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Journal articles on the topic 'Circinus'

Author: Grafiati

Published: 10 March 2023

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1

Do Duy, Tho, and Warrick A. Lawson. "Evidence for the absorption of crystalline silicates at 11.1 $\mu$m in the spectra of the nucleus of the Circinus galaxy." Monthly Notices of the Royal Astronomical Society: Letters 488, no. 1 (June 18, 2019): L75—L79. http://dx.doi.org/10.1093/mnrasl/slz096.

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Abstract Several mid-infrared spectra of the Circinus galaxy nucleus taken with T-ReCS on Gemini South and MIDI on VLTI have consistently shown an inflection centred around 11 $\mu$m. We ascribe this feature to the absorption of crystalline silicate, based on their similarity in profile shape and improvement in fitting quality using a partially crystalline silicate model, compared to entirely amorphous models. Spectral fits reveal a fraction of 0.6–2.0 per cent of crystalline forsterite in the nucleus of the Circinus galaxy, which is similar to the values obtained for the interstellar medium (ISM) of the Milky Way. This is probably the first detection of crystalline silicate absorption in the nucleus of this Seyfert 2 galaxy. In addition, the presence of large grain-size amorphous silicates, together with the similarity in profile shape of the optical depth of Circinus with those of young stellar objects in the Milky Way, implies that most of the contribution to the spectra of Circinus comes from dust in the star formation regions near the centre of the nucleus or along the line of sight to the Earth, rather than in the ISM of Circinus. We also compare our optical depths of Circinus with those in previous studies.

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2

Veilleux, Sylvain, and Jonathan Bland-Hawthorn. "Artillery Shells over Circinus." Astrophysical Journal 479, no. 2 (April 20, 1997): L105—L108. http://dx.doi.org/10.1086/310588.

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3

Lutz, D., R. Genzel, E. Sturm, A. F. M. Moorwood, E. Oliva, A. Marconi, and H. Netzer. "AGN Spectra as Seen by the Infrared Space Observatory: First Results." International Astronomical Union Colloquium 159 (1997): 333–36. http://dx.doi.org/10.1017/s0252921100040379.

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AbstractWe discuss 2.5–45 µm spectra of the Circinus galaxy and of Cen A, obtained with the Short Wavelength Spectrometer (SWS) on board the Infrared Space Observatory. The large number of detected ionic fine structure lines, observable also in visually obscured sources, provides strong constraints on the shape of the ionizing spectrum, which is found to exhibit a UV bump peaking at ~ 70 eV in the case of Circinus. Pure rotational emission of molecular hydrogen, directly probing warm molecular gas, can for the first time be detected in external galaxies.

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4

Mondal, Samaresh, Agata Różańska, Patrycja Bagińska, Alex Markowitz, and Barbara De Marco. "Spectral state transitions in Circinus ULX5." Astronomy & Astrophysics 651 (July 2021): A54. http://dx.doi.org/10.1051/0004-6361/202140459.

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Context. We performed timing and spectral analyses of multi-epoch Suzaku, XMM-Newton, and NuSTAR observations of the ultraluminous X-ray source (ULX) Circinus ULX5 with the aim of putting constraints on the mass of the central object and the accretion mode operating in this source. Aims. We investigate whether the source contains a stellar mass black hole (BH) with a super-Eddington accretion flow or an intermediate mass black hole accreting matter in a sub-Eddington mode. Moreover, we search for major observed changes in spectra and timing and determine whether they are associated with major structural changes in the disk, similarly to those in black hole X-ray binaries. Methods. We collected all available broadband data from 2001 to 2018 including Suzaku, XMM-Newton, and NuSTAR. We a performed timing and spectral analyses to study the relation between luminosity and inner disk temperature. We proceeded with time-averaged spectral analysis using phenomenological models of different accretion modes. Finally, we constructed the hardness ratio versus intensity diagram to reveal spectral state transitions in Circinus ULX5. Results. Our spectral analysis revealed at least three distinctive spectral states of Circinus ULX5 that are analagous to state transitions in Galactic black hole X-ray binaries. Disk-dominated spectra are found in high flux states and the power-law dominated spectra are found in lower flux states. The source was also observed in an intermediate state, where the flux was low, but the spectrum is dominated by a disk component. Over eighteen years of collected data, ULX5 appeared two times in the high, three times in the low, and two times in the intermediate state. The fastest observed transition was ∼seven months. Conclusions. Our analysis suggests that the central object in Circinus ULX5 is a stellar mass BH (< 10 M⊙) or, possibly, a neutron star (NS) despite there being no detection of pulsations in the light curves. The fractional variability amplitudes are consistent with state transitions in Circinus ULX5, wherein higher variability from the power law-like Comptonized emission becomes suppressed in the thermal disk-dominated state.

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5

Yang, Y., A. S. Wilson, G. Matt, Y. Terashima, and L. J. Greenhill. "SUZAKUOBSERVATIONS OF THE CIRCINUS GALAXY." Astrophysical Journal 691, no. 1 (January 7, 2009): 131–39. http://dx.doi.org/10.1088/0004-637x/691/1/131.

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6

Smith, David A., and Andrew S. Wilson. "AChandraObservation of the Circinus Galaxy." Astrophysical Journal 557, no. 1 (August 10, 2001): 180–92. http://dx.doi.org/10.1086/321667.

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7

Noroozi, S., M. Haas, Z. Chen, and R. Chini. "Hα emission objects in Circinus." Astronomische Nachrichten 334, no. 3 (March 2013): 282–87. http://dx.doi.org/10.1002/asna.201211843.

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8

Rector, T. A., L. Prato, and A. L. Strom. "Herbig–Haro Outflows in Circinus W." Astronomical Journal 160, no. 4 (September 29, 2020): 189. http://dx.doi.org/10.3847/1538-3881/abb3d3.

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9

Haynes, RF. "Cir X-1 Revisited: 843 MHz Observations of Cir X-1 and G321·9?0·3." Australian Journal of Physics 40, no. 6 (1987): 741. http://dx.doi.org/10.1071/ph870741.

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New high-sensitivity results at 843 MHz are presented for the Circinus X-I (Cir X-I) and SNR G 3 21 �9 - 0 . 3 regions. We summarise current observational data for Cir X-I and discuss appropriate models.

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10

Mikami, T., and K. Ogura. "H emission stars in the Circinus region." Monthly Notices of the Royal Astronomical Society 270, no. 1 (September 1, 1994): 199–204. http://dx.doi.org/10.1093/mnras/270.1.199.

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11

McCallum, Jamie N., Simon P. Ellingsen, David L. Jauncey, James E. J. Lovell, and Lincoln J. Greenhill. "Scintillation in the Circinus Galaxy H2O Megamasers." Astronomical Journal 129, no. 3 (March 2005): 1231–36. http://dx.doi.org/10.1086/427399.

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12

Coriat, M., R. P. Fender, C. Tasse, O. Smirnov, A. K. Tzioumis, and J. W. Broderick. "The twisted jets of Circinus X-1." Monthly Notices of the Royal Astronomical Society 484, no. 2 (January 10, 2019): 1672–86. http://dx.doi.org/10.1093/mnras/stz099.

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13

D’Ai, A., R. Iaria, T. Di Salvo, G. Lavagetto, and N. R. Robba. "A Complex Environment around Circinus X‐1." Astrophysical Journal 671, no. 2 (December 20, 2007): 2006–16. http://dx.doi.org/10.1086/522565.

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14

Bradt, Hale, Robert Shirey, and Alan Levine. "Observations of circinus X-1 with RXTE." Nuclear Physics B - Proceedings Supplements 69, no. 1-3 (January 1999): 273–81. http://dx.doi.org/10.1016/s0920-5632(98)00225-4.

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15

Tennant, A. F. "Circinus X-1, as viewed by EXOSAT." Advances in Space Research 8, no. 2-3 (January 1988): 397–404. http://dx.doi.org/10.1016/0273-1177(88)90436-x.

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16

Elmouttie, M., R. F. Haynes, and K. L. Jones. "12CO J = 1 → 0 Observations of the Circinus Galaxy using the Mopra 22 m Radio Telescope." Publications of the Astronomical Society of Australia 14, no. 2 (1997): 140–45. http://dx.doi.org/10.1071/as97140.

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AbstractThe J = 1–0 rotational transition of carbon monoxide has been used to trace the molecular gas at five different positions in the Circinus galaxy using the Australia Telescope National Facility's 22 m radio telescope at Mopra. The intensity profile of the central CO emission has a full width at half maximum of 550 pc. The 12CO (1–0) spectrum at the centre of the galaxy has an integrated temperature of 145 K km S−1, with components peaking at 0·62 K and ranging in velocity from 200–600 km S−1. The total mass of molecular gas in the Circinus galaxy, assuming that the CO intensity profile of the galaxy is similar to the radio continuum, is at least 7·5±4·1 × 108 M⊙. This estimate, combined with previously published far infrared data, yields a value for the star-forming efficiency, SFE = 16±9 L⊙ M⊙‒1.

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17

HAWKES, J., G. ROWELL, B. DAWSON, F. AHARONIAN, M. BURTON, Y. FUKUI, N. FURUKAWA, et al. "INVESTIGATION OF DENSE GAS TOWARDS RELATIVISTIC OUTFLOW SOURCES." International Journal of Modern Physics: Conference Series 28 (January 2014): 1460198. http://dx.doi.org/10.1142/s2010194514601987.

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We probe the interstellar medium towards the objects Circinus X-1, a low-mass X-ray binary with relativistic jets; and the highly energetic Westerlund 2 stellar cluster, which is located towards TeV gamma-ray emission and interesting arc- and jet-like features seen in Nanten 12CO data. We have mapped both regions with the Mopra radio telescope, in 7 mm and 12 mm wavebands, looking for evidence of disrupted/dense gas caused by the interaction between high energy outflows and the ISM. Towards Westerlund 2, peaks in CS(J=1-0) emission indicate high density gas towards the middle of the arc and the endpoint of the jet; and radio recombination line emission is seen overlapping the coincident HII region RCW49. Towards Circinus X-1, 12CO(J = 1-0) Nanten data reveals three molecular clouds that lie in the region of Cir X-1. Gas parameters for each cloud are presented here.

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18

Fender, R. P. "New Radio Observations of Circinus X-1: A Summary." International Astronomical Union Colloquium 164 (1998): 343–44. http://dx.doi.org/10.1017/s025292110004584x.

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AbstractNew radio observations from the Australia Telescope Compact Array of the radio jet X-ray binary Circinus X-1 are summarized. Radio flux density monitoring around nearly an entire orbit is presented, confirming continued radio flaring around phase 0.1 (near periastron passage) as well as a lesser enhancement half an orbit later.

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19

Harnett, J. I., R. F. Haynes, R. Wielebinski, and U. Klein. "Radio Polarization Studies of Some Southern Galaxies." Symposium - International Astronomical Union 140 (1990): 225–26. http://dx.doi.org/10.1017/s0074180900190059.

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We have begun a long-range project to study southern galaxies using the radio telescopes at Parkes and Molonglo, the Siding Spring optical facilities and soon, the Australia Telescope. Here we present the results of polarization mapping at two wavelengths of the galaxies NGC 55, 253,4945, M 83 and the Circinus Galaxy.

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20

Elmouttie, E., R. F. Haynes, K. L. Jones, M. Ehle, R. Beck, and R. Wielebinski. "The polarized radio lobes of the Circinus galaxy." Monthly Notices of the Royal Astronomical Society 275, no. 1 (July 1995): L53—L59. http://dx.doi.org/10.1093/mnras/275.1.l53.

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21

Haynes, R. F., M. M. Komesaroff, A. G. Little, D. L. Jauncey, J. L. Caswell, D. K. Milne, M. J. Kesteven, K. J. Wellington, and R. A. Preston. "A radio nebula associated with Circinus X-1." Nature 324, no. 6094 (November 1986): 233–35. http://dx.doi.org/10.1038/324233a0.

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22

Elmouttie, M., M. Krause, R. F. Haynes, and K. L. Jones. "A disturbed molecular disc in the Circinus galaxy." Monthly Notices of the Royal Astronomical Society 300, no. 4 (November 1998): 1119–26. http://dx.doi.org/10.1046/j.1365-8711.1998.02002.x.

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23

Jones, K. L., B. S. Koribalski, M. Elmouttie, and R. F. Haynes. "Large-scale Hi structure of the Circinus galaxy." Monthly Notices of the Royal Astronomical Society 302, no. 4 (February 1999): 649–62. http://dx.doi.org/10.1046/j.1365-8711.1999.02057.x.

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24

Schulz, N. S., T. E. Kallman, D. K. Galloway, and W. N. Brandt. "The Variable Warm Absorber in Circinus X‐1." Astrophysical Journal 672, no. 2 (January 10, 2008): 1091–102. http://dx.doi.org/10.1086/523809.

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25

Schulz, Norbert S., Timothy E. Kallman, Sebastian Heinz, Paul Sell, Peter Jonker, and William N. Brandt. "The young Be-star binary Circinus X-1." Proceedings of the International Astronomical Union 14, S346 (August 2018): 125–30. http://dx.doi.org/10.1017/s1743921319002497.

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AbstractCir X-1 is a young X-ray binary exhibiting X-ray flux changes of four orders of magnitude over several decades. It has been observed many times since the launch of the Chandra X-ray Observatory with high energy transmission grating spectrometer and each time the source gave us a vastly different look. At its very lowest X-ray flux we found a single 1.7 keV blackbody spectrum with an emission radius of 0.5 km. Since the neutron star in Cir X-1 is only few thousand years old we identify this as emission from an accretion column since at this youth the neutron star is assumed to be highly magnetized. At an X-ray flux of 1.8×10−11 erg cm−2 s−1 this implies a moderate magnetic field of a few times of 1011 G. The photoionized X-ray emission line properties at this low flux are consistent with B5-type companion wind. We suggest that Cir X-1 is a very young Be-star binary.

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26

Shirey, Robert E., Hale V. Bradt, and Alan M. Levine. "The Complete “Z” Track of Circinus X‐1." Astrophysical Journal 517, no. 1 (May 20, 1999): 472–87. http://dx.doi.org/10.1086/307188.

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27

Bianchi, S., G. Matt, F. Fiore, A. C. Fabian, K. Iwasawa, and F. Nicastro. "Flux and spectral variations in the Circinus Galaxy." Astronomy & Astrophysics 396, no. 3 (December 2002): 793–99. http://dx.doi.org/10.1051/0004-6361:20021414.

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28

For, B. Q., B. S. Koribalski, and T. H. Jarrett. "Gas and star formation in the Circinus galaxy." Monthly Notices of the Royal Astronomical Society 425, no. 3 (August 27, 2012): 1934–50. http://dx.doi.org/10.1111/j.1365-2966.2012.21416.x.

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29

Dobashi, Kazuhito, Fumio Sato, and Akira Mizuno. "Nest of Molecular Outflows in the Circinus Cloud." Publications of the Astronomical Society of Japan 50, no. 6 (December 1, 1998): L15—L19. http://dx.doi.org/10.1093/pasj/50.6.l15.

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30

Fidelis, V. V. "X-ray emission properties from Circinus X-1." Astronomical & Astrophysical Transactions 26, no. 4-5 (October 2007): 235–39. http://dx.doi.org/10.1080/10556790601156709.

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31

Iaria, R., M. Spano, T. Di Salvo, N. R. Robba, L. Burderi, R. Fender, M. van der Klis, and F. Frontera. "On the Soft Excess in the X‐Ray Spectrum of Circinus X‐1: Revisitation of the Distance to Circinus X‐1." Astrophysical Journal 619, no. 1 (January 20, 2005): 503–16. http://dx.doi.org/10.1086/426422.

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32

Whiteoak, J. B., and J. D. Bunton. "FST Observations of NGC 4945 and the Circinus Galaxy." Publications of the Astronomical Society of Australia 6, no. 2 (1985): 171–74. http://dx.doi.org/10.1017/s1323358000018014.

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AbstractThe Fleurs synthesis telescope, which provides 20 arcsec resolution at 1.4 GHz, was used to map the continuum emission in NGC 4945 and the Circinus galaxy. Both objects have prominent small-diameter radio nuclei, containing 50% to 75% of the total intensity, superimposed on extended emission associated with the outer regions of the galaxies. The scale of the nuclei, together with the large velocity widths of the associated spectral-line profiles, are not unlike those encountered in the central region of the Galaxy.

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33

Fonseca-Faria, M. A., and A. Rodríguez-Ardila. "The two-phase gas outflow in the Circinus Galaxy." Proceedings of the International Astronomical Union 15, S359 (March 2020): 272–73. http://dx.doi.org/10.1017/s1743921320002082.

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AbstractWe employ Multi Unit Spectroscopic Explorer (MUSE) data to study the ionized and very ionized gas phase of the feedback in Circinus, the closest Seyfert 2 galaxy. The analysis of the nebular emission allowed us to detect a remarkable high-ionization gas outflow, out of the galaxy plane, traced by the coronal lines [Fe viii] 6089Å and [Fe x] 6374Å, extending up to 700 parsecs north-west from the nucleus. The gas kinematics reveal expanding gas shells with velocities of a few hundred km s-1, spatially coincident with prominent hard X-ray emission detected by Chandra. Density and temperature sensitive line ratios show that the extended high-ionization gas is characterized by a temperature of up to 18000 K and a gas density of ne > 102 cm−3. We propose two scenarios consistent with the observations to explain the high-ionization component of the outflow: an active galactic nuclei (AGN) ejection that took place ⁓105 yr ago or local gas excitation by shocks produced by the passage of a radio jet.

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34

Duncan, A. R., R. T. Stewart, and R. F. Haynes. "H position determination of the binary Circinus X-1." Monthly Notices of the Royal Astronomical Society 265, no. 1 (November 1, 1993): 157–60. http://dx.doi.org/10.1093/mnras/265.1.157.

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35

Packham, Christopher, James T. Radomski, Patrick F. Roche, David K. Aitken, Eric Perlman, Almudena Alonso-Herrero, Luis Colina, and Charles M. Telesco. "The Extended Mid-Infrared Structure of the Circinus Galaxy." Astrophysical Journal 618, no. 1 (December 6, 2004): L17—L20. http://dx.doi.org/10.1086/427691.

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36

Harrison, Thomas E., Dawn M. Gelino, Michelle Buxton, and Tyler Fost. "HERSCHELOBSERVATIONS OF CIRCINUS X-1 DURING OUTBURST AND QUIESCENCE." Astronomical Journal 148, no. 1 (June 13, 2014): 22. http://dx.doi.org/10.1088/0004-6256/148/1/22.

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37

Tauris, T. M., R. P. Fender, E. P. J. van den Heuvel, H. M. Johnston, and K. Wu. "Circinus X-1: survivor of a highly asymmetric supernova." Monthly Notices of the Royal Astronomical Society 310, no. 4 (December 1999): 1165–69. http://dx.doi.org/10.1046/j.1365-8711.1999.03068.x.

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38

Mennickent, R., J. Greiner, J. Arenas, G. Tovmassian, E. Mason, C. Tappert, and C. Papadaki. "The remarkable properties of the symbiotic star AE Circinus." Monthly Notices of the Royal Astronomical Society 383, no. 3 (December 7, 2007): 845–56. http://dx.doi.org/10.1111/j.1365-2966.2007.12604.x.

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39

Weiss, W. W., H. E. Fröhlich, A. Pigulski, A. Popowicz, D. Huber, R. Kuschnig, A. F. J. Moffat, et al. "The roAp starα Circinus as seen by BRITE-Constellation." Astronomy & Astrophysics 588 (March 17, 2016): A54. http://dx.doi.org/10.1051/0004-6361/201526997.

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40

Roman-Lopes, A. "Discovery of two Galactic Wolf-Rayet stars in Circinus." Monthly Notices of the Royal Astronomical Society 410, no. 1 (November 4, 2010): 161–65. http://dx.doi.org/10.1111/j.1365-2966.2010.17431.x.

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41

Iaria, R., T. Di Salvo, L. Burderi, and N. R. Robba. "Spectral Evolution of Circinus X‐1 along Its Orbit." Astrophysical Journal 561, no. 1 (November 2001): 321–28. http://dx.doi.org/10.1086/323226.

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42

Marco, Olivier, and Almudena Prieto. "Tracing the coronal emission in Circinus with VLT/NACO." Proceedings of the International Astronomical Union 2004, IAUS222 (March 2004): 335–36. http://dx.doi.org/10.1017/s1743921304002480.

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43

Menna, M. T., J. M. Muller, L. A. Antonelli, L. Burderi, T. Di Salvo, F. Fauci, M. Guainazzi, A. La Barbera, V. La Parola, and R. Robba. "Circinus X-1 observed with BeppoSAX wide field cameras." Nuclear Physics B - Proceedings Supplements 69, no. 1-3 (January 1999): 282–85. http://dx.doi.org/10.1016/s0920-5632(98)00226-6.

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44

Parkinson, P. M. Saz, D. M. Tournear, E. D. Bloom, W. B. Focke, K. T. Reilly, K. S. Wood, P. S. Ray, M. T. Wolff, and Jeffrey D. Scargle. "Long‐Term X‐Ray Variability of Circinus X‐1." Astrophysical Journal 595, no. 1 (September 20, 2003): 333–41. http://dx.doi.org/10.1086/377193.

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45

Fender, Robert, Ralph Spencer, Tasso Tzioumis, Kinwah Wu, Michiel van der Klis, Jan van Paradijs, and Helen Johnston. "An Asymmetric Arcsecond Radio Jet from Circinus X-1." Astrophysical Journal 506, no. 2 (October 20, 1998): L121—L125. http://dx.doi.org/10.1086/311660.

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46

Liu, Jiren, Sebastian F. Hönig, Claudio Ricci, and Stéphane Paltani. "X-ray signatures of the polar dusty gas in AGN." Monthly Notices of the Royal Astronomical Society 490, no. 3 (October 18, 2019): 4344–52. http://dx.doi.org/10.1093/mnras/stz2908.

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ABSTRACT Recent mid-infrared interferometry observations of nearby active galactic nuclei (AGN) revealed that a significant part of the dust emission extends in the polar direction, rather than the equatorial torus/disc direction as expected by the traditional unification model. We study the X-ray signatures of this polar dusty gas with ray-tracing simulations. Different from those from the ionized gas, the scattered emission from the polar dusty gas produces self-absorption and neutral-like fluorescence lines, which are potentially a unique probe of the kinematics of the polar dusty gas. The anomalously small Fe Kα/Si Kα ratios of type 2 AGN observed previously can be naturally explained by the polar dusty gas, because the polar emission does not suffer from heavy absorption by the dense equatorial gas. The observed Si Kα lines of the Circinus galaxy and NGC 1068 show blueshifts with respect to the systemic velocities of the host galaxies, consistent with an outflowing scenario of the Si Kα-emitting gas. The 2.5–3 keV image of the Circinus galaxy is elongated along the polar direction, consistent with an origin of the polar gas. These results show that the polar-gas-scattered X-ray emission of type 2 AGN is an ideal objective for future X-ray missions, such as Athena.

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47

Hagiwara, Yoshiaki, Shinji Horiuchi, Masatoshi Imanishi, and Philip G. Edwards. "Second-epoch ALMA Observations of 321 GHz Water Maser Emission in NGC 4945 and the Circinus Galaxy." Astrophysical Journal 923, no. 2 (December 1, 2021): 251. http://dx.doi.org/10.3847/1538-4357/ac3089.

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Abstract We present the results of second-epoch ALMA observations of 321 GHz H2O emission toward two nearby active galactic nuclei, NGC 4945 and the Circinus galaxy, together with Tidbinbilla 70 m monitoring of their 22 GHz H2O masers. The two-epoch ALMA observations show that the strengths of the 321 GHz emission are variable by a factor of at least a few, confirming a maser origin. In the second epoch, 321 GHz maser emission from NGC 4945 was not detected, while for the Circinus galaxy the flux density significantly increased and the velocity gradient and dispersion have been measured. With the velocity gradient spanning ∼110 km s−1, we calculate the disk radius to be ∼28 pc, assuming disk rotation around the nucleus. We also estimate the dynamical mass within the central 28 pc to be 4.3 × 108 M ☉, which is significantly larger than the larger-scale dynamical mass, suggesting the velocity gradient does not trace circular motions on that scale. The overall direction of the velocity gradient and velocity range of the blueshifted features are largely consistent with those of the 22 GHz maser emission in a thin disk with smaller radii of 0.1–0.4 pc and molecular outflows within ∼1 pc from the central engine of the galaxy, implying that the 321 GHz masers could trace part of the circumnuclear disk or the nuclear outflows.

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48

Pesce, D. W., J. A. Braatz, and C. M. V. Impellizzeri. "SUBMILLIMETER H2O MEGAMASERS IN NGC 4945 AND THE CIRCINUS GALAXY." Astrophysical Journal 827, no. 1 (August 9, 2016): 68. http://dx.doi.org/10.3847/0004-637x/827/1/68.

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49

Guo, Xiao-Lei, Yu-Liang Xin, Neng-Hui Liao, and Yi-Zhong Fan. "The Circinus Galaxy Revisited with 10 yr Fermi-LAT Data." Astrophysical Journal 885, no. 2 (November 6, 2019): 117. http://dx.doi.org/10.3847/1538-4357/ab44ba.

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Andonie, Carolina, Claudio Ricci, Stéphane Paltani, Patricia Arévalo, Ezequiel Treister, Franz Bauer, and Marko Stalevski. "A multiwavelength-motivated X-ray model for the Circinus Galaxy." Monthly Notices of the Royal Astronomical Society 511, no. 4 (February 16, 2022): 5768–81. http://dx.doi.org/10.1093/mnras/stac403.

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Abstract:

ABSTRACT Reprocessed X-ray emission in active galactic nuclei can provide fundamental information about the circumnuclear environments of supermassive black holes. Recent mid-infrared studies have shown evidence of an extended dusty structure perpendicular to the torus plane. In this work, we build a self-consistent X-ray model for the Circinus Galaxy including the different physical components observed at different wavelengths and needed to reproduce both the morphological and spectral properties of this object in the mid-infrared. The model consists of four components: the accretion disc, the broad-line region (BLR), a flared disc in the equatorial plane, and a hollow cone in the polar direction. Our final model reproduces well the 3–70 keV Chandra and NuSTAR spectra of Circinus, including the complex Fe Kα zone and the spectral curvature, although several additional Gaussian lines, associated with either ionized iron or broadened Fe Kα/Kβ lines, are needed. We find that the flared disc is Compton-thick ($N_{\rm H,d}= \rm 1.01^{+0.03}_{-0.24}\times 10^{25}\, cm^{-2}$) and geometrically thick ($\mathrm{ CF}=0.55^{+0.01}_{-0.05}$), and that the hollow cone has a Compton-thin column density ($N_{\rm H,c}= \rm 2.18^{+0.47}_{-0.43}\times 10^{23}\, cm^{-2}$), which is consistent with the values inferred by mid-infrared studies. Including also the BLR, the effective line-of-sight column density is $N_{\rm H}= \rm 1.47^{+0.03}_{-0.24}\times 10^{25}\, cm^{-2}$. This approach to X-ray modelling, i.e. including all the different reprocessing structures, will be very important to fully exploit data from future X-ray missions.

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