ph.GA), ddc:520, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], density [energy]
Abstract

Astronomy and astrophysics 675, A138 (2023). doi:10.1051/0004-6361/202346056, The origin of the gamma-ray emission from M87 is currently a matter of debate. This work aims to localize the VHE (100 GeV-100 TeV) gamma-ray emission from M87 and probe a potential extended hadronic emission component in the inner Virgo Cluster. The search for a steady and extended gamma-ray signal around M87 can constrain the cosmic-ray energy density and the pressure exerted by the cosmic rays onto the intra-cluster medium, and allow us to investigate the role of the cosmic rays in the active galactic nucleus feedback as a heating mechanism in the Virgo Cluster. H.E.S.S. telescopes are sensitive to VHE gamma rays and have been utilized to observe M87 since 2004. We utilized a Bayesian block analysis to identify M87 emission states with H.E.S.S. observations from 2004 until 2021, dividing them into low, intermediate, and high states. Because of the causality argument, an extended ($\gtrsim$kpc) signal is allowed only in steady emission states. Hence, we fitted the morphology of the 120h low state data and found no significant gamma-ray extension. Therefore, we derived for the low state an upper limit of 58'(corresponding to $\approx$4.6kpc) in the extension of a single-component morphological model described by a rotationally symmetric 2D Gaussian model at 99.7% confidence level. Our results exclude the radio lobes ($\approx$30 kpc) as the principal component of the VHE gamma-ray emission from the low state of M87. The gamma-ray emission is compatible with a single emission region at the radio core of M87. These results, with the help of two multiple-component models, constrain the maximum cosmic-ray to thermal pressure ratio $X_{{CR,max.}}$$\lesssim$$0.32$ and the total energy in cosmic-ray protons (CRp) to $U_{CR}$$\lesssim$5$\times10^{58}$ erg in the inner 20kpc of the Virgo Cluster for an assumed CRp power-law distribution in momentum with spectral index $\alpha_{p}$=2.1., Published by EDP Sciences, Les Ulis

Published
2023
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26. ContiTronic: the intelligent conveyor belt from ContiTech.

Author

Alles R., Wach T., Alles R., and Wach T.

Abstract

ContiTech has investigated the use of radio frequency identification and found that specially developed transponders can be vulcanised into rubber conveyor belts without impairing their performance capabilities. Transponders are integrated circuits incorporating a receiver, one or more data memories and a transmitter. The system opens up a whole range of new applications in bulk materials handling within various sectors of industry, facilitating the recording and logistical tracking of conveyor belts while in service or stored as well as the ordering of replacements. The system was tested at the lignite mining operations in Hambach, Germany. The transponders operated for 18 months with more than 99.8% reliability, demonstrating their suitability for use under adverse conditions., ContiTech has investigated the use of radio frequency identification and found that specially developed transponders can be vulcanised into rubber conveyor belts without impairing their performance capabilities. Transponders are integrated circuits incorporating a receiver, one or more data memories and a transmitter. The system opens up a whole range of new applications in bulk materials handling within various sectors of industry, facilitating the recording and logistical tracking of conveyor belts while in service or stored as well as the ordering of replacements. The system was tested at the lignite mining operations in Hambach, Germany. The transponders operated for 18 months with more than 99.8% reliability, demonstrating their suitability for use under adverse conditions.

27. Oral Squamous Cell Carcinoma and What We Lose During Formalin Fixation: An Evaluation of Changes in Macroscopic Resection Margins Utilizing Virtual Three-Dimensional Imaging Techniques with Analysis Based on 947 Measurements.

Author

Michcik A, Jopek M, Pęksa R, Choma P, Garbacewicz Ł, Polcyn A, Wojciechowska B, Wach T, Sikora M, Iacoviello P, Audino G, and Drogoszewska B

Abstract

Background: An adequate OSCC macroscopic resection margin (MRM) is essential for effective treatment. This study analyzed the effects of formalin fixation (FF) on the MRM., Material and Methods: A total of 42 patients were enrolled in this study. Tumors from the floor of the mouth (FOM; n = 23), the tongue (TC; n = 10), and the maxilla (MT; n = 9) were studied. A 3D scanner was used to create virtual models, and further analysis was conducted according to the established protocol., Results: The most significant shrinkage was observed in the TC (MRM n = 121; Med. = 1.5 mm; p val. = 7.05 × 10 -18 ), with a maximum shrinkage of 28%. For the FOM (n = 262; Med. = 0.8 mm; p val. = 6.76 × 10 -18 ), the greatest MRM shrinkage was 26%. In the MT group (n = 91; Med. = 0.9 mm; p val. = 2.69 × 10 -9 ), the shrinkage was 18.7%. Among MRMs >8 mm (n = 159), FF led to 58.5% of them shrinking to ≤8 mm, resulting in a false decrease in the safe MRM ( p val. = 1.11 × 10 -27 ). Overall, the average shrinkage for all specimens was μ= 2.57 mm ( p val. = 8.89 × 10 -10 ) alongside and μ= 2.35 mm ( p val. = 4.09 × 10 -6 ) across. The tumors themselves showed minimal changes: μ= 0.69 mm ( p val. = 9.73 × 10 -3 ) alongside and μ= 0.8 mm ( p val. = 2.52 × 10 -7 ) across., Conclusion: Formalin fixation (FF) caused the shrinkage of the OSCC MRM, particularly in tongue cancers. Even after proper surgical excision in the postoperative results, the number of normal MRMs was underestimated. This should be considered when interpreting the results of surgical treatment. However, FF had a minimal impact on the overall shrinkage of the tumors themselves.

Published
2024
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28. Umbilical and Placental Derivatives in Temporomandibular Joint Treatment: A Systematic Review.

Author

Lubecka K, Chęciński M, Chęcińska K, Bliźniak F, Wach T, Szuta M, Chlubek D, and Sikora M

Abstract

Objectives : This review aimed to gather and summarize the existing information on the clinical application of allogeneic umbilical and placental derivatives in the treatment of temporomandibular joint disorders. Methods : Research on the impact of the use of umbilical and placental derivatives on reducing pain and improving mobility in the temporomandibular joint was included in the article. Medical databases, including ACM, BASE, Cochrane, Scopus, Google Scholar, ClinicalTrials.gov, and PubMed, were searched. The final search was conducted on 20 October 2024. Results : Out of the 43 records found, 5 were considered eligible for further analysis and showed that the use of placental and umbilical derivatives has the greatest potential in the treatment of ankylosis. The intra-articular administration of these tissues into the TMJ brings beneficial results, but they are similar to other, parallel methods, such as PRP or corticosteroids. Conclusions : The studies discussed may guide researchers in expanding clinical trials, particularly by including more patients with TMDs, and have promising potential in ankylotic disorders, where amniotic membrane use has shown clear benefits.

Published
2024
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29. Virtual Tumor Mapping: A New Standard for Surgeon-Pathologist Collaboration in Treating Oral Squamous Cell Carcinoma.

Author

Michcik A, Jopek M, Pęksa R, Choma P, Garbacewicz Ł, Polcyn A, Wach T, Sikora M, and Drogoszewska B

Abstract

Background: The histopathological assessment is critical in the comprehensive treatment process for patients diagnosed with oral squamous cell carcinoma (OSCC). A detailed and precise specimen characterization is essential to facilitate effective surgeon-pathologist communication. Methods: In response to this need, a user-friendly virtual communication protocol utilizing a 3D scanner has been developed. This study involved 50 patients with OSCC, whose resected tumors were directly scanned in the operating room and subsequently annotated and characterized using available software. Results: The direct application of annotations and descriptions onto the virtual tumor specimens significantly enhanced the quantity and accuracy of information conveyed to the pathologist. Conclusions: The proposed solution's repeatability and standardized approach make integration into routine clinical practice feasible, thereby establishing a potential new standard in the field.

Published
2024
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30. Personalized Temporomandibular Joint Total Alloplastic Replacement as a Solution to Help Patients with Non-Osteosynthesizable Comminuted Mandibular Head Fractures.

Author

Pruszyńska P, Kozakiewicz M, Szymor P, and Wach T

Abstract

Background : Treatment methods for mandibular head fractures are controversial, although effective techniques for open reduction and rigid fixation (ORIF) have been known since the late 1990s. Notably, some forms of posttraumatic comminution of the mandibular head can be reduced or fixed. Methods : This study presents a personalized treatment to cure patients with nonreduced comminuted fractures of the mandibular head: total temporomandibular joint alloplastic replacement (18 patients). The reference group included patients who underwent ORIF (11 patients). Results : Personalized alloplastic joint replacements resulted in a more stable mandibular ramus after three months compared with ORIF. Conclusions : The authors recommend not performing osteosynthesis when the height of the mandibular ramus cannot be stably restored or when periosteal elevation from most of the mandibular head is necessary for ORIF. Personalized TMJ replacement should be considered in such patients. Personalized medicine allows patients to maintain a normal mandibular ramus height for a long period of time.

Published
2024
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31. Association between Clinical Manifestations in Temporomandibular Joint Disorders and Corresponding Radiographic Findings.

Author

Wojciechowska B, Szarmach A, Michcik A, Wach T, and Drogoszewska B

Abstract

Background : Temporomandibular disorders are common conditions characterized by discomfort within the temporomandibular joints, acoustic changes, and restricted mandibular movement. Accurate diagnosis and subsequent treatment rely heavily on clinical examination, but it is often necessary to add radiological examinations to the diagnostics. Magnetic Resonance Imaging (MRI) is the gold standard for visualizing the disc, while cone-beam computed tomography (CBCT) is primarily used for evaluating condylar morphology. Ultrasound (US) serves as a real-time imaging modality for soft tissues. The objective of the present study was to explore the association between clinical manifestations observed in patients with temporomandibular joint disorders and corresponding radiographic findings. Methods : A total of 63 adult patients (51 female and 12 male) with temporomandibular joint disorders were included in this cross-sectional study. Each patient underwent a clinical examination, followed by appropriate radiological examinations (MRI, CBCT, or US). The level of statistical significance was set at an alpha of 0.05. The Shapiro-Wilk test assessed the normality of numerical variables. The Wilcoxon rank sum test compared two independent groups with non-normally distributed data. Relationships between categorical variables were evaluated using the Pearson chi-square test or Fisher's exact test. The Kendall tau (τ) method analyzed the correlation between two binary variables. Results : The analysis included 63 patients with TMD, predominantly females (80.95%). Ages ranged from 18 to 74 years with a median of 39 years. In the CBCT study, we observed rarefied changes in the left bone structures in patients with bruxism ( p = 0.010). MRI and ultrasound imaging revealed changes in patients with limited jaw opening: erosions in the right mandibular head on ultrasound ( p = 0.008) and abnormal right bone structures on MRI ( p = 0.009). In CBCT, asymmetry in the left joint space was correlated with a high incidence of right side muscle tension ( p = 0.004). Additionally, both CBCT and ultrasound showed a correlation between muscle tension and erosion ( p = 0.040 in ultrasound, p = 0.020 in CBCT). Acoustic changes, when compared with radiological imaging, were evident in all three studies, like temporomandibular joint pain or palpation. Conclusions : Our study compared three radiographic imaging methods with clinical examinations to assess their correlation with clinical symptoms. Each imaging technique provided unique insights depending on the specific symptoms presented. The observed correlations varied, highlighting the unique contributions of each modality to the diagnostic process. This underscores the importance of employing multiple diagnostic approaches for a thorough assessment of the temporomandibular joint. However, a limitation of our study is the small sample size and the uneven distribution of participants among the groups. Additionally, not all patients underwent every imaging modality.

Published
2024
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32. Association Study of Serotonin 1A Receptor Gene, Personality, and Anxiety in Women with Alcohol Use Disorder.

Author

Boroń A, Suchanecka A, Chmielowiec K, Chmielowiec J, Lachowicz M, Strońska-Pluta A, Trybek G, Wach T, González Domenech PJ, and Grzywacz A

Subjects
Humans, Female, Adult, Middle Aged, Genotype, Genetic Predisposition to Disease, Alleles, Genetic Association Studies, Case-Control Studies, Receptor, Serotonin, 5-HT1A genetics, Alcoholism genetics, Alcoholism psychology, Personality genetics, Anxiety genetics, Polymorphism, Single Nucleotide
Abstract

Alcohol use disorder is considered a chronic and relapsing disorder affecting the central nervous system. The serotonergic system, mainly through its influence on the mesolimbic dopaminergic reward system, has been postulated to play a pivotal role in the underlying mechanism of alcohol dependence. The study aims to analyse the association of the rs6295 polymorphism of the 5HTR1A gene in women with alcohol use disorder and the association of personality traits with the development of alcohol dependence, as well as the interaction of the rs6295, personality traits, and anxiety with alcohol dependence in women. The study group consisted of 213 female volunteers: 101 with alcohol use disorder and 112 controls. NEO Five-Factor and State-Trait Anxiety Inventories were applied for psychometric testing. Genotyping of rs6295 was performed by real-time PCR. We did not observe significant differences in 5HTR1A rs6295 genotypes ( p = 0.2709) or allele distribution ( p = 0.4513). The AUD subjects scored higher on the anxiety trait ( p < 0.0001) and anxiety state ( p < 0.0001) scales, as well as on the neuroticism ( p < 0.0001) and openness ( p = 0134) scales. Significantly lower scores were obtained by the AUD subjects on the extraversion ( p < 0.0001), agreeability ( p < 0.0001), and conscientiousness ( p < 0.0001) scales. Additionally, we observed a significant effect of 5HTR1A rs6295 genotype interaction and alcohol dependency, or lack thereof, on the openness scale ( p = 0.0016). In summary, this study offers a comprehensive overview of alcohol dependence among women. It offers valuable insights into this complex topic, contributing to a more nuanced understanding of substance use among this specific demographic. Additionally, these findings may have implications for developing prevention and intervention strategies tailored to individual genetic and, most importantly, personality and anxiety differences.

Published
2024
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33. Bone Metabolism and Dental Implant Insertion as a Correlation Affecting on Marginal Bone Remodeling: Texture Analysis and the New Corticalization Index, Predictor of Marginal Bone Loss-3 Months of Follow-Up.

Author

Wach T, Szymor P, Trybek G, Sikora M, Michcik A, and Kozakiewicz M

Abstract

Background/Objectives: The general condition of implantology patients is crucial when considering the long- and short-term survival of dental implants. The aim of the research was to evaluate the correlation between the new corticalization index (CI) and patients' condition, and its impact on marginal bone loss (MBL) leading to implant failure, using only radiographic (RTG) images on a pixel level. Method: Bone near the dental implant neck was examined, and texture features were analyzed. Statistical analysis includes analysis of simple regression where the correlation coefficient (CC) and R2 were calculated. Detected relationships were assumed to be statistically significant when p < 0.05. Statgraphics Centurion version 18.1.12 (Stat Point Technologies, Warrenton, VA, USA) was used to conduct the statistical analyses. Results: The research revealed a correlation between MBL after 3 months and BMI, PTH, TSH, Ca 2+ level in blood serum, phosphates in blood serum, and vitamin D. A correlation was also observed between CI and PTH, Ca 2+ level in blood serum, vitamin D, LDL, HDL, and triglycerides on the day of surgery. After 3 months of the observation period, CI was correlated with PTH, TSH, Ca 2+ level in blood serum, and triglycerides. Conclusion: The results of the research confirm that the general condition of patients corresponds with CI and MBL. A patient's general condition has an impact on bone metabolism around dental implants. Implant insertion should be considered if the general condition of the patient is not stable. However, CI has not yet been fully investigated. Further studies are necessary to check and categorize the impact of corticalization on marginal bone loss near dental implants.

Published
2024
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34. New Radiological Corticalization Index as an Indicator of Implant Success Rate Depending on Prosthetic Restoration-5 Years of Follow-Up.

Author

Wach T, Okulski J, Zieliński R, Trybek G, Michcik A, and Kozakiewicz M

Abstract

The new Radiological Corticalization Index (CI) is an indicator that describes bone remodeling near the dental implant's neck at the pixel level and is not visible to the naked eye. The aim of this research was to evaluate the correlation between the CI and bone remodeling using only radiographic (RTG) images. RTG samples were divided into groups depending on prosthetic restoration; the implant neck area around dental implants was examined, and texture features of the RTG images were analyzed. The study also investigated the type of prosthetic restoration and its influence as a factor on bone structure. The statistical analysis included evaluating feature distribution, comparing means ( t -test) or medians (W-test), and performing a regression analysis and one-way analysis of variance or the Kruskal-Wallis test, as no normal distribution or between-group variance was indicated for the significant differences in the investigated groups. Differences or relationships were considered statistically significant at p < 0.05. The research revealed correlations between single crowns, overdenture restoration, bridge restoration, platform switching, prosthetic fracture, CI, and also marginal bone loss where p was lower than 0.05. However, the corticalization phenomenon itself has not yet been fully explored. The findings suggest that, depending on the type of prosthetic restoration, the corticalization index may correlate with marginal bone loss or not. Further research is necessary, as the index is suspected to not be homogeneous.

Published
2024
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35. Efficacy of Computed Tomography and Magnetic Resonance Imaging in the Assessment of Depth of Invasion in Oral Squamous Cell Carcinoma: Analysis of 125 Clinical Cases.

Author

Michcik A, Polcyn A, Garbacewicz Ł, Wach T, Sikora M, Bień M, and Drogoszewska B

Abstract

Radiological diagnosis of oral squamous cell carcinoma (OSCC) is one of the main steps in treatment planning. T (tumor size), DOI (depth of invasion) (AJCC 8th edition), and nodal metastases (N+) were evaluated using CT and MRI to assess the most effective imaging method. The effectiveness of the radiological imaging methods was compared with histopathological results. Imaging diagnostic studies were performed and retrospectively analyzed in 125 patients with OSCC (CT n = 54 and MRI n = 71). Histopathology evaluated T, DOI, and N+. The radiological T results of CT in comparison with histopathological examination showed agreement in 62.5% of cases for T1, 56.25% for T2, 25% for T3, and 42.8% for T4 ( p -value = 0.07), and regarding MRI, 52.2% for T1, 36.4% for T2, 33.3% in T3, and 33.3% for T4. The DOI results of CT and MRI juxtaposed against the histopathological findings were as follows: for CT, n = 18 for DOI ≤ 10 mm and n = 36 for >10 mm; for MRI, n = 29 for DOI ≤ 10 mm and n = 42 for >10 mm (DOI CT vs. DOI hist. pat. p -value = 0.23; DOI MRI vs. DOI hist. pat. p -value = 0.006). Regarding nodal metastasis, n = 21 for N0 and n = 32 for N+ for CT ( p -value = 0.02), and n = 49 for N0 and n = 22 for N+ for MRI ( p -value = 0.1). In the radiological N+ group, the histopathological findings coincided with the results of MRI and CT in 27% and 62.5% of cases, respectively (N0: 83.6% for MRI; 85.7% for CT). Upon evaluating T, a decreasing percentage of overlapping results with an increasing tumor size was observed. The accuracy of both imaging studies was at a similar level, with a slight advantage for MRI. Among the patients on whom CT was performed, DOI analysis did not show statistically significant differences. This led to the conclusion that, in most cases, the DOI results based on CT overlapped with those described via histopathological examination. However, among the group of patients with MRI as the imaging method of choice, the differences proved to be statistically significant ( p -value = 0.006). The results of this study indicate that CT is a more accurate method for DOI assessment. The results of the radiologic metastasis evaluation (N+ group) overlapped more in the CT group, while the percentage of corresponding results in the radiologic N0 vs. hist. pat. N0 group was high and similar in both groups. These results indicate that it is easier to confirm the absence of a metastasis than its presence.

Published
2023
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36. Which of the 37 Plates Is the Most Mechanically Appropriate for a Low-Neck Fracture of the Mandibular Condyle? A Strength Testing.

Author

Okulski J, Kozakiewicz M, Krasowski M, Zieliński R, and Wach T

Abstract

(1) Background: The mandible is the most frequently injured component of the facial skeleton, with 25-45% of mandibular fractures involving the condylar process. This study aims to mechanically compare which plates are most suitable for use in low-neck fractures of the condyle. (2) Methods: Polyurethane mandibular models with simulated low-neck fractures were tested using 37 distinct plate designs. These plates were fabricated from 1 mm thick, grade 23 titanium sheets. The models were then subjected to force tests on a strength machine, and the correlation between applied force and fracture displacement was recorded. (3) Results: For low-neck fractures, XCP side-dedicated 3+5 and ACP-T plates demonstrated strength comparable to that of two straight plates, the current gold standard in osteosynthesis. (4) Conclusions: The Mechanical Excellence Factor (MEF) introduced by the authors provides a more accurate metric for theoretically predicting a plate's mechanical strength compared to the Plate Design Factor (PDF). Eight plate characteristics were utilized to calculate the MEF. Employing the MEF allows for rapid, preliminary validation before undertaking strength tests. Furthermore, the findings of this study can guide the selection of the most durable plate designs for subsequent fatigue testing.

Published
2023
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37. Oral squamous cell carcinoma - do we always need elective neck dissection? evaluation of clinicopathological factors of greatest prognostic significance: a cross-sectional observational study.

Author

Michcik A, Polcyn A, Sikora M, Wach T, Garbacewicz Ł, and Drogoszewska B

Abstract

The aim of the study was to find clinical and pathological factors with the greatest prognostic significance in patients with OSCC. The analysis included 125 patients grouped according to the tumor primary site (TPS): the floor of the mouth (FOM), tongue (TC) and retromolar triangle (RMT). Grading (G), tumor size (pT), nodal metastases (NM), local recurrence (LR), nodal recurrence (NR), perineural invasion (PNI), lymphovascular invasion (LVI), extranodal extension (pENE), and nodal yield (NY) were evaluated in each group., Results: With regard to TPS, FOM appeared to be the most metastatic. However, the recurrence rate was similar to TC tumors, which were characterized by higher G than those in other locations. When analyzing G, the highest percentage of LR (40.5%) and NM (34.5%) was observed among patients with G2. As G increased, so did the number of pENE G1 - 7.4%; G2 - 31%; G3 - 35.7%; LVI: G1 - 25.9%; G2 - 50%; G3 - 57.1%; PNI: G1 - 29.6%; G2 - 47.6%; G3 - 92.9%; NR G1 - 14.8%; G2 - 32.1%; G3 - 21.4%. Grading did not affect the type of growth and did not directly affect the occurrence of NR. pT and DOI increased the frequency of NM but we did not observe any effect of pT and DOI on LR, PNI, and LVI. NY in the study group did not increase the risk of NR., Conclusion: Tumor primary sites within the FOM, TC, and pT classification are the factors that increase the risk of NM and LR. However, apart from the primary site predisposing to the occurrence of NM, the histological structure of the tumor turned out to be the most important feature affecting the patient's prognosis. The number of cases of pENE+, LVI+, PNI+, NM+, and NR+ increased with the increase in G. Although the pT, DOI increased the frequency of NM, we did not observe the effect of the pT and DOI on LR, PNI and LVI. Thus, even in the case of a small tumor of the FOM and TC with at least G2, elective neck dissection should be performed each time., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Michcik, Polcyn, Sikora, Wach, Garbacewicz and Drogoszewska.)

Published
2023
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38. Is Corticalization in Radiographs Related to a Higher Risk of Bone Loss around Dental Implants in Smoking Patients? A 5-Year Observation of Radiograph Bone-Texture Changes.

Author

Wach T, Hadrowicz P, Trybek G, Michcik A, and Kozakiewicz M

Abstract

Background: Currently, the topic of dental implants is widely researched. However, still compromising are the factors that can affect implant loss as a consequence of marginal bone loss. One of the factors is smoking, which has a devastating effect on human health and bone structure. Oral health and jaw condition are also negatively affected by smoking. The aim of this study was to evaluate the peri-implant jawbone corticalization phenomenon in tobacco smokers., Methods: A total of 2196 samples from 768 patients with an implant in the neck area were checked, and texture features were analyzed. The corticalization phenomenon was investigated. All analyses were performed in MaZda Software. The influence of corticalization was investigated as a factor on bone structure near the implant neck. The statistical analysis included a feature distribution evaluation, mean ( t -test) or median (W-test) comparison, analysis of regression and one-way analysis of variance or Kruskal-Wallis test as no normal distribution or between-group variance was indicated for the significant differences in the investigated groups. Detected differences or relationships were assumed to be statistically significant when p < 0.05., Results: The research revealed that MBL was correlated with smoking after 5 years (0.42 mm ± 1.32 mm 0 mm ± 1.25 mm), the Corticalization Index was higher in the smoker group on the day of surgery, and it became higher after 5y of observation (185.98 ± 90.8 and 243.17 ± 155.47). The implant-loss frequency was higher in the group of smokers, too, compared to non-smokers (6.74% and 2.87%). The higher the torque value during the implant placement, the higher the Corticalization Phenomenon Index., Conclusions: The research revealed a correlation between smoking and changes in bone structure in radio textures near the implants. The corticalization phenomenon is important, may be detected immediately after implant placement and may be one of the indicators of the implant success rate.

Published
2023
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39. Exploring the Importance of Corticalization Occurring in Alveolar Bone Surrounding a Dental Implant.

Author

Kozakiewicz M and Wach T

Abstract

Several measures describing the transformation of trabecular bone to cortical bone on the basis of analysis of intraoral radiographs are known (including bone index or corticalization index, CI). At the same time, it has been noted that after functional loading of dental implants such transformations occur in the bone directly adjacent to the fixture. Intuitively, it seems that this is a process conducive to the long-term maintenance of dental implants and certainly necessary when immediate loading is applied. The authors examined the relationship of implant design features to marginal bone loss (MBL) and the intensity of corticalization over a 10-year period of functional loading. This study is a general description of the phenomenon of peri-implant bone corticalization and an attempt to interpret this phenomenon to achieve success of implant treatment in the long term. Corticalization significantly increased over the first 5-year functional loading (CI from 200 ± 146 initially to 282 ± 182, p < 0.001) and maintained a high level (CI = 261 ± 168) in the 10-year study relative to the reference bone (149 ± 178). MBL significantly increased throughout the follow-up period—5 years: 0.83 ± 1.26 mm (p < 0.001), 10 years: 1.48 ± 2.01 mm (p < 0.001). MBL and radiographic bone structure (CI) were evaluated in relation to intraosseous implant design features and prosthetic work performed. In the scope of the study, it can be concluded that the phenomenon of peri-implant jawbone corticalization seems an unfavorable condition for the future fate of bone-anchored implants, but it requires further research to fully explain the significance of this phenomenon.

Published
2022
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40. Are Torque-Induced Bone Texture Alterations Related to Early Marginal Jawbone Loss?

Author

Wach T, Skorupska M, and Trybek G

Abstract

The reason why marginal bone loss (MBL) occurs after dental implant insertion without loading has not yet been clearly investigated. There are publications that confirm or reject the notion that there are factors that induce marginal bone loss, but no research investigates what exactly occurs in the bone surrounding the implant neck. In this study, 2196 samples of dental implant neck bone radiographs were analyzed. The follow-up period was 3 months without functional loading of the implant. Marginal bone loss was evaluated in relation to the torque used during the final phase of implant insertion. Radiographic texture features were also analyzed and evaluated. The analyses were performed individually for the anterior and posterior part of the alveolar crest in both the mandible and maxilla. After 3 months, an MBL relation with higher torque (higher than 40 Ncm; p < 0.05) was observed, but only in the lower jaw. The texture features Sum Average (SumAverg), Entropy, Difference Entropy (DifEntr), Long-Run Emphasis (LngREmph), Short-Run Emphasis (ShrtREmph), and discrete wavelet decomposition transform features were changed over time. This study presents that MBL is related to the torque value during dental implant insertion and the location of the procedure. The increasing values of SumAverg and LngREmph correlated with MBL, which were 64.21 to 64.35 and 1.71 to 2.01, respectively. The decreasing values of Entr, DifEntr, and ShrtREmph also correlated with MBL, which were 2.58 to 2.47, 1.11 to 1.01, and 0.88 to 0.84, respectively. The analyzed texture features may become good indicators of MBL in digital dental surgery.

Published
2022
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41. What Does Bone Corticalization around Dental Implants Mean in Light of Ten Years of Follow-Up?

Author

Kozakiewicz M, Skorupska M, and Wach T

Abstract

The phenomenon of peri-implant bone corticalization after functional loading does not yet have a definite clinical significance and impact on prognosis. An attempt was made to assess the clinical significance of this phenomenon. This prospective study included 554 patients. Standardized intraoral radiographs documenting the jawbone environment of 1556 implants were collected. The follow-up period was 10 years of functional loading. Marginal alveolar bone loss (MBL) and radiographic bone structure (bone index, BI) were evaluated in relation to intraosseous implant design features and prosthetic work performed. After five years, bone structure abnormalities expressed by a reduction of BI to 0.47 ± 0.21 and MBL = 0.88 ± 1.27 mm were observed. Both values had an inverse relationship with each other (p < 0.0001). Reference cancellous bone showed BI = 0.85 ± 0.18. The same relationship was observed after ten years of functional loading: BI = 0.48 ± 0.21, MBL = 1.49 ± 1.94 mm, and again an inverse relationship (p < 0.0001). Increasing corticalization (lower BI) is strongly associated with increasing marginal bone loss and increasing corticalization precedes future marginal bone loss. Marginal bone loss will increase as corticalization progresses.

Published
2022
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42. Are recent available blended collagen-calcium phosphate better than collagen alone or crystalline calcium phosphate? Radiotextural analysis of a 1-year clinical trial.

Author

Wach T and Kozakiewicz M

Subjects
Bone Regeneration, Collagen, Humans, Wound Healing, Bone Substitutes, Calcium Phosphates
Abstract

Objectives: The purpose of this study is to compare bone regeneration properties of recently available collagen-calcium phosphate (C-CP) blend as bone substitute (BS) material in oral surgery with calcium phosphate (CP) as well as collagen material (Collagen). Is C-CP better than the classic loose CP, or is it at least equally effective in the jawbone regeneration with the superiority of a coherent consistency?, Materials and Methods: This study included 102 patients during 12-month follow-up. All patients underwent the following surgical procedures: sinus lift (52patients) and tooth extraction (50patients). Patients were divided into 3 groups which are as follows: experimental group with C-CP, CP and pure Collagen as control groups. Texture analysis was performed in intra-oral radiographs. Analyses were performed in the MaZda 4.6 software. Average 2444-pixel ROIs were established in the image of BS materials and normal trabecular bone for texture comparison to evaluate the jawbone regeneration process. Four features were calculated and investigated., Results: Texture analyses revealed that all 4 features described the healing process well. Reference textural value of feature SumOfSqrs < 102.37 was soft tissue, DifEntr < 1.1 was not the bone, Entr < 2.62 was not a bone and LngREmph > 1.8 was soft tissue. For 12 months, bone regeneration was proved by 3 of 4 investigated features. Only Entr indicated to CP remnants in the ROI (p < 0.05)., Conclusions: This study proves that blended collagen-calcium phosphate as a BS material can bring satisfactory and predictable outcomes in jawbone regeneration., Clinical Relevance: Clinicians can choose a satisfactory and predictable material for bone regeneration treatment.

Published
2021
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43. Fast-Versus Slow-Resorbable Calcium Phosphate Bone Substitute Materials-Texture Analysis after 12 Months of Observation.

Author

Wach T and Kozakiewicz M

Abstract

The development of oral surgery and implantology has led to the need for better and more predictable materials. Various substitute materials are now used for bone regeneration. The replacement of scaffolding material by new bone tissue is the most important condition. This study aimed to evaluate the effects of the resorbability of bone substitute materials during regeneration to the jawbone. The study included 88 patients during the 12-month follow-up. All the patients had undergone oral surgical procedures using two different substitute materials-Cerasorb (high-rate resorbable (β-tricalcium phosphate)) and Endobone (low-rate resorbable (hydroxyapatite)). Texture analysis was performed in intraoral radiographs, in which regions of interest were established for the bone substitute materials and reference bone. Five texture features were calculated, namely the sum average (SumAverg), entropy (Entropy), and three Harr discrete wavelet transform coefficients. This study revealed that all 5 features described the healing process well. Entropy was decreased in both cases with time; however, in Cerasorb cases, the texture feature values were very close to those of the reference bone after 12 months of healing ( p < 0.05). The wavelet transform coefficient at scale 6 also showed that longitudinal objects appeared in implantation sites, similar to trabecular bone ( p < 0.05) after 12 months of healing. The slow-resorbing material restored the structure of the alveolar crest better in terms of producing large objects similar to the components of a barrel bone image (wavelet coefficients), but required a longer time for reconstruction. The fast-resorbing material showed a texture image with a similar scattering of structures to that of the reference bone (entropy) after 12 months.

Published
2020
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44. Influence of General Mineral Condition on Collagen-Guided Alveolar Crest Augmentation.

Author

Kozakiewicz M, Szymor P, and Wach T

Abstract

The local regeneration of bone defects is regulated by general hormone, enzyme, ion, and vitamin levels. General diseases and dysregulation of the human mineral system can impact this process, even in alveolar crest. The aim of this study is to investigate a relation between bone density, measured in two-dimensional X-rays, and general mineral condition of patients. The study included 42 patients on whom tooth extractions were performed. Data were divided into two groups: the region where collagen scaffold (BRM) was used and the reference region of intact normal bone (REF). Two-dimensional intraoral radiographs were taken in all cases just after the surgery (00 M) and 12 months later (12 M). Thyrotropin (TSH), parathormone (PTH), Ca 2+ in serum, HbA1c, vitamin 25(OH)D 3 , and spine densitometry were checked. Digital texture analysis in MaZda 4.6 software was done. Texture Index (TI: BRM 1.66 ± 0.34 in 00 M, 1.51 ± 0.41 in 12 M, and REF 1.72 ± 0.28) and Bone Index (BI: BRM 0.73 ± 0.17 in 00 M, 0.65 ± 0.22 41 in 12 M, and REF 0.80 ± 0.14) were calculated to evaluate bone regeneration process after 12 months of healing (TI ( p < 0.05) and BI ( p < 0.01) are lower in BRM 12 M than in REF). This showed a relation between BI and TSH (R 2 = 26%, p < 0.05), as well as a between BI and patient age (R 2 = 65%, p < 0.001), and a weak relation between TI and TSH level (R 2 = 10%, p < 0.05). This study proved that a collagen scaffold can be successfully used in alveolar crest regeneration, especially in patients with a high normal level of TSH in the middle-aged population.

Published
2020
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45. New Oral Surgery Materials for Bone Reconstruction-A Comparison of Five Bone Substitute Materials for Dentoalveolar Augmentation.

Author

Kozakiewicz M and Wach T

Abstract

This article presents a comparison of bone replacement materials in terms of their ability to produce living bone image at the place of their implantation. Five bone replacement materials are compared (Osteovit-porous collagen, Cerasorb Foam-collagen scaffolding of synthetic β tricalcium phosphate, Osbone-synthetic hydroxyapatite, Endobone-deproteinized bovine-derived cancellous bone hydroxyapatite, and Cerasorb-synthetic β tricalcium phosphate). Intraoral radiographs are taken immediately after implantation and 12 months later. The texture analysis was performed to assess (texture index, TI) the level of structure chaos (entropy) in relation to the presence of longitudinal elements visible in radiographs (run length emphasis moment). The reference ratio of the chaotic trabecular pattern (Entropy) to the number of longitudinal structures, i.e., trabeculae (LngREmph), is 176:100 (i.e., 1.76 ± 0.28). Radiological homogeneity immediately after the implantation procedure is a result of the similar shape of its particles (Osbone, Endobone and Cerasorb) or radiolucency (Osteovit, Cerasorb Foam). The particles visible in radiographs were similar in the LngREmph parameters applied to the reference bone, but not in the co-occurrence matrix features. The TI for Osteovit during a 12-month follow-up period changed from 1.55 ± 0.26 to 1.48 ± 0.26 ( p > 0.05), for Cerasorb Foam from 1.82 ± 0.27 to 1.63 ± 0.24 ( p < 0.05), for Osbone from 1.97 ± 0.31 to 1.74 ± 0.30 ( p < 0.01), and for Endobone from 1.86 ± 0.25 to 1.84 ± 0.25 ( p > 0.05), The observed structure in the radiological image of bone substitute materials containing calcium phosphates obtains the characteristics of a living bone image after twelve months.

Published
2020
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46. Two different techniques of manufacturing TMJ replacements - A technical report.

Author

Kozakiewicz M, Wach T, Szymor P, and Zieliński R

Subjects
Adult, Aged, Arthroplasty, Replacement instrumentation, Arthroplasty, Replacement methods, Female, Humans, Lasers, Male, Mandibular Prosthesis, Middle Aged, Temporomandibular Joint Disorders surgery, Computer-Aided Design, Joint Prosthesis, Prosthesis Design methods, Temporomandibular Joint surgery
Abstract

Introduction: Presently, during the surgical treatment of the patients in maxillofacial surgery, one can use various medical implants. Moreover custom made implants are being used. Replacements may be fitted to the structure and shape of the human skull owing to CAD/CAM (custom aided design/manufacture) called customized implants. This study was aimed to report for the first time clinical material from which custom implants, using two different techniques, were manufactured to reconstruct the temporomandibular joint (TMJ)., Material and Methods: In this study, eleven patients with an average age of 54 years were included. All of the patients underwent TMJ reconstruction using direct metal laser sintering (DMLS) or computer numerical control milling (CNC) techniques for implant manufacture. Four of the eleven patients had a malignancy diagnosis, and seven had a benign diagnosis. Patients complained of hypomobility of the TMJ, facial asymmetry, pain and swelling of the preauricular region. Treatment included 7 CNC milled implants and 4 implants in DMLS., Results: More metallic implant parts with a rough surface were associated with the DMLS technique. Post operational, uneventful healing was observed in all clinical cases during an average of 26.8 months of follow-up. Three months post-operation, facial nerve palsy, swallowing disturbances and pain were not observed. Infections, allergic reactions to materials and re-ankylosis were also not observed. Replacements received correct forms and functions owing to the CAM techniques. Post-operational maximal interincisal opening improved (p < 0.01) and was not significantly related to preoperational opening, age, sex, diagnosis or adjuvant radiotherapy., Conclusion: Considering both methods, the feature that differentiates the manufacture technique is the more subtractive surface finishing required for the DMLS implant than the CNC implant. Both techniques resulted the same clinical outcomes and can be used successfully in patients with neoplastic lesions and other TMJ disorders. Unfortunately, DMLS is more vulnerable to fracture., (Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Published
2017
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49. [Total nitrogen, alpha-amine nitrogen and pH in the cultural filtrates of various leptospiral serotypes being cultured in a liquid Korthof's medium (author's transl)].

Author

Wach T and Hencner Z

Subjects
Hydrogen-Ion Concentration, Leptospira growth & development, Leptospira interrogans growth & development, Leptospira interrogans metabolism, Leptospira interrogans serovar canicola growth & development, Leptospira interrogans serovar canicola metabolism, Nitrogen analysis, Species Specificity, Culture Media, Leptospira metabolism, Nitrogen metabolism
Published
1978

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