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Journal articles on the topic 'Comptonization'

Author: Grafiati

Published: 4 June 2021

Last updated: 20 February 2023

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1

Steiner, James F., Ramesh Narayan, Jeffrey E. McClintock, and Ken Ebisawa. "A Simple Comptonization Model." Publications of the Astronomical Society of the Pacific 121, no. 885 (November 2009): 1279–90. http://dx.doi.org/10.1086/648535.

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2

Chen, Yu-Peng, Shu Zhang, Long Ji, Shuang-Nan Zhang, Ling-Da Kong, Peng-Ju Wang, Zhi Chang, Jing-Qiang Peng, Jin-Lu Qu, and Jian Li. "Insight-HXMT Observation of 4U 1608–52: Evidence of Interplay between a Thermonuclear Burst and Accretion Environment." Astrophysical Journal 936, no. 1 (August 30, 2022): 46. http://dx.doi.org/10.3847/1538-4357/ac87a0.

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Abstract A Type I burst could influence the accretion process through radiation pressure and Comptonization both for the accretion disk and the corona/boundary layer of an X-ray binary, and vice versa. We investigate the temporal evolution of a bright photospheric radius expansion (PRE) burst of 4U 1608–52 detected by Insight-HXMT in 1–50 keV, with the aim to study the interplay between the burst and persistent emission. Apart from the emission from the neutron star (NS) surface, we find residuals in both the soft (<3 keV) and hard (>10 keV) X-ray bands. Time-resolved spectroscopy reveals that the excess can be attributed to either an enhanced preburst/persistent emission or the Comptonization of the burst emission by the corona/boundary layer. The Comptonization model is a convolution thermal-Comptonization model (thcomp in XSPEC), and the Comptonization parameters are fixed at the values derived from the persistent emission. We find, during the PRE phase, after the enhanced preburst/persistent emission or the Comptonization of the burst emission is removed, the NS surface emission shows a plateau and then a rise until the photosphere touches down on the NS surface, resulting in a flux peak at that moment. We speculate that the findings above correspond to the lower part of the NS surface that is obscured by the disk being exposed to the line of sight due to the evaporation of inner disk by the burst emission. The consistency between the f a model and convolution thermal-Comptonization model indicates the interplay between thermonuclear bursts and accretion environments. These phenomena do not usually show up in conventional blackbody model fittings, which may be due to the low count rate and narrow energy coverage in previous observations.

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3

Celotti, A., G. Ghisellini, and A. C. Fabian. "Bulk Comptonization spectra in blazars." Monthly Notices of the Royal Astronomical Society 375, no. 2 (February 21, 2007): 417–24. http://dx.doi.org/10.1111/j.1365-2966.2006.11289.x.

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4

Ghisellini, G., and A. Celotti. "Quasi–thermal comptonization and GRBs." Astronomy and Astrophysics Supplement Series 138, no. 3 (September 1999): 527–28. http://dx.doi.org/10.1051/aas:1999339.

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5

Dziełak, Marta A., Barbara De Marco, and Andrzej A. Zdziarski. "A spectrally stratified hot accretion flow in the hard state of MAXI J1820+070." Monthly Notices of the Royal Astronomical Society 506, no. 2 (June 14, 2021): 2020–29. http://dx.doi.org/10.1093/mnras/stab1700.

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ABSTRACT We study the structure of the accretion flow in the hard state of the black hole X-ray binary MAXI J1820+070 with NICER data. The power spectra show broad-band variability which can be fit with four Lorentzian components peaking at different time-scales. Extracting power spectra as a function of energy enables the energy spectra of these different power spectral components to be reconstructed. We found significant spectral differences among Lorentzians, with the one corresponding to the shortest variability time-scales displaying the hardest spectrum. Both the variability spectra and the time-averaged spectrum are well-modelled by a disc blackbody and thermal Comptonization, but the presence of (at least) two Comptonization zones with different temperatures and optical depths is required. The disc blackbody component is highly variable, but only in the variability components peaking at the longest time-scales ($\lower.5ex\hbox{$\,\, \buildrel\gt \over \sim \,\,$}1$ s). The seed photons for the spectrally harder zone come predominantly from the softer Comptonization zone. Our results require the accretion flow in this source to be structured, and cannot be described by a single Comptonization region upscattering disc blackbody photons, and reflection from the disc.

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6

Vilhu, Osmi, Juri Poutanen, Petter Nikula, and Jukka Nevalainen. "Thermal Comptonization in GRS 1915+105." Astrophysical Journal 553, no. 1 (May 20, 2001): L51—L54. http://dx.doi.org/10.1086/320489.

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7

Socrates, Aristotle. "RELATIVISTIC ACCRETION MEDIATED BY TURBULENT COMPTONIZATION." Astrophysical Journal 719, no. 1 (July 23, 2010): 784–89. http://dx.doi.org/10.1088/0004-637x/719/1/784.

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8

Dreissigacker, Oliver. "Comptonization as Blazar High Energy Emission." Symposium - International Astronomical Union 175 (1996): 421–22. http://dx.doi.org/10.1017/s0074180900081316.

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We explain the overall continuous Grazar (Gamma Ray Blazar) spectrum from the synchrotron turnover to the EGRET GeV detections by means of Comptonization in the parsec scale jet's substructures.While making use of the constraints on the synchrotron spectrum and other measurable quantities, no exotic particle acceleration is needed to achieve the high energy output.We show, that the “Lighthouse Model” of blobs of relativistic electrons, travelling with the jet plasma at relativistic speeds, produce both, correct timescales and shapes for the lightcurve, and correct ratios and slopes of the synchrotron, X-ray and γ-ray branches.

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9

Socrates, Aristotle, Shane W. Davis, and Omer Blaes. "Turbulent Comptonization in relativistic accretion disks." Advances in Space Research 38, no. 12 (January 2006): 2880–83. http://dx.doi.org/10.1016/j.asr.2006.08.002.

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10

Maraschi, L., and S. Molendi. "Thermal Comptonization in standard accretion disks." Astrophysical Journal 353 (April 1990): 452. http://dx.doi.org/10.1086/168633.

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11

Titarchuk, Lev, and Xin-Min Hua. "A Comparison of Thermal Comptonization Models." Astrophysical Journal 452 (October 1995): 226. http://dx.doi.org/10.1086/176293.

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12

Petrucci, P. O., D. Gronkiewicz, A. Rozanska, R. Belmont, S. Bianchi, B. Czerny, G. Matt, et al. "Radiation spectra of warm and optically thick coronae in AGNs." Astronomy & Astrophysics 634 (February 2020): A85. http://dx.doi.org/10.1051/0004-6361/201937011.

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A soft X-ray excess above the 2–10 keV power-law extrapolation is generally observed in the X-ray spectra of active galactic nuclei. The origin of this excess is still not well understood. Presently there are two competitive models: blurred ionized reflection and warm Comptonization. In the case of warm Comptonization, observations suggest a corona temperature in the range 0.1–2 keV and a corona optical depth of about 10–20. Moreover, radiative constraints from spectral fits with Comptonization models suggest that most of the accretion power should be released in the warm corona and the disk below is basically non-dissipative, radiating only the reprocessed emission from the corona. However, the true radiative properties of such a warm and optically thick plasma are not well known. For instance, the importance of the Comptonization process, the potential presence of strong absorption and/or emission features, and the spectral shape of the output spectrum have been studied only very recently. Here, we present simulations of warm and optically thick coronae using the TITAN radiative transfer code coupled with the NOAR Monte-Carlo code, the latter fully accounting for Compton scattering of continuum and lines. Illumination from above by hard X-ray emission and from below by an optically thick accretion disk are taken into account, as well as (uniform) internal heating. Our simulations show that for a large part of the parameter space, the warm corona with sufficient internal mechanical heating is dominated by Compton cooling and neither strong absorption nor emission lines are present in the outgoing spectra. In a smaller part of the parameter space, the calculated emission agrees with the spectral shape of the observed soft X-ray excess. Remarkably, this also corresponds to the conditions of radiative equilibrium of an extended warm corona covering a non-dissipative accretion disk almost entirely. These results confirm that warm Comptonization is a valuable model that can explain the origin of the soft X-ray excess.

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13

Bassi, T., J. Malzac, M. Del Santo, E. Jourdain, J.-P. Roques, A. D’Aì, J. C. A. Miller-Jones, et al. "On the nature of the soft γ-ray emission in the hard state of the black hole transient GRS 1716−249." Monthly Notices of the Royal Astronomical Society 494, no. 1 (March 18, 2020): 571–83. http://dx.doi.org/10.1093/mnras/staa739.

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ABSTRACT The black hole transient GRS 1716−249 was monitored from the radio to the γ-ray band during its 2016–2017 outburst. This paper focuses on the spectral energy distribution (SED) obtained in 2017 February–March, when GRS 1716−249 was in a bright hard spectral state. The soft γ-ray data collected with the INTEGRAL/SPI telescope show the presence of a spectral component that is in excess of the thermal Comptonization emission. This component is usually interpreted as inverse Compton emission from a tiny fraction of non-thermal electrons in the X-ray corona. We find that hybrid thermal/non-thermal Comptonization models provide a good fit to the X-/γ-ray spectrum of GRS 1716−249. The best-fitting parameters are typical of the bright hard state spectra observed in other black hole X-ray binaries. Moreover, the magnetized hybrid Comptonization model belm provides an upper limit on the intensity of the coronal magnetic field of about 106 G. Alternatively, this soft γ-ray emission could originate from synchrotron emission in the radio jet. In order to test this hypothesis, we fit the SED with the irradiated disc plus Comptonization model combined with the jet internal shock emission model ishem. We found that a jet with an electron distribution of p ≃ 2.1 can reproduce the soft γ-ray emission of GRS 1716−249. However, if we introduce the expected cooling break around 10 keV, the jet model can no longer explain the observed soft γ-ray emission, unless the index of the electron energy distribution is significantly harder (p < 2).

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14

Kaufman, J., and O. M. Blaes. "Bulk Comptonization by turbulence in accretion discs." Monthly Notices of the Royal Astronomical Society 459, no. 2 (April 5, 2016): 1790–802. http://dx.doi.org/10.1093/mnras/stw761.

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15

Skibo, J. G., C. D. Dermer, R. Ramaty, and J. M. McKinley. "Thermal Comptonization in Mildly Relativistic Pair Plasmas." Astrophysical Journal 446 (June 1995): 86. http://dx.doi.org/10.1086/175770.

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16

Socrates, Aristotle, Shane W. Davis, and Omer Blaes. "Turbulent Comptonization in Black Hole Accretion Disks." Astrophysical Journal 601, no. 1 (January 20, 2004): 405–13. http://dx.doi.org/10.1086/380301.

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17

Pavlov, G. G., Yu A. Shibanov, and P. Mészáros. "Comptonization in strongly magnetized and nonmagnetized plasmas." Physics Reports 182, no. 3 (October 1989): 187–210. http://dx.doi.org/10.1016/0370-1573(89)90125-7.

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18

Lyubarskii, Yu �. "Comptonization in a superstrong magnetic field. I." Astrophysics 28, no. 1 (1988): 106–11. http://dx.doi.org/10.1007/bf01014858.

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19

Lyubarskii, Yu �. "Saturated comptonization in a superstrong magnetic field." Astrophysics 25, no. 2 (1987): 577–86. http://dx.doi.org/10.1007/bf01006289.

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20

Ghisellini, Gabriele, and Annalisa Celotti. "Quasi-thermal Comptonization and Gamma-Ray Bursts." Astrophysical Journal 511, no. 2 (February 1, 1999): L93—L96. http://dx.doi.org/10.1086/311845.

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21

Liang, E. P., A. Crider, M. Böttcher, and I. A. Smith. "GRB 990123: The Case for Saturated Comptonization." Astrophysical Journal 519, no. 1 (July 1, 1999): L21—L24. http://dx.doi.org/10.1086/312100.

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22

Bartlett, James G., and Joseph Silk. "A Comptonization model for the submillimeter background." Astrophysical Journal 353 (April 1990): 399. http://dx.doi.org/10.1086/168625.

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23

Xu, Yueming, Randy R. Ross, and Richard McCray. "Comptonization of gamma rays by cold electrons." Astrophysical Journal 371 (April 1991): 280. http://dx.doi.org/10.1086/169891.

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24

Canfield, E., W. M. Howard, and E. P. Liang. "Inverse Comptonization by one-dimensional relativistic electrons." Astrophysical Journal 323 (December 1987): 565. http://dx.doi.org/10.1086/165853.

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25

Gierliński, Marek, and Andrzej A. Zdziarski. "Patterns of energy-dependent variability from Comptonization." Monthly Notices of the Royal Astronomical Society 363, no. 4 (October 10, 2005): 1349–60. http://dx.doi.org/10.1111/j.1365-2966.2005.09527.x.

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26

Hua, Xin-Min, and Lev Titarchuk. "Time Variation of Emissions from Comptonization Sources." Astrophysical Journal 469 (September 1996): 280. http://dx.doi.org/10.1086/177778.

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27

Lyubarskii, Yu �. "Comptonization in a superstrong magnetic field. II." Astrophysics 28, no. 2 (1988): 253–62. http://dx.doi.org/10.1007/bf01004077.

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28

Zotti, G. De, and C. Burigana. "The Cosmic Microwave Background Spectrum: Theoretical Framework." Highlights of Astronomy 9 (1992): 265–71. http://dx.doi.org/10.1017/s1539299600009035.

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AbstractPreliminary analyses of COBE/FIRAS data have already produced a spectacularly accurate determination of the microwave background spectrum for 1 cm ≤ λ ≤ 500 μm. The absence of detectable deviations from a blackbody spectrum sets strong constraints on physical conditions of the intergalactic plasma and, in particular, has ruled out the possibihty of a truly diffuse thermal bremsstrahlung origin of the X-ray background. General arguments suggest that comptonization distortions due to heating of the intergalactic medium associated with the formation of cosmic structures, with hot protogalactic winds, or with the ionizing flux from AGNs, are likely to be very small (comptonization parameter y ≲, 10-4). A larger signal is expected from the integrated re-radiation from dust in external galaxies; to what extent this may conceal possible comptonization distortions depends on the maximum redshift at which galaxies contain substantial amounts of dust and on the temperature distribution of dust grains. In any case, a precise determination of either the y parameter or the background from distant galaxies requires a careful subtraction of the emission from the Milky Way.The great success of COBE strengthens the need for a parallel improvement in the accuracy of spectral measurements in the Rayleigh-Jeans region, where imprints of physical processes occurring at very early epochs (such as, e.g., the dissipation of small scale density inhomogeneities) may show up.

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29

Zdziarski, Andrzej A., Michał Szanecki, Juri Poutanen, Marek Gierliński, and Paweł Biernacki. "Spectral and temporal properties of Compton scattering by mildly relativistic thermal electrons." Monthly Notices of the Royal Astronomical Society 492, no. 4 (January 17, 2020): 5234–46. http://dx.doi.org/10.1093/mnras/staa159.

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ABSTRACT We have obtained new solutions and methods for the process of thermal Comptonization. We modify the solution to the kinetic equation of Sunyaev and Titarchuk to allow its application up to mildly relativistic electron temperatures and optical depths $\gtrsim {1}$. The solution can be used for spectral fitting of X-ray spectra from astrophysical sources. We also have developed an accurate Monte Carlo method for calculating spectra and timing properties of thermal Comptonization sources. The accuracy of our kinetic equation solution is verified by comparison with the Monte Carlo results. We also compare our results with those of other publicly available methods. Furthermore, based on our Monte Carlo code, we present distributions of the photon emission times and the evolution of the average photon energy for both up and down scattering.

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30

Guilbert, P. W., and S. Stepney. "Pair production, Comptonization and dynamics in astrophysical plasmas." Monthly Notices of the Royal Astronomical Society 212, no. 3 (February 1, 1985): 523–44. http://dx.doi.org/10.1093/mnras/212.3.523.

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31

Hua, Xin-Min. "Monte Carlo simulation of Comptonization in inhomogeneous media." Computers in Physics 11, no. 6 (1997): 660. http://dx.doi.org/10.1063/1.168615.

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32

Rephaeli, Yoel. "Cosmic microwave background comptonization by hot intracluster gas." Astrophysical Journal 445 (May 1995): 33. http://dx.doi.org/10.1086/175669.

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33

Petrucci, P. O., F. Haardt, L. Maraschi, P. Grandi, J. Malzac, G. Matt, F. Nicastro, L. Piro, G. C. Perola, and A. De Rosa. "Testing Comptonization Models UsingBeppoSAXObservations of Seyfert 1 Galaxies." Astrophysical Journal 556, no. 2 (August 2001): 716–26. http://dx.doi.org/10.1086/321629.

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34

Poutanen, Juri. "Frequency-Dependent Polarization in Comptonization Models for AGN." Symposium - International Astronomical Union 159 (1994): 472. http://dx.doi.org/10.1017/s007418090017651x.

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The angular distribution and the polarization of radiation as a function of the angle and frequency for the two-phase model of accretion disks in AGN are found. The results depend strongly on the temperature of the hot corona.

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35

Reig, P., N. D. Kylafis, and H. C. Spruit. "Orbital Comptonization in accretion disks around black holes." Astronomy & Astrophysics 375, no. 1 (August 2001): 155–60. http://dx.doi.org/10.1051/0004-6361:20010827.

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36

Hujeirat, A., M. Camenzind, and A. Burkert. "Comptonization and synchrotron emission in 2D accretion flows." Astronomy & Astrophysics 386, no. 2 (May 2002): 757–62. http://dx.doi.org/10.1051/0004-6361:20020234.

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37

Daugherty, Joseph K., and Alice K. Harding. "Comptonization of thermal photons by relativistic electron beams." Astrophysical Journal 336 (January 1989): 861. http://dx.doi.org/10.1086/167057.

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38

Niedzwiecki, A., and A. A. Zdziarski. "Bulk motion Comptonization in black hole accretion flows." Monthly Notices of the Royal Astronomical Society 365, no. 2 (January 11, 2006): 606–14. http://dx.doi.org/10.1111/j.1365-2966.2005.09752.x.

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39

Skibo, J. G., C. D. Dermer, R. Ramaty, and J. M. McKinley. "Thermal Comptonization in Mildly Relativistic Pair Plasmas: Erratum." Astrophysical Journal 463 (May 1996): 391. http://dx.doi.org/10.1086/177253.

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40

GHOSH, HIMADRI, SUDIP K. GARAIN, SANDIP K. CHAKRABARTI, and PHILIPPE LAURENT. "MONTE CARLO SIMULATIONS OF THE THERMAL COMPTONIZATION PROCESS IN A TWO-COMPONENT ACCRETION FLOW AROUND A BLACK HOLE IN THE PRESENCE OF AN OUTFLOW." International Journal of Modern Physics D 19, no. 05 (May 2010): 607–20. http://dx.doi.org/10.1142/s0218271810016555.

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A black hole accretion may have both the Keplerian and the sub-Keplerian component. In the so-called Chakrabarti–Titarchuk scenario, the Keplerian component supplies low-energy (soft) photons while the sub-Keplerian component supplies hot electrons which exchange their energy with the soft photons through Comptonization or inverse Comptonization processes. In the sub-Keplerian component, a shock is generally produced due to the centrifugal force. The postshock region is known as the CENtrifugal pressure–supported BOundary Layer (CENBOL). In this paper, we compute the effects of the thermal and the bulk motion Comptonization on the soft photons emitted from a Keplerian disk by the CENBOL, the preshock sub-Keplerian disk and the outflowing jet. We study the emerging spectrum when the converging inflow and the diverging outflow (generated from the CENBOL) are simultaneously present. From the strength of the shock, we calculate the percentage of matter being carried away by the outflow and determine how the emerging spectrum depends on the outflow rate. The preshock sub-Keplerian flow is also found to Comptonize the soft photons significantly. The interplay between the up-scattering and down-scattering effects determines the effective shape of the emerging spectrum. By simulating several cases with various inflow parameters, we conclude that whether the preshock flow, or the postshock CENBOL or the emerging jet is dominant in shaping the emerging spectrum depends strongly on the geometry of the flow and the strength of the shock in the sub-Keplerian flow.

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41

Zdziarski, A. A. "Radiative Processes and Geometry of Spectral States of Black-hole Binaries." Symposium - International Astronomical Union 195 (2000): 153–70. http://dx.doi.org/10.1017/s0074180900162898.

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I review radiative processes responsible for X-ray emission in the hard (low) and soft (high) spectral states of black-hole binaries. The main process in the hard state appears to be thermal Comptonization (in a hot plasma) of blackbody photons emitted by a cold disk. This is supported by correlations between the spectral index, the strength of Compton reflection, and the peak frequencies in the power-density spectrum, as well as by the frequency-dependence of Fourier-resolved spectra. Spectral variability may then be driven by the variable truncation radius of the disk. The soft state appears to correspond to the smallest truncation radii. However, the lack of high-energy cutoffs observed in the soft state implies that its main radiative process is Compton scattering of disk photons by nonthermal electrons. The bulk-motion Comptonization model for the soft state is shown to be ruled out by the data.

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42

Koljonen, Karri I. I., Diana C. Hannikainen, Michael L. McCollough, Guy G. Pooley, Sergei A. Trushkin, and Robert Droulans. "The X-ray spectral and timing properties of a major radio flare episode in Cygnus X-3." Proceedings of the International Astronomical Union 8, S290 (August 2012): 237–38. http://dx.doi.org/10.1017/s1743921312019795.

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AbstractThe microquasar Cygnus X-3 is known for massive outbursts that emit radiation from radio to γ-rays associated with jet ejection events. Using Principal Component Analysis to probe fast (~1 min) X-ray spectral evolution followed by subsequent spectral fits to the time-averaged spectra (~3 ks), we find that the overall X-ray variability during major outbursts can be attributed to two components. The spectral evolution of these components are best fitted with hybrid Comptonization and thermal bremsstrahlung components. Most of the X-ray variability is attributed to the hybrid Comptonization component. However, the spectral evolution of the thermal component is linked to a change in the X-ray spectral state. Phase-folding the fit results shows that the thermal component is restricted to two orbital phase regions opposite to each other, possibly indicating a flattened stellar wind from the Wolf-Rayet companion.

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43

Baughman, David C., and Peter A. Becker. "An Analytical Fourier Transformation Model for the Production of Hard and Soft X-Ray Time Lags in Active Galactic Nuclei: Application to 1H 0707-495." Astrophysical Journal 932, no. 2 (June 1, 2022): 113. http://dx.doi.org/10.3847/1538-4357/ac6e67.

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Abstract The variability of the X-ray emission from active galactic nuclei is often characterized using time lags observed between soft and hard energy bands in the detector. The time lags are usually computed using the complex cross-spectrum, which is based on the Fourier transforms of the hard and soft time series data. It has been noted that some active galactic nuclei display soft X-ray time lags, in addition to the more ubiquitous hard lags. Hard time lags are thought to be produced via propagating fluctuations, spatial reverberation, or via the thermal Comptonization of soft seed photons injected into a hot electron cloud. The physical origin of the soft lags has been a subject of debate over the last decade. Currently, the reverberation interpretation is recognized as a leading theory. In this paper, we explore the alternative possibility that the soft X-ray time lags result partially from the thermal and bulk Comptonization of monochromatic seed photons which, in the case of the narrow-line Seyfert 1 galaxy 1H 0707-495, may correlate with fluorescence of iron L-line emission. In our model, the seed photons are injected into a hot, quasi-spherical corona in the inner region of the accretion flow. We develop an exact, time-dependent analytical model for the thermal and bulk Comptonization of the seed photons based on a Fourier-transformed radiation transport equation, and we demonstrate that the model successfully reproduces both the hard and soft time lags observed from 1H 0707-495.

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44

Sandoval-Villalbazo, A. "A 1D kinetic model for cosmic microwave background comptonization." Revista Mexicana de Física 66, no. 3 May-Jun (May 1, 2020): 352. http://dx.doi.org/10.31349/revmexfis.66.352.

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This work presents a novel derivation of the expressions that describe the distortions of the CMB curve due to the interactions between photons and the electrons present in dilute ionized systems. In this approach, a simplified a one-dimensional evolution equation for the photon number occupation is applied in order to describe the aforemationed interaction. This methodology allows to emphasize the physical features ot the Sunyaev-Zeldovich effect and suggests the existence of links between basic statistical physics and complex applications involving radiative processes.

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45

Czerny, B., and M. Zbyszewska. "Comptonization of the Lyman edge in active galactic nuclei." Monthly Notices of the Royal Astronomical Society 249, no. 4 (April 15, 1991): 634–39. http://dx.doi.org/10.1093/mnras/249.4.634.

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46

Arbeiter, C., M. Pohl, and R. Schlickeiser. "Synchrotron Self‐Comptonization in a Relativistic Collision Front Model." Astrophysical Journal 627, no. 1 (July 2005): 62–74. http://dx.doi.org/10.1086/430118.

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47

Lee, H. C., and G. S. Miller. "Comptonization and QPO origins in accreting neutron star systems." Monthly Notices of the Royal Astronomical Society 299, no. 2 (September 1, 1998): 479–87. http://dx.doi.org/10.1046/j.1365-8711.1998.01842.x.

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48

Ghisellini, Gabriele, and Francesco Haardt. "On thermal Comptonization in e[SUP]+/-[/SUP] pair plasmas." Astrophysical Journal 429 (July 1994): L53. http://dx.doi.org/10.1086/187411.

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49

Adegoke, Oluwashina, Gulab C. Dewangan, Pramod Pawar, and Main Pal. "UV to X-Ray Comptonization Delay in Mrk 493." Astrophysical Journal 870, no. 2 (January 9, 2019): L13. http://dx.doi.org/10.3847/2041-8213/aaf8ab.

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Gornostaev, M. I., and G. V. Lipunova. "Comptonization of CMB in galaxy clusters. Monte Carlo computations." Monthly Notices of the Royal Astronomical Society 499, no. 2 (October 1, 2020): 2994–3005. http://dx.doi.org/10.1093/mnras/staa3010.

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Abstract:

ABSTRACT The problem under consideration is to determine the change of the cosmic microwave background (CMB) spectral shape due to the thermal Sunyaev–Zeldovich (tSZ) effect. We numerically model the spectral intensity of the CMB radiation Comptonized by the hot intergalactic Maxwellian plasma. To this aim, a relativistic Monte Carlo code with photon weights is developed. The code enables us to construct the Comptonized CMB spectrum in a wide energy range. The results are compared with known analytical solutions and previous numerical simulations. We also calculate the angular distributions of the intensity of radiation emerging from the cloud, which show that the spectral shape of the tSZ effect is not universal for different directions of escaping photons. The numerical method can be applied to simulate the processes of Comptonization for different optical depths, temperatures, initial spectra of photon sources, and their spatial distributions, the obtained results may have implications on investigating the profiles of galaxy clusters.

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