Sasmirala Individual Information for NGC 3393

Description

NGC 3393 is a face-on barred spiral galaxy at a redshift of z = 0.0125 (D ~ 61.6 Mpc) with a close binary AGN (separation ~ 0.5arcsec ~ 150 pc; PA~ 40^∘; [fabbiano_close_2011]), which optically appears as a Sy 2 [veron-cetty_catalogue_2010]. The binary AGN is presumably the result of a minor merger, which did not significantly affect the host morphology (see also [contini_evidence_2012]). Both are surrounded by an S-shaped NLR extending 1.8arcsec ~ 0.4 kpc on either side along a PA~ 55^∘ [schmitt_comparison_1996, cooke_narrow-line_2000] coinciding with a double-sided jet along a PA~ 50^∘ [morganti_radio_1999, schmitt_jet_2001]. Water maser emission tracing the accretion disc was detected oriented perpendicular to the jet and NLR (PA~-34^∘; [kondratko_discovery_2006, kondratko_parsec-scale_2008]). Apart from IRAS, NGC 3393 was also observed with Spitzer/IRS and MIPS in the MIR. A compact dominating nucleus embedded within the spiral-like host emission was detected in the MIPS 24 μm image. The IRS LR staring-mode spectrum exhibits bright forbidden emission lines, possibly weak silicate 10 μm absorption, almost no PAH emission and a red spectral slope in νF_ν-space (see also [shi_9.7_2006, sargsyan_infrared_2011]). Therefore, star formation seems to be weak at arcsecond scales. We observed the nuclear region of NGC 3393 with VISIR in four different N-band filters in 2008 (two published in [gandhi_resolving_2009]), and weakly detected one compact source but no second. The low S/N of all observations prohibits any constraining results about the nuclear extension, which is however consistent with being unresolved. We co-added all obtained 8 images centred on the detected nucleus, which results in an elongated source, which might comprise both nuclei (FWHM(major axis)~ 0.4arcsec;PA~ 53^∘). In this case, the emission peak would correspond to the south-western nucleus, which would also dominate the re-measured nuclear VISIR fluxes of the individual filters. These are consistent with the values in [gandhi_resolving_2009] and on average ~ 39% lower than the IRS spectrum.

• [contini_evidence_2012] M. Contini. Evidence of merging in the seyfert galaxy NGC 3393, revealed by modelling the spectra . MNRAS , 425 pp. 1205–1214, September 2012.
• [cooke_narrow-line_2000] Andrew J. Cooke, J. A. Baldwin, G. J. Ferland, Hagai Netzer, and Andrew S. Wilson. The narrow-line region in the seyfert 2 galaxy NGC 3393 . ApJS , 129 pp. 517–545, August 2000.
• [fabbiano_close_2011] G. Fabbiano, Junfeng Wang, M. Elvis, and G. Risaliti. A close nuclear black-hole pair in the spiral galaxy NGC3393 . Nature , 477 pp. 431–434, September 2011.
• [gandhi_resolving_2009] P. Gandhi, H. Horst, A. Smette, S. Hönig, A. Comastri, R. Gilli, C. Vignali, and W. Duschl. Resolving the mid-infrared cores of local seyferts . A&A , 502 pp. 457–472, August 2009.
• [kondratko_discovery_2006] P. T. Kondratko, L. J. Greenhill, J. M. Moran, J. E. J. Lovell, T. B. H. Kuiper, D. L. Jauncey, L. B. Cameron, J. F. Gómez, C. García-Miró, E. Moll, I. de Gregorio-Monsalvo, and E. Jiménez-Bailón. Discovery of water maser emission in eight AGNs with 70 m antennas of NASA's deep space network . ApJ , 638 pp. 100–105, February 2006.
• [kondratko_parsec-scale_2008] Paul T. Kondratko, Lincoln J. Greenhill, and James M. Moran. The parsec-scale accretion disk in NGC 3393 . ApJ , 678 pp. 87–95, May 2008.
• [morganti_radio_1999] R. Morganti, Z. I. Tsvetanov, J. Gallimore, and M. G. Allen. Radio continuum morphology of southern seyfert galaxies . A&AS , 137 pp. 457–471, June 1999.
• [sargsyan_infrared_2011] Lusine Sargsyan, Daniel Weedman, Vianney Lebouteiller, James Houck, Donald Barry, Ashot Hovhannisyan, and Areg Mickaelian. Infrared spectra and spectral energy distributions for dusty starbursts and active galactic nuclei . ApJ , 730 pp. 19, March 2011.
• [schmitt_comparison_1996] Henrique R. Schmitt and Anne L. Kinney. A comparison between the narrow-line regions of seyfert 1 and seyfert 2 galaxies . ApJ , 463 pp. 498, June 1996.
• [schmitt_jet_2001] H. R. Schmitt, J. S. Ulvestad, R. R. J. Antonucci, and A. L. Kinney. Jet directions in seyfert galaxies: Radio continuum imaging data . ApJS , 132 pp. 199–209, February 2001.
• [shi_9.7_2006] Y. Shi, G. H. Rieke, D. C. Hines, V. Gorjian, M. W. Werner, K. Cleary, F. J. Low, P. S. Smith, and J. Bouwman. 9.7 μm silicate features in active galactic nuclei: New insights into unification models . ApJ , 653 pp. 127–136, December 2006.
• [veron-cetty_catalogue_2010] M.-P. Véron-Cetty and P. Véron. A catalogue of quasars and active nuclei: 13th edition . A&A , 518 pp. 10, July 2010.

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.