Sasmirala Individual Information for Circinus

Description

The highly inclined Circinus spiral galaxy, which lies within 10^∘  of the Galactic plane, harbours one of the nearest AGN at ~ 4.2 ± 0.8 Mpc [tully_extragalactic_2009]. It is optically classified as a Sy 2 with polarized broad lines [oliva_spectropolarimetry_1998]. A nuclear water-maser disc (PA~ 56^∘; [greenhill_warped_2003]) and a recent starburst [maiolino_seyfert_1998, sanchez_sinfoni_2006] have been found on parsec-scales, while a one-sided kiloparsec-scale ionization cone is also present in this object (PA~-44^∘; [marconi_prominent_1994, wilson_hubble_2000]). The first ground-based MIR observations were preformed by [moorwood_infrared_1984], and first N-band images were taken by [siebenmorgen_origin_1997, siebenmorgen_mid-infrared_2004] and [krabbe_n-band_2001] with ESO 3.6m/TIMMI, TIMMI2 and ESO MPI 2.2m/MANIAC respectively. The images show a nuclear point source with weak diffuse emission and marginally-extended emission on 20 pc (1arcsec) scale in the north-south directions. However, this morphology could not be verified by [galliano_mid-infrared_2005] based on their N- and Q-band TIMMI2 images. Circinus was also observed with Spitzer/IRAC, IRS and MIPS but its nucleus is saturated in all IRAC and MIPS PBCD images and thus, they are not analysed. The IRS LR staring-mode PBCD spectrum is also partly saturated but shows a steeply rising spectral slope towards longer wavelengths and a deep silicate 10 μm absorption feature without strong PAH emission. These spectral characteristics are verified to be unchanged for the nucleus at subarcsecond scales by the T-ReCS spectra published in [roche_mid-infrared_2006]. The T-ReCS and VISIR N- and Q-band images obtained by [packham_extended_2005] and [reunanen_vlt_2010] show an east-west elongation with ~ 4arcsec diameter roughly coincident with the ionization cones (PA~ 100^∘). Our reanalysis of these T-ReCS and VISIR images provides consistent results when using similar measurement methods. In addition, we analyse 20 VISIR N- and Q-band images (unpublished, as far as we are aware). Owing to the extended emission evident in the images, we measure only the unresolved nuclear fluxes. Note that the T-ReCS N and VISIR Q2 measurements are treated as upper limit on the unresolved flux because they lack a suitable standard star observations for the PSF determination. The average photometric flux level is ~ 30% lower than that of the IRS and T-ReCS spectra from 2004, the latter taken from [gonzalez-martin_dust_2013]. Therefore, we do not attempt to correct our 12 and 18 μm continuum flux estimates for the silicate features. The variation in the individual photometric measurements of the different epochs indicates MIR variability in Circinus but requires a more detailed analysis. Note that MIR interferometric measurements of Circinus further resolve its nuclear MIR structure to consist of a polar elongated extended structure, and a compact flattened disc-like structure perpendicular to the ionization cones ([tristram_resolving_2007, tristram_dusty_2013]).

• [galliano_mid-infrared_2005] E. Galliano, D. Alloin, E. Pantin, P. O. Lagage, and O. Marco. Mid-infrared imaging of active galaxies. active nuclei and embedded star clusters . A&A , 438 pp. 803–820, August 2005.
• [gonzalez-martin_dust_2013] O. González-Martín, J. M. Rodríguez-Espinosa, T. Díaz-Santos, C. Packham, A. Alonso-Herrero, P. Esquej, C. Ramos Almeida, R. Mason, and C. Telesco. Dust in active galactic nuclei. mid-infrared t-ReCS/Gemini spectra using the new RedCan pipeline . A&A , 553 pp. 35, May 2013.
• [greenhill_warped_2003] L. J. Greenhill, R. S. Booth, S. P. Ellingsen, J. R. Herrnstein, D. L. Jauncey, P. M. McCulloch, J. M. Moran, R. P. Norris, J. E. Reynolds, and A. K. Tzioumis. A warped accretion disk and wide-angle outflow in the inner parsec of the circinus galaxy . ApJ , 590 pp. 162–173, June 2003.
• [krabbe_n-band_2001] Alfred Krabbe, Torsten Böker, and Roberto Maiolino. N-band imaging of seyfert nuclei and the mid-infrared-x-ray correlation . ApJ , 557 pp. 626–636, August 2001.
• [maiolino_seyfert_1998] R. Maiolino, A. Krabbe, N. Thatte, and R. Genzel. Seyfert activity and nuclear star formation in the circinus galaxy . ApJ , 493 pp. 650, January 1998.
• [marconi_prominent_1994] A. Marconi, A. F. M. Moorwood, L. Origlia, and E. Oliva. A prominent ionization cone and starburst ring in the nearby circinus galaxy. . The Messenger , 78 pp. 20–24, December 1994.
• [moorwood_infrared_1984] A. F. M. Moorwood and I. S. Glass. Infrared activity in circinus and NGC 4945 - two galaxies containing luminous H2O masers . A&A , 135 pp. 281–288, June 1984.
• [oliva_spectropolarimetry_1998] E. Oliva, A. Marconi, A. Cimatti, and S. Di Serego Alighieri. Spectropolarimetry of the circinus galaxy . A&A , 329 pp. L21–L24, January 1998.
• [packham_extended_2005] Christopher Packham, 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 . ApJL , 618 pp. L17–L20, January 2005.
• [reunanen_vlt_2010] J. Reunanen, M. A. Prieto, and R. Siebenmorgen. VLT diffraction-limited imaging at 11 and 18μm of the nearest active galactic nuclei . MNRAS , 402 pp. 879–894, February 2010.
• [roche_mid-infrared_2006] Patrick F. Roche, Christopher Packham, Charles M. Telesco, James T. Radomski, Almudena Alonso-Herrero, David K. Aitken, Luis Colina, and Eric Perlman. Mid-infrared, spatially resolved spectroscopy of the nucleus of the circinus galaxy . MNRAS , 367 pp. 1689–1698, April 2006.
• [sanchez_sinfoni_2006] F. Mueller Sánchez, R. I. Davies, F. Eisenhauer, L. J. Tacconi, R. Genzel, and A. Sternberg. SINFONI adaptive optics integral field spectroscopy of the circinus galaxy . A&A , 454 pp. 481–492, August 2006.
• [siebenmorgen_mid-infrared_2004] R. Siebenmorgen, E. Krügel, and H. W. W. Spoon. Mid-infrared emission of galactic nuclei. TIMMI2 versus ISO observations and models . A&A , 414 pp. 123–139, January 2004.
• [siebenmorgen_origin_1997] R. Siebenmorgen, A. Moorwood, W. Freudling, and H. U. Kaeufl. Origin of the IR continuum in the circinus galaxy. . A&A , 325 pp. 450–456, September 1997.
• [tristram_dusty_2013] K. R. W. Tristram, L. Burtscher, W. Jaffe, K. Meisenheimer, S. F. Hönig, M. Kishimoto, M. Schartmann, and G. Weigelt. The dusty torus in the circinus galaxy: a dense disk and the torus funnel . Astronomy & Astrophysics , December 2013. arXiv:1312.4534 [astro-ph].
• [tristram_resolving_2007] K. R. W. Tristram, K. Meisenheimer, W. Jaffe, M. Schartmann, H.-W. Rix, Ch. Leinert, S. Morel, M. Wittkowski, H. Röttgering, G. Perrin, B. Lopez, D. Raban, W. D. Cotton, U. Graser, F. Paresce, and Th. Henning. Resolving the complex structure of the dust torus in the active nucleus of the circinus galaxy . A&A , 474 pp. 837–850, November 2007.
• [tully_extragalactic_2009] R. Brent Tully, Luca Rizzi, Edward J. Shaya, Hélène M. Courtois, Dmitry I. Makarov, and Bradley A. Jacobs. The extragalactic distance database . AJ , 138 pp. 323–331, August 2009.
• [wilson_hubble_2000] A. S. Wilson, P. L. Shopbell, Chris Simpson, T. Storchi-Bergmann, F. K. B. Barbosa, and M. J. Ward. Hubble space telescope imaging of the circinus galaxy . AJ , 120 pp. 1325–1341, September 2000.

Images

SEDs

MIR SED. The description of the symbols in all the SED plots (where present) is the following: Grey crosses and solid lines mark the Spitzer/IRAC, MIPS and IRS data. The colour coding of the other symbols is as follows: green for COMICS, magenta for Michelle, blue for T-ReCS and red for VISIR data. Darker-coloured solid lines mark spectra of the corresponding instrument. The black filled circles mark the nuclear 12 and 18 micron continuum emission estimate from the data (where present). The ticks on the top axis mark positions of common MIR emission lines, while the light grey horizontal bars mark wavelength ranges affected by the silicate 10 and 18 micron features.